ok my motor lasted about 230 miles with the turbo on it so the car has sat for the past 4 weeks as i am trying to figure out my plan of attack. for the longest time i was wanting to go with a 396cid low compression motor and a t-88 turbo on custom manifolds. i was looking at numbers just over 1000 (flywheel) on dest top dyno. then for fun i plugged in a 383cid and saw that it would only make 10 less HP and TQ. since 383s are the norm and most say easier to build what you you guys do?
would I be able to run 5.7 rods with a 3.875 crank and dished pistons so that i could keep the compression down with a 396?
what set up for a 396 and 20psi would you guys use? would you just stay with the easier and stronger 383? i want to get a forged rotating assembly from either Nu-teck or Combo. i know it will be expensive but i plan on it taking a while. the motor comes out this weekend and heads to the machine shop soon after.

 

I wouldn't count it making 1000+hp just because DDD says so, but I do agree that the hp difference will be small. The low CR will have little to do with 383 v. 396 and will be dependent primarily on the size of the combustion chambers and the pistons chosen, though all else equal it will be a bit lower with a 383. As far as a 383 being stronger, it's not.

But depending on the rods chosen, the extra .125" stroke of the 396 can pose problems with clearancing the block and since the benefit is small, I'd go with the 383.

Rich Krause

 

i know DDD isn't 100% but its a good tool to work with when you want ideas. the only reason i figured a 396 might be weaker was because of the removal of more material.

 

1000rwhp is a tremendous undertaking, I know first hand. ARE has done it with a 422 w/400 shot, and W2W has done it with a 387 C5R and 2000 cfm blower. And I will do it in the next few weeks with 1600 cfm and a 200 shot. In any case, we're talking at least $20 to $30,000.

 

I'm guessing it will cost more than $20.

 

I agree!

 

first off i am not talking about wheel horsepower i'm talking fly wheel. a t-88 will support that much power with ease so thats no problem. so if i went with an all forged motor with 4 bolt mains, big heads, balanced and all then that shouldn't create a problem right? i have the turbo department covered ($1000 turbo and about $1000 for the manifolds) with a short block costing say 5k to build add another $1000 for whatever and i am only 8k in to that point. i have no clue where these huge numbers come from sometimes

can anyone tell me if the 5. 7 rods will create too much side load in a 396? would that be a good way to lower the compression?
thanks for the help keep it coming.

 

I'll tell you where the other numbers come from

Turbo intake piping, oil lines and misc other stuff: $500 - 1K
Custom Catback to handle that HP: 1K
Tranny: 2K (auto or manual)
Rear End: 1-2K
Fuel System: 1.5K
Suspension mods to try and keep it on the ground 1-2K +
Wheels and tires to help 1-2K
New computer and/or tuning 1-3K (depending on setup)

Those are just a few things that I came up woth off the top of my head and that adds up to about $15K and I'm sure there's stuff I forgot.

 

i understand all the other car stuff but i am only asking about the motor. my car is already turbocharged so i have the intercooler, piping that will need little modification for a new turbo location, FAST ems, i don't run exhaust just downpipe. i have a shop lined up to put in my cage, 160# injectors , aeromotive fuel pump, and a full BMR suspension with a moser rear end will all be in this summer as will a T-56 and spec clutch.
yes the entire cost of the car will be over 30K but i am not asking about all that. i just want to know if the 396 of or the 383 would be the better motor for 20psi and 1000 Flywheel HP and TQ.

 

Call Jayson at MTI and ask him your question.

 

what is MTI and do they have a phone number? i have never heard of them.

 

Motorsports Technology, Inc in Houston, TX. Premier LS1 builders.

 

so do they work with LT1s as well? thank you for the info i will try to look them up.

 

Yes, they do.

 

MTI doesnt work or cary parts on LT1 cars any more. They have a prety much shop car which is a 95 Fireawk, Fikse mags, big vortech blower, after cooler, 383, afr headed, well built car and when it was a six speed on a shot of gas it was hitting in the high 9XXrwhp range. That car belongs to Dave Lewis, but they are always messing with it. Last i heard it got some suspension work and a TH200R4. All this on the stock pcm. Jayson will still take care of any car he has built in the past and that hawk is evidence of it. With an LT1, most people who had the money to pay big shops like MTI to work on them have LS1s now. Most of the do it your self weekend racers have the Lt1 cars now adays.