Are the GT40s worth it?

[Ike83]

My buddy and I were at the junkyard today, and we happened to pass by a 5.0L Explorer. Now, he has a 5.0L Explorer (I'm not sure which year), so we stopped for a second and he ended up pulling a few things off of it for his truck. Since the Explorer was "fresh in" to the junkyard, it still had the upper and lower intake, and also the heads were still intact.

This has led me to a few questions:

1) Would it be beneficial to obtain these heads and port them, and would they ultimately flow better than the ported E7s that are currently on my foxbody?

2) If I do obtain them, would they fit my vehicle without any issues? Specifically, will they fit with my aftermarket headers, and also, will there be any fitment issues with my 1.7 roller rockers?

3) How hard is it to perform a 3-angle valve job?

 

[LarsD]

Yes I would get them if you can get them for a decent price. GT40P heads flow better then then E7's easily. I'd get the heads and intake. The headers may/may not work, depends on the brand. When I had mine I had the FFRP "P" headers and they were some of the best fitting headers I've ever used.

 

[Ike83]

Yes I would get them if you can get them for a decent price. GT40P heads flow better then then E7's easily. I'd get the heads and intake. The headers may/may not work, depends on the brand. When I had mine I had the FFRP "P" headers and they were some of the best fitting headers I've ever used.

What if they're just the regular GT40s (not the GT40p's)? Are the regular GT40s still worth it? Also, will they fit my 1.7rr's, and how hard is it to perform a 3-angle valve job on a set of heads?

 

[mob]

Some explorers had the gt40 heads, I cant remember what years. Check to see if they have 3 or 4 vertical bars in the front of them.

Even if you just bolt on the stock gt40 or gt40p heads they will outflow e7's. (You will need to install new valve springs because the stock gt40/p springs cant even hold the stock mustang cam) It would be a good idea to get them check out at a machine shop and probably have a little milling done on them, valve job, and install new springs. You can port them if you want but that bumps the cost up.

 

[Ike83]

Some explorers had the gt40 heads, I cant remember what years. Check to see if they have 3 or 4 vertical bars in the front of them.

Even if you just bolt on the stock gt40 or gt40p heads they will outflow e7's. (You will need to install new valve springs because the stock gt40/p springs cant even hold the stock mustang cam) It would be a good idea to get them check out at a machine shop and probably have a little milling done on them, valve job, and install new springs. You can port them if you want but that bumps the cost up.

So, obviously I'll have to get new roller rockers and valve springs for the GT40s then, right? The current aftermarket springs and roller rockers that I have on my E7s won't work at all on the GT40s, will they?

 

[mob]

You dont need new rockers, just new springs, the rockers on the gt40's and e7's are identical. If you plan on running the stock cam just swap your springs and rockers from the e7's over to the gt40's and you will be fine, just dont run the stock gt40 springs. Make sure to mark each rocker, valve and spring/retainer as they come out and put them back on the gt40's in the same orientation if you end up doing this.

EDIT: just saw you have aftermarket 1.7's and springs, just swap those over to the gt40's they will work.

If you plan on getting a valve job done, milling, and porting, you need to leave all that up to a machine shop, but machine work on heads adds up VERY quickly, and a set of heads that were supposed to be a bargin turn out to be a hole in your pocket. If your going cheap keep em cheap, if you wanna go all out go with aluminums, its not worth spending 500 bucks on a set of gt40's in the end of it all.

 

[lincoln+ford]

You dont need new rockers, just new springs, the rockers on the gt40's and e7's are identical. If you plan on running the stock cam just swap your springs and rockers from the e7's over to the gt40's and you will be fine, just dont run the stock gt40 springs. Make sure to mark each rocker, valve and spring/retainer as they come out and put them back on the gt40's in the same orientation if you end up doing this.

EDIT: just saw you have aftermarket 1.7's and springs, just swap those over to the gt40's they will work.

If you plan on getting a valve job done, milling, and porting, you need to leave all that up to a machine shop, but machine work on heads adds up VERY quickly, and a set of heads that were supposed to be a bargin turn out to be a hole in your pocket. If your going cheap keep em cheap, if you wanna go all out go with aluminums, its not worth spending 500 bucks on a set of gt40's in the end of it all.

Excatly i almost fell and said yes when i had the machine shop cut my heads for dual valve springs.But then the idea of not dirivng my car cuz i wanted.The heads to get a valve job/baked/washed/resurfaced so i just said no.I only paid $125 for them so yeah which isnt the best i kind of paid alot.But hey they only had 60k.

 

[2000xp8]

Mob is right, becareful with the finances on them.
Remember the set of heads is worth about $300 on the street.
Heads $300
Springs $100
Valve job $200
Headers if they are P's $200

While i understand you may get them cheaper, they still have a $300 value, so if you get them for $50, they could be sold and you could put $250 more towards aluminum heads.

Gt40y aluminum heads can be found new for $699 (that's what i payed for my set, that i sold).
Gt40x heads (better than y's) i have seen for $899.
Then there is always used aluminum heads to be had in the $800 range.

My point is, if you get them cheap, slap some springs on them and run em, just don't blow too much money on them or you will be a grand deep and making 20rwhp less than people who payed the same for aluminum heads.

 

[Ike83]

I was going to port the head myself. My buddy and I both have dremmels, and we've ported and polished several pieces in our day. I also have a 2004 WRX (2.0L turbo), and I've ported the intercooler, TB, and uppipe at this point. Now, I know that I'm going to need to be a little more careful in porting a set of heads, but I'm really not scared of the notion by any means.

I just have a few questions:

1) As far as I understand, the intake ports can be gasket matched, correct? Whereas the exhaust ports can be widened out a little bit, but I don't necessarily want to gasket match the exhaust side (on a N/A vehicle), because then I'll run the risk of losing back pressure. Is this true so far?

2) The guy I bought my Mustang from did the head work himself, so I'm confident that I could perform this procedure as well. However, is a 3-angle valve job something that can be done in a garage with a dremmel, or is it something that has to be accomplished by a machine shop (be honest here, I'd rather do the work myself if I can). Also, if it can be done at home, I could always reference off the E7s to get an idea of how it's supposed to look.

3) Besides swapping over my roller rockers and springs, are there any other parts that I'm going to need to grab off of the Explorer while I'm there today, besides of course the heads themselves. I deleted my EGR, but are there any other little trinkets that I'll need to make sure I obtain, or are the heads themselves all I need (meaning I can just slap the heads on and hook 'em up with no special types of modifications to make them fit).

 

[2000xp8]

You can't do a 3 angle valve job at home. It requires precision.

 

[Ike83]

Alright, we ended up pulling the heads off of the Explorer, so my questions are now going to pertain to the process involved with porting and polishing them.

How hard is it?

I've ported and polished many other things in my day, just not a pair of heads. The way I see it (or so I've heard), I'm going to simply port the intake side to match the gasket. Is this right?

Also, is there anything I need to watch out for when doing this? Or is it as simple as opening them up, and polishing them to a smooth finish?

 

[rbonella]

port matching and porting are two intirely different things. I would recommend buying some junk heads and practicing for a while. There is a reason why fox lake charges so much for great port work. You can't go in there and start taking material off, or hogging things out. I have never ported heads so I can't talk with experience, but if I was having some heads ported...I would spend the money to have a professional do the work. Like mentioned above, you can easily spend A LOT of $ porting, where in the long run you should have simply bought some alum heads. My friend started porting his e7's (he's an idiot for the record) and ended up going through the water jackets.....ruined! Take your time, ans weigh out all your options thuroughly

 

[90mustangGT]

Porting with a dremel or even die grinder through iron is going to be a daunting, time consuming task.

I know many people with E7's who simply port matched the intake, and ground down the EGR humps on the exhaust side and had pretty good results and not too much work. Do the same with the GT40's and then get the valves reground and lapped in good, better springs and have some fun at a low cost.

 

[mob]

You can port your heads with a carbide bits, I did it to mine and spent most of the time on the bowls. I grinded down the valve guide buldges and rounded out the bowls. Also removed the smog bump in the exhaust. I didnt even touch the intake ports. I did mine with a dremel because my die grinder wouldnt spin fast enough (I dont think my air compressor was good enough) Took me a few days to get both heads but i was satisfied with them.

 

[Maryland Stang]

I agree with Mob. You really don't want to gasket match anything. There is a huge misconception that a whole lot of people subscribe to. If you want to you can port match but it really only needs to be done on the outside radius'. If you get a Fel-Pro 1262-S3 gasket and try to gasket match to that all you'll end up with is a intake runner that's bloated in the middle. You'd want to just try to match the ports up. Nothing more. I once saw a set of aluminum big block Chevy heads ($$$$) that has been virtually destroyed by gasket matching. The guy found the largest port intake gaskets he could and then ground on the heads to match it. He had this huge bell shaped port that was probably the vilest flowing piece of junk in the world.

I took the advice of one very, very respected engine builder (CI) over at the Corral and left my ports alone completely. I only had the machine shop work on the bowl and they did a great job there and a little ways into the runners. The rest of the runners they left alone.

The only time I would say it's okay to work on the ports of a street car is if the intake manifold ports are larger than the head ports. Then I would just match the ports up.

 

[57fairlane]

Then there is always used aluminum heads to be had in the $800 range.

no kidding, I bought a set of used windsor jr aluminum heads for $800 . . . I had to drive 2 hours to get them but they were fresh and didn't need any work.

I am all about some garage built stuff but if you don't have a die grinder/good 220v air compressor/carbide bits I wouldn't bother unless you don't have a job/have tons of free time.

The first set of heads you do will easily take twice as long as ones after you get the hang of it. I have done 5 sets of e7s and I still probably have about 5-6 hours in a set of iron sbf heads and thats with putting them on a bridgeport first.

 

[Ike83]

I agree with Mob. You really don't want to gasket match anything. There is a huge misconception that a whole lot of people subscribe to. If you want to you can port match but it really only needs to be done on the outside radius'.

When you say outside radius, are you referring to the tiny sliver of metal that you can see hanging over the gasket when the gasket is placed over the head?

If you are, then that's really all I plan on doing. I plan on getting rid of that little lip, and then polishing off the rough surface inside the ports. I'm not really planning on "hoggin anything out", rather I'd prefer to just smooth things out and git rid of the rough manufacturer's surface, if you know what I mean. That way the air travels smoother down the ports, instead of against the rough surface that undoubtedly hinders velocity.

Would I be alright in this case, if my intentions are only to do minimal work to the heads, instead of ripping through them to see how far I can go?

If you get a Fel-Pro 1262-S3 gasket and try to gasket match to that all you'll end up with is a intake runner that's bloated in the middle. You'd want to just try to match the ports up. Nothing more.

1) Will the gasket that's currently on my 'E7 heads to Cobra intake' be the same gasket that I'll need for the 'GT40s to Cobra intake'?

2) Also, my lower intake is also ported and polished. Will I need to match the intake ports on the GT40s to the ports on my lower intake?

 

[Maryland Stang]

When you say outside radius, are you referring to the tiny sliver of metal that you can seen hanging over the gasket when the gasket is placed over the head?

1) Will the gasket that's currently on my 'E7 heads to Cobra intake' be the same gasket that I'll need for the 'GT40s to Cobra intake'?

2) Also, my lower intake is also ported and polished. Will I need to match the intake ports on the GT40s to the ports on my lower intake?

Again with the gasket. Don't worry about the gasket. Take that completely out of the job. Measure the intake manifold ports and the head ports. If the intake ports are bigger than the head ports then you have a problem. Otherwise leave them alone.

If you had an engine that you were seriously racing in the NHRA or NMRA then you should worry about making sure the ports are perfectly matched so you could get that last 5 horsepower that port matching provides.

I would use (and did) the gasket I referenced above. It is a steel core gasket and it can't be sucked into the intake ports. There have been too many cases of normal gaskets getting sucked into the ports.

 

[Maryland Stang]

Here. If you want to properly match the ports follow the instructions in this article. Any other method is just a waste of time since no one ever bothers to make sure the head and intake ports line up properly once they're bolted down.

Port Matching - Intake & Head Porting - Tech - How To - Circle Track

 

[Ike83]

Again with the gasket. Don't worry about the gasket. Take that completely out of the job. Measure the intake manifold ports and the head ports. If the intake ports are bigger than the head ports then you have a problem. Otherwise leave them alone.

So, you're saying forget the gasket altogether. What's most important is simply making sure that the intake ports match the head ports...period...gotcha.

Now, from what I've read so far (and I haven't gotten to your link yet), porting the heads isn't so much about removing material, as it is about optimizing the ports to increase air flow.

Next question, can I perform this procedure with a dremmel and some carbide bits?