When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I see that most stroker kits come with a 4" stroke crankshaft. I also noticed that they are all forged. I have a few questions about this.
1) Is it always necessary to have a forged crankshaft? Let's say you just wanted to increase CID on a daily driver, but not spend a fortune. Would you really need a forged crank for a modest HP goal? By modest, I'm thinking 400-500hp at the crank. I figured the torque on a stroker would be much higher than the stock stroke in the same engine.
2) Would a stroke longer than 4" cause issues? I found a 4.1" crankshaft on Summit's website. It was non-forged, and much cheaper then the 4" forged cranks. The 4.1" stroke could offer some appealing CIDs. Here's some examples I came up with based on a CID calculator...(392 CID from a bored 4.8 or 5.3, 427 CID from a honed 6.2)
3) Obviously, boost will increase HP more than any stroker combination. Would a cheap junkyard 4.8/5.3 be worth boring/stroking?
The problem you run into is the sleeve length on most LS motors is like 5.45 inches. To do the stroker correct you need to have sleeves of like 5.8 inches which only come in the LS7 and resleeved applications like RED or Texas Speed offer. I am not sure if other blocks have longer sleeves stock maybe someone on here can chime in.
1.) For 400-500HP just keep your stock crank. You don't need a bigger cubic inch motor to get to that HP goal.
2.) You will run into clearance issues with cranks bigger that 4" and you're going to bring the piston out of the sleeve too far down (Engine won't live long)
What brand makes a none forged 4.100" stroke crank? How are you calculating your cubic inches?
3.) You can stroke it but for the goal you have you don't need boost nor a stroker to achieve 400-500hp
1.) For 400-500HP just keep your stock crank. You don't need a bigger cubic inch motor to get to that HP goal.
2.) You will run into clearance issues with cranks bigger that 4" and you're going to bring the piston out of the sleeve too far down (Engine won't live long) What brand makes a none forged 4.100" stroke crank? How are you calculating your cubic inches?
3.) You can stroke it but for the goal you have you don't need boost nor a stroker to achieve 400-500hp
Utinator,, there was a build thread on here about two years ago with a cast LS stroker crank. It was a total POS. It needed to have the standard size LS rod narrowed as the journals on the crank were narrow if i recall correctly.
Also some of the cast crank stuff is horrible balance wiae and ends up costing like $450 to balance. At that point the cast crank is within $250 or so of the coat of a forged crank.
The new GM 6.6 liter gas engine has a 3.858 stroke crank
I've not seen pricing on that crank. It might be more reasonable in cost. I think its possible this Gen V 58x crank may work in earlier LS engines.
Fwiw both my strokers have Callies CompStar cranks, both are 4 inch and are problem free.
If I recall correctly, KCS one of the moderators built with 6.0 with a 4.25 inch stroke crank a couple of years ago. The engine didn't have piston rock issues and wasn't an oil burner either. Correct piston selection and attention to detail goes a long way to avoiding issues. Key is getting the right taper piston. I think the 6.0 has the shortest cylinders of the LS engines.
Ok. I don't think my ideas about the 4.1" stroke would be cost efficient. I wasn't sure about the sleeve length. I figured that would be an issue at some point, but I didn't know what the length limit was. I suppose there are ways to make a 4.1" stroke work, but I don't think it will be cheap. It would be cool to have either a 392 CID or 427 CID for cheap. The 4.1" crank I found on Summit was posted above. If you have to pay extra to get it balanced, then it's not worth it.
I was thinking that there are a lot of really cheap 4.8s and 5.3s. If you bore an iron 4.8/5.3 out to 3.902 with a 4.1" crank, you get 392 CID. I doubt many people use the stock 4.8 crank in rebuilds. If you are replacing the 4.8 crank, you might as well go way bigger. The 4.1" crank cost about the same as a 3.622" crank. It seems that the stock sleeves might be a bigger issue though.
I have found a couple 6.2s for cheap, but they needed to be re-sleeved due to DoD lifter failure. I'm not sure what a re-sleeve job costs, but that would be a prime opportunity to install longer sleeves. With longer sleeves, the 4.1" crank might be do-able, as long as the journals aren't an issue. You would need about a 4.072" bore with the 4.1" stroke to achieve a 427 CID.
The new 6.6L crank would also make some interesting builds. I haven't seen one for sale yet. I'm sure there are a lot of people waiting for one to become available.
Ok. I don't think my ideas about the 4.1" stroke would be cost efficient. I wasn't sure about the sleeve length. I figured that would be an issue at some point, but I didn't know what the length limit was. I suppose there are ways to make a 4.1" stroke work, but I don't think it will be cheap. It would be cool to have either a 392 CID or 427 CID for cheap. The 4.1" crank I found on Summit was posted above. If you have to pay extra to get it balanced, then it's not worth it.
I was thinking that there are a lot of really cheap 4.8s and 5.3s. If you bore an iron 4.8/5.3 out to 3.902 with a 4.1" crank, you get 392 CID. I doubt many people use the stock 4.8 crank in rebuilds. If you are replacing the 4.8 crank, you might as well go way bigger. The 4.1" crank cost about the same as a 3.622" crank. It seems that the stock sleeves might be a bigger issue though.
I have found a couple 6.2s for cheap, but they needed to be re-sleeved due to DoD lifter failure. I'm not sure what a re-sleeve job costs, but that would be a prime opportunity to install longer sleeves. With longer sleeves, the 4.1" crank might be do-able, as long as the journals aren't an issue. You would need about a 4.072" bore with the 4.1" stroke to achieve a 427 CID.
The new 6.6L crank would also make some interesting builds. I haven't seen one for sale yet. I'm sure there are a lot of people waiting for one to become available.
Are you sure it’s not the lifter bores that needs re-sleeving?
That particular engine suffered catastrophic failures. I could see pieces missing from the sleeve. The guy selling it said it was a DoD lifter that caused the problem. Yeah, it need some work.
Well, it’s been a couple years. I figured I’d ask again. Does anyone have experience with a 4.1” crank in a stock engine? I know you can use much longer strokes in aftermarket blocks, but not many people can afford to build those.
I just sold the 5.3L “truck” engine I built. Now, I’m looking for my next engine to build. I would love to have a 427, but the block/part options are limited with stock blocks. The 6.2L honed to 4.070 with a 4.1” stroke would be close enough. Wisco makes pistons for this. I also saw a 6.0L bored to 4.070 with a 4.1” crank for sale. I’m just not sure about the reliability.
Damn, I wished I'd never seen that. Price is reasonable and last I checked, HPR does good work. If the LS3 in my vette ever ***** the bed....Hell, I may not wait that long. That's a lot of engine for the $'s
Well, it’s been a couple years. I figured I’d ask again. Does anyone have experience with a 4.1” crank in a stock engine? I know you can use much longer strokes in aftermarket blocks, but not many people can afford to build those.
I just sold the 5.3L “truck” engine I built. Now, I’m looking for my next engine to build. I would love to have a 427, but the block/part options are limited with stock blocks. The 6.2L honed to 4.070 with a 4.1” stroke would be close enough. Wisco makes pistons for this. I also saw a 6.0L bored to 4.070 with a 4.1” crank for sale. I’m just not sure about the reliability.
The 4" stroke in a stock, unsleeved engine is still iffy because it pulls the piston to far down into the block. Why do you want that much stroke? Cubic inches are cubic inches, and the length of the stroke does not change torque or horsepower produced.
That is very interesting, but also very expensive. That's why I don't want to order from a shop. I was planning on building a complete running stroker engine for around $5-$6k.If it costs more than that, then it would be cheaper to just buy a turbo kit.
I don't see how Wisco can make a piston that will work with a 4.250" stroke in a stock 6.2L block. That seems a bit extreme. It might be possible with an LS7 block, but I don't think I would try it with any other stock block. The 4.1" stroke might be more reasonable, but that's still a lot.
That is very interesting, but also very expensive. That's why I don't want to order from a shop. I was planning on building a complete running stroker engine for around $5-$6k. If it costs more than that, then it would be cheaper to just buy a turbo kit.
In 2017, my ERL LSA 416's short block cost ~$5,500 and that was a good price before the pandemic and Joe-flation that ran prices up.
I suggest getting a parts list for a build and adding up the cost of the parts, machine work etc and see if you can build a running stroker on paper for less than $6,000
Best cost per hp is probably a junkyard motor with a fat shot of NOS or forced induction because NA hp tends to be expensive.
I don't see how Wisco can make a piston that will work with a 4.250" stroke in a stock 6.2L block. That seems a bit extreme. It might be possible with an LS7 block, but I don't think I would try it with any other stock block. The 4.1" stroke might be more reasonable, but that's still a lot.
The key is having a top notch LS engine builder like Erik Koenig (details) do the short block build with the 4.250 stroke. Erik has developed custom parts and has access to parts not available the rank and file builder. Being a former instructor at SAM, School of Automotive Machinist, Eric has vast experience in high performance engine development and building. There's a price that goes with true experience and expertise like an HPR built engine has.
@KCS one of our moderators worked with Erik, HPR & Wisco to develop the custom pistons required for the 4.25 stroke LS build I believe KCS even used this super trick piston in a 6.0 iron block successfully that has the shortest cylinder length of all LS engines.
Wisco makes a piston for a 4.1" crank. Maybe they used this same "technology" that Eric helped develop...? I read some reviews on a different piston manufacturer that makes a piston for a 4.1" crank. Those pistons didn't clear the counter weights on the crank at BDC. Hopefully, those people got their money back. I might try to call Wisco just to confirm they have actually test fitted their pistons, and that they don't have excessive play or rock at BDC. Those 2 things would be my main concern with such a long stroke. I would be curious as to how far the piston comes out of the block at TDC. The stock pistons usually come out .004"-.006" with the stock crank. I wonder if the 4.1" crank pushes them any further...?
I would definitely be using a "junkyard" motor. I don't see the point in buying a new crate motor. I have found bare 6.2L blocks for around $650 or less. I can get heads for about $600-800. The rotating assembly is about $2000. I might need a machine shop to mill the heads, and maybe balance the rotating assembly if it's not already balanced. That's less than $500. That's about all the machine work I would need. On my 5.3L rebuild, I only used a machine shop to mill and flow test the heads. As long as I get a good bare block, I shouldn't need any other machine work. I already have a parts list for a complete Gen-4 engine rebuild. The stroker I built on paper comes out to roughly $5000-$6000 for everything. There are a few variables that I can't account for right now. That's why it's such a large price range.
Wisco makes a piston for a 4.1" crank. Maybe they used this same "technology" that Eric helped develop...? I read some reviews on a different piston manufacturer that makes a piston for a 4.1" crank. Those pistons didn't clear the counter weights on the crank at BDC. Hopefully, those people got their money back. I might try to call Wisco just to confirm they have actually test fitted their pistons, and that they don't have excessive play or rock at BDC. Those 2 things would be my main concern with such a long stroke. I would be curious as to how far the piston comes out of the block at TDC. The stock pistons usually come out .004"-.006" with the stock crank. I wonder if the 4.1" crank pushes them any further...?
I believe Wiseco was the first player to develop a suitable piston for LS strokers with 4 inch stroke and longer cranks. I think Brian Nutter who's now at Summitracing was with Wiesco was involved. I'm sure other were involved as well. That was like ~15+ years ago. Other manufacturers also have suitable stroker pistons as well.
I would definitely be using a "junkyard" motor. I don't see the point in buying a new crate motor. I have found bare 6.2L blocks for around $650 or less. I can get heads for about $600-800. The rotating assembly is about $2000. I might need a machine shop to mill the heads, and maybe balance the rotating assembly if it's not already balanced. That's less than $500.
and other videos are pretty interesting. Lot of the factory parts are off a little bit. There's several videos worth checking out etc.
With any used block for a stroker build I'd be concerned with making sure the ring seal is optimized and cylinder holes as perfect as possible due to the nature of the beast etc. Definitely at least a clean up hone is almost for sure is needed etc for a used block.
That's about all the machine work I would need.
On my 5.3L rebuild, I only used a machine shop to mill and flow test the heads. As long as I get a good bare block, I shouldn't need any other machine work. I already have a parts list for a complete Gen-4 engine rebuild. The stroker I built on paper comes out to roughly $5000-$6000 for everything. There are a few variables that I can't account for right now. That's why it's such a large price range.
Look forward to following your build and learning experience, if you do a build thread.
The 4" stroke in a stock, unsleeved engine is still iffy because it pulls the piston to far down into the block. Why do you want that much stroke? Cubic inches are cubic inches, and the length of the stroke does not change torque or horsepower produced.
Stroke will affect torque output immensely, because it’s adds cubic inches from a longer arm which is leverage. Cubic inches strictly from bore sizing will give the engine the ability to get more air in, and give it an opportunity to rev, but the shorter stroke (comparatively speaking) will hurt torque.
7 Most Reliable High-Performance Engines GM Has Ever Built
Slideshow:These GM engines didn't just make huge power, they survived abuse, boost, track days, and six-digit mileage with a reputation for refusing to quit.
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.
Max recommended stroke? 
