Is Our 383 STROKER Crankshaft JUNK?! 

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.

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 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...😊

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.

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!

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.

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!

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.

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!!

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

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.

I have seen Eagle crankshafts with same issue. Thankfully it was caught before it was balanced. I would definitely turn it.

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!

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.

Callie’s forged 383 crank would be wonderful here but it’s over 1100 bux.

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 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

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...

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.

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.

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.

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.

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!!!

I used to love operating the honing machine.. your stroke speed looks much faster than I remember..

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

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

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.

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.

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 think the fact that you could use your index locks and the crank is that close to perfect in stroke and index is amazing.

Great job guys, can't wait to see what you do with the crank.

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. 😞

Great job guys, you’re both always willing to teach, and share your knowledge. I always enjoy learning from your experiences.

Lots of respect to you guys for not just trying 'to get by' with this crank. Great Craftsmanship.

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 👍🏼

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!

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.

a "profilometer"? I didn't even know that was a word 😂 awesome stuff! Can't wait for my 413 to be shown here!!!

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!😀

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.

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.

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.

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

It would be cool to see Lake speed JR come in & talk about getting the best finish without 500k equipment

I believe in the cleaning guy let the magic flow awesome video as always stay safe my friends

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!

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.

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.

Hey guys, could that out-of-spec section of the crank be spray welded and reground, as Adam does on his Abom79 channel? Great videos, I love watching them.

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.

I’m enjoying following this build

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.

Jim you have a wealth of knowledge and you do first rate work thanks for sharing what you do best

I wish yall were closer , we need a better machine shop here in North Texas

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.

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.

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.

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.

Every time I watch ya'll I learn something !!! Thank You!

Just curious, a) are these parts serialized and b) what did the vendor have to say about your findings?

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.

After this engine build I see a large increase in business coming your way!

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.

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!

Id like to see yall do a everything zeroed fully diminishing returns build just to satisfy my ocd

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.

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.

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 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.

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)😅

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.

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

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 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.

Rigid flexibility...Rigid on perfection, flexible to get to perfection. Excellent plan!!!

When Mfg. don't count on you having precision measuring tools.

As I was watching the video I noticed that it looks like the block is moving side to side @ 3:56. Does this block move normally with the Honing stroke? Just curious. Thanks so much for the great info in your videos as machining is truly an art.

What a bummer, sad that you cant trust the Mfg to do QC before shipping! I sort of had a bad feeling about crank when the HUGE balance hole was needed on the counterbalance...

Goes to show you that the Chineseium stuff is not up to snuff these days.

The challenge is on! 14:42 Definitely a raise 🤑+ pizza🍕 and a new broom 🧹. 🤣👍

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!

I feel Y'all's pain. I'm waiting on some plus + .001" rods and mains so I can put a Buick Grand National engine back together. Previous builder thought that .0015- .0018 were good specs for a 600 whp build apparently..

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 👍

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.

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

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

yea profilometer is important. head gasket and ring companies spec a required surface finish but most machine shops or even engine builders do not even check. they will o-ring the engine before fixing the surface finish.

It would be interesting to see what the balance on the second crankshaft is without the weight on the flywheel, Is it already internally balanced? I noticed on the balancing video that the drilling was always in the same area as the weight on the flywheel. Made me wonder if the crank was already balanced from the factory.

Love this video! At work we need to measure the surface finish on the ID of tubes used in the purification of injectable medicines. What is profilometer you bought?

Good to keep the Cleaning Guy busy.

In high school I was in a machinist occupational program and was pretty good at it: they never gave us the phone number or info to the machinists union so I got a construction job since I'd no idea where to apply as a machinist -- pre-internet days

You guys need a engine dyno. What spec for surface finish did the ring manufacturer recommend?

“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.

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

Super cool technology. Gotta stay in or ahead of the game

Looking forward to seeing what the cleaning guy comes up with on that crank!

That sucks that you can’t trust a new crank. They give you a different crank but what about the time you have balancing your set up.

Have you watched any of the videos from @TotalSeal Piston Rings on cylinder honing?

We've all been there... Assumption is the mother of all...