Two Seperate questions here:
First: The new LSX block is going to be released this march. On streetfire.com they have a SEMA interview with a GM design engineer where they discuss the differences with the other LS family of engines. What do you think the cost estimate would be to build this motor with it's maximum bore and stroke. I'm interested in haaving a engine built for the street to run on 91 oct. (Educated Guess on Power???)

Second I'm active duty military and stationed out of my home state (Arizona) how is that going to wark with emmisions??? Is this my loophole for installing Longtube headers. Anyother owners with longtubes run into emmisions issues. Understand not carb approved and catalyst id moved farther away from exhaust ports, but if the car is warm during the test will it make a difference?

Thanks for any support.

 

I am not sure what the true price of the block would be: for example, list price on a C5R at the time I bought one was around $8-9K but I got mine through a GM dealer from GMPP for about $5500.

Cost depends on what parts you put inside it and what talent you hire to build it. Premium rotating assemblies and custom pistons would run about $2500 for the whole short block. Good strong stuff (Eagel) might run only $1200-$1500. Assembly: you could do it yourself (assume maybe $500 for machining) or have it done in various price range: I paid $5000 extra to have my engine assembled by a proven NASCAR engine builder ('96 Daytona winner, etc.) which was probably overkill for a street engine, but fun.

I would think if you had the block already, and watched the budget, you could build a good short block for about $3500 additional (over the cost of the block). I have no doubt that fairly soon now various shops and sources will offer short blocks with the LSX, at around 480-500 cubic inches, probably initially for about $8K and then coming down to maybe $5-6.

Put really good heads on this engine (big, ported LS7 heads, or the the best AFRs, ported some more and polished) and a cam that is just streetable, with the best valve gear, and that is another $4000-$5000. Say $10,000 complete on a budget and $15,000 premium, and I see no reason why you would not get close to 650 RWHP in a 6-spd manual 'vette. With a milder but more streetalbe cam and tune (daily driver) I think 580 RWHP and 620 RWT would be attainable in a well behaved, nearly stock-idle motor on pump gas.If you SC it, you would have to use something big, a Kenny Bell or a Procharger F series unit, which would run about $10+K but the time it was in the car but you would be looking at 900 to maybe 1000 RWHP with not real hassles.

By the way, if I were building this type of engine (and I am thinking about doing one) I would anticipate having to try two or three different cams in it before i found the one I wanted: its typical on new engines wqhere there is ilittle experience that even very educated guesses just do not quite get it right the first time or two. This happened when I did my 426 C5R.

 

Thanks for the good info. I'm hoping that engine builders will charge less than 8-9K for a short block. I hear from the same interview previously mentioned that this bare block would cost about 2,500. I'm not sure how high end of a rotating assembly I need to go. This will be an NA motor. I wanted at least forged internals. Do you know of any reputable corvette shops in Southern California?? I've bought generic shorts blocks before (383 and 4.6) but not for an LS motor. 650rwhp is what I'm hoping for. Am I correct to understand that components that I buy for my LS2 will fit the LSX block. I'm looking to buy Long tube headers (dynatech), CAI (haltech), and FAST intack manifold.

Thanks alot for the help.

 

From what I hear, most components like oil pump, etc., for LS engines will fit the LSX. but realize the rods will have to be different, the crank different, the pistons, the pushrods, etc. -- it is a decked block as far as I understand and so all that will have to be different. GM has said standard LS heads will fit, as will other accessories, but of course you will need a different intake manifold (with most decked blows the heads are about 1/4 inch farther apart, etc. ).

 

Thanks alot for the input.