Rotating assy rec.
 

I’m planning to buy a new rotating assembly, I have a new LS3 block, AFR 260 heads and all the rest. Was planning on a destroked engine first but have been rethinking. Going 4.00” stroke.
Any recommendations, Scat, Manley, Callies? They are pretty much the same price, any quality difference?

If you can’t decide between destroking and stroking..why not a stock crank?

K1 and Callies seem to be the most popular. I've seen K1 offer discounts when you buy the crank and rods from them together.

Yes... the happy (and cheaper...) medium.

Well, the short stroke will be a whole lot more expensive, so I’ll sit on those parts for now.

Callies Compstar is a good quality piece.

Sounds like you need to nail down what your actual goals are - that'll allow you to make good decisions on how to get there.

A destroker only makes sense to me if there is some compelling reason to keep displacement down. To take advantage of the shorter stroke (and longer rods it makes room for) you'll have to spin the engine faster, which will require an expensive fancy valvetrain arrangement. Overall, it tends to be pretty "racey", whereas a stroker turning 6500rpm will make great power, won't require anything fancy on the top end, and will likely be a more reliable "workhorse" for a long time.

That said, I do love the idea of a 4.8 (3.268" stroke) with a 4.065 bore (5.55L). Or better yet, a 4.125" bore (5.7L). All kinds of room for valves and airflow around them! But again, unless there's some kind of rule against the bigger displacement, there's really no good reason to give it up.

Edit to add:

If the engine is to live, piston speed MUST be kept at or below 25 meters/sec. This applies to all piston engines.

For reference, a 4" stroke LS7 @ 7000rpm has a piston speed of 23.7m/s. If you reduce stroke to 3.268, you'll need 8550rpm to hit that same 23.7m/s. A cup car engine (4.185x3.25) hits 25m/s @ 9200rpm...

It’s a very light midengine car I’m planning the destroked engine for (stock LS3 in the car as of now) mostly for the “right” sound and high rev. But as you said the valve train needed to accomplish this will be expensive, so I’ll just stay with the ls3 for now.
Instead of having the brand new block and AFR heads just laying around I thought I could use it for my other car but then I need another rotating assembly. So, if I should buy a new RA I might as well go with a 4.00” stroke.
That’s the reason behind it all, not that I can’t make up my mind.

Callies & K1 really have it done to a science. I favor Callies, only because I've had good results with their cranks. I would buy and use a K1 as well.

Thanks a lot, that helps me narrow it down

I have had good success with Callies, Manley and stock parts. Molnar Performance I have heard great things about. Tom Molnar split off from K1 and is now on his own.

Highly recommend Mahle powerpak pistons. Because of the small ring pack you can run a 4" stroke crank and a long rod and still not have the wrist pin impinge on the oil ringland.

A stroked ls3 will be nice, especially with good heads. Run a Holley sniper or Fast 102 with short runners to limit torque, and make tons of high rpm power. Long runner intakes like stock LS3 and long runner fast intake will be all done by 6500, and won't give you the power curve you're looking for.

With the right parts a 4" stroke engine can have a similarly shaped power curve to a short stroke screamer.

https://ls1tech.com/forums/dynamomet...l#post20107577

Check out the power curve on this thing. That's 8000 rpm btw out of a 427.

Another option is going with the K1 3.9" crank and the JE pistons designed for it. They are lightweight. That would give you something like a 406cid that will rev a bit better. Still getting the LS3 bore and almost all the stroke.

I have a Callies Magnum 3.27" stroke crank with Howards billet rods (used) if you are interested.... PM me.

Molnar has been my go to in 2017 and up to current for quality, good pricing, and not just blowing smoke up your ass with what their products can do. It helps to have the founder of the company (Tom Molnar) at the helm who also co-founded K1 (then left and founded Molnar) plus he was the engineer who made the Oliver Speedway rod :)

Did some more research and also called Molnar, K1 and Callies, they all say the same if you really question them.
3.9” is as far as you should go with a stock GM ls3 block, that is for a street driven car. More than 3.9” and you will have piston rock and wear the skirts out with high oil consumption and blow by as a result.
For all out race engine it doesn’t matter since they are overhauled quite often.

Correctly build NA 4 inch stroke crank LS 1/2/3 engines aren't oil burners and don't have piston rock issues.

Rock & oil burning nightmares are true if dealing with an engine assembler instead of an engine builder. There are a lit if bad shops that assembly vs build. Pick the wrong piston for a 4 inch stroke and you'll have a mess of oil consumption etc. However,Both Wiseco, Diamondand probably a few others have special taper pistons that move the ring package up. The trick piston with correct taper allows it to stay centered better with far less rock.

I have a LS1 383 w/4 inch stroke Callies crank / Wiseco pistons with 11,000 mikes burns less oil than a new stock LS1. The level on the dip stick barely moves over 3,000 miles. Checked at each gas fill.

Likewise have a 416 4 inch stroke Callies that burn oil like a stock LS1 (1/2 quart 2,000 miles) also Wiseco but built looser for harder performance use.

Builder said reasonable to expect 50,000 to 75,000 miles before refresh needed with normal daily driver use and some performance use. Beating on every day and every weekend tithe strip then expect less.

When new and stock my 99 TA wanted 1/2 quart every 1,500 to 2,000 miles :)

Personally, I'd be reluctant to go more than 4 inch stroke on a stock LS1/LS2/LS3 sleeve block if it was a daily driver.

As 99 says, piston choice is the key. Using a 4032 piston and reduced piston-to-wall clearance leaves less room for rocking.

That’s true, you will have a tighter piston-to-wall clearance when cold, but once up to running temp the 4032 and 2618 alloy will have pretty much the same clearance.
The taper on the other hand makes sence.

Lots of street driven cars out there with 4” stroke cranks seem to say otherwise. You should see what actual piston manufacturers say. Summit posted a REALLY good explanation of how strokers work a little while back. I would suggest searching their posts and reading up on it.

Spent half hour but can’t find any Summit post on 4” stroke cranks.

I think this is it....https://www.onallcylinders.com/2019/...s-engine-easy/