Has anyone here had any experience with max valve lift on gt40P heads? Took these heads over to the machine shop and they will measure for me but I was wondering if anyone could learn me with there experiences with P heads.....
Everybody isn't looking for 100hp more... Not interested in Blowing or turboing it either.. Interested in having a nice driving convertible to drive to the Keys, St. Pete, or maybe up to the Pensacola Naval Air Museum....Waste of $ time and effort for 30 HP, i.e. buy some aftermarket alum heads and get 100 HP.
I agree with you about the flow numbers ( my research) ..Over .500 isn't going to gain you much. I was trying to find a flow bench video on the GT40P's but can't seem to locate it. I found one for TFS170's and going from .500 to .600 showed no gain. I can't imagine 40P's would do better.
There's a number of spring kits for .550 lift on those heads, so I believe that would be the max i would target. I cannot find any springs for over .550.
The machine shop is going to check the clearance after I buy the parts.. I didn't want to end up with a cam that did not work hence the reason for my questionI never got to run the Explorer heads I had, but I don't think there's any issues with lifts in the mid .500s as that's about where I was looking to go with them. It wouldn't hurt to have them checked to make sure, but I don't think they'll have to machine the guides if that's the route you're looking to take.
I'm pretty sure the heads won't necessarily be the limiting factor as far as your cam selection goes, it'll be the valve springs and piston to valve clearance. I don't know the numbers off the top of my head, but stock Explorer GT40 heads valve springs are only good to something like .400 lift at the valve. The good news is there are a few different sources that sell a kit for these heads to be able to get you into the .550 range or so. Trick Flow sells a kit, and there's a site called alexparts.com that sells different kits as well:
FORD, SMALL BLOCK 302 HO w/ E7, GT40P & GT40 - Alex's Parts Sales
www.alexsparts.com
So if you are looking at a specific cam, select the correct springs and you should be good - just don't forget to check PtV clearance when you're putting everything back together!
On a side note, if you're interested in building a pretty good combo on your own, I suggest watching this video. I think he does an excellent job explaining the cam and head flow relationship.
View: https://youtu.be/JPAeepqrY-0
I'm pretty sure the heads won't necessarily be the limiting factor as far as your cam selection goes, it'll be the valve springs and piston to valve clearance. I don't know the numbers off the top of my head, but stock Explorer GT40 heads valve springs are only good to something like .400 lift at the valve. The good news is there are a few different sources that sell a kit for these heads to be able to get you into the .550 range or so. Trick Flow sells a kit, and there's a site called alexparts.com that sells different kits as well:
FORD, SMALL BLOCK 302 HO w/ E7, GT40P & GT40 - Alex's Parts Sales
www.alexsparts.com
So if you are looking at a specific cam, select the correct springs and you should be good - just don't forget to check PtV clearance when you're putting everything back together!
On a side note, if you're interested in building a pretty good combo on your own, I suggest watching this video. I think he does an excellent job explaining the cam and head flow relationship.
View: https://youtu.be/JPAeepqrY-0
I'm getting ready to install some GT-40Ps on a fresh shortblock and will give you my .02 worth. I did some accepted home porting mods to my heads and used Alex's beehive spring kit: https://www.alexsparts.com/new-sb-f...t-max-output-525-lift-vsk7eb49-mc-hyd-roller/Has anyone here had any experience with max valve lift on gt40P heads? Took these heads over to the machine shop and they will measure for me but I was wondering if anyone could learn me with there experiences with P heads.....