Thule

i am thinking about change out my flat top pistons for a set w/bigger valve"seats" to be able to install a bigger cam,

i've bin thinking about goin 383cid, and use my 99+style ls1 block, with a 4.00" crankshaft,
but i've bin wondering, is the longer stroke the right way for me, over a built 346?
currently i rev the motor to 7k and i am shooting 150,compr 11,1, the car is just a weekend driver and i take it to the track when i can,
i want more power, and i want to shoot 200,

my amature engine knowledge tells me that longer stroke set up would have more tourqe,and be less rev happy than bigger bore set up,

so my question is, am i better off with a 383cid rather than a built 346. or is the longer stroke set up not offering the engine character i am looking for? and maybe not worth the 1k that the crankshaft would cost me,


what i want is a bigger bore block, but that is just not an option a.t.m,

best regards, Thule
sorry fo the bad spelling, not from the us

Texas_WS6

iTrader: (9)

4" stroke is not a problem at all, and you I am dure he ment to say valve "relief" not seat. There are good pistons out there that will do what you want, I am assuming you do not plan to reuse your pistons. Another option for more displacement is a 6.0L block or a 6.2L block. I am taking my 408 turbo car to 7000 rpm no problem.

Good luck.

Texas_WS6

iTrader: (9)

You can find 6.0L iron blocks pretty easily and they are less expensive then the 4" crank.

KCS

iTrader: (20)

Thule,

I would say that the answer depends on how often you use the nitrous kit. You will definetely gain more torque with the extra 36ci, and depending on the heads and camshaft, you can see ~40hp more as well, but is that worth it when you are spraying a 200 shot of nitrous? Isn't a 250hp jet cheaper than a crankshaft?

Also, as already mentioned, what about a 6.0L iron block? It will require just as much machining as the LS1 block will for a 347 or a 383, it is cheaper than an aftermarket forged crank, plus you will be able to use a larger selection of heads with the 4.00" or larger bore. You can even begin machining the block without taking the engine out of the car you have now. With a stock stroke crank and a 4.030" bore, you can get 370ci easily, 375ci if you go with a 4.060" bore. You could even sell your old shortblock to offset the cost of the new engine.

Just some suggestions, hope it helps.

-Kent

Thule

thanks for the advise, i would go with another block if i could, but a.t.m my country's current exchange i totaly fuc*ed, and shipping insanely expensive,
and purchasing parts like i did not possable for a.t next 2 years,
if i go 383 the only parts i will need to buy and ship over hear are the crank and the cam,
the block would take more space and be much expensiver to ship, and i would need more parts,

my current motor is brand new, with under 100miles on it, so the idea was to reuse almost anything, just change out the pistons/crank/cam and go 383 and get more out of my set up,

but w/o a question i would go 4.030 bore or bigger if i could, and will probably when i can,

99blancoSS

iTrader: (115)

Excellent advise by KCS, but being out of country makes the 383 is a good option for you then, your still going to pay a hefty shipping charge on the crank and pistons. We can do a rotating assembly for you and save you some money on a few things if your interested. What rods are you using that your going to re-use?