Just wondering what kind of rpm limits there are on a 4" stroke, since it pulls the piston so far out of the hole.

I Was thinking the next upgrade step for my motor would be a stroker, with an llsr cam for increased rpm capability, but if the extra stroke limits how high I can spin it it doesnt make much sense.

 

This topic came up years back. IIRC 7000ish was considered max safe at that time on a stock sleeve. Lots of happy guys run a 414ish CID LS3 based stroker and run em hard. How big do you wanna go?

 

I was just planning on a 383. Currently have a stock displacement ls1 and figured 383 was the cheapest way to make more power.

 

K1 on Piston Speed is a pretty good article with details and explanation. (Edited link)

~4,000 to 4,200 fpm should live vey well with 4 inch stroke ir about ~ 6,500 rpm. This was what my 383 LS1 stroker was cammed around for long life.

7,000 rpm is certainly doable with 4 inch stroke, more stress, etc that's about 4,665 fpm...GM's 4 inch stroke LS7 had thus red line and a factory warranty in the C6 Z06

7,500 rpm is about 5,000 fpm becomes extremely challenging for 4 inch stroke....from what I understand pretty much maxed out for us mortal types...I wouldn't expect that to be long-lasting

 

We pulled a couple of pistons out of my buddies 408 turbo deal.
Rev limiter set to 7500, and he hits it on every burnout......just how he is.

The skirts were pretty beat up where they extend below the bore.

 

Thats the real consideration here. How long will it run vs how hard do you want to run it? Upping performance lowers reliability. Considering that for a 383 you could step to a sbe 6.0L for a a lot less, spin it slightly higher, and still hit the same number. Cost vs is always the final solution

 

Joe Honeycutt went over 10k with a 4” crank. Others were seeing over 9k pretty regularly in the LSX all motor classes.

 

I did consider doing a 6.0. But to be cost effective I'd have to go iron block, and I'm not a huge fan of the extra weight, especially since I'm going N/A. Plus with a SBE, I'd at minimum have to do new rod bolts to handle the much higher rpm, so add in machining costs for that.

Honestly I was just looking to see if an LLSR cam was worth the extra work over a hydraulic, but it looks like I won't be spinning any higher than I am currently.

 

I like the 6.2 aluminum 414 stroker builds. Run mid/low tens all day reliable na