So does the 302 in the Explorer have an actual GT-40 intake or is it a modified version? What about the heads, are they a GT-40 or something similar? I'm guessint they flow better then my stock heads on the 88 302.
the search will pull up a lot of info on both
I just got a 98 Explorer motor and it has the gt40P heads.
don't know why i didn't see this before.. guess i'm not the only 1 who missed it lol
the heads are GT40P's on 90% of explorer motors.. some of the early 5.0 explorers had the regular GT40's I THINK.. the GT40P's are 1 of the best heads you can get for a windsor motor.. the intake ISN'T a GT40, but it does flow better than what you currently have on your car..
i don't know what's currently done to your motor, whether it's an SO or HO, etc etc.. but whatever it is, if the top end is stock, the explorer setup is better.. if you have an HO, it'll go on without an issue.. if it's SO, you've got some decision making to do, because the GT40P valves are larger and will make contact with your pistons.. you have a few options to make it work, but i'd suggest either a rebuild with new pistons OR a healthy HO shortblock
Or, its more like the ptv clearance is almost identical between the h.o. and s.o. bottom end, and if you can run the s.o. pistons, you won't need a new motor or bottom end, and you'll have slightly higher compression, giving you more power. A h.o. cam and s.o. pistons with gt40 heads, should clear, but always check you ptv.
i give up lol.. everyone says different bs about the PTV clearance.. i don't personally know from experience, because SO pistons are trashcan material to me
You will not have any piston to valve problems with the SO piston IF you're running the stock SO or HO cam. The HO cam has only .440" lift. I wouldn't run the SO pistons with any after market cam because even if you keep the lift low it can still hit if the duration is high enough. You can safely run .500" lift with HO piston IF you keep the duration under 220* at .050". Millions of mustang guys run "E" cams with stock pistons with no issues. The "E" cam has .498" lift and 220* duration at .050". If you have the whole explorer engine just put a HO cam in it and swap the engine, problem solved, no PTV issues.
Lots of guys here run the e camand gt40's without ptv on a stock bottom end. I just don't get what all the hate is against the stock s.o. pistons. I have seen many over the years take nitrous till the block split, endure superchargers and rpm's. What makes them so cruddy stock?
Careful everyone, be mindful of the geometry of camshafts....LIFT does not a good or bad PTV clearance make ;) the entire profile really needs to be known among other things if you want to somehow *calculate* it or do some hand-waving.
I had hoped for this as well for the red cougar's engine. Turned out with the H.O. cam and GT40 non-P, F3ZE heads, S.O. bottom end, there is NOT enough clearance. The bigger valves I determined to be the sole cause of this, but my comment about cam designs still stands.
DONT DESPAIR though....I have to go now but I will link to my build thread where I show you how to easily flycut your S.O.'s so everything will fit, with a valve, a power drill, and sticky sandpaper. If you want to dig yourself it's in here somewhere. Also search google for a thread on http://www.ls1tech.com, that's where I found it.
they're cast junk.. they've been trashcan material since i had my first bird and i found the edge of the decks were brital, chewed to hell and starting to break away.. i've only used stock HO pistons twice, everything else has been aftermarket
here it 'tis..
http://www.google.com/url?sa=t&rct=j&q=flycutting%20pistons&source=web&cd=1&ved=0CCEQFjAA&url=http%3A%2F%2Fls1tech.com%2Fforums%2Fgeneration-iii-internal-engine%2F709183-how-flycut-pistons.html&ei=zMUMT-6xDsKtsQLVo-WMBg&usg=AFQjCNF_m-nki9BFuZDDrfoeSg456l9cUA&cad=rja
Yup tharr she blows!!! Really good write-up, follow it to the letter and you'll be mint. Tedious? Yes a bit...my arms were about useless after lifting the heads on and off about 2000 times LOL. But so worth it. And if you just make 'em look like what you see on H.O.pistons, go about 1/4" deep, not like you'll lose enough compression to piss you off, and using a valve that is just slightly bigger than the one that has to go there....you've got it made.
I was soooooo pumped to know that I could keep the entire original bottom end. Hehe.
for SBF guys using any type of GT40 head, it's been recommended to use chevy valves to do the fly cuts
I just picked up a set of gt40p heads and explorer intake for mine. When I saw this post I was hoping to read they would work without cutting the pistons. lol
They will with the stock cam. But you'll need GT40P headers. The plugs dont fit the exhaust manifold with the P heads. I was going to run a set of P heads on my engine but the stock manifold would'nt clear and I didnt have money for headers so I used E7s. I have a set of GT40P heads and headers I just bought last payday that will recieve big valves and screw in studs.
Tad bigger than the GT40 exhaust valve, which is of course bigger than the intake...so all your bases are covered and then some.
that's why they say to use GM valves.. lol of course valves from a specific head, but i forget what head/year exactly.. never put much thought into it, since i don't deal with the SO pistons
The need for special headers is a myth. All you need are 90 degree plug boots and you're golden. I have the P engine, and BBK headers. Instead of spending funds on different headers, I bought new plug wires with 90 degree boots and never looked back. No burnt wires either.
The plugs are close though still right? As in, no taking plugs out without removing the headers first? Granted in this day plugs ought to last you 100k.
I can swap my plugs with the headers in place.
vinnie, there are some headers that do interfere with the plugs, yours aren't 1 of them.. stock 5.0 stang headers WILL NOT work, as the primary tubes run directly into the plug's 'area'.. so you're right in saying it's false, but there's a bit of truth behind it, as some headers will interfere
Ahhh yea see I would cheap out and find stock stang shorties :hick: lol. But at least widely available ones like BBK's are good, not like there's ONE brand/style of header and you have to hunt it down.
BBK and Ford Racing headers are the only ones that I know of that fit P heads.
lol Thats what I am running now. Stock mustang shorties.
Hi, its been awhile since I've been on this forum. Nice to see its still here! So from this thread I take it that GT40P's will not work with stock SO pistons, Stock HO cam and 1.6's without valve reliefs. That sucks as I just pulled a set from the local yard. Likewise the stock mustang HO headers wont work either? Thought I saw a set work as I was googling. Oh well. I'm a little concerned about grinding valve reliefs in the stock SO pistons as the top faces don't seem very thick when compared to the 86 flat tops (with reliefs) I have in my mustang. How deep can be cut?
Everyone should read through all of this........
http://forums.corral.net/forums/5-0-5-8-engine-tech/1014187-anything-everything-gt40p.html