GT40 2 bar heads...???

[ZEN50]

Anyone have any experience with the GT40 2 bar heads? Casting number is F3JE. From what I have learned is that these are a marine head. What does that exactly mean I'm not sure yet? Just trying to gather some more info on these and if they worthwhile to use in a car application.

Thanks,
Zen

[Mgino757]

Got pics?

[FoxChassis]

Same size valve as all other GT-40 heads (not GT-40P heads) but have the largest combustion chamber of all GT-40 and GT-40P heads. Compression ratio will drop some but not as low as 1979-84/85 CFI.

[ZEN50]

Same size valve as all other GT-40 heads (not GT-40P heads) but have the largest combustion chamber of all GT-40 and GT-40P heads. Compression ratio will drop some but not as low as 1979-84/85 CFI.

That's some of the info I got from Ford Racing (Performance) also. I think they told me 69cc, approx. compression ratio of 8.2 ????

Does anybody run these on a street car? Are they worthless for a street performance application?

Will try to get some pics up...

[bwguardian]

They would probably make a good candidate for a forced induction power plant...

[FoxChassis]

I think spec is 66-69 cc so 69cc is on the high side of the variance. Not a great choice for natural aspiration and flat or dished pistons. I'm with bwguardian...would be better for forced induction where you'd want lower static CR.

[BlackMamba]

Anyone have any experience with the GT40 2 bar heads? Casting number is F3JE. From what I have learned is that these are a marine head. What does that exactly mean I'm not sure yet? Just trying to gather some more info on these and if they worthwhile to use in a car application.

Thanks,
Zen

I have the marine gt40 heads too but they have the 3 bars and the port for the thermactor/crossover tube in the back.
I'll try and get the casting number later tonight.

[ZEN50]

Yeah, that was pretty much my understanding of it also. Could the heads be machined for more compression or is that just opening up a can of new problems?

I guess the search is on for some new heads!

[FoxChassis]

You could cut them to drop the cc down some but not sure if you could cut enough to make a difference. Cut too much off and then you have trouble getting the intake to align and seal properly. The only thing the "J" heads have going for them is larger valves and improved flow over earlier late model factory heads. Other GT-40 heads are better only because they have smaller chambers for a bump in CR.

[BlackMamba]

double post

[ZEN50]

II bar pic.....

[cb84capri]

Those would be good heads for someone looking to do a budget 351w build, will net around 10:1 compression there. Someone would probably trade you their GT40s for them.

Cale

[ZEN50]

Sounds good to me Cale, get a hold of me

[cb84capri]

Haha sorry Zen I guess it does kind of sound like I was hinting at something. Did you end up getting some heads off of Mitch?

Cale

[ZEN50]

Yeah, sure did. Met him in Lansing yesterday. Was thinking about contacting you but figured you were probably working.

[cb84capri]

Ah man! I got some parts here with your name on 'em too!

I'm glad you got some heads better suited to your needs.

Cale