Questions about Cobra Jet 5.0

[Andrew Hill]

Originally Posted by Jesse Kershaw

The 2012 Cobra Jet engine is very similar to the stock Mustang GT engine combination. The most notable difference is the pistons that add compression and the cams.

The intent of the Cobra Jet's with the 4.6L 3v and the 5.0L was to make it affordable for racers to build street cars into competitive NHRA Stockers. Even the 3v cylinder heads CNC ported are less money than getting a "valve job" on many vintage set of heads.

NHRA tech has told me that in general they will accept a replacement piston that is slightly less compression BUT that it must be submitted as an offical replacement piston. A racer or engine builder can submit a stock 5.0L or 3v piston, or an Aluminator piston as a replacement for the Cobra Jet piston and ask for it to be approved.

The 5.0L and 4.6L Cobra Jet models are a great bargain for building a Stocker, especially starting from a street car.

What was the reason for making the changes to the pistons and cams? Why not just use the entire street motor if they are so similar?

[Greg Hill]

Andrew, I thought it would be obvious, to make things fairer for the rest of us.

[Ed Wright]

Originally Posted by Greg Hill

Andrew, I thought it would be obvious, to make things fairer for the rest of us.

Yeah, that's the ticket.

[201250]

NHRA tech has told me that in general they will accept a replacement piston that is slightly less compression BUT that it must be submitted as an offical replacement piston. A racer or engine builder can submit a stock 5.0L or 3v piston, or an Aluminator piston as a replacement for the Cobra Jet piston and ask for it to be approved.

I didn't know we could do that. WOW Can I send one of the Manley rods and have it approved also. Kdanner is right can I use the 6r80 trans as approved along with a beefed up 8.8 instead of the 9"?

[ALMACK]

Originally Posted by 201250

I didn't know we could do that. WOW Can I send one of the Manley rods and have it approved also. Kdanner is right can I use the 6r80 trans as approved along with a beefed up 8.8 instead of the 9"?

I see no reason why you couldn't use the 8.8 rear.

I also think that since the 6 speed automatic trans is heavier than the C-4 or the CJ Powerglide....oopps, I mean the C-2, that there shouldn't be a problem using it....just my .02c

[Andrew Hill]

Originally Posted by Greg Hill

Andrew, I thought it would be obvious, to make things fairer for the rest of us.

Of course, how could I miss that? It makes sense now.

[BlueOval Ralph]

Not sure Jesse can answer this, might have to ask someone else, just look at the SNAFU on the on the Blueprints sheets at NHRA! 3 years three screw ups! This was years screw up

2010 Specs
500 hp SS/S ENGINE WITH WHIPPLE S/C IS LISTED AS A 2 INTAKE VALVES 1 EXHAUST VALVE. SHOULD HAVE BEEN AA 4 VALVE MOTOR.
This was last year till just befor INDY.
Ralph

Originally Posted by Andrew Hill

What was the reason for making the changes to the pistons and cams? Why not just use the entire street motor if they are so similar?