Is Our 383 STROKER Crankshaft JUNK?!
HTML-код
- Опубликовано: 19 авг 2023
- We have good news and bad news...
The good news is that we have our cylinder block machining complete and even checked our cylinder surface finish with a profilometer! That bad news is we got ahead of ourselves on our crankshaft...
Make sure you check out the entire playlist if you haven't!
• Building A 383 Stroker...
Instagram: @jamsionline
Facebook: JAMSI Online
TikTok: @jamsionline
Websites: www.jamsionline.com
www.jimsmachineinc.com
For business inquires: Contact info@jamsionline.com
#383stroker #automotivemachining #jimsautomotivemachineshop 
Авто/Мото
The cleaning guy made a good catch. You need to keep him around the shop more. Maybe even give him the keys to the door and let him answer the business phone...I think he can handle it by now...😊
Every Scat crank that ever crossed my bench was messed up in some way. It got to the point we just stopped buying them. This was years ago, I was told they got it together in recent years. Apparently not, lol.
The shop I used for years would not touch Scat or Eagle products. He would flat out tell you to take that crap somewhere else😂. He built NHRA world record holding engines and could afford to turn away work.
@mikemaccracken3112 the Eagles were much less problematic than Scat, still cheap cranks, but better.
If only we could all afford to use Bryant. Hear Winberg is good too but no personal experience.
Callies can be a "low dollar" alternative.
On those same "low dollar builds" you can use Scat rods. Used to go through boxes of them checking bend and twist. Set the ones out of spec aside until there was a full set and return them. Match up rods by weight to have some decent ones to start with. Rinse and repeat.
@@88SC Lunati,Callie’s,Manley,Ross,CP,Carillo,JE,Diamond,Wiseco etc. No off shore parts.
@@mikemaccracken3112 I wonder if "Offshore" parts would be a problem if it wasn't a place like red China. Would you be afraid of using an OEM Subaru crank?
I am always amazed by the knowledge that the cleaning guy has! You are truly blessed to have him as a mentor and father! Both of you are humble and always strive to make things as perfect as humanly possible. Your customers know this and are willing to pay whatever you charge whilst knowing that they are getting the best product possible!
I cannot imagine how many people are knocking on your door to have work done! Another stellar video!
I built a 383 LT1 or had it built. sent the block, eagle rotating assembly (rods, crank, cam, chain, pistons, rings, arp studs, and bearings) to have done what you guys are doing. The assembly was supposed to have been balanced and blue printed from Eagle, but I asked the shop to verify.. well, long story short, they said it was good to go, I got the short block back fully assembled, timing chain, oil pan, front cover, I put the heads on, and intake + acc., I didn't even get break in time, less than 500 miles, and the crank broke. Had another shop to tear down to find out why, and they said the crank was tapered too much and had a step on the journal. So yea I lost a high end build for this same thing.. got so aggravated I converted the entire car to an LS.. loved the sound of the 383, but LS is still running 10yrs later!
Hello Guys, I am from Brazil and despite my work is not related to car engines, I love your videos and your tireless search for perfection.
You guys are a source of inspiration to those who really cares about quality.
Well said.
Me also. Dude
There is a Silver lining to this. Now that the crankshaft is balanced. When you throw it in the garbage it will fly straight. We also get a couple more Videos about the 383. This series is a favorite of mine. It's good to show the Ups and Downs it keeps your channel real. Keep up the good work.
Definitely not going in the garbage. They can regrind the journals to be finished properly and sell it in the future.
That was a Joke, Earth Humor. Lets see how many people get that reference. If you do say so in a reply but do NOT say where it's from to keep people guessing.
Since I started using an SJ-210 about six or seven years ago, I found it to be an indispensible part of my honing operation. I've learned that cylinders and sleeves from different sources can require tweaks in the finishing operations. What I always assumed to be right, as in "this is how we always did it," turned out to be pretty close, but not 100% by any means. If you have any finishing issues, the guys at Total Seal Piston Rings are very helpful.
Good call. The crank is already balanced to your parts. You have the equipment and skills to get it right. It shouldn’t take much, if any, to rebalance.
Hey buddy. Not sure if you notice yourself, it sure took me a while to notice on my own arms but i see when you hold something in your left hand it starts shaking. I have the same thing from boring mountainbolts under water for so many years giving me nervedamage, not saying you have that but i would have it checked out. Just a friendly advice, we're all getting older and we gotta look out for eachother.
He's acknowledged his tremor in the past. Most definitely aware of it.
It's called getting old. Just like we all do.
Alot of guys got em, I'd say he just need to keep his hands clean from fluids. Trans guy I'd seen had bad shakes, doc said wear gloves the fluid is soaking up into your hands.
Yeah from years of oil and being a grease monkey. Unfortunately it can be passed down. Every transmission guy I know had tremors. ATF is nasty shit. Wear gloves people!
He has tremors
I am a retired machinist/supervisor of over 40 years. While I never worked in automotive, I did work oilfield and very large compressors. When we did a crank, much larger than you are working with, (several thousand pound cranks) we also put special indicators between the counter balances to see how much the crank was flexing which causes runout. We then put adjustable bearing blocks at the journals and dilwedd the flex out of the crank to keep the crank from flexing while spinning before we started a grind.
My guess is that the previous person that ground that crank spun it too fast and it flexed while grinding causing the runout not to mention what he/she did to put a step in that journal. Also we never ran three jaw chucks because just tightening them up can flex/bend a piece of work. You can check that claim out yourself with an indicator. We ran face plates and bolted the cranks to them to keep the stress off of the cranks or precision shafts we made. You mentioned nothing can be perfect. Well, I assure you that when we were done we had zero runout on our cranks and shafts. If the time is taken and done properly you can get zero runout at least on your indicator.
If I talk to someone who says "It measured perfect"....my internal respect monitor goes way down because to a precision minded person there is NO such thing as 'perfect'. It was great to hear this from the 'crank grinding guy'. :)
Everything has dimensional variances and if your equipment doesn't show them...then you just aren't measuring things close enough. Once you start slipping past 'as close as we can get it' to 'it's within tolerance' then the tendency to use the tolerances to speed up production rather than to give you room to correct problems rears its' ugly head. Good machine work being demonstrated here!!
the thing is, even temperatures inside the shop can change the size of any metal device used for measuring.
i was QA at a valve co that made food grade 3A stainless steel valves we used a much older profelometer to see how well the electropolishing and chromium was being deposited along with refracted lasers with certain polarities in the color to see fine flaws in the polish as any imperfections could harbor bacteria and materials which could make cleaning difficult real pain in the tail getting into smaller than 3/8 ID valve assemblies to do readings on surface finish
I have seen Eagle crankshafts with same issue. Thankfully it was caught before it was balanced. I would definitely turn it.
You are so lucky to have your dad work with you, make the most of it mate! Love your videos, you guys are just so wholesome it's incredible!
I'm not a machinist in any way, shape or form but I find this content highly entertaining. It definitely feeds the dopamine fiend in me. Thank you!
I’m with ya. Not a machinist but really appreciate fine craftsmanship.
Never assume a part is in spec just because it's new, especially an off-shore crank from Scat. They're known for cheap prices, not precision machining.
Eagle is usually worse
Great video, You guys just work together so well. I love your dad and his "Im sure I can handle it" Attitude. I would bet he doesn't get to excited about a things when they go sideways. As long as the "hired help" learned from there mistake.
I give you guys credit for taking on other's poor work. Maybe in the initial production, maybe some shop thinking they were capable of perfecting something that they were not capable of doing and returning it on the sly, or from a supplier who accepts returns without verifying condition.
I worked in a factory for over 38 years grinding to tight close tolerances and I was just tired of fixing other problems caused by other people. Certified junk fixer. Glad to see you don't use their instruments. Keep up your high standards, people deserve quality.
Callie’s forged 383 crank would be wonderful here but it’s over 1100 bux.
Lots of respect to you guys for not just trying 'to get by' with this crank. Great Craftsmanship.
I realy like that your pointing out flawns on new products it realy makes a guy thing about what parts we buy and not to trust it just because its new . Thanks gor the great vidios
Thanks for sharing this video. Years ago I was a Mac Tools distributor and serviced this shop and an employee named "Chappy". I remember back then these were the guys to see. They had a great reputation then and I see they still do. These days it's very difficult to find a reputable professional machine shop. Kudos to them for continuing their art and keeping this trade alive. Great job guys!!!
First class father and son team I am so impressed every time I watch these videos.
Thank you folks very educational. Anyone that lives in Colorado
needs engine work
these are your first class professionals That are obviously very honest and care it's hard to find
today.
Great job guys, can't wait to see what you do with the crank.
Great job guys, you’re both always willing to teach, and share your knowledge. I always enjoy learning from your experiences.
I would have returned rhis to the manufacturer or third party you purchased from. Thats just crazy. It appears somrone messed it up, some newbe and to save face, "oh defect from part, well just swap it out" you guys are true professionals in this industry. Thank you for the insane detail you go into. This shows your knowlege and your willingness to grow andearn more as other shops give you pointers. You guys rock. I will have to see how much it is to ship my next build to you to do a full machine on my LS2. There are shops here local in Phoenix, that ive done business with for 20 years. But i want to see you guys do my build and i will know for sure its going to be solid. Also love to have a series made from it to have documentation on its full machine process
They won't take it back since it was balanced. They will say that you messed it up. Just goes to show that new ain't always good.
@@hotpuppy1 Most places you can get them to take it back or exchange, but if they are able to repair it and get it back within spec, then I would demand a steep money back for dealing with it. If they purchased it from a company that they do business with on a regular basis, I'm sure they would have no problem returning, or exchanging. Now if they are a new customer and this is the first order, then alot of companies will go "wait a second here" and scrutinize it more... but either way, they learned a leaason, always mic the lobbs, even when new.
I'm not an engine guy, but I am an engineer and I can't believe clevite will only promise .001 out of round! Thats absurd in my book. You weren't even trying to check concentricity between journals. I'm honestly not sure how they could could possibly grind a crank that far out of round aside from silly high of tool pressures. Guess trying to push parts out the door. Making something round is one of the most basic operations you can do in grinding (getting the size perfect is much harder than getting it round right?). With a little patience I've set 30 meter linear rails to +/- .001 and the machine runs compensation on top of that to account for concrete foundation deflection.
I believe in the cleaning guy let the magic flow awesome video as always stay safe my friends
This video is proof of your loyalty to your customers that when the engine is to your specifications and if it’s not the engine won’t leave the shop now that’s quality service right here.
Really enjoying coming back and watching your videos, there is something incredibly wholesome and honest about them that makes them so great to watch. Looking forward to the next installment!
I'd LOVE to get an engine built by the cleaning guy. I'm 68. I'm not a big one on burnout contest, (which, to me, is a gratuitous waste of resources). I could go to my, (hopefully! 😁 ), eternal reward knowing that my 10 year old grandson would be driving a vehicle with a engine that, with good maintenance, would last a half a million miles. Craftsmanship like this is as rare as hen's teeth these days. I wish you weren't a half continent away from me. 😞
I used to love operating the honing machine.. your stroke speed looks much faster than I remember..
Nice job again guys, that is a perfect example that it`s better to assume that aftermarket parts are not good to go out of the box and that is when a good machine shop comes to rescue.
I am looking forward to see that crank grinding challenge and more of the SBC vids, thank you!😀
I think the fact that you could use your index locks and the crank is that close to perfect in stroke and index is amazing.
Love the channel/content. Makes me wish I’d have gotten into machining. Also makes me want to send you my engine components. Respect the work ethic you both possess. Keep it up guys 👍🏼
Great video. Why would you not send the crank back, and get a real new one? The company messed this up, not you. I realize you would have to re-balance the new one, although a 10/10 crank will work too. Either way, great contact, and you two are really funny, I love watching the high quality , thank you, Jim
a "profilometer"? I didn't even know that was a word 😂 awesome stuff! Can't wait for my 413 to be shown here!!!
It goes to show you that one needs to still check new parts. I’ve heard people complain about scat cranks, but it’s seems like all parts are touch and go in 2023.
As a long times machinist, you can't go wrong with Mitutoyo measuring equipment except for Interapid indicators and the Starrett non-rotating blade depth mics. Unfortunately most Starrett and Brown & Sharp stuff is complete garbage now. Earlier in my carrier I had to return 11 pairs of 0-12 inch Brown & Sharp dial calipers. A bunch of guys wanted them for their personal boxes because of a promo. Some would measure good in the first few inches then be off by .003 over 10 inches. Others were too tight throughout the spectrum or had various other issues. Mitutoyo is the way to go.
As a machinist as well, almost all Mitutoyo stuff is top tier. I agree on the indicators, the interapids are nice due to the dual direction. I do love my brown and sharp best best 1/2 thou indicator as well. Starrett is mostly riding on their name only any more.
@@nwngunner A while back I bought a new Starrett non-rotating blade mic set. When it came in the barrel wasn't spinning freely and I struggled to remove the barrel. Once I removed the barrel, a bunch of fine chips and oil came out. It looked like someone had sabotaged it after inspection. Even their own employees don't like them.
What a difference between how you do things and how we did things out in the garage and backyard back in the '60s and '70s... Can't help wondering how random new stock cranks from each decade from the 1950s to the present would check out...
This shop’s practices and procedures mimic those of quality shops in the 60’s and 70’s. Stock performance engine forged cranks from GM, Ford and Mopar were spot on.
Great channel. Great content. As an engineer who plays with wrenches more than most engineers, I appreciate the education I get from watching your channel.
same here.
Every time I watch ya'll I learn something !!! Thank You!
I had Jim do some extensive head work on a set of 461's that I put in a hotrodded 400 in about 1988 or 89. Steve from LaSalle Manufab sent me to you. I remember seeing your old shop El Camino around town in Greeley a lot. I moved to Arizona years ago, and I just came across your videos. When I saw your familiar face I was amazed. Good luck with your business! I still have hotrod stuff, but a whole lot more expensive now.
I’m enjoying following this build
Nice catch guys. I love how you could have used the first crank but chose to do it better, rather then just throwing it in the motor and hoping for the best. You guys ROCK!!!! Keep it going guys.
Love the professionalism of you guys. Just shows that the word "new" in itself doesn't mean anything. The lesson seems to be, trust no-one and check everything yourself. I really admire the cleaning guys skill with that crank grinder. Thank you.
Man I'd really love to hear brand's of parts you find are good bang for the buck and ones to stay away from. I'm sure you don't want to trash brands you work with but that is some highly valuable info that you guys definitely have.
In the absence of an explicit roundness requirement for a circular feature on an engineering drawing, the feature of size tolerance implicitly controls roundness. If the feature of size tolerance allows more roundness variation than can be tolerated, a roundness control should be specified.
It would be cool to see Lake speed JR come in & talk about getting the best finish without 500k equipment
Well, looking forward to seeing the work to sort out that crank. Good work on checking it out and finding all the issues, looks like someone had a play with it for sure.
I worked at a machine shop in 2001-2003, my supervisor said .0001 was the only acceptable number and Even that was not what he liked to see. That being said I appreciate your attention to details and your work to make it as close to “perfect” as possible
Eagle and Scat usually are off out of the box from people I know that used them. I have always used resurfaced OEM cranks for my limited engine builds, but that's what I've been told by several people that do use them.
Yes scat especially
When I built my 383 in 1989 they didn't sell cheap cranks, I had to make my own from a 400. I did it on a 465 Van Norman crank grinder
What you are talking about, is called integrity. As a former machinist, I pushed for that in the shops I worked in. Any time I received a part that someone else had started, I took the time to measure every fit before putting it into another machine. It saves time, money, and needless fighting over who did what! Some people try to hide their mistakes, instead of learning from them.
The challenge is on! 14:42 Definitely a raise 🤑+ pizza🍕 and a new broom 🧹. 🤣👍
The out of round 3 tenths wouldn't bother me as much as the taper. One shop I worked at had a crank grinder that ground a full. 001" out of round. I refused to use it. Guy that worked there told me every guy that worked in that shop since the machine was new in 1962 complained about it. We had Jamison Equipment work on it 2 times, including rebuilding head and tailstock and scraping the table and the gibs and ways. Never changed a thing. One day the late Jim Gessford came in after he sold his shop and started selling equipment for Jamison and I was telling him how disappointed I was in that grinder and all the money we dumped into it only to have it grind out of round. He says it sounds like it's lined up perfectly and that's not correct it needs to have a slight misalignment just like toe-in on a car front end. He told me how to check it and what to do and with 4 little pieces of .0015 shim stock that machine would freeze the needle on the Arnold Guage!!!! I was amazed, that was 1989 and I'm forever grateful to Jim Gessford, he was a self taught genius of a machinist and equipment rebuilding. My biggest regret was not going to work for him when he offered me a position once. I would have learned a lot more and probably still been doing machine work.
Yeah I read and learned old ways about shimming and comes from the pre-war days rebuilding by hand I been doing this stuff since 68 but too too precise equals stress and redo because of over precision and being too picky the engine will still run
@@brantardrey7360 I was referring to shimming on the crankshaft grinder to get it inline so it would grind perfectly round. Not shimming the engine, that went away when insert bearings came out in the early 50s. Way before my time.
Goes to show you that the Chineseium stuff is not up to snuff these days.
I’m sure the casing from china was likely fine. Remember Scat cranks are ground and machined in their California facility. So unfortunately a United States workforce screwed this one likely.
Wow, some deep precision here, the guy in his garage would probably go with all factory stuff right outta the bags and might not even have a micrometer. Lol it'll be interesting to see the grind and rebalance.
Love the content. I have some experience with surface roughness measurement using a Mitutoyo SJ-410. The greatest advancement in understanding the condition of a surface for me came with the implementation of a software application called OmniSurf, published by Digital Metrology. You pull the data from the gage directly, and you can perform offline form removal and filtering. It's a game-changer! Keep doing what you are doing. It's fantastic!
After this engine build I see a large increase in business coming your way!
It'll turn out nice. Bummer you didn't catch it before hand but it's not a mistake until it leaves the door.
Next one perhaps consider a 2 valve releif piston, less quench. Mahle makes pretty affordable stuff that works well for the street in NA form via their powerpak line.
It's nice to see that you are a progressive automotive machine shop. Always expanding to involve the latest technology. That bore finish meter is all the rage these days.
When Mfg. don't count on you having precision measuring tools.
I don't usually comment here but this is a damn cool video. I like the combination of knowledge, with a little bit of levity. I like the challenge aspect and have full confidence that the cleaning guy will get er done.
I am impressed by how an engine is built together, one would think it would be easy to put an engine together, but no it involves a lot of measurements and not least tools to do this.
That's debatable. You can build an engine with plasti-gage and a torque wrench borrowed from auto zone, and nothing but box wrenches. You wouldn't want to do that with a high performance engine. But you can build a reliable with truck engine like that. Especially when you're talking older platforms, small block Chevrolet and Ford, old Mopar. Farmers have been doing it for decades.
Looking forward to seeing what the cleaning guy comes up with on that crank!
Rigid flexibility...Rigid on perfection, flexible to get to perfection. Excellent plan!!!
I wish yall were closer , we need a better machine shop here in North Texas
Super cool technology. Gotta stay in or ahead of the game
My money is on the Cleaning Guy! I believe he can do it with one hand behind his back. I applaud your level of quality. Be Safe.
I enjoy watching you guys work and have a lot of respect for your knowledge and skills. Have to say though - if all the crank journals (in the same plane) show the same out-of-round condition, I would first check the off-set or indexing of the crank holding fixture. But a variance in that dimension wouldn't account for the tapered journal diameter!
I was just wondering if you can order an oversized crank and then plan to do all the final machining yourself. That way you don't have to rely on someone else to get the size, roundness, taper, offset, etc. all correct.
God bless you guys 👍 you doing awesome
That stinks ! Glad it can be salvaged ! Thanks for sharing !
Id like to see yall do a everything zeroed fully diminishing returns build just to satisfy my ocd
Good to keep the Cleaning Guy busy.
I always used to work better at night! I think it came from working during Winston Cup Points meets, on weeks leading up to, and weekend of. 😊😊😊 Lots of midnight oil burning. AND some truly heroic feats of labor (as well as napping on a cot)😅
So I was watching that whole video thinking why don't just regrind that dodgy New crank than redoing all your machine work, balancing again,,,, and there it was, the challenge,,,,, I thought I'd missed the bit of undersized crank bearings,,,,, enjoy your videos, looking forward to watching the crank fix
I used profilometers a lot in aircraft hydraulic and fuel valve machining and assembly. We called them "creepers" in the shop because the probe moves so slowly.
We've all been there... Assumption is the mother of all...
Must have been a new trainee at the crank company or it was a Friday afternoon 😂that sucks glad you guys are so don’t take this the wrong way but OCD on the jobs you do it’s a great thing in my opinion thanks for sharing
Or Wong was hungover on a Monday
David Vizard goes into the science about flat top pistons for street / strip engines…
Explains the burn rate across the piston using pump gas..
David has a spec build 383 Chevy that 621hp on pump gas - like 580 ft lbs of torque
Just curious, a) are these parts serialized and b) what did the vendor have to say about your findings?
Most these cranks are Chinese junk. SCAT seems to be finished better but I’ve seen some straight junk from Eagle. There are some good cranks but they are gonna cost you more than $400
I am not an engineer, nor do I have any experience of engine machining, but I do like watching rebuild videos. I have seen some videos where the very last process in cylinder bore honing involves the use of wire brushes. Apparently, it makes sure no bits of honing stone/media are left in the cross hatching. What are your thoughts on this? Keep up the good work.
How easy would it have been to just throw that crank in and send it out? Too easy.
As he states more than likely would never see an issue, but if there was it would be just as easy to blame it on the owner as operation abuse.
Not settling for just ok work is what will separate the OK Shops from the GREAT Shops and this is why the serious person will seek out the Great Shop when needing peace of mind machine work that they can and will trust.
If I was several hundred miles closer they would have all my work, fortunately I do a shop that provides the same caliber of work only 50 miles away, but let me say if my shop were to close I would definitely look into shipping my work to Jim's Automotive in Colorado.
Honesty is WORTH a Lot of Money.
Hello gentlemen, just found your channel and love the content.
You have a new subscriber here 👍
I'm impressed with the care and attention attention and prepping this engine is receiving ,I don't think this is cleaning guy's first engine Build ,you have a good mentor your Dad Just for Grins ask him for me How many engines he's built in his life time what was his first engine build ,and what was his favorite engine build ,love the video
I love how you guys strive for perfection in these engines but when it comes to 3 ten thousands of a inch you might be getting a little compulsive if it was a 3000 hp dragster engine id say worry about it but it’s not it’s a 383 stroker sometimes you just have to keep on building but that’s my opinion I do know if I need a engine built I’m coming to you guys lol😂 god bless
Yeah you're right because being over perfectionist cause of a lot of stress and worry for something that doesn't matter because production engines aren't that close even if it's a performance production engine and I've been building since 1968 as a kid and I used to do a lot on home machine work rebuilding and everything and I did a lot of perfection stuff some guys used to say you're a good mechanic but you take too long because I was trying to be a perfectionist
I'm a machinist my profession, but I work offshore in the USA as a Cleaner😂. It's more money than working in my country. I going to start my own shop soon
You guys are great.
I have a Scat 9000 crank in my 496 and it was a bear to balance. It was supposed to be internally balanced and it required 2 shots of mallory and an external balance flexplate to get right.
Another good video as usual! Not many shops doing quality work like you guys!!👍👍👍👍👍👍
Keep up the great work fellas 😎🤙🇺🇲
“5” in the hole lol. I know, no one is perfect. I have to cut stuff occasionally that’s still too short even after two cuts lol. It happens.
Balanced or not I would be on the phone making sure that vendor knows what’s up. Why would they take a return (makes the most sense) and not spec it out before returning it to stock?? Great content gentlemen 👍
Hard to get out of the box quality anymore. Hardly anyone cares. It’s all about how much $ can be made in the shortest amount of time.
New & Improved = easier and cheaper to manufacturer!
Good video Jim's.
Never go on a hot date without your profilometer! 😂
Have you ever checked a cylinder after removing the torque plate to see just how much it affects final dimensions? How can a a solid torque plate (steel? aluminum?) simulate the distortion a cylinder head, (either cast or aluminum) , with all it's internal passages,voids, cooling jackets, ports, even combustion chambers will have on a cylinder? An inch thick solid steel plate without a head gasket is not going to stress the bore exactly like a cylinder head. Yes "everyone" says they're essential,and it's always been done like that, so there it is.
This proofs the point that even if you get new parts send it to a machine shop to get everything checked before assembly if you don’t have the tools or experience to do it yourself.
Heck , offset grind the crank go from 3.750" to 3.800" and go to the small journal rods. Maybe cut . 030" off the piston, and maybe run a
.040" - .050" MLS head gasket gasket , with the piston at zero deck, or or possibly
.010"- .015" proud , with the gasket and the relief should leave plenty of clearance. Tight quench pads, performance is much greater, and polish the chambers while while it's apart, maybe ceramic coat the chambers and exhaust ports! I guarantee it will produce more power than without the mods, definitely would require checking the valve clearance, and quench clearance, also get more cid. Aswell, near 390cid it's been years since I did the math, my 385 stroker, I was thinking about getting a 3.850, maybe offset grind that to 3.900, possibly 3.925", 3.950" and possibly shorten the rods a bit by resizing them, tak about .020"off the rod only then resize the journal end , then take a bit off the piston, if required, mill the heads, so the piston can fit in the head slightly, with about .020" larger diameter, than the piston, allowing the rings to reach closer to the deck, all this making a more efficient engine, especially with about 200-220psi,/11:1+ compression. For a streetable engine, with the quench pads so tight, they have clearance, however carbon cannot build up, the pressures involved blows the surfaces clean constantly, although, with heavy bearing wear, or spun bearing, it will definitely make contact, this really produces power in a engine, greatly improves combustion, it's basically Ben Almeda's religion, it only confirmed what I already knew! Also plenty of piston to valve clearance will reduce shrouding, the piston can shroud the valves also! Especially domed pistons!