There has been some speculation that maybe the Fast intake lets #7 run lean and enhances the possibilty of it nuking. Two of my friends have lost #7 piston. I'm getting ready to do a Fast 90 and NW TB. Aside from having my injectors flow tested and putting the richest one in #7, I have another idea that I'd like some comments on.

Tony Mamo, Vengance, and a few others port these intakes, if #7 runner was left unported is there a possibility that if it stayed unported that it might run a little richer and have less chance of detonation? If it's true that air flow from the plenum gives a little FI effect then maye not porting #7 might somewhat balance out the air flow.

 

hm...i dunno about any of that....i just put on a FAST 90/NW90. i ported the FAST myself, gained about 30rwhp. i've had no problems.

BUT a buddy has had #7 go out TWICE now, and he's running the same setup only he has trickflow heads. i'm stock heads/bottom end, just cam and intake....

i'm gonna hang around here and see what people say...

 

Can this thread be posted in external engine, I posted here by accident. Thanks

 

sounds like it would make sense to me i dont see why you could not try it. or you could try putting a slightly larger injector at the #7.

 

putting the highest flow injector in #7 is a good idea.

I am just going to skip the fast, and go with a eldebrock super vic. Jr.- it is a lot more FI friendly in my opinion.

 

What causes one cylinder to run lean?

 

The theory is that forced air goes directly through the throttle body straight back through the plenum. Then it hits the back of the plenum and is forced into #7 inlarger amounts larger than in the other cylinders, thus making #7 run leaner.

 

but wouldnt the valve be closed and not let the air enter the combustion chamber if infact the timming is correct and all valves are opening and closing as they should be?

 

By not porting #7 runner air flow would be slightly restricted, thus run slightly richer.