So per my old mans guidance who recently retired (so an old wise man of the trade) You lap the valves until you no longer see any shiny or un-lapped looking metal on both mating surfaces. Both should have a even matte finished look when done. I did see a couple spots on your lapped valve which to me looks like you could continue lapping to remove. I'm also far from an expert but I was blessed and fortunate enough to have my old man next to me giving guidance and inspection when I did my valves. Only exception would be if your valve has a deep pit of some sort which would require realistically too much lapping to remove, at that point if it's small you can probably just run it as is. If it's large then a new valve maybe in need.
I have to state when testing for barometric pressure (positive or negative) that on earth we cannot exceed any less than 29 inHg. So the fact that your valves held at 29inHg means they were sealing up to a potential of 99.9%-100% Just a little thing we were taught in trade school for a/c applications - thought I'd share. Love your vids btw!
Thanks for putting all this stuff together man, I just got my spare engine for my NB that I'll be going through and refurbishing, these videos are an immense help!
Good job dude! Next time you do this job though try to spin the valves as far as you can either way. Short strokes, say if the valve only turns 1/4 turn either way, may result in a valve with a face matched to a seat only in a specific position, resulting in different sealing capability as it naturally spins around while the engine is running. You should be able to easily get two full valve rotations each direction by hand. Also, what you’re looking for is a uniform band of dull grey all around the valve face and seat. Keep up the good work!
My dad always done his on valves and had some of the best performing engins around. I'm 48 and I remember him using those suction cups since I was riding a tricycle. Always remembered playing with them as well.
Another thing to look out for is where the lapping marks are on the valve and seat. If its not in the middle it can indicate a valve that is too recessed or too proud, that will require the seats to be cut. Lapping isn't a replacement for machining and it wont have the same gains as a proper multi-angle valve job but its a great way to make sure your previous valve job is sealing when doing a rebuild. I've heard machinists say that if the valves need to be lapped after a valve job then the machining wasn't done correctly.
"I've heard machinists say that if the valves need to be lapped after a valve job then the machining wasn't done correctly." Absolutely correct. By the 1980's machining equipment had progressed to a point that no lapping was necessary. The fit was good enough with a quality faced or new valve and cut seat that within a VERY short time of starting the engine the valves will hammer themselves into a 100% perfect fit.
Valve lapping can be used to correct small imperfections or to see where your valve face is hitting on the seat to low or too high depending on where you want it. It's not meant to fix valves or valve seats. They also make many different lapping compound grits.
Nice video. This is very helpful as I am working on lapping my existing valves on a Toyota V6. I don’t have a vacuum tester though. The machine shop inspected my heads and identified the leaking valves. He told me that a valve job could be 700 and higher. He suggested that I lap the valves myself and replace the seals. He then said to come back and resurface them. I originally took on this job due to a blown head gasket. The car seemed to run fine prior to starting this; however, I guess I would never know if it was down a bit on power as I bought it used.
Your mechanic gave you bad advice...lapping wont fix leaky valves or an engine needing a valve job. It actually makes sealing worse. Id look around for your own machinist for a valve job next time you have it apart.
@@gordocarbo I spoke to a machinist. Did what he suggested. Turned out great. 20,000 miles later and two trips around the US and truck is running great.
I’ve had many heads go to the machine shops for value work. For the last 40 years I do all the final assembly and lapping. I also do my own seals after I bought a guide tool from Comp Cams. I have the inside mics and a spring checker to set them one at a time where I want them. I even have purchased valve keepers with different placement of the securing ring. It takes time but at least I know exactly what I have..good video..
Even though I'm not a professional, I always try my best to double check the "professionals" work just to put a final set of eyes on it. At the end of the day, it's my investment that's going into the car, never hurts to double check things!
great vid, lapped valves on power equipment for years. Still learned new stuff from this though, now we're going to have to make psyched and stoked into a new word and use it... get pstyched would be a good t shirt. Could write the words between a pair of pop up miata lights on the front
I like how you do it by hand and that's the correct way going in both directions. Using a drill you can burn up your guides and heat up your stems and recess your seats unneccesary. An engines valves never spin like in a drill
The content they offer is top notch, and great for a variety of skill levels. I just recently started taking the courses but have been following their channel for years just loving the 15-20+ minute deep dives into the time attack cars and all the technology they employ.
@@TheCarPassionChannel agreed. Great resource. Looking forward to feeding the brain and eventually throwing a wrench. Hopefully non Aussie/NZ people can understand the accents!
Based on the exhaust valve results I would be tempted to replace the exhaust valves. Probably not worth the cost for marginal improvement but still tempting. I'm excited to see how well your hot vs cold compression/leak down values compare. Always wondered how valve jobs ensure proper seating during operation temperature.
Very cool. I've always wanted to try this myself. Interesting to see how quickly the tone changes as you grind down to the finer grit. Many years ago I ported a head myself but left the valves to the engine shop. I also just did my research and didn't go overboard, the engine shop guys said I did a really good job. I was stoked considering it was the first time I'd ever held a die grinder 😅
I ised to rebuild subbie motors and its very intimidating at first. But once you get it, you got it. Btw....styked is a cross between stoked and psyched. Hahaha
the tool is genius one thing to think about is in other videos ive seen that when they raise the valve to get more grease on the surface they do it very slowly to not possibly fling a grain of sand into the stem
Great video! It was your other video that inspired me to build my own tester. I made mine with a $15 vacuum pump & it worked great. In fact I just uploaded a video yesterday on it. In my video I show you how to test without installing your seals. I thought you might be interested.
Remember grinding paste came in double ended tub,fine one end coarser the other,initial lap with coarse then finish with fine,want an even matt surface.
Love the before and after. Especially on new machined valves. Would have been interesting to see new valves PLUS re-ground seats vs lapping. Many claim lapping these days is a waste of time, but I don't believe that.
The need to lap engine valves had become largely obsolete by the 1970's (when I went to trade school) such had been the improvement in equipment and methodology. The tools and method called 'syncro seating' is still be far the best and accurate method. This will put the valve and seat contact surfaces so close to perfect that withing minutes of starting the engine and the valve impacting the seat a few thousand times a minute it will quickly 'hammer' itself into a 100% perfect fit. The valves used in a lot of hi performance engines must NEVER be lapped as it will destroy the coating on these 'hi-tec' valves.
3:14 These numbers are considered "good enough" for just regular street use. You don't want to see a number lower than 24. If you go crazy with lapping and go from 280 all the way to 1200 grit, you can get 29-30 in/mg and the needle drop time is measure in days and not seconds.
Притирка клапанов now I know what this is .. I’m glad you didn’t messed it up. I wonder how many people just through new valves into an old head and make it even worser than it was.
first /// wait I mean 3rd. Your tester is excellent. And you can only ever get 29 lbs of vacuum (this is the limit on earth) but compression can be much higher. How do you know if the seal is good at the exhaust/take ports?
On my BMW e36 24 valve cylinder head I was able to lap all the valves to peg Vaccum at 29in-Hg and achieve a leak-down time of greater than 2 mins on each cylinder for both intake and exhaust. I know this is a diminishing return as valves open/close in milliseconds however I wanted to see if it was possible. I used 600 grit followed by 1000 grit lapping compound.
Have you looked into doing a DIY porting job? The heads have casting flashes that can get drimmeled down as well as the plunge cut where air feeds into the valves.
When i lapped the valves for my k24 build. I used the drill method, i had severe pitting on the valves /seats. That's a good idea with the block off tool, i'm curious what mine would show now lol.
How long did the grinding and cleaning process take? Of course, filming everything adds time, but a ballpark estimate would be helpful for people who might attempt this themselves
We'll see, I got almost a half point of extra compression from the shave too. The problem is the compressor on the turbo is at max flow already, so I don't there will be much top end. We'll see!
an easy way to tell if valves are leaking first take a compression reading then remove plugs add 1 small spoon mtr oil in each plug hole now take a new compression reading if oil helps its the rings are leaking if no help valves are leaking this test is for low comression readings
Hell of a great job, thanks for sharing your knowledge. But can it replace valve job done by the shop? Also, when the shop cut the valve seat, there are 3 angle cut. But they charge $400 easy. Will the shop job last longer? Again, great job and thanks for sharing.
Another awesome how to Greg! And you always come out with relevant videos when I need them lol. One question, you swapped the valves, but are you doing anything to prevent the intake valve problem that happened? Or will this just become a maintenance job for you?
I think in a previous video he said he was using longer springs. They were slightly lighter but also longer so when they were in the head they had more weight on them. Volvo ones maybe? I don't remember
My best guess is that the springs didn't provide enough seat pressure for the combo of boost and RPM, so I've upgraded to a spring with more seat pressure. You can find that lengthy video a few spots back if you care to learn more. But no, I'd rather melt this engine down for scrap over replacing the valves every 13k miles 😅
Gotcha, so the method I described still works the same way, just in a different way from how it's described on the package. (States: "Grinds down to a 220 grit")
You were bold enough to go forward with the valves for the first time, why not sand the head on a sheet of glass or granite? The worst thing that can happen is that you gain very valuable experience... experience can not be bought but has to be lived 🙏🏼
This gives me hope never built an engine and just lapped the valves always sent it out to the machine shop. I am building a performance boat I just got the short block together last night. I dont really have the extra money to have th heads machined and was just going to lap them. I have a blast cabinet i am going to take them all apart clean the valves and sand blast the heads and try this if the valves and seats are salvagable . Gave me new up I can pull this off the heads are after market performance heads . My bucket list get the engine in and get out and start living aagin gotta get out of the grave called a rut
As a weekend mechanic My mentor is a greybearded lifetime hotrodder/GM master technician I ported/polished my own head on a 1.6T mini cooper, lapped in the new valves and was nearly 3 valves into reassembly when he walked by and made me do the old leakdown test WD40 a damp rag and compressed air, every single valve seat blew bubbles Re lapped every valve again, only three valves blew bubbles Re lapped a third time, reassembled and everything was air tight
Awesome video as usual, why are you not removing just a TINY BIT of cylinder head material to deshroud the inlet valves?? The incoming charge hits the back of the valve and wants to continue on that path into the cylinder at quite an extreme angle. It hitting a virtually 90 Deg wall just after the valve seat, at PEAK velocity is a killer. The reason I know this is that I sent my BP5 head off to Blink Motorsport in the UK. They rebuilt it with standard exhaust valves and standard diameter supertech inlet valves with a little bit of bowl work but next to no porting. End result, seriously!! noticeable more power across the board with new (mild) cams and original HLAs and valvetrain. The most usable power is gained at smaller valve lifts as this is the most time of the stroke that you will see. 12mm lift is cool at 12mm but if the cylinder is struggling to pull in charge at 0-10mm then its a pretty meaningless number as it occurs so briefly in the cycle. A tiny bit of headwork around that vertical step will bring massive benefits across the rev range. FUCKING LOVE THE TIME, WORK AND EFFORT THAT YOU PUT IN TO GIVE US THESE VIDEOS!!!! ❤️
You're supposed to use valve lapping paste. Not valve grinding paste. Grinding paste is for reshaping a mating surface. Which should only be done when imperfections are verified. If the surface is smooth you only use lapping paste to clean and mate the surfaces.
While u have the head off for extended amounts of time are you supposed to use any grease around the pistons before u start it up again? Or engine oil?
@@TheCarPassionChannel hey dude, I know this is random but I swear you need to come to the UK and see some peoples cars you can get a good nbfl with just rusty arches for £1000 all day
"*Please note that some heads WILL need a valve job (where the valves and/or seats have a new face machined at the correct angles). But it's not always needed." WRONG! If you've gone to the trouble and expense of removing the cylinder head for overhaul ALWAYS either replace the valves or reface them if they are uncoated steel type. Same with valve seats. They should always be recut. If done with good equipment, no lapping of valves should be necessary. For 'hi tec' coated vales e.g. found in every modern performance motorcycle, valves should never be resurfaced or lapped. P.S. 'A Grade' qualified mechanic with over 50 years experience.
![How To Lap Valves, Spring Height Micrometer, and Reface Valve Stems [EXPLAINED]](http://i.ytimg.com/vi/ziPg0qUF4Lg/mqdefault.jpg)
![BLACK BAG - Official Trailer [HD] - Only in Theaters March 14](http://i.ytimg.com/vi/Du0Xp8WX_7I/mqdefault.jpg)
So per my old mans guidance who recently retired (so an old wise man of the trade) You lap the valves until you no longer see any shiny or un-lapped looking metal on both mating surfaces. Both should have a even matte finished look when done. I did see a couple spots on your lapped valve which to me looks like you could continue lapping to remove. I'm also far from an expert but I was blessed and fortunate enough to have my old man next to me giving guidance and inspection when I did my valves. Only exception would be if your valve has a deep pit of some sort which would require realistically too much lapping to remove, at that point if it's small you can probably just run it as is. If it's large then a new valve maybe in need.
Scientific method. This is what i like. No anecdotes, no old timer lore, hard data that proves claims. Well done sir!
I have to state when testing for barometric pressure (positive or negative) that on earth we cannot exceed any less than 29 inHg. So the fact that your valves held at 29inHg means they were sealing up to a potential of 99.9%-100%
Just a little thing we were taught in trade school for a/c applications - thought I'd share. Love your vids btw!
Thanks for putting all this stuff together man, I just got my spare engine for my NB that I'll be going through and refurbishing, these videos are an immense help!
Same here!!!
Good job dude! Next time you do this job though try to spin the valves as far as you can either way. Short strokes, say if the valve only turns 1/4 turn either way, may result in a valve with a face matched to a seat only in a specific position, resulting in different sealing capability as it naturally spins around while the engine is running. You should be able to easily get two full valve rotations each direction by hand. Also, what you’re looking for is a uniform band of dull grey all around the valve face and seat. Keep up the good work!
Only lap valves with short strokes to show if your valve or valve seat are uneven.
My dad always done his on valves and had some of the best performing engins around.
I'm 48 and I remember him using those suction cups since I was riding a tricycle.
Always remembered playing with them as well.
Another thing to look out for is where the lapping marks are on the valve and seat. If its not in the middle it can indicate a valve that is too recessed or too proud, that will require the seats to be cut.
Lapping isn't a replacement for machining and it wont have the same gains as a proper multi-angle valve job but its a great way to make sure your previous valve job is sealing when doing a rebuild.
I've heard machinists say that if the valves need to be lapped after a valve job then the machining wasn't done correctly.
"I've heard machinists say that if the valves need to be lapped after a valve job then the machining wasn't done correctly." Absolutely correct. By the 1980's machining equipment had progressed to a point that no lapping was necessary. The fit was good enough with a quality faced or new valve and cut seat that within a VERY short time of starting the engine the valves will hammer themselves into a 100% perfect fit.
Valve lapping can be used to correct small imperfections or to see where your valve face is hitting on the seat to low or too high depending on where you want it. It's not meant to fix valves or valve seats. They also make many different lapping compound grits.
Smokers: we put cigarettes behind our ears.
Construction workers: we put pencils behind our ears.
Meanwhile Miata dad: 0:05
Stop everything, CPC video to watch. Full send.
I love the measured before and after results. It’s a very good confident builder for my first valve lapping.
Lmao wearing the glove with the cut fingers was a nice touch! 😂
Cannot wait for some more canyon driving uploads as soon as everything is back together. Amazing content as always Greg.
I believe the exhaust valve seats are hardened and therefore take more lapping to get perfect like the intake valve seats.
Great Video! I learned a lot. I still got to get enough guts to do my valve seals myself. Thanks for what you are teaching the community. Best Always,
Nice video. This is very helpful as I am working on lapping my existing valves on a Toyota V6. I don’t have a vacuum tester though. The machine shop inspected my heads and identified the leaking valves. He told me that a valve job could be 700 and higher. He suggested that I lap the valves myself and replace the seals. He then said to come back and resurface them. I originally took on this job due to a blown head gasket. The car seemed to run fine prior to starting this; however, I guess I would never know if it was down a bit on power as I bought it used.
Your mechanic gave you bad advice...lapping wont fix leaky valves or an engine needing a valve job. It actually makes sealing worse. Id look around for your own machinist for a valve job next time you have it apart.
@@gordocarbo I spoke to a machinist. Did what he suggested. Turned out great. 20,000 miles later and two trips around the US and truck is running great.
I’ve had many heads go to the machine shops for value work. For the last 40 years I do all the final assembly and lapping. I also do my own seals after I bought a guide tool from Comp Cams. I have the inside mics and a spring checker to set them one at a time where I want them. I even have purchased valve keepers with different placement of the securing ring. It takes time but at least I know exactly what I have..good video..
Even though I'm not a professional, I always try my best to double check the "professionals" work just to put a final set of eyes on it. At the end of the day, it's my investment that's going into the car, never hurts to double check things!
Better grab a cold one. Miata dad's video's are always worth it
great vid, lapped valves on power equipment for years. Still learned new stuff from this though, now we're going to have to make psyched and stoked into a new word and use it... get pstyched would be a good t shirt. Could write the words between a pair of pop up miata lights on the front
I like how you do it by hand and that's the correct way going in both directions. Using a drill you can burn up your guides and heat up your stems and recess your seats unneccesary. An engines valves never spin like in a drill
thanks greg, been thinking about a HP academy course for a while - pulled the trigger after applying your code.
The content they offer is top notch, and great for a variety of skill levels. I just recently started taking the courses but have been following their channel for years just loving the 15-20+ minute deep dives into the time attack cars and all the technology they employ.
@@TheCarPassionChannel agreed. Great resource. Looking forward to feeding the brain and eventually throwing a wrench. Hopefully non Aussie/NZ people can understand the accents!
Based on the exhaust valve results I would be tempted to replace the exhaust valves. Probably not worth the cost for marginal improvement but still tempting. I'm excited to see how well your hot vs cold compression/leak down values compare. Always wondered how valve jobs ensure proper seating during operation temperature.
Love still seeing new stuff on the channel keep up the good work buddy
Very cool. I've always wanted to try this myself. Interesting to see how quickly the tone changes as you grind down to the finer grit. Many years ago I ported a head myself but left the valves to the engine shop. I also just did my research and didn't go overboard, the engine shop guys said I did a really good job. I was stoked considering it was the first time I'd ever held a die grinder 😅
I ised to rebuild subbie motors and its very intimidating at first. But once you get it, you got it. Btw....styked is a cross between stoked and psyched. Hahaha
This is awesome. I don't have a Miata but I have a spare KA24E head for my hardbody I want to rebuild. Thanks for the bomb ass tips on saving me 💰!
God damn, this is definitely something I'm gonna try when I finally get the chance to pull my engine.
the tool is genius
one thing to think about is in other videos ive seen that when they raise the valve to get more grease on the surface they do it very slowly to not possibly fling a grain of sand into the stem
Thanks for this video! It something that I'm going to have to do soon, I have a new head coming for my 1.6 and this is something I've never done
Awesome dude! You are a smart young man. I will be doing this on an old Ferrari this weekend. Thanks!
Great attitude dude, I am one like you, love to do it my self, passion on it man❤
Great video! It was your other video that inspired me to build my own tester. I made mine with a $15 vacuum pump & it worked great. In fact I just uploaded a video yesterday on it. In my video I show you how to test without installing your seals. I thought you might be interested.
Always a quality video from you Greg good work! :)
I'm learning so much from the way you present dude
Thanks for taking the time to do these videos. Really useful learning for those doing work I’m their MX5/Miatas
Could you please do the compression test with the new lapped valves. I would like to know the results now, how much it changed
Remember grinding paste came in double ended tub,fine one end coarser the other,initial lap with coarse then finish with fine,want an even matt surface.
Another awesome video from the miata dad. Cant wait to see some more mountain road driving and some more mad skids videos!!!
Love the before and after. Especially on new machined valves. Would have been interesting to see new valves PLUS re-ground seats vs lapping. Many claim lapping these days is a waste of time, but I don't believe that.
The need to lap engine valves had become largely obsolete by the 1970's (when I went to trade school) such had been the improvement in equipment and methodology. The tools and method called 'syncro seating' is still be far the best and accurate method. This will put the valve and seat contact surfaces so close to perfect that withing minutes of starting the engine and the valve impacting the seat a few thousand times a minute it will quickly 'hammer' itself into a 100% perfect fit.
The valves used in a lot of hi performance engines must NEVER be lapped as it will destroy the coating on these 'hi-tec' valves.
3:14 These numbers are considered "good enough" for just regular street use. You don't want to see a number lower than 24. If you go crazy with lapping and go from 280 all the way to 1200 grit, you can get 29-30 in/mg and the needle drop time is measure in days and not seconds.
introducing a bit of moisture helps the suction cup suck on better, think a bit of spit on the suction cup edge and it will loose vacuum slower ;)
So cool to see real, measurable results!!!
Притирка клапанов now I know what this is .. I’m glad you didn’t messed it up. I wonder how many people just through new valves into an old head and make it even worser than it was.
smart that vacum set up. I have a vacum pump and I will copy it. Thanks
looks exactly how it should after grinding. "frosted"
You really should have more subscribers. Great work.
fun fact: valve lapping/grinding compound is the secret to unscrewing stuck screws
Antisieze is basically very final metal ground into a paste, as the metal gets pushed into threads it cleans then and lubes it
@@Pippy1 i mean a little dab of it on a screw driver gives it an unbelievable about of grip
The fingerless gloves had me dying not gonna lie😂
first /// wait I mean 3rd.
Your tester is excellent. And you can only ever get 29 lbs of vacuum (this is the limit on earth) but compression can be much higher.
How do you know if the seal is good at the exhaust/take ports?
29.92 is the limit of vacuum, not just on Earth but everywhere :)
Great tool creation...fine video
On my BMW e36 24 valve cylinder head I was able to lap all the valves to peg Vaccum at 29in-Hg and achieve a leak-down time of greater than 2 mins on each cylinder for both intake and exhaust. I know this is a diminishing return as valves open/close in milliseconds however I wanted to see if it was possible. I used 600 grit followed by 1000 grit lapping compound.
Have you looked into doing a DIY porting job? The heads have casting flashes that can get drimmeled down as well as the plunge cut where air feeds into the valves.
This head has mild porting already, and without a way to actually test what I'm doing, I'm not going to take it any further myself.
There are also different valve lapping grit compounds .
ASMR valve grinding noises, that sound is satisfying 10/10
Might just upload 5 minutes of that, to a new channel ASMcaR
When i lapped the valves for my k24 build. I used the drill method, i had severe pitting on the valves /seats. That's a good idea with the block off tool, i'm curious what mine would show now lol.
What about ceramic coating the head before installation?
will you try to port and polish that mad lad head? would love to see those gains on the dyno, either way keep it up!!!
Mad lad head has massive porting and decking already. I'm excited to see what it does.
How long did the grinding and cleaning process take? Of course, filming everything adds time, but a ballpark estimate would be helpful for people who might attempt this themselves
*Pressure to pull head intensifies*
Great video as usual.
Man im getting exited for the dyno session, there needs to be some extra power from better sealing valves. Love the content
We'll see, I got almost a half point of extra compression from the shave too. The problem is the compressor on the turbo is at max flow already, so I don't there will be much top end. We'll see!
Funny I was doing the exact same thing last week. Exactly step by step. Haha. Good stuff.
an easy way to tell if valves are leaking first take a compression reading then remove plugs add 1 small spoon mtr oil in each plug hole now take a new compression reading if oil helps its the rings are leaking if no help valves are leaking this test is for low comression readings
Hell of a great job, thanks for sharing your knowledge. But can it replace valve job done by the shop? Also, when the shop cut the valve seat, there are 3 angle cut. But they charge $400 easy. Will the shop job last longer? Again, great job and thanks for sharing.
Another awesome how to Greg! And you always come out with relevant videos when I need them lol.
One question, you swapped the valves, but are you doing anything to prevent the intake valve problem that happened? Or will this just become a maintenance job for you?
I think in a previous video he said he was using longer springs. They were slightly lighter but also longer so when they were in the head they had more weight on them. Volvo ones maybe? I don't remember
My best guess is that the springs didn't provide enough seat pressure for the combo of boost and RPM, so I've upgraded to a spring with more seat pressure. You can find that lengthy video a few spots back if you care to learn more. But no, I'd rather melt this engine down for scrap over replacing the valves every 13k miles 😅
the compound doesn't grind down, the coarser compound just gets pushed out leaving the finer grit behind. That's the whole idea
Gotcha, so the method I described still works the same way, just in a different way from how it's described on the package. (States: "Grinds down to a 220 grit")
You were bold enough to go forward with the valves for the first time, why not sand the head on a sheet of glass or granite? The worst thing that can happen is that you gain very valuable experience... experience can not be bought but has to be lived 🙏🏼
Head had a relatively fresh surface already, wasn't needed
This gives me hope never built an engine and just lapped the valves always sent it out to the machine shop. I am building a performance boat I just got the short block together last night. I dont really have the extra money to have th heads machined and was just going to lap them. I have a blast cabinet i am going to take them all apart clean the valves and sand blast the heads and try this if the valves and seats are salvagable . Gave me new up I can pull this off the heads are after market performance heads . My bucket list get the engine in and get out and start living aagin gotta get out of the grave called a rut
You got this!!!
Great work bro! Is it a must that u get the heads shaved after lapping or can they go without if i already have them cleaned? Thanks
In my opinion you pay somebody if you don't know how to do or if it's costing you money to do it yourself . But I never let nobody toutch my things
Great video
Can't wait for new Dyno!
As a weekend mechanic
My mentor is a greybearded lifetime hotrodder/GM master technician
I ported/polished my own head on a 1.6T mini cooper, lapped in the new valves and was nearly 3 valves into reassembly when he walked by and made me do the old leakdown test
WD40 a damp rag and compressed air, every single valve seat blew bubbles
Re lapped every valve again, only three valves blew bubbles
Re lapped a third time, reassembled and everything was air tight
Awesome video as usual, why are you not removing just a TINY BIT of cylinder head material to deshroud the inlet valves?? The incoming charge hits the back of the valve and wants to continue on that path into the cylinder at quite an extreme angle.
It hitting a virtually 90 Deg wall just after the valve seat, at PEAK velocity is a killer.
The reason I know this is that I sent my BP5 head off to Blink Motorsport in the UK. They rebuilt it with standard exhaust valves and standard diameter supertech inlet valves with a little bit of bowl work but next to no porting.
End result, seriously!! noticeable more power across the board with new (mild) cams and original HLAs and valvetrain.
The most usable power is gained at smaller valve lifts as this is the most time of the stroke that you will see.
12mm lift is cool at 12mm but if the cylinder is struggling to pull in charge at 0-10mm then its a pretty meaningless number as it occurs so briefly in the cycle.
A tiny bit of headwork around that vertical step will bring massive benefits across the rev range.
FUCKING LOVE THE TIME, WORK AND EFFORT THAT YOU PUT IN TO GIVE US THESE VIDEOS!!!! ❤️
Man, I really considered de-shrouding the valves while the head was off. Your comment amplifies my regret.
You're supposed to use valve lapping paste. Not valve grinding paste. Grinding paste is for reshaping a mating surface. Which should only be done when imperfections are verified. If the surface is smooth you only use lapping paste to clean and mate the surfaces.
ALL BOW DOWN TO THE MIATA DAD CRAIG🙌
The saga continues.
You got an idea how many hp/torque improvement this could have added?
Did you get the head shaved before lapping? Just wondering before I get my valves founf
What if you replaced the exhaust valves and just lapped them like the intake
can you give us the gauge pump on where to get it from.
In the description there's a link to my video showing how to build the tool itself, all the parts are linked on that video
While u have the head off for extended amounts of time are you supposed to use any grease around the pistons before u start it up again? Or engine oil?
Yes you’re supposed to pre lube them I believe
Yeah whenever I pull the head I usually just drop an ounce or so of oil in each cylinder and cycle the engine
@@TheCarPassionChannel hey dude, I know this is random but I swear you need to come to the UK and see some peoples cars you can get a good nbfl with just rusty arches for £1000 all day
if avalve gets misked up will it lap right
You'll want to keep the same valves mated with their respective ports. 🤓
I’m here dad
MAESTRO !!!!!
What parts are needed to build the tool?
@@markthaxton7139 see the video before this one where I build the tool, links in description
Key secret: lap until the valve goes quite.
Well now I'm hype for rotary miata. Don't tease me like this lol
Sooo closeee
**rob dahm has entered the chat**
so early today!!!!
Use just 2-3 little drops of compound.
That was way to much.
instructions unclear, choked on valves, they tasted like titanium. next time im giving my valves to the pros to lap up
An easier test is blue dye test
"*Please note that some heads WILL need a valve job (where the valves and/or seats have a new face machined at the correct angles). But it's not always needed."
WRONG! If you've gone to the trouble and expense of removing the cylinder head for overhaul ALWAYS either replace the valves or reface them if they are uncoated steel type. Same with valve seats. They should always be recut. If done with good equipment, no lapping of valves should be necessary. For 'hi tec' coated vales e.g. found in every modern performance motorcycle, valves should never be resurfaced or lapped.
P.S. 'A Grade' qualified mechanic with over 50 years experience.
4th
First
It's all man made 😅