I am having an ls7 built BY TTP w/tfs 245 heads,a super victor intake w/4500 series plate,11.3 comp and a big *** cam.The engine will be N/A and i'll be shifting around 7000 rpm. My question is that the bore is a 4.145 ,will this be ok in a N/A no nitrous car??? I know thats too thin for a power adder but will it live N/A????

 

I'm no guru, but from my reading and research, you'll get a failure at the top of the sleeve(s), they split/crack when you bore too much. And its pretty prevalent from what I've heard. And I've spoken with Steve at RED, he knows better than anyone.
And thats with N/A only high power builds. One bit of detonation and bye-bye.

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My 441 is a 4.125 stroke and 4.125 bore-built for N/A-if Cartek could've went bigger they would have.

 

It depends on who does the block and whether it's a wet or dry sleeve. 4.185is just fine naturally aspirated and 4.200 is more common than you would think. I go at least 4.155 as it gives you another go around at 4.185 later (with 100% reliability and good ring availability).

 

Oops, I thought he was talking about boring the stock sleeves to 4.145.

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Crap, sorry I was under the impression you were sleeving. Thanks LS6427 for phrasing things the other way.

1sickbird: 4.145 may be ok if you're at the end of the line. Take all of this with a grain of salt as you are speaking to a guy that once lightened 7 old TRW's (1985 vintage) 20 grams each to match one new ('97 vintage)TRW after a dropped valve. Here's my justification:

You've already got a block, crank, and just have to buy pistons. Will .010" of sleeve (on each side) make or break an engine? Not in my experience...until you've wrung it out for the very...last....time. Then you feel GOOD because you got your money's worth for not wasting a very expensive block before it was time.

You haven't invested in a new block yet, but must invest in a bore/hone/pistons (usually a net savings versus sleeving). If it DOES have issues (probably won't)-worst case scenario is a split cylinder leaking water and it pretzles a rod/wristpin. 2nd worst case is oiling and blowby (upside is it runs fine and gives you time to save money for a new block). Best case scenario is it's fine. What are the worst case scenario costs? Time, effort, and maybe a connecting rod and piston (buy spares). Only then do you have to purchase the block you WOULD of had to buy and have it bored to 4.145 to match your rotating assembly.

I look at issues like these as lessons, other people REALLY get torqued. Ask yourself who you are and pull the trigger. Most importantly...keep us updated so you can educate the world on your findings. If you do have a problem and hold me personally responsible, you can rest with the satisfaction that you didnt have to PAY me for this advice.

-Nutter

 

Do a 440. 4.130 x 4.100.

EDIT: i would rethink that intake manifold... Why spend alot of money on a good solid motor and get that intake? Look at something Cary makes...

 

If you are not resleeving I wouldn't take the bore past 4.125 and with a 4.125 stroke you'll get 441 cubes. Brian says "maybe" a 4.145 will be ok with a grain of salt, haha -I'd stick to 4.125 if I were you with the stock bores.
What does TTP say about it? How many motors have they done with that bore size? What are the cars making? and running at the track? THESE are the questions I'd be asking as well.