lol... That is actually something I'd like to do sometime in the future.

 

I think the most you can practically do is 414 cid. That would be 4.060 x 4.0. You could maybe go 4.090 x 4.0 if you have a good block, but that would still only be 420 cid.

However, as most have mentioned, the cid isn't the hard part. The heads are. The LS7 heads flow something like 360 cfm and have very good flow "quality". The only way to get there on an SBC/LT1 is 18 deg heads, which are very expensive to set up ($5k or so) and the LT1 intake won't work at all.

 

Just drop the cash on a LS7

 

Lingenfelter built a 454 SBC once...about 10-15 years ago. Somewhere I have it in a magazine. It can be done, but its not cheap.

 

Hell you can build a 500 cube SBC, but it's lots of work. For big cubes in a Small Block the LS motors are the best way to do that.

Bret

 

511ci LSx block from GMPP

 

If you werent listening lol [EDIT] an LS engine, I wanna do an LT1 engine. So for all the people that say it cant be done.... just wait and see, there are other ways around the problems you are talking about. You can flow the right about into a head, just have to have te perfect head to fuel it. My 388 is my engine for the car I have and will make well near 500hp so I am not trying to make big horsepower, I already have a big horsepower engine, I just wanna build this engine for my ta and Im sure that it wont cost 12k cuz thats how much a LS7 is.

 

Good luck. Keep us posted

 

Assuming you want to get a little more RWHP than your 388, $12K for a 427 LT1 might be low.

 

lol, I guess all the guys running NA 383's with 500rwhp and block fill in .030" over bores just to keep the ring seal up don't know what they are talking about. Good luck man.

Bret

 

 

Did you take the time to "search" for the guy who built the sleeved 427ci LT1? I mentioned it in another thread you resurrected from the dead at the same time you posted this new one.

 

I think the point that everyone is trying to make is that we know it can be done, as it has been done. You will not make the power/dollar spent that you would with an LS based engine. Whatever you spend on an LTx, you could probably make another 50hp at a minimum with the same money spent. Proving a point is a great way to throw away too much money.

 

First, I completely agree with what most of the others are saying about this being an expensive idea, better ways to get there, etc., etc.

However, you didn't ask whether it was wise just how to do it - honoring the spirit of your question, here's where I would start:
http://www.theengineshop.com/prods_p...townBlocks.htm

Wouldn't be a "pure" LT1 but if I just HAD to have 427ci in my 93-97 F-body, that block is what I'd start with and figure out the heads / intake options from there to get where I wanted to be. Just my $.02 worth...

 

Why not a 426 or a 428 or a 499? I.e, why would you pick 427 other than there is such an animal. Just curious.