370 vs 408 for pushing water/lifting heads w/GT91
#22
My first combo was a stock crank 370 with ported L92 heads and compstar rods, 88mm turbo and 15.5 psi was good enough to run 5.63 in the 1/8th on the way to a 8.84 pass.
It was a good runner, and pretty budget. Ran great on the street.
It just was not strong enough to last.
The thin deck GM heads gave up the ghost and pushed water, even with ARP studs and MLS LS9 gaskets, every time I leaned on it a little. Upon teardown we noticed that the main caps were walking around a bit, caused by crank flex, most likely.
I like the 370, and feel any larger cubes and the turbo would be too small. My goal is to max out this GT47-88 turbo.....1500hp.
My new Virginia Speed motor that is being built right now will be a 370 again. this time we took the same iron block, half filled it with hard block, Shawn double o-ring setup, Callies Dragonslayer 3.625" crank, Callies rods, Wiseco pistons, ETP LS7 heads, and some of Shawn's magic.
I have never been overly impressed with the 408's. Just my opinion.
In the future, a 106mm would be my next turbo.
It was a good runner, and pretty budget. Ran great on the street.
It just was not strong enough to last.
The thin deck GM heads gave up the ghost and pushed water, even with ARP studs and MLS LS9 gaskets, every time I leaned on it a little. Upon teardown we noticed that the main caps were walking around a bit, caused by crank flex, most likely.
I like the 370, and feel any larger cubes and the turbo would be too small. My goal is to max out this GT47-88 turbo.....1500hp.
My new Virginia Speed motor that is being built right now will be a 370 again. this time we took the same iron block, half filled it with hard block, Shawn double o-ring setup, Callies Dragonslayer 3.625" crank, Callies rods, Wiseco pistons, ETP LS7 heads, and some of Shawn's magic.
I have never been overly impressed with the 408's. Just my opinion.
In the future, a 106mm would be my next turbo.
#23
Hmmm.. that sounds like an interesting combination! I am going 370 iron block and the same setup as Veee8 but starting with the 106mm. ARP main studs & pined mains. I am going to try out the stock crank from a budget perspective and hope it handles it.
Chris
Chris
#24
A Garrett GT106 will be tough to spool with a 370, but with the right convertor and 3 step it can be done.
#25
I am and always have been a fan of the 370ci LSX based engine for a Turbo application. Had one in the old shop car with a TC76 running some 9.40's. I will have one in my next shop car with Twin 67's. It's all going in my 70 Camaro unless it sells Sunday. If it does then I will pick up a high mileage LS1 for cheap and play with it.
#26
I am and always have been a fan of the 370ci LSX based engine for a Turbo application. Had one in the old shop car with a TC76 running some 9.40's. I will have one in my next shop car with Twin 67's. It's all going in my 70 Camaro unless it sells Sunday. If it does then I will pick up a high mileage LS1 for cheap and play with it.