180 Deg Headers

[Scott Calabro]

Can any of the engine junkies here can explain why Ford chose to use the famous 180 deg exh. on the GT40, but cars like Chevy powered Lola's and McLarens did not ?

Could it have something to do with the different engine firing order of the two engine types ?

I've always wondered.

Best,
S

 

[Jac Mac]

I think you will find it goes back to Fords Indy car program and the little 255cu in engine which was fitted to the first GT40's. Since the rear of the Mono was designed to accomodate this exhaust design the principle continued. The 180 deg design probably helped the small engine a bit by giving it a flatter torque curve and would have helped in the noise dept, though that was not much of an issue back then.

As with A/C you have to take weight into consideration along with fabrication time and given the option most would prefer the easy build of one set per bank to fitting/fabricating 180 deg exhausts. Unfortunately I fit in the category that likes a challenge & prefer 180 deg headers( or even better 8 into 1.)

Jac Mac

 

[Scott Calabro]

Thanks jac mac. Do I read it right then that the 180 deg. exhaust would make more power ?
S

 

[Jac Mac]

Thanks jac mac. Do I read it right then that the 180 deg. exhaust would make more power ?
S

The short answer is yes purely because the even firing order per collector allows more equal scaveging of each cylinder. However many builders overlook the collector design,pipe size,length,and order in which the primarys feed into the collector or snooker themselves in primary pipe design and negate any advantage they might have gained.

Jac Mac