How many ways can you stroke a lq4 motor? I know you can use a 4inch crank shaft, but is there a way to achieve this with a stock crank and shorter or longer rods/pistons. Me and a friend is having a debate.

 

Only the crank determines the stroke. Longer rods or different compression heights don't change the stroke, which is determined by the throw of the crank.
Think of how an engine operates, and you will wonder, as I did, how or why you could even ask such a question. SMH....

 

thats exactly what I told him

 

WOW, I really expected this question to come from someone with 1 or 2 posts, not a 8 year member with over 1,000!!!!

 

Lol for real 😂

 

did you not see where I said me and a friend was having a debate and I was trying to explain to him it has to do with the crankshaft he didn't believe me and wanted me to make a post to prove him wrong smh

 

It's a good question worthy to an experienced member when one stops and thinks about the question.

Technically, yes you can stroke the motor with the stock crank by doing off set grinding the stock crank. It was fairly popular back in 1999-2001 due to the high $4000 coat of stroker crank kits.

With an offset ground LS crank the stroke can be increased to about 3.825 from 3.62 stroke. However special bearings are required and getting a set of honda bearing sized (or other) small block chevy rods can end up being expensive. Usually enough so that just getting an aftermarket LS stroker crank is the smarter option. Sometimes used NASCAR rods with the right bearing size show up and can make the off set grind almost tempting.

However, with the machine work costing $250 to $350 to properly off grind and reheat treat the stock crank etc one could sell the old stock stroke crank for $150 to $250 and be $400 to $600 towards a new aftermarket 4 inch crank that will make more cubes! Plus no worries about finding special custom parts sometimes expensive to finish the project.

I researched the option in detail back in 2003-2004 when I had access to a set of inexpensive Honda bearing small block chevy rods. However the price of stroker cranks came down. I decided $1,000 aftermarket Callies crank was a more cost for the cube effective choice way back then. The logical argument for the aftermarket crank is even greater today unless you can get the special rods for free. Even then the aftermarket crank is better due to cubes

BTW - if you want to do an offset grind, PM me I might be able to find the contact info for a good crank shop. I revisited the offset idea back in 2016 to 2018.

Also GM offers a new 3.85 or 3.86 stroke crank in the 6.6 liter L8T engine Gen V engine. I don't know if it will work in an earlier Gen 3/4 block. It costs about $595 if you shop around.

 

good to know. I didn't know that

 

Happy to share some of that old info

Back in the day when the board was founded, one of the mods ChrisARE360 or something like that had an LS1 360 with an offset ground crank

 

You'll notice it still involves the crank ONLY where it comes to changing stroke.
Your buddy must be really dense where it comes to engine knowledge. Have him read some books, IF he can...

 

SMH

We all started learning somewhere and LS1Tech is a good place to start. I think we should be nice and polite to folks that come to LS1Tech to ask legitimate engine questions.

When I think of some of the first questions I asked 35 years ago about engines - I'm grateful folks took time to answer and explain.

Seems like a good tradition to continue

 

Maybe where your friend is getting confused is static compression ratio. Crank, rods, and piston wrist pin to crown distance all affect compression ratio. But of those, only crank journal offset from centerline (crank throw) changes stroke as well.

 

his exact words were you can keep the stock crank no modifications just shorten the rods, I told him then he would have compression issues and the piston would not reach the top, but he wanted to argue I told him I can simply ask the question on ls1tech.

 

ill just get him to read the replies lol

 

If he was a friend who knows you are knowledgeable on engines, he should not have thrown down the gauntlet and had you post his ignorant line of thinking here.
It is one of the most basic principles of engine operation.
I hope he learns a bit more soon. Sounds like you could be of help there.
Happy hotrodding!

 

exactly man. My words to him before I posted the question was "man I don't want to post that dumb *** question" lol I'm like dude I was just talking about this to someone else but he wanted to argue and i had to prove him wrong

 

Well, I kinda hope he is a little embarrassed after this.
Reading your sig tells me you know your stuff. Your bud should respect that

 

thanks again

 

You can phrase it as, stroke is a property of the crankshaft; specifically, how far the rod journals are offset from the mains. Butt: when you change the stroke, those other things HAVE TO change as well; the "height" of the block, from crank centerline to deck, is always the same (within a small tolerance), but the sum of ½ the stroke, plus the rod length center-to-center, plus the piston height from center of the pin to the top surface, must equal the block height (again, within a small tolerance). So if you increase the stroke, at least one of those other things must decrease. Usually it's the piston dimensions. Sometimes it's necessary to increase the rod length along with the stroke so that the entire rotating assembly can fit below the bottom of the pistons when they're at BDC, or sometimes people just do that to get more favorable mechanical ratios between stroke and rod length, so it ends up a double whammy at shortening the piston height. But those other parts by themselves do not determine the stroke, only the crank does.

 

I dunno, man. I've had arguments with some really stupid guys, and even when you give them overwhelming proof, most of them are too stubborn to admit defeat.