GT40p's almost finished

Topic: GT40p's almost finished (Read 1625 times) previous topic - next topic

GT40p's almost finished

March 05, 2007, 11:33:28 PM

Yep, was out at the guy's shop today doing the portwork on the heads and intake. Had to bring him some new spring retainers and valve stem locks. He's getting 218-220cfm out of the intake ports WITH the intake manifold bolted on! He only best a 152cfm on one of the exhaust ports but for whatever reason his exhaust flow measurements are lower than average (by 10-15cfm or more)on his flowbench. That was with 1.46" valves. I am going to take him my MAC headers so he can see how much he can widen the ports and have him order me some 1.55" exhaust valves. Should have them all ready to go by the end of next week.

GT40p's almost finished

Reply #1 – March 07, 2007, 11:15:44 PM

I'm swapping in a GT-40P HO into my bird next week. I'll let you know how it runs soon:D

GT40p's almost finished

Reply #2 – March 10, 2007, 01:05:53 AM

Can't wait to hear how yours turns out. Will you be running a stock HO cam or something else?

GT40p's almost finished

Reply #3 – March 11, 2007, 11:15:27 PM

I'm sticking with SD so the stock HO cam. If you have something like an E303 then it should run harder:D

GT40p's almost finished

Reply #4 – March 12, 2007, 12:37:19 AM

I wish I would have went that route just so I didn't have to mess with converting over to mass air. I still haven't bought a maf yet, I've been tring to find a good deal on like a 75mm or something but haven't been lucky. Still need a clutch too. And yes I have an E-303 already installed:D .

GT40p's almost finished

Reply #5 – March 12, 2007, 01:06:46 AM

Yeah I didn't feel like getting all the extra parts for MA just so I could run a different cam. I really don't think I'm going to need anything more than a stock HO cam as I'm mostly going to be using the car for street driving. Besides I really didn't want to loose the low end torque that the HO cam is famous for.

GT40p's almost finished

Reply #6 – March 12, 2007, 08:47:27 AM

Quote

He only best a 152cfm on one of the exhaust ports but for whatever reason his exhaust flow measurements are lower than average (by 10-15cfm or more)on his flowbench. That was with 1.46" valves. I am going to take him my MAC headers so he can see how much he can widen the ports and have him order me some 1.55" exhaust valves

You could always try running 1.7 ratio rockers on the exhaust side and a 1.6 ratio rockers on the intake side. Windsor motors respond well to this.

GT40p's almost finished

Reply #7 – March 12, 2007, 03:37:35 PM

Quote from: 86elan;132748

Yep, was out at the guy's shop today doing the portwork on the heads and intake. Had to bring him some new spring retainers and valve stem locks.

Whats the deal with the locks and retainers? Was it for the exhaust springs?

I found some vague information saying that the GT40P's use a taller exhaust valve, and require different locks and retainers, but thats all the information i could find.

What springs, locks and retainers are you running?

GT40p's almost finished

Reply #8 – March 12, 2007, 11:31:58 PM

Quote from: Tbird232ci;134031

Whats the deal with the locks and retainers? Was it for the exhaust springs?

I found some vague information saying that the GT40P's use a taller exhaust valve, and require different locks and retainers, but thats all the information i could find.

What springs, locks and retainers are you running?

Apparently on the gt40p's the exhaust valve is rotated when it opens. I am using Comp Cams steel retainers and locks. The new valves will use the same locks and retainers as the intake valves.

GT40p's almost finished

Reply #9 – March 12, 2007, 11:33:54 PM

Quote from: V8Demon;133950

You could always try running 1.7 ratio rockers on the exhaust side and a 1.6 ratio rockers on the intake side. Windsor motors respond well to this.

That thought crossed my mind but have already ordered the valves.