Sehr Performance Machine / Randi's 400 Pontiac
Randi came to us with a 400 Pontiac project for his 1968 Firebird. He
didn't want to go crazy on the build but he wanted something that would
give him performance that is better than original.
With that goal in mind Scott did some custom porting on his heads, upgraded
his valve train and went with a Custom COMP cam and lifters and aluminum
roller rockers. We maintained his complete original rotating assembly but
had to re-balance his crankshaft, it had been poorly balanced sometime in
the past and was out by 127 grams on one end and 181 grams on the other. A
single plane intake with a 780 Quick Fuel carb got it breathing and the
fire is lit with a Flamethrower ignition package. Custom cut and fitted
8mm plug wires are standard equipment here at Sehr. Headman custom coated
headers will be added at installation time.
The results were a satisfying 543.5 Hp @ 5500rpm and torque reading of
519.8 @ 5400rpm. Corrected to sea level the numbers are 577 Hp and 551 Tq
with nearly 400 lb of torque at 3500rpm.
The First time my 400 Big Block got started.
Pontiac running 2009 big cam idle
1964 Pontiac Tempest, 2dr Post, 455 .040 over, 4X heads, Comp XE274
cam,Performer RPM manifold w/ Edelbrock Performer 800cfm, Full Pypes X Exhaust with RacePro mufflers.
Engine has Holley 3130/750 now and different timing set up. Made huge
difference. I could never get the Edelbrock carb to work right. And yes
the Mr Gasket header gasket on the driver side was leaking just 40 minutes
after break in.