Thanks guys for the valuable input! Ive been really thinking about the bore size and the only problem i have with going with a smaller bore size is that it means if i want to go bigger later i have to send the block out again to be re-sleeved. i hadn't really considered the head gasket issues... i know its no grantee but with ARP studs i should be OK. i will defiantly let whoever specs my cam know about my rod length. i will be using HKE so i should be OK there.

Any thoughts on cam specs?

Aaron

 

I don't understand the short stroke if you are staying with hydraulic valvetrain? The top end rpm limit to any LS engine is usually the hydraulic valvetrain and not the stroke, etc. Since you are doing a ERL sleeved deal you would have plenty of sleeve at BDC support to run the longer strokes and make more power under the curve. I'd build it as big as possible if it's a all motor deal or stick with a 4" stroke on standard deck height blocks to keep the piston/rings safer on nitrous. I just don't see the point of the ERL sleeved block to run stock stroke as street engine with hydraulic valvetrain.

 

I'm having the block done to give me a bigger bore... Erl is doing the work because i like the guys that work there and they do good work... I'm going with a 4.185 bore and having the capabilities of running any crank combo i want in the future. just because you haven't done a short stroke build doesn't mean its a bad idea. in theory my motor should breath better than all the stroked out 4.000 bore guys because my valve wont be cupped as bad by the cylinder wall. wisco has all the parts i need off the shelf as of last week when i checked.

thanks

 

Don't get me wrong, I'd rather have a larger bore, shorter stroke 400ci engine over a square 400ci engine if I was restricted to 400ci any day. I like the erl stuff also, but just figured you would want to maximize the ci since you are already spending the money on the nice block. If you go to the max bore now you won't be changing the crank and pistons later as there will be no room left for a over hone.

 

I think even though he is using a expensive erl block. The rest of his build is budget minded. Like stock ls3s and stock crank.

 

He is looking at the dry sleeve ERL which is cheaper and lighter than an LSX block, so still budget minded if he already has a block to sleeve

 

Dry sleeve from ERL is $2250 + core (It was like $1500 or so) now after checking the other day. Cool stuff, but our idea of budget must be different. I wanted to build a 454+ or so and have been checking around.

 

You definentally have the right idea about the bore size helping the heads with breathing. However, LS3's do breathe very well with 4.065 bores, let alone a 4.185 Bore. I highly doubt there would be much difference from a 4.155 and a 4.185 bore. Very Small amount of power to gain. Sure it SHOULD make more power b/c it's gonna want to move more air, with less valve shroud to prevent it. But it seems like there is a tough decision for you. All bore setup now 4.185 and hope you don't hurt the engine on N20 and have no room for a re-hone or rebore and no option of putting a 4.00 or 4.1, or 4.125 stroke crank in it b/c the bores are damaged at that point.
OR, go with a 4.155" bore, sacrifice a little valve shrouding (which I don't see being an issue AT ALL), and having the ability to do a rebore, change the crank to whatever stroke you desire, and not have to worry about buying another resleeved block from ERL in the event something goes wrong with this engine.
As for reboring the engine later, it's not very expensive at all to do, and by doing that would give you a FRESH bore to start out with if/when you do a larger stroke crankshaft. A perfectly round bore with no wear is gonna help seal the rings better than with a bore that has Some wear. So going smaller now is not necessarily a bad thing.

***Smaller Bore now = more material in between the bores for better head gasket sealing, more material to bore later in the event of an engine failure, the ability to use another crank in the event of a failure, and as well as the ability to start fresh with a new bore if/when you do a larger crank...

***Larger Bore = possibly a little more power now, but at the sacrifice that if anything goes wrong, Now you have to buy a new sleeved block, rather than just fix whats wrong with the 1 with a 4.155" bore. So It's more of a luck of the draw kinda thing when going MAX Bore.

IMHO, I always choose peace of mind over All OUT! I would much rather have a second chance (you could say) than go all out and be screwed if something goes wrong.

Either way, I think you'll have a Very strong running engine no matter what you decide. I'm not trying to tell you what to do obviously, I just wanted to give my .02.

 

They damn sure did and its only availible up to a 4.125" bore according to their new website.