gt40s what cam?

jghood13

New Member
Oct 2, 2003
160
0
0
NY
I have decided to build
a .30 over block 10.13 compresion pistons with a 58cc head
gt40p heads
explorer intake
mac short tube
1.7s
70mm tb
77 proM

But what CAM should I use?
And what compresion should I expect with the heads
 
jghood13 said:
I have decided to build
a .30 over block 10.13 compresion pistons with a 58cc head
gt40p heads
explorer intake
mac short tube
1.7s
70mm tb
77 proM

But what CAM should I use?
And what compresion should I expect with the heads
If you are on a budget, the stock cam would work great with the 1.7's. If you are building a cam around 1.7 rockers, it is tough to choose a cam because most are designed using a 1.6 rocker. Honestly, unless you are willing to change the springs, there isn't a cam that you can run with 1.7 rockers that won't present a problem with the stock springs. If you would change the springs, the only 2 cams that I can think of off the top of my head would be the B-cam and the 15511 from Crower. Some diss the alphabet cams, but the B-cam is the exception. It's low lift and long(er) duration make it a great, torquey cam. But yes, there are better out there. Better as far as value and price is concerned? I would argue against that.

Joe
 
Some have had good success as well with the Crane 2031. It was designed for the 1.7 rockers, specfically for the 93-95 Cobras. I have seen others with good success with the E or B cam as well.

Good Luck
 
if better off I would run the 1.6s I would also like to know what kinda springs to use.

And would I be better off putting bigger valves,valve springs, and rockers on my stock heads and having them millied
 
jghood13 said:
if better off I would run the 1.6s I would also like to know what kinda springs to use.

And would I be better off putting bigger valves,valve springs, and rockers on my stock heads and having them millied
No, use the P heads. If you use 1.6's I would say use the Crower 15511 cam. That is probably the best "small" cam on the market that you don't have to change your valve springs for.

Joe
 
As of now I am definatly going with the gt40p heads and explorer intake I just need to know what year the P's came on the explorer I can get a junk yard motor complete for a hundred dollars some one please give me the year
 
jghood13 said:
As of now I am definatly going with the gt40p heads and explorer intake I just need to know what year the P's came on the explorer I can get a junk yard motor complete for a hundred dollars some one please give me the year
I believe it was 97 and up, when the P heads came on the Explorer/Mountaineer motors. I would double check that though. As far as the heads, it really depends on what cam you want to run. Out of the box, they don't flow much past .450 lift, so a Crower cam would be more than enough, and the stock springs would suffice. If you want to run something bigger, I would order the bare castings and assemble them yourself. The P heads have a 62.5cc combustion chamber, and if the stock heads are 9:1, the P's are going to be somewhere between 8.7 and 8.8:1 depending on headgasket thickness.

Joe
 
I am getting the 98 dexplorer motor monday or tuesday.
How much should I mill the heads?
What valves, valve springs, cam and rockers should I now run for the most power?
Is it worth if to upgrade all of this or should I use componets out of the mustang or explorer and just upgrade the cam?
BY THE WAY THANKS FOR YOUR HELP
 
jghood13 said:
I am getting the 98 dexplorer motor monday or tuesday.
How much should I mill the heads?
What valves, valve springs, cam and rockers should I now run for the most power?
Is it worth if to upgrade all of this or should I use componets out of the mustang or explorer and just upgrade the cam?
BY THE WAY THANKS FOR YOUR HELP
You can only mill about 40-thousandths off the heads before you have to start milling the manifold. I would mill 35-thousandths off just to stay on the safe side.

I would keep the stock valve train for several reasons. You don't need a large cam with stock P heads. They have max flow in the .450 to .475 lift ranges which is still within the capabilities of the stock springs. If you put aftermarket springs on the car, make sure they have the right pressures at the seat and at max. lift or else you could flat spot the cam. I would keep the stock valvetrain, and put the Crower in there.

Joe
 
Joes95GT said:
You can only mill about 40-thousandths off the heads before you have to start milling the manifold. I would mill 35-thousandths off just to stay on the safe side.

I would keep the stock valve train for several reasons. You don't need a large cam with stock P heads. They have max flow in the .450 to .475 lift ranges which is still within the capabilities of the stock springs. If you put aftermarket springs on the car, make sure they have the right pressures at the seat and at max. lift or else you could flat spot the cam. I would keep the stock valvetrain, and put the Crower in there.

Joe


This is what almost the same stuff I found out when researching gt40 heads, only I found that the heads liked around .475-.500 (the .500 as an absolute max) that and a split pattern cam, diff. numbers on int. and exh sides of cam and look for something that fav. the exh. side. I think it was like a 4-6* diff. in favor of exh. dur. and a .008-.012 in lift on the exh. not 100% sure though.
 
blksn955.o said:
This is what almost the same stuff I found out when researching gt40 heads, only I found that the heads liked around .475-.500 (the .500 as an absolute max) that and a split pattern cam, diff. numbers on int. and exh sides of cam and look for something that fav. the exh. side. I think it was like a 4-6* diff. in favor of exh. dur. and a .008-.012 in lift on the exh. not 100% sure though.
Thats right. The P's really lack on the exhaust side. If the exhaust side gets opened up properly, and the right cam is used, it will perform right with an AFR headed car.

JG - do not get stud mount rockers, the GT40P heads are pedestal mount heads and will accept only pedestal mount rockers.

Joe
 
jghood13 said:
I know there is some one on this forum that does head work who is it and how much do the charge?
Thumper (Mike) does excellent work and will work the P head quite nicely. I think he charges something like $600 for the work, plus shipping. If he ported them, you could run a bigger cam than .500 lift because the heads would be able to breathe past the point where they choked off before. However, like I said before, if you go past .500 lift, you are better off buying the bare castings and putting all the valvetrain together yourself. It's all money....

Joe
 
600 dollars is to much for now I can do a little work to the exsaust side my self with out a problem would this do to open the up and could I then still use the same cam but make up a little more power