I started this video scratching my head but ended it patting myself on the back for actually understanding this! Credit to you Pete. PHENOMENAL videos 👍
Thank you Pete for taking the time to educate your viewers. Your channel is Priceless. If I had discovered your channel when I was a lot younger, it would have changed the trajectory of my whole life, i am pretty sure you are impacting so many lives. I am almost going to retire in a few years, but now you have given me tools on how to stay active. It was by accident that I discovered your channel. Thanks a lot.
Mannn, you're like a genius at this! I thought I knew a good decent deal about engines.. I've barely even scratched the surface lol thanks for the vids!
Great video series! I like rebuilding engines and working on cars. When I cc my heads I do it with the spark plugs in. Depending on how far into the chambers your plugs go will affect your true static compression ratio. Thanks for sharing!
This video is incredible. It is very similar to the mathematical principals related to scientifically proven equations utilized in accident reconstruction to determine speeds of vehicles using the conservation of linear momentum formulas. I had no knowledge how to calculate dynamic compression. Thanks again!
Petes Garage What you were explaining on the measurement process is a trigonometric function (sin cos). The classes I took were taught well for accident reconstruction and practical. Believe me I'm no mathematical wiz lol, but just like your teaching style anyone willing to learn it is much easier for.
Great job, I designed a 229 cid V6 on paper in my twenties before building it while in the Navy. I angle milled the heads aboard the ship after matching, porting and polishing. As I recall, the stock smog head was 115 cc chambers before porting. I used mineral oil to cc heads, not water, worked well. It has been a long time so I enjoyed listening to you, great memory refresher. My strait six 1997 Jeep Wrangler is tired and I am planning on rebuilding it with 4.7 specs from the stock 4.0 L. On a personal note, I used Rhodes hydraulic lifters years ago. I recommend you look into them, they vary your lift and duration. I also discovered they now make hydraulic roller lifters. This helps your dynamic compression ratio, with a race cam with a lot of lift and duration, reduces the variables window, normalizes. Once again great job, J & L is about 15 miles away from me, nice to know.
Mate can I just say this video and series is the most informative I have seen, you don't skip over important steps that most other engine building videos do. I have been looking at these video's to see how to re-build an old Ford 300 i6 on a 1979 f250, I understand most of the steps to building and engine but the camshaft, valves and how to tighten down the rocker arms have been a little confusing until now thank you for the help. I am 17 and still in school I now see why they teach you trigonometry.
Damn it..!! You just ruined my day even more. Here's why. I just purchased a rebuilt 1977 454 with 1972 oval port heads and stock intake for $1500.To PUT in my son 1988 Blazer.upon removal of intake manifold to replace the gaskets. I notice something i never seen before. Under the oil splash shield of the intake was what looked like Asphalt took a grinder to the rivets.remove shield and found a Mountain of Asphalt well i freaked out Because the older guy i bought it from showed a video of it running on stand. So i pulled the oil pan and found a brand new super clean bottom end. That was what i wanted . but the oil pan bottom looked like my bronco 265k mile transmission pan. Year after a filter change fine black clutch material.and white gel like stringy stuff probably from water droplets new oil that was more black than a clear amber color but no scratches on cylinder walls.. But then notice intake valves look like 50k mile on leaking valves seal built up on 5 of the 8.other 3 look perfect as did the exhaust valve were clean.. The next day that intake sat in sunlight asphalt facing up started to puddle up on intake . Now im im buying new oil pump spending $700 on the heads and realizing i dont know what cam in this just know its bored .40 over. I paid 1500 to clean up someone mess.. Then i find you. Not a bad thing since im all ready torn down. Might asceell be Replacing the cam too..so i know whats in it. Iam going tobe tearlng it all down and starting over aren't I..?. This started off as a birthday present. He doesn't know he comes home in 2 more weeks . Not going to happen is it. Ps. The money i had for other part for the truck that sitting for two years this motor eating up so fast My 77 Les Paul in the pawn shop with my 63 strat and a Ar-15 next willbe my desert Eagle and another Bushmaster.. oh hell no that ain't happening ..what do i do..? Any advise would be welcomed Thanks
This is some really good knowledge and can be helpful from beginner to seasoned. Great channel and please don't let a few negative comments stop you from continuing to provide the content. Just earned another subscriber here! Thank you!
I remember having to learn all this in the early 80's. My teacher bent me over the goals on how math would make me look like a genius. He was so right!
@01:00 I had a 'Doc Brown' moment (the part where he was watching himself on the camcorder ref. the amount of gigawatts of energy needed for the flux-capacitor to function). +Petes Garage "!!CLUNK!!" That's the sound of not one penny dropping; but a whole bucketful of pennies simultaneously hitting the floor. it happend whilst watching the the previous posting, concerning camshaft theory/timing/etc (alas, comments were disabled). it's a mystery to me; how you can take all that knowledge and experience - and then concisely express the whole 'shabang' in such a way that a 'normal' layman/enthusiast can understand it all! I cannot even explain to the wife, the reasons why her car was overheating....and not to 'go on one', because it's repairable,lol. pete....again - thankyou mate for posting!
This is really informative. I work on firearms and like engines, there is much more than turning the key and starting the engine. A lot of work goes in with many failures before they find a formula that works. Firearms are much the same.
Pete, I've learned so much from watching all your videos. These will help me a lot when I go to build up my 300 straight six. I was a little intimidated at first because my first complete rebuild will at the same time be a custom build for a little performance, but your videos helped ease the tension a lot.
Hey Pete! I did find your serie's on how to build an engine, and what to choose, and several other great stuff! I follow your serie's, and you mensioned some things for I did not relise that they are there. FANTASTIC! I am gonna build a 3sgte toyota street legal high horsepower engine, wich will ride here in the Netherlands, and there is so much stuff to see in the internet, but not too much, I am now looking for about half a year, what good suppliers are there, what should be done, what NOT to do, etc etc. Here in Holland we say (translated); Don't go over one night ice. Anyway Pete, thank you already and all the best!
never let down when watching your videos. I always learn something and that's why I keep looking forward to your videos. I never knew there were 2 types of CR. in my build which I mentioned in the previous video, which was a sbf 331 I now need to take into consideration my DCR. im hoping for 10:1 SCR but my DCR might be a factor in the octane I am able to use. In Canada Ontario to be more specific we are mostly giving 91 octane as a premium and very seldom do we see 97 octane. so in my DCR im hoping to be able to use 91 octane with no problem. again as I learned in this video, cylinder head choice plays a big part in your DCR and cam selection too.. all engine components when building something all need to work together. the more I watch the more I learn and im happy I found Petes Garage subscription :) on to the next video :)
I'm glad that you mentioned picking heads by CFM alone is not-completely-good idea. I was looking at aftermarket GM LS heads and they said 330 CFM on a 4.155" bore, but the heads are meant to be used on a 3.9" bore. Valve shrouding would be a big problem.
Hi Pete, Fantastic information displayed in your videos. Truly gives the DIYers at home a greater understanding in the planning process of engine building. I have a topic request, one that is probably frequently asked and it is this.. Introducing forced induction systems to engine flow and power output calculations. Possibly covering the different types of forced induction systems and how they influence camshaft and cylinder head choice. If you have the time and components laying around I believe it would make a very interesting and helpful video to many of us viewers :) Thank You!
Pete, thanks for a great video it really helped. I had to draw a diagram, but then I was able to calculate the dynamic compression ratio. This is a great series, looking forward to when the Cobra runs!
I love this video series! I've been binge watching all parts back to back! Very interesting stuff, I started out this series knowing absolutely nothing about engines and now I feel like I know a little something.. all that being said.. my eyes glazed over about 20 minutes into this particular video. lol
+Walter Shmitty LOL....that's awesome. I know it's difficult to follow if you're not totally into the material. I try to cover as much as possible so people don't have to answer questions. Thank you for taking the time to watch
I was looking at the math for the RD and RR. At first I assume all calculations are in degrees for the sin and cos parts. RD = .5 * 3.5 * sin(72)(in degrees) is 0.9511 RR = .5 * 3.5 * cos(72)(in degrees) = 0.3090 I am posting since I plugged sin 72 radians at first and got 0.2538 which is what you have posted in the video for the RD. So, I took a look what would happen in degrees and the cos was a positive number. These values would change the outcome by: PR1 = 2.381 PR2 = 2.072 DST = 2.7 Great videos by the way.
here in Australia we rate our fuel different than usa our 98 is your 93 octane because we rate our fuel of its highest rating, usa takes it off the average between motor octane and research octane which is also good to know... its also good to know the motor octane number which is the lowest number , this tells you how your fuel will react to higher reving loads at a hoter tempreture, good to know on the race track, eg our 98 ron pump fuel is only 85 mon when tested , this would be sold as 93 in usa I believe, e85 pump is 107 octane in Australia more than enough for racing and cheap as 98 to buy.... great vid as always... cheers
+carblingautomotive That is an excellent point. In the US the formula for for calculating the octane is right on the pump. R + M / 2. It is important to understand the difference. Thank you for helping us understand the difference.
7:15 you must clean out all the vaseline to get an accurate reading before you smoosh down the plexiglass plate. nothing in the chamber, no blobs. it will affect the CC amount. great video's!
all your vids are very helpful.my 91 silverado I dropped a carburetor 350 in is giving me some problems so i've been watching all these videos I think I'm going big block next time this is the second sbc it's had.thanks
All good stuff. Any first time builders/modders out there watch this video FIRST before buying parts [especially the cam] and thank Pete later. Second, decide what rpm range your motor will mainly live in [sub 4k/3-5k/over 4k], then go watch his carb selection video if the build isn't going to be EFI.
Hey Pete, Love the info especially the math and engineering aspect of the vids. I am a third yr Mechanical E @ University of Alabama (tuscaloosa) and there is not an automotive track at all so your videos really give me the somewhat in depth info I need.
Lots to think about. Cam duration... Intake flow... Stroke... bore... rod length... This is proper engine building I think. Not just "Stage 2 cams with stage 2 tune and stage 2 turbo". I am learning things are a lot more complex
thanks pete trying to decide on where to go with my truck it's an 89 chevy surburban with a 350 with a 700 r4 trans 5.7 liter i want to rebuild it myself however i haven't work on cars or truck in twenty plus years due to taking a different approach in life and now i would like to do it myself because i'm able and have a little money hint hint little money so your video is extremely helpful in the decision making process thanks any feedback is appreciated
Liked the video. Would the cc's change if you had a sparkplug in the hole instead of petroleum jelly? How does the angle of the sparkplug affect performance?
I answered that a couple times. The volume of the spark plugs are constant so the change would be just the plugs. You are looking for actual volume. The angle of the plug does affect performance...but so does plug type and fuel octane.
@@PetesGarage thanks for getting back to me. So how wrong would I be to pick your brain. Sbc rebuilds no big deal. This is really my first full on high performance. Build. Don't want to screw up up. Lot of money, lot of really nice parts. So anyway your videos are very well thought out.
This is the best instruction video I have ever seen! Thank you so much for taking the time to make it! I started watching because I have a 91 Volvo 740 turbo with a B230FT engine. I am planning a build for the car and felt overwhelmed with how much to decide at the machine shop! This video series helped a lot in deciding what to do. My only question is, how does your build sound? I want to hear it!
I was the 666 like. Is that a good thing? I love this engine building video series. I have a completely machined Toyota 3TC 1.8l engine that I will be assembling and because of this series I am much better off. No paper towels or teeshirt material for me.
Hey peter loving these videos will be subscribing for sure. In relevance to get your stand point could it also be possible to duplicate the same combustion chamber CC test with oil which one would be the most time and cost effective during the engine assebly with an over all cost Benefit aspect taking into considerstion reusing the oil over and over with minimal loss of oil and cleaning products if not the same used to adequatly clean up the cylinder head afterwards for both possible methods if the same product would be used this would remain non applicable unless a Considerable amount more is used to clean up one process over the other aswell the time to clean the surfaces?. Aswell In regards to using the petroleum jelly to fill the spark plug hole would the use of the same spark plug per cylinder for each engine with repeated use in mind be possible with one method without possible oxidisation to the spark plug causing potential FM making even in my opinion this being not viable if the oil method its more cost beneficial however for both labour and resource/material cost. Unless the water method would be safe over prolonged use by the means of using WD40 or something along those lines to put the spark plug back away to be reused when building the same type of engine. does the same short motor with different cylinder heads use different spark plugs making it pointless to have a bunch of spark plugs lying around and would the spark plug petrude beyond the flat mating surface of the cylinder head making this impossible to test as a Variable with the combustion chamber CC test. if it is possible rather than petroleum jelly would it give a different end result or reading of a considerable amount creating the different of measurement to throw the compression ratio say for example from 10:1 up to 10.1:1 or 10.2+:1 or be so small of an amount like 0.1 or 0.3 of a CC that again it would be negligible with near no effect. I have a tendancy to over think as well as i prefer tolerances to be minimal best way to describe what im trying to say with that statement which may open up another question with the thrust end play tolerance of 0.001 to 0.003 if i had a 0.002- 0.003 reading id try to Aqcuire a part to hopefully bring the gap back between 0.0015 - 0.002 on an engine build however i understand that could bring about extra labour cost driving up over all customer build cost but as this would be the lengths id go to again as an example and the question, would it even be worth it long term for the life of the engine. Hope to see some more great vids this is both refreshing and helping to clarify alot having a some what mechanical mind with my own experiences as well as future aspirations of building my own engine. I tend to have a NASA scientist engineering mentality with high standards and forget the KISS method of keep it simple stupid method sometimes but i also have ADHD and theres something about doing this and looking into these things just just calms me call it a little OCD but its just how i am with things. This might be a bunch of silly questions to you but i wont know if i dont ask so hopefully if you feel its reasonable given if you have the time to do so could i ask would you consider making a video to outline this
Mexico? I'm only half joking - import duties are typically a fraction of what sales tax is in most states, which is one factor as to why so much manufacturing has moved there. What's 5% improved margins on a small [$1M] business? Oh...just a new bmw with all the options every two years [if that's your thing].
You have a great set of videos here and absolutely love it for when I rebuild my engine in my truck. But I have a few questions, One. Instead of plugging the spark plug whole with jelly. Why not use a spark plug since it will be in there when you put it all together, or is it since spark plugs very in size it is the standard to do it this way. Also you talked about not getting enough air and fuel in to the chamber, well what if you used a turbo, I am thinking about putting on a turbo and not to clear on what it does other then give you more horsepower. Also I have a few videos that I would like to see, one would be about the turbo if it is apart of engine building and I would also love to see video that tie every thing you talked about in these videos and pulled it all together in "hypothetical" engines, one built for the drag race one built for tractor pulling and one that would be just a beefed up "every day" or "Budget" engine. An Everyday engine that I am talking about would be what I want to have. higher torque, better fuel usage, I am not wanting to do burn outs or win any tractor pulls I just want to pull better. I myself have a 302 EFI Ford in a 1995 F150 4x4. Also writing this has given me an Idea for another Series and that Would be the Drive train Since You do Have such an anuchsew set of videos. But I dont want to take up to much of your time
Thanks Justin. The volume of the spark plug is inconsequential. Plugging the hole gives absolute volume. A turbo just sucks the exhaust gas out of the cylinder thereby reducing back pressure. This gives HP back to the engine and sort of pulls it along. Those are some great video ideas. I make videos as projects come up. If those come along I'll be sure to makes them.
Hey Pete! I've been having fun with some 50cc 2 stroke engines. And, after watching your video, I understood, that I would like to build a 4 stroke multi-cylinder engine for experience. Are there any particular engines you could suggest? I'm looking for something not too big, not too expensive and with a lot of available parts. Thanks in advance :)
I don't know if I missed it or not but I never did see or hear a range for fuel needed once you know your DCR. I figured mine out and it is 8.9. N/A engine 412 cubic inches. I can't find any info on what dynamic compression you can have in relationship to the octane of fuel.
Hi Pete. I love your series. I have never built an engine or raced, but do have some knowledge just through interest. I apologize for what may be a simple question. I watched this and understand Dynamic Compression. Out of curiosity I tried to find that number on my 2017 GMC 5.7 but couldn't find it. I did find the static compression to be 11:1, but they still recommend 87 octane. Admittedly it runs fine on that, but I am wondering how they accomplish that. Again I could not find the Dynamic Compression on it, but I would assume with 11:1 static it would need higher octane. I guess if we knew that number it would answer this question. Thanks for your series. It has me thinking!!
Is there a spreadsheet floating around out there on the net with all this stuff already set up where I can just punch in the variables and it will calculate it all?
@@PetesGarage Thanks again for your videos. I also don't drink or smoke, so it's good to hear there are other people like that out there. Get some rest!
If your spark plug extends into the head significantly, would it be more accurate to put a plug in, so it can take up the space it would normally take up, or would it make make that much of a difference?
I have 403 olds in my 79 trans am. what would you recommend i do with cylinder heads and camshaft if i want to have a cruise engine that occasionally races street? I am aware these engines are very tamed due to smog standards but i'm not sure where to start pete.
Just a thought but shouldn't you do the combustion cc check with your spark plugs installed to get a more accurate reading because they effectively lower the cc of the chamber.
Thanks you Pete put on a very good educational seminar. And I have a question what is a good medium size Cam's put in a 5.3 Chevy avalanche 2003 Stockton board 20 over pistons stock crankshaft I do not want to use the stall converter I where thinking somewhere about this size 32:45 195 /197 485/487 /116lobe Or a little bit bigger 👍
You havent mentioned valve diameter at all, head flow is ultimately decided by the first point of restriction and that is intake valve diameter, the bore x sroke x rpm will give engine cfm @ max rpm, intake valve diameter is the factor that ultimately decides A/F flow
You are absolutely correct. There are a few things I am assuming. When heads are purchased I am assuming the valve size is taken into account when the desired flow and volume is determined. I did not want to get into changing seats, valves and other head parts.
hey pete.....great videos,.....i'm learning a lot from your vids and other internet sites.......seems getting a good mechanic you can thrust is so hard now a days.....now i'm no mechanic....but i'm learning..... i like and owned fast cars....i have a general idea about engines and how they work but i'm just wondering, if you're checking for CC's on the head, wont the head gasket and spark plug affect the equation????
The spark plugs will, but the should all be the same. The gasket thickness is included in the compression equation. In this step you are looking for the true volume of the head
Hi Pete, great videos with lots of healpfull info. I have calculated my static compression as 9.99:1 that's a standard 351c 4.00 bore 3.5 stroke. With factory flat top pistons but with my head volume 62cc was 62.8 before the machining. My heads were 62.8cc machined down 0.005" to get spot on 62cc. I tried to do the dynamic stroke calculations but get different results. RD =1/2 ST x (sine ICA). You get 0.2535 in red I get RD = 1/2 3.5 x (sine 72) RD = 1.75 x (0.951056516) = 1.66434 You get 0.2535 in red , what am I doing wrong. I want to get the hang of this calculation as I want to know what ICA I need which will Determine what camshaft I buy.
Am i right in thinking if you have dished or domed pistons you'll need to add the positive or negative displacement of this to the head cc before dividing by it?
I was wondering why nobody I know talks about dynamic cr. Now I know. Lots of math involved! Haha. I’m in the planning stage of building a low buck LA block Dodge. I am debating if I should stick with the LA (have headers and Mopar M1 intake), or go with a Magnum build. More $$$, but more power. Maybe Magnum heads on my LA. I am looking to get 400hp.
Hi. I like all the good info. I’m rebuilding my fuel injected 5.9 360 magnum. I’m trying to figure out good heads to get that are durable and reliable. Not for racing. I also want to increase the HP a bit. I was thinking of raising the compression slightly. Stock is 9.1:1. What would be the best way to gain some HP with this rebuild keeping it durable and able to run with oem computer. Thank you.
Hey Pete, great video! But I am brand new to engines and I just know the parts and don't really know what compression ratio is, and I am wondering what you think I should learn about engines (and how) before I come back and watch this series again so that I understand it better. I was also thinking about getting a long block from a u-pull-it or eBay and taking it apart and putting it back together again just to learn, but I don't really want to spend a lot on an old V8 so I was thinking about buying a I6 or I4 engine by Nissan or another manufacturer for cheap, I'm probably not going to ever put the engine in a car and I'm guessing that its going to get pretty beat up as I have never touched an engine past the head covers. Just wondering what cheap engine you think I should find that can is good to learn from, easy to find and not going to break the bank. Thanks
I don't know if it was simply coincidental, but the two numbers you had, one, being the cc'd value of the cylinder divided by the cc'd value of the combustion chamber, differed by about 47, from the final value of the volume. I sound confusing, but at 22:02, the numbers differ by 47, which is also 47 degrees ABDC. Just speaking my thoughts I suppose.
For that whole “x-CFM x 2 = Power Capability” rule of thumb only apply to N/A engines? I’d assume so and if so, would that be assuming 100% volumetric efficiency? Thanks. Edit: Also, in regards to DCR, essentially SCR isn’t necessarily as important as DCR, correct?
Pete's Garage thank you very much. I’m still in high school and go to a tech school for auto tech. I’m in my senior year so I’m trying to accumulate as much knowledge that’s a little bit more complex than simple mechanics because this stuff is super interesting!
Hey Sir Peter How are you doing? Is DST, Dynamic stroke length remaining ATDC (AFTER TOP DEAD CENTER) OR ABDC (AFTER BOTTOM DEAD CENTER) after intake valves are closed? Thank you. 17:45
Pete, wouldn't you want to install the spark plugs when measuring the head volume? wouldn't the space taken by that affect the compression ratio slightly?
That is an excellent point. The volume of the plug is negligible since it has both positive and negative volumes. You can put them in if you like, but the water measuring process does not had the discrimination to really notice the difference.
So why is the intake valve still open after bottom dead center? Shouldnt it be closed right at bottom dead center to take advantage of more compression?
I started this video scratching my head but ended it patting myself on the back for actually understanding this! Credit to you Pete. PHENOMENAL videos 👍
Thank you my friend
Thank you Pete for taking the time to educate your viewers. Your channel is Priceless. If I had discovered your channel when I was a lot younger, it would have changed the trajectory of my whole life, i am pretty sure you are impacting so many lives. I am almost going to retire in a few years, but now you have given me tools on how to stay active. It was by accident that I discovered your channel. Thanks a lot.
It's so refreshing to listen to someone that loves what they do !
Thank you for doing what you do.
I appreciate that!
Mannn, you're like a genius at this! I thought I knew a good decent deal about engines.. I've barely even scratched the surface lol thanks for the vids!
You know more than you think. There are people who know way more than me. Thanks for your comment
Great video series! I like rebuilding engines and working on cars. When I cc my heads I do it with the spark plugs in. Depending on how far into the chambers your plugs go will affect your true static compression ratio. Thanks for sharing!
+xlr8r3VA You are correct. Thank you for sharing that with everyone!
It's such a amazing series , can't thank him enough.
Thank you my friend
@@PetesGarage , thank u sir🙏
Pugs, Pink Floyd, and tons of wisdom? Thanks to you I am ready to rebuild my 350. Thank you
I know you can do it!
This video is incredible. It is very similar to the mathematical principals related to scientifically proven equations utilized in accident reconstruction to determine speeds of vehicles using the conservation of linear momentum formulas. I had no knowledge how to calculate dynamic compression. Thanks again!
Now THAT is easy for you say...lol. Thanks Troy
Petes Garage What you were explaining on the measurement process is a trigonometric function (sin cos). The classes I took were taught well for accident reconstruction and practical. Believe me I'm no mathematical wiz lol, but just like your teaching style anyone willing to learn it is much easier for.
Wow that is a great compliment, thank you
Great job, I designed a 229 cid V6 on paper in my twenties before building it while in the Navy. I angle milled the heads aboard the ship after matching, porting and polishing. As I recall, the stock smog head was 115 cc chambers before porting. I used mineral oil to cc heads, not water, worked well. It has been a long time so I enjoyed listening to you, great memory refresher. My strait six 1997 Jeep Wrangler is tired and I am planning on rebuilding it with 4.7 specs from the stock 4.0 L. On a personal note, I used Rhodes hydraulic lifters years ago. I recommend you look into them, they vary your lift and duration. I also discovered they now make hydraulic roller lifters. This helps your dynamic compression ratio, with a race cam with a lot of lift and duration, reduces the variables window, normalizes. Once again great job, J & L is about 15 miles away from me, nice to know.
Cool stuff, Thank you Alan!
WOW... PETE IS SMART nice video pete thanks I learn something every time I watch your videos keep sending me videos I need it
Thank you very much Douglas, stay tuned...
Mate can I just say this video and series is the most informative I have seen, you don't skip over important steps that most other engine building videos do. I have been looking at these video's to see how to re-build an old Ford 300 i6 on a 1979 f250, I understand most of the steps to building and engine but the camshaft, valves and how to tighten down the rocker arms have been a little confusing until now thank you for the help. I am 17 and still in school I now see why they teach you trigonometry.
That's awesome! Good luck with your engine
Damn it..!!
You just ruined my day even more.
Here's why.
I just purchased a rebuilt 1977 454 with 1972 oval port heads and stock intake for $1500.To PUT in my son 1988 Blazer.upon removal of intake manifold to replace the gaskets.
I notice something i never seen before. Under the oil splash shield of the intake was what looked like Asphalt took a grinder to the rivets.remove shield and found a Mountain of Asphalt well i freaked out
Because the older guy i bought it from showed a video of it running on stand.
So i pulled the oil pan and found a brand new super clean bottom end. That was what i wanted . but the oil pan bottom looked like my bronco 265k mile transmission pan. Year after a filter change fine black clutch material.and white gel like stringy stuff probably from water droplets new oil that was more black than a clear amber color but no scratches on cylinder walls.. But then notice intake valves look like 50k mile on leaking valves seal built up on 5 of the 8.other 3 look perfect as did the exhaust valve were clean..
The next day that intake sat in sunlight asphalt facing up started to puddle up on intake .
Now im im buying new oil pump spending $700 on the heads and realizing i dont know what cam in this just know its bored .40 over. I paid 1500 to clean up someone mess..
Then i find you. Not a bad thing since im all ready torn down. Might asceell be Replacing the cam too..so i know whats in it.
Iam going tobe tearlng it all down and starting over aren't I..?. This started off as a birthday present. He doesn't know he comes home in 2 more weeks . Not going to happen is it.
Ps. The money i had for other part for the truck that sitting for two years this motor eating up so fast My 77 Les Paul in the pawn shop with my 63 strat and a Ar-15 next willbe my desert Eagle and another Bushmaster.. oh hell no that ain't happening ..what do i do..? Any advise would be welcomed Thanks
I'd just tear it down and rebuild it with what is ok. Sometimes you can reuse many parts and it will be fine. Take it apart and look
This is some really good knowledge and can be helpful from beginner to seasoned. Great channel and please don't let a few negative comments stop you from continuing to provide the content. Just earned another subscriber here! Thank you!
I appreciate that!
If I ever have a motor built you will be the man I go to!!
I'm ready Jamie....let's do it
@@PetesGarage where are you located?
I remember having to learn all this in the early 80's. My teacher bent me over the goals on how math would make me look like a genius.
He was so right!
He'd get arrested for doing that today....lol
I have been doing this for quite a few years very informative awesome job cant say enough about those numbers
Thanks Rodger
@01:00 I had a 'Doc Brown' moment (the part where he was watching himself on the camcorder ref. the amount of gigawatts of energy needed for the flux-capacitor to function).
+Petes Garage
"!!CLUNK!!"
That's the sound of not one penny dropping; but a whole bucketful of pennies simultaneously hitting the floor. it happend whilst watching the the previous posting, concerning camshaft theory/timing/etc (alas, comments were disabled). it's a mystery to me; how you can take all that knowledge and experience - and then concisely express the whole 'shabang' in such a way that a 'normal' layman/enthusiast can understand it all! I cannot even explain to the wife, the reasons why her car was overheating....and not to 'go on one', because it's repairable,lol.
pete....again - thankyou mate for posting!
I learned a ton from this series, thanks a lot!
This is really informative. I work on firearms and like engines, there is much more than turning the key and starting the engine. A lot of work goes in with many failures before they find a formula that works. Firearms are much the same.
+Gary Rumer That is really cool.
Pete, I've learned so much from watching all your videos. These will help me a lot when I go to build up my 300 straight six. I was a little intimidated at first because my first complete rebuild will at the same time be a custom build for a little performance, but your videos helped ease the tension a lot.
It's not that difficult...you can do it. Good luck!
Hey Pete!
I did find your serie's on how to build an engine, and what to choose, and several other great stuff! I follow your serie's, and you mensioned some things for I did not relise that they are there. FANTASTIC!
I am gonna build a 3sgte toyota street legal high horsepower engine, wich will ride here
in the Netherlands, and there is so much stuff to see in the internet, but not too much,
I am now looking for about half a year, what good suppliers are there, what should be done, what NOT to do, etc etc. Here in Holland we say (translated); Don't go over one night ice.
Anyway Pete, thank you already and all the best!
Thank you my friend...here in the US we say Det finns ingen ersättning för förflyttning
never let down when watching your videos. I always learn something and that's why I keep looking forward to your videos. I never knew there were 2 types of CR. in my build which I mentioned in the previous video, which was a sbf 331 I now need to take into consideration my DCR. im hoping for 10:1 SCR but my DCR might be a factor in the octane I am able to use. In Canada Ontario to be more specific we are mostly giving 91 octane as a premium and very seldom do we see 97 octane. so in my DCR im hoping to be able to use 91 octane with no problem. again as I learned in this video, cylinder head choice plays a big part in your DCR and cam selection too.. all engine components when building something all need to work together. the more I watch the more I learn and im happy I found Petes Garage subscription :) on to the next video :)
+david cabral That is awesome David! You will find a drop in you DCR which may fit the 91 octane available. I'm just South of the border in Buffalo
Well done, Pete. I made a spreadsheet with those same calculations.
Great idea. A spreadsheet works well. I can do it quick on a calculator, but the apps work pretty cool too.
I'm glad that you mentioned picking heads by CFM alone is not-completely-good idea. I was looking at aftermarket GM LS heads and they said 330 CFM on a 4.155" bore, but the heads are meant to be used on a 3.9" bore. Valve shrouding would be a big problem.
Yeah...that's one of the most common mistakes. There is more to it than a flow number. Thanks for sharing the info.
Hi Pete,
Fantastic information displayed in your videos. Truly gives the DIYers at home a greater understanding in the planning process of engine building.
I have a topic request, one that is probably frequently asked and it is this.. Introducing forced induction systems to engine flow and power output calculations. Possibly covering the different types of forced induction systems and how they influence camshaft and cylinder head choice.
If you have the time and components laying around I believe it would make a very interesting and helpful video to many of us viewers :)
Thank You!
I think I can put that together for you. Let me finish this one first....thanks!
Man that's more than I can digest in one video, but very interesting, Great Video nice tutorial Thanks William Orange county, ca.
Thank you William
Pug 31:04 good video, love the information I'm watching all of these.
Shelby the Pug!
Pete, thanks for a great video it really helped. I had to draw a diagram, but then I was able to calculate the dynamic compression ratio. This is a great series, looking forward to when the Cobra runs!
+Daniel Westerbaan Thanks my friend...I'm almost ready
Thanks for sharing your knowledge with all
God bless you. Thank you very much for this lesson
So nice of you
I love this video series! I've been binge watching all parts back to back! Very interesting stuff, I started out this series knowing absolutely nothing about engines and now I feel like I know a little something.. all that being said.. my eyes glazed over about 20 minutes into this particular video. lol
+Walter Shmitty LOL....that's awesome. I know it's difficult to follow if you're not totally into the material. I try to cover as much as possible so people don't have to answer questions. Thank you for taking the time to watch
I was looking at the math for the RD and RR.
At first I assume all calculations are in degrees for the sin and cos parts.
RD = .5 * 3.5 * sin(72)(in degrees) is 0.9511
RR = .5 * 3.5 * cos(72)(in degrees) = 0.3090
I am posting since I plugged sin 72 radians at first and got 0.2538 which is what you have posted in the video for the RD. So, I took a look what would happen in degrees and the cos was a positive number.
These values would change the outcome by:
PR1 = 2.381
PR2 = 2.072
DST = 2.7
Great videos by the way.
excellent, discussion on compression ratio / DCR is awesome
Thanks John
here in Australia we rate our fuel different than usa our 98 is your 93 octane because we rate our fuel of its highest rating, usa takes it off the average between motor octane and research octane which is also good to know... its also good to know the motor octane number which is the lowest number , this tells you how your fuel will react to higher reving loads at a hoter tempreture, good to know on the race track, eg our 98 ron pump fuel is only 85 mon when tested , this would be sold as 93 in usa I believe, e85 pump is 107 octane in Australia more than enough for racing and cheap as 98 to buy.... great vid as always... cheers
+carblingautomotive That is an excellent point. In the US the formula for for calculating the octane is right on the pump. R + M / 2. It is important to understand the difference. Thank you for helping us understand the difference.
7:15 you must clean out all the vaseline to get an accurate reading before you smoosh down the plexiglass plate. nothing in the chamber, no blobs. it will affect the CC amount. great video's!
Great point, thank you
all your vids are very helpful.my 91 silverado I dropped a carburetor 350 in is giving me some problems so i've been watching all these videos I think I'm going big block next time this is the second sbc it's had.thanks
That's a bummer. You have a nice truck there
Love this video me and my dad are rebuilding his 53 dodge and this has helped us a lot thanks!!! Oh and you are left handed like me!
That is awesome! You are lucky to be able to work with your dad, I hope he is left handed like us
I rename petes garage into petes university after this episode.
I wouldn't go that far....although I may get some Federal funding
Petes Garage great channel. Learned a lot so far.
fuelbasti 1721 cam
Freaking awesome dude I enjoy watching ur videos keep up the good work
All good stuff. Any first time builders/modders out there watch this video FIRST before buying parts [especially the cam] and thank Pete later. Second, decide what rpm range your motor will mainly live in [sub 4k/3-5k/over 4k], then go watch his carb selection video if the build isn't going to be EFI.
I didn't know anything about engines when I started these videos but now I've at least scratched the surface
+Marshell Shaub Excellent, I just want to help with the basics
Hey Pete,
Love the info especially the math and engineering aspect of the vids. I am a third yr Mechanical E @ University of Alabama (tuscaloosa) and there is not an automotive track at all so your videos really give me the somewhat in depth info I need.
Joshua Penn That's awesome Joshua! Congrats and keep learning.
Amazing video. Really helped me figure out the correlation of the numbers.
Excellent...now can you explain it to me?...lol
Lots to think about. Cam duration... Intake flow... Stroke... bore... rod length...
This is proper engine building I think. Not just "Stage 2 cams with stage 2 tune and stage 2 turbo". I am learning things are a lot more complex
There's a lot of information, but you can figure it out Jason
Pete...yer work is greatly appreciated. thank you
Thank you Aaron
This was so helpful. Thanks!
Thanks Logan
This video is INSANE!!!!
There's always a little insanity
Excellent video...i really appreciate it. I'm in the process of determining my proper config/combo
I'm glad to help.
This the most informative video series I have seen on RUclips. Awesome work brother! Keep them coming
Thank you very much Rick
I love this. Its so interesting that i would love to build engines for living.
Newbpwng SO would I...lol
Another fantastic video. This is a GREAT series.
Thank you for these. Study hard
Absolutely
thanks pete trying to decide on where to go with my truck it's an 89 chevy surburban with a 350 with a 700 r4 trans 5.7 liter i want to rebuild it myself however i haven't work on cars or truck in twenty plus years due to taking a different approach in life and now i would like to do it myself because i'm able and have a little money hint hint little money so your video is extremely helpful in the decision making process thanks any feedback is appreciated
You can do it. I'll help you as much as I can.
thanks pete god bless appreciate it
good education for the beginner thanks
Good stuff.
Great series of videos very educational KUTGW Pete!
Liked the video. Would the cc's change if you had a sparkplug in the hole instead of petroleum jelly? How does the angle of the sparkplug affect performance?
I answered that a couple times. The volume of the spark plugs are constant so the change would be just the plugs. You are looking for actual volume. The angle of the plug does affect performance...but so does plug type and fuel octane.
Excellent the math really seems to be the key. Thank you
It really is!
@@PetesGarage thanks for getting back to me. So how wrong would I be to pick your brain. Sbc rebuilds no big deal. This is really my first full on high performance. Build. Don't want to screw up up. Lot of money, lot of really nice parts. So anyway your videos are very well thought out.
I'll help if I can
@@PetesGarage I really appreciate that.
This is the best instruction video I have ever seen! Thank you so much for taking the time to make it!
I started watching because I have a 91 Volvo 740 turbo with a B230FT engine. I am planning a build for the car and felt overwhelmed with how much to decide at the machine shop!
This video series helped a lot in deciding what to do.
My only question is, how does your build sound? I want to hear it!
+Matthew O'connell Thank you. I am getting close to getting it on the dyno. I will make a video of the whole process
Fantastic videos Pete very educational. Keep them coming!
Can you do a rebuild for a 2az-fe engine. I like your channel so much!
Yes, as soon as I get one
good video it's a lot of information
Thank you
On Ford small block Windsor engines there is restrictors cast in that need to be ground out with a rotary tool to maximize flow on the exhaust side.
Thanks for sharing
I was the 666 like. Is that a good thing? I love this engine building video series. I have a completely machined Toyota 3TC 1.8l engine that I will be assembling and because of this series I am much better off. No paper towels or teeshirt material for me.
+Anthony Munn That's awesome Anthony. Thanks so much for watching, glad it helped
Hey peter loving these videos will be subscribing for sure.
In relevance to get your stand point could it also be possible to duplicate the same combustion chamber CC test with oil which one would be the most time and cost effective during the engine assebly with an over all cost Benefit aspect taking into considerstion reusing the oil over and over with minimal loss of oil and cleaning products if not the same used to adequatly clean up the cylinder head afterwards for both possible methods if the same product would be used this would remain non applicable unless a Considerable amount more is used to clean up one process over the other aswell the time to clean the surfaces?.
Aswell In regards to using the petroleum jelly to fill the spark plug hole would the use of the same spark plug per cylinder for each engine with repeated use in mind be possible with one method without possible oxidisation to the spark plug causing potential FM making even in my opinion this being not viable if the oil method its more cost beneficial however for both labour and resource/material cost.
Unless the water method would be safe over prolonged use by the means of using WD40 or something along those lines to put the spark plug back away to be reused when building the same type of engine.
does the same short motor with different cylinder heads use different spark plugs making it pointless to have a bunch of spark plugs lying around and would the spark plug petrude beyond the flat mating surface of the cylinder head making this impossible to test as a Variable with the combustion chamber CC test.
if it is possible rather than petroleum jelly would it give a different end result or reading of a considerable amount creating the different of measurement to throw the compression ratio say for example from 10:1 up to 10.1:1 or 10.2+:1 or be so small of an amount like 0.1 or 0.3 of a CC that again it would be negligible with near no effect.
I have a tendancy to over think as well as i prefer tolerances to be minimal best way to describe what im trying to say with that statement which may open up another question with the thrust end play tolerance of 0.001 to 0.003 if i had a 0.002- 0.003 reading id try to Aqcuire a part to hopefully bring the gap back between 0.0015 - 0.002 on an engine build however i understand that could bring about extra labour cost driving up over all customer build cost but as this would be the lengths id go to again as an example and the question, would it even be worth it long term for the life of the engine.
Hope to see some more great vids this is both refreshing and helping to clarify alot having a some what mechanical mind with my own experiences as well as future aspirations of building my own engine.
I tend to have a NASA scientist engineering mentality with high standards and forget the KISS method of keep it simple stupid method sometimes but i also have ADHD and theres something about doing this and looking into these things just just calms me call it a little OCD but its just how i am with things.
This might be a bunch of silly questions to you but i wont know if i dont ask so hopefully if you feel its reasonable given if you have the time to do so could i ask would you consider making a video to outline this
There are so many questions in there I don't know which to answer
VERY GOOD VIDEO MY BROTHER..
Much appreciated
I love this guys channel!
I knew Morgan Freeman would love it...lol
How would you factor in boost into calculating static and dynamic compression ratios for a forced induction engine?
There are actually constants that you put in the formulas. You can Google adding boost to compression ratio calculations and you'll find a bunch
Great vid. Learned a lot here...thank you!
You could be tight Clint. Let me look through the calcs
Hey Pete. Where do you shop for your engine parts and around how much did you spent building this engine?
Mexico? I'm only half joking - import duties are typically a fraction of what sales tax is in most states, which is one factor as to why so much manufacturing has moved there. What's 5% improved margins on a small [$1M] business? Oh...just a new bmw with all the options every two years [if that's your thing].
Nice video.thanks.
You have a great set of videos here and absolutely love it for when I rebuild my engine in my truck. But I have a few questions, One. Instead of plugging the spark plug whole with jelly. Why not use a spark plug since it will be in there when you put it all together, or is it since spark plugs very in size it is the standard to do it this way. Also you talked about not getting enough air and fuel in to the chamber, well what if you used a turbo, I am thinking about putting on a turbo and not to clear on what it does other then give you more horsepower.
Also I have a few videos that I would like to see, one would be about the turbo if it is apart of engine building and I would also love to see video that tie every thing you talked about in these videos and pulled it all together in "hypothetical" engines, one built for the drag race one built for tractor pulling and one that would be just a beefed up "every day" or "Budget" engine.
An Everyday engine that I am talking about would be what I want to have. higher torque, better fuel usage, I am not wanting to do burn outs or win any tractor pulls I just want to pull better. I myself have a 302 EFI Ford in a 1995 F150 4x4.
Also writing this has given me an Idea for another Series and that Would be the Drive train Since You do Have such an anuchsew set of videos. But I dont want to take up to much of your time
Thanks Justin. The volume of the spark plug is inconsequential. Plugging the hole gives absolute volume.
A turbo just sucks the exhaust gas out of the cylinder thereby reducing back pressure. This gives HP back to the engine and sort of pulls it along.
Those are some great video ideas. I make videos as projects come up. If those come along I'll be sure to makes them.
Pete, youre a badass
I hope that's a good thing....lol
Hey Pete!
I've been having fun with some 50cc 2 stroke engines. And, after watching your video, I understood, that I would like to build a 4 stroke multi-cylinder engine for experience. Are there any particular engines you could suggest? I'm looking for something not too big, not too expensive and with a lot of available parts. Thanks in advance :)
The best engine to use is a Chevy 350. Most common and tons of parts available
Thanks a lot!
I don't know if I missed it or not but I never did see or hear a range for fuel needed once you know your DCR. I figured mine out and it is 8.9. N/A engine 412 cubic inches. I can't find any info on what dynamic compression you can have in relationship to the octane of fuel.
That's pretty low, any octane will work
Hi Pete. I love your series. I have never built an engine or raced, but do have some knowledge just through interest. I apologize for what may be a simple question. I watched this and understand Dynamic Compression. Out of curiosity I tried to find that number on my 2017 GMC 5.7 but couldn't find it. I did find the static compression to be 11:1, but they still recommend 87 octane. Admittedly it runs fine on that, but I am wondering how they accomplish that. Again I could not find the Dynamic Compression on it, but I would assume with 11:1 static it would need higher octane. I guess if we knew that number it would answer this question. Thanks for your series. It has me thinking!!
If you had the cam specs it may help. That can lower dynamic compression within range
Hey Pete, how would you clean of the petroleum jelly after checking the cc's in the combustion chambers
Can you find the volume of the chamber with the spark plugs installed? Great presentation. Funny dog barking in the back ground.
Yes, just do the same for all chambers, the object is to make sure they're all similar
Is there a spreadsheet floating around out there on the net with all this stuff already set up where I can just punch in the variables and it will calculate it all?
Pete, love your videos, thank you. You either look extremely tired, or you were smoking a little of the wacky tobaccy....... :)
I'm always extremely tires. I don't smoke, or even drink for that matter.
@@PetesGarage
Thanks again for your videos. I also don't drink or smoke, so it's good to hear there are other people like that out there. Get some rest!
I need more stroke length on my rod!
Good man
If your spark plug extends into the head significantly, would it be more accurate to put a plug in, so it can take up the space it would normally take up, or would it make make that much of a difference?
It would be different. But all things being equal the final ratio would be extremely close
I have 403 olds in my 79 trans am. what would you recommend i do with cylinder heads and camshaft if i want to have a cruise engine that occasionally races street? I am aware these engines are very tamed due to smog standards but i'm not sure where to start pete.
Just a thought but shouldn't you do the combustion cc check with your spark plugs installed to get a more accurate reading because they effectively lower the cc of the chamber.
That is true. However, in the scale of the measurement it is fairly negligible.
Thanks you Pete put on a very good educational seminar. And I have a question what is a good medium size Cam's put in a 5.3 Chevy avalanche 2003 Stockton board 20 over pistons stock crankshaft I do not want to use the stall converter I where thinking somewhere about this size 32:45 195 /197 485/487 /116lobe
Or a little bit bigger 👍
Choose based on the springs in the heads
When you said 250 cfm port flow was good for 600 hp, is that intake and exhaust overall or mainly the intake flow? I'm assuming intake only?
Correct, intake only
He said 300cfm
You havent mentioned valve diameter at all, head flow is ultimately decided by the first point of restriction and that is intake valve diameter, the bore x sroke x rpm will give engine cfm @ max rpm, intake valve diameter is the factor that ultimately decides A/F flow
You are absolutely correct. There are a few things I am assuming. When heads are purchased I am assuming the valve size is taken into account when the desired flow and volume is determined. I did not want to get into changing seats, valves and other head parts.
hey pete.....great videos,.....i'm learning a lot from your vids and other internet sites.......seems getting a good mechanic you can thrust is so hard now a days.....now i'm no mechanic....but i'm learning..... i like and owned fast cars....i have a general idea about engines and how they work but i'm just wondering, if you're checking for CC's on the head, wont the head gasket and spark plug affect the equation????
The spark plugs will, but the should all be the same. The gasket thickness is included in the compression equation. In this step you are looking for the true volume of the head
Hi Pete, great videos with lots of healpfull info.
I have calculated my static compression as 9.99:1 that's a standard 351c 4.00 bore 3.5 stroke.
With factory flat top pistons but with my head volume 62cc was 62.8 before the machining.
My heads were 62.8cc machined down 0.005" to get spot on 62cc.
I tried to do the dynamic stroke calculations but get different results.
RD =1/2 ST x (sine ICA). You get 0.2535 in red
I get RD = 1/2 3.5 x (sine 72)
RD = 1.75 x (0.951056516) = 1.66434
You get 0.2535 in red , what am I doing wrong.
I want to get the hang of this calculation as I want to know what ICA I need which will
Determine what camshaft I buy.
Let me do that calcs againg
Am i right in thinking if you have dished or domed pistons you'll need to add the positive or negative displacement of this to the head cc before dividing by it?
That is correct....add volume for a dish, subtract for a dome.
you ROCK!!!!!!!!
Rock on my friend!
I was wondering why nobody I know talks about dynamic cr. Now I know. Lots of math involved! Haha. I’m in the planning stage of building a low buck LA block Dodge. I am debating if I should stick with the LA (have headers and Mopar M1 intake), or go with a Magnum build. More $$$, but more power. Maybe Magnum heads on my LA. I am looking to get 400hp.
Tough decision
Hi. I like all the good info. I’m rebuilding my fuel injected 5.9 360 magnum. I’m trying to figure out good heads to get that are durable and reliable. Not for racing. I also want to increase the HP a bit. I was thinking of raising the compression slightly. Stock is 9.1:1. What would be the best way to gain some HP with this rebuild keeping it durable and able to run with oem computer. Thank you.
That's tough with the OEM computer.
Hey Pete, great video! But I am brand new to engines and I just know the parts and don't really know what compression ratio is, and I am wondering what you think I should learn about engines (and how) before I come back and watch this series again so that I understand it better. I was also thinking about getting a long block from a u-pull-it or eBay and taking it apart and putting it back together again just to learn, but I don't really want to spend a lot on an old V8 so I was thinking about buying a I6 or I4 engine by Nissan or another manufacturer for cheap, I'm probably not going to ever put the engine in a car and I'm guessing that its going to get pretty beat up as I have never touched an engine past the head covers. Just wondering what cheap engine you think I should find that can is good to learn from, easy to find and not going to break the bank. Thanks
It's a great idea to get a junk engine and tear it apart. I have videos about compression ratios, static and dynamic. Keep on learning
I don't know if it was simply coincidental, but the two numbers you had, one, being the cc'd value of the cylinder divided by the cc'd value of the combustion chamber, differed by about 47, from the final value of the volume. I sound confusing, but at 22:02, the numbers differ by 47, which is also 47 degrees ABDC. Just speaking my thoughts I suppose.
On which calculation?
For that whole “x-CFM x 2 = Power Capability” rule of thumb only apply to N/A engines? I’d assume so and if so, would that be assuming 100% volumetric efficiency? Thanks.
Edit: Also, in regards to DCR, essentially SCR isn’t necessarily as important as DCR, correct?
Yes, it is for N/A engine assuming 100%. DCR is more important
Pete's Garage thank you very much. I’m still in high school and go to a tech school for auto tech. I’m in my senior year so I’m trying to accumulate as much knowledge that’s a little bit more complex than simple mechanics because this stuff is super interesting!
Great job Peter, stay in school and never stop learning
nice AK on the wall.
Shop security
Hey Sir Peter How are you doing? Is DST, Dynamic stroke length remaining ATDC (AFTER TOP DEAD CENTER) OR ABDC (AFTER BOTTOM DEAD CENTER) after intake valves are closed? Thank you. 17:45
It is ABDC. You lose a little of the volume because of valve overlap when the piston is on the way back up on the compression stroke.
Pete, wouldn't you want to install the spark plugs when measuring the head volume? wouldn't the space taken by that affect the compression ratio slightly?
That is an excellent point. The volume of the plug is negligible since it has both positive and negative volumes. You can put them in if you like, but the water measuring process does not had the discrimination to really notice the difference.
So why is the intake valve still open after bottom dead center? Shouldnt it be closed right at bottom dead center to take advantage of more compression?
The piston is not on its way up immediately after BDC. It takes a little rotation before it starts to move up.