i think i spun a rod bearing (haven't pulled it out yet to find out for sure) and want to take this opportunity to build a sweet street/strip motor out of my LT4.
any advice as to what i should build? a 396?? a 409??
any advice on rotating assembly etc would be appreciated too...
i plan on reusing my GTP heads, and intake...
will i need bigger injectors? (i have 28#'s now) i think i'm maxing them out already so i would guess i'll need to go up.
thanks in advance for any input!!
Re: any advice for what i should build my LT4 into?? (SonnyinVA)
396.
For a street/strip setup, I've come to the conclusion (after ridiculous amounts of homework) that a 396 is the best build. If you were looking to road race- 383; all out drag race- 396< ; but for a dual purpose street/strip engine, 396 is the way to go. Parts are fairly cheap, you can use an LT block (you retain the opti, waterpump, accessories...), and you'll have gobs of torque.
IMO, MORE performance builds the best 396 around (As far as I know, Mike Osucha was the first tuner to start building 396's on the LT short blocks.) That's their specialty and they will build the engine to your specifications. I don't know anything about the stats of your current heads, but if your looking to tweak the thing to its max. capacity, you might want to consider selling the GTP heads and going with a set of AFR's. MORE has an in-house machine shop and they do all of their own machining (Nice to know that every bit of work is done under the same roof).
OR, you could have a local shop assemble/machine the engine and save some $$$.
Hope to be in your shoes soon! Keep us up on your decisions... :cheers:
Re: any advice for what i should build my LT4 into?? (SonnyinVA)
I agree with 365ZUm, the 396 is a good all around motor. The 3.875 stroke is relatively easy to accomodate into the average LTx block. Larger strokes like 4.0" for a 409 really starts narrowing down the "good" blocks. More clearancing is required and may make some blocks unusable. I "think" that you may need to use a smaller base circle cam to reduce interference problems with the 4.0" crank.
All of these things are doable, but $wise the 396 is doable with "average"/common parts (can more than likely be done with the engine you posess) whereas the 409 needs some luck and additional work. For instance racenet.net lists a 383 and 396 shortblock as costing $500 less than a 409 short block (about 10%). In the grand scheme of things $500 probably won't be a show stopper, how much do you want to spend?
Re: any advice for what i should build my LT4 into?? (John W)
thanks for pointing out the racenet site... although, i can't find any info about the short blocks. i see the price but that's it.
i like the 409 shortblock idea... saves me from trying to make one work.
just for a price comparison, a motown 415 shortblock is $4600 (without exchange) so i guess $4800/$5300 seems a lil high to me for a 396/409 WITH EXCHANGE. i know it won't work with all the LT4 stuff, but the motown block seems like it would be a better block to have.
couple more questions...
1. any impressions about racenet's price for the 396 or 409 short block??
2. any estimates on how much would it cost to build a 396 myself out of the block i have?? including machine shop and all forged internals etc??
wouldn't it be cheaper than $4800???
3. anybody else know any good sites for shortblock assemblies??
Flatlander racing has a fairly extensive online parts list. http://www.flatlanderracing.com. Between racenet and flatlander you should be able to come up with a good combination of parts to suit your needs.
EDIT ---- Looking at the link above for nu-tek, a good ballpark for forged parts is ~$2100 and labor is about ~$1650 (machine, balance, assemble short block)
Corvette Store
any advice for what i should build my LT4 into??
