What is the largest CI that LT5 can be built to with stock crank?
 

This question is not for me, but one of the ZR-1 guys in Japan. He needs to rebuild his motor and want to build the biggest LT5 possible, but purchasing a new crank is not feasible with cost and shipping. Does anyone know what combination of liners/pistons/rods can be used and what size it will end up?

Sorry if this information is already available and posted. I could not find it if so.

Thanks!!

Re: What is the largest CI that LT5 can be built to with stock crank?
 

Is he willing to do an offset grind on the crank or keep it totally stock? I believe Pete is the person to answer this question.

Re: What is the largest CI that LT5 can be built to with stock crank?
 

yeah pete can give you all the info ,but i believe its 401ci, offset grinding the crank and using 4.125 piston and liners

Re: What is the largest CI that LT5 can be built to with stock crank?
 

Guys i'm no engine builder/expert.

I would say stock crank offset to 3.75 with 4.125 bore makes 401.
i know this will work very well.

I also know stock crank can be offset to 3.85 but i don't know much about 1.900 rods,this will make a 411ci.

I hear different stories on the 1.900 rods they work fine in a 9k RPM Honda some say LT5 parts are heavier so it won't work.:dontknow:
Flyan Ryan might have more input on the 1.900 rods durability.

Pete

P.S.
My choice is 401 should get around 500rwhp w/stock cams cost is about a 1/3 of a 415ci. for the do it yourselfer.

Re: What is the largest CI that LT5 can be built to with stock crank?
 

Thanks guys!!!

I found this on EES: Using your stock crankshaft:
4.100 bore, 3.75 stroke = 396cid
4.125 bore, 3.75 stroke = 401cid

So if this is it I'll pass on to the guy.

Thanks again!!

Re: What is the largest CI that LT5 can be built to with stock crank?
 

I'll ask him. I imagine he will want keep it stock. Thanks!

Re: What is the largest CI that LT5 can be built to with stock crank?
 

The max I would take off the crank is .100 this gives you 2.00 rod journal and stroke of 3.75 I know some people have cut other stock cranks farther, but a LT-5 hollow crank??? I would not like to find out the hard way.
If shipping is a problem, getting the block here and back wont work for the 4.100/125. Unless AES or EES is selling the liners now? Last I heard they only do short block assembled. So your looking at sending 4" liners over sea's.

3.75x4.00 = 377ci

Go with Ron Woods HD liners punch it .060 over = 388ci.

Re: What is the largest CI that LT5 can be built to with stock crank?
 

Okay, thanks for the info and I'll pass it on. He has been in communication with one of the builders already and they were going to send him a package for $15K to build in Japan. Sounds a little risky but I'm not sure what kind of shops he has access to there. Thanks again.

Re: What is the largest CI that LT5 can be built to with stock crank?
 

Hey guys. Well here's what a person has to deal with. As stated by diaper boy Kevin, 2.0" is standard 'Small Journal' Small Block Chev., is a good size, bearings available no problem. Next is 'Large Honda' size, 1.889", then is 'Small Honda' size, 1.85", then is I.R.L. or Mitsubishi size, 1.779". I'm having a crank done right now by Dave at Mile High Crank in Denver & before anything can happen we have to make sure it won't be too thin where the rod journal lightening hole is. The other thing a person has to watch is the oil hole, the more it gets off-set, the oil hole will want to 'Walk Over' to the crank radius, too much & it'll bleed off pressure at the bearing edge, obviously. So can a factory LT-5 crank go to the I.R.L. size of 1.779" for an approx. stroke of 3.98"? I'm not sure...never taken one that far.....yet :cool:. For the record I have used that I.R.L. size in a 900 HP+ engine & when torn down, the bearing look near perfect. Also, when off-setting that much, must make sure to Re-Nitride.

Re: What is the largest CI that LT5 can be built to with stock crank?
 

Thanks for taking time to share the info Ryan!!!!