silver-mod-o

iTrader: (15)

if youre dead set on a 408 and a blower, shoot for a hair over 10:1 compression and slap a TVS2300 on there and call it a day

fish5225

First, the engine builder Bret Bowers needs most of the credit. If you take popular hotrodding magazine there is a nice article on Bret and shop discussing last years entry in the engine masters competition. He really knows his stuff. With that in mind when we built the motor we expected to make in excess of 700hp. The 408 is a torque monster and since horsepower is a function of torque we felt with an optimized heads, valuetrain and the right cam, with the all forged motor we would be in that range. The only variable was the 1900 as we didn't know if it could keep up with the engine. We obviously we very happy with its performance. At the upper rpm range the boost did jump up 6.5-7lbs but most of the dyno run was right at 6lbs. The Magnacharger system is just really efficient. Please call Bret Bowers at Racing Engine Design he knows the specifics. The dyno run is on youtube and Bret says that are going to post on their website soon. Bottom line, the maggie was pushing a lot of cool air and was probably optimized to get 6-7 lbs of boost on this big of a motor speaks extremely well for the setup.

slowfive0

That is super impressive and my hats off too you guys! But am I the only one thinking: hmmmmmm, what if that was a 2300.....

fish5225

We think this setup with a 2300 would make in excess of 800 hp. Unfortunately the drivetrain in my Denali won't hold the power. I know that when the 2300 came out Detwiller was making 950 hp on a small block lsx motor. I can't remember if it was a 427, but I think 800 is possible on the 408if you run more boost.

slowfive0

WOW!!! That would be awesome!!!

fish5225

2300 here I come. Turns out that I broke a valve spring and just detonated my motor. Pieces of the value shot through the manifold and pounded 5 of my Arias pistons. Both heads totaled and minor scarring on the cylinder walls. So with no hesitation and since my engine builder can make me a sweet deal, we are going to bore to 40 over, new pistons and rings, L92 heads and the bigger blower. I'll post the dyno run when we get it put together.

zippy

This topic has came up a few times over the years and I always have the same opinion. Go for it. A few have done the 408 and MP112. You will make pretty good torque with decent hp. Keep the camshaft small and compression up. Go for 10.5:1 compression or so and keep the duration down to around the size of the GT2-3. What you'll end up with is a 408 that has about 6psi and makes plenty of power below 5500rpm. The reason I say do the 408 is that if you're going to build the motor and you can afford the 408 it's by far the way to go. You can always change intakes, cams, heads, etc., but you don't want to change the short block. Build the best short block you can and work with what you have. You also don't want to fall into that theory of it's a 408 and it needs this. You can run a 408 with stock heads, small cam, etc.

1slow01Z71

iTrader: (36)

Back in the day Whitt1 seemed pretty happy with his 408/112 combo in that tahoe. Wonder what ever happened to his whipple project