Any issues with bolting E7's to vintage motors?

Desert Stallion · Dec 13, 2003

Just curious. I've got an extra set of E7's I've cleaned up and ported, and my aunt's 67 Fastback is perty much stock, save for the '68 302. Just wondering if the E7's will bolt on without too much hassle, and if they're worth the fuss over the stock heads.

Thanks all.

D.Hearne · Dec 13, 2003

Yes, they'll bolt on wothout problems, but yuo will see a drop in compression, about a full point to a point and a half

Bullitt · Dec 13, 2003

you can always get them decked a bit to raise that compression back up.

don't go too far though as you'll have to mill the manifold then.

Desert Stallion · Dec 13, 2003

What's the combustion chamber cc on the old heads compared to the E7's? Around 5xcc to the E7's 69cc?

Damn, didn't remember that. Question remains, would the higher flow of the ported E7's compensate for the loss in compression?

D.Hearne · Dec 13, 2003

Your 68 heads will either be 54 or 58 cc's depending on the casting#'s and the production tolerances. The E7's run about 63-65 cc's. According to Ford, you can mill them up to .040 without alignment problems. I milled a set of Canfields, .060, the block was decked .005 and I used a Felpro race head gasket and had to mill my intake. How much you may need to mill the intake will vary. It's best to ( as well in pushrods also) to do the final assembly, then set the intake down without gaskets, then using a feeler gauge, check the fit before milling the intake. When I bolted the milled Canfields in place, I tried the Ford A321 intake I had on before the head swap and the Edelbrock Vic Jr. I ended up using and the fit was different between the two. What you need to check is how the manifold to head faces line up and the distance under the intake to block gasket rail.

Desert Stallion · Dec 13, 2003

Well, I honestly have no interest in having the heads milled. The idea was that since I had the ported E7's laying around, that they would be a bolt-on upgrade over the stock heads.

If I'd actually lose performance from that drastic of a losss in compression then it's not worth it. I just kinda thought the better flow characteristics of the newer ported heads would be of some benefit.

D.Hearne · Dec 13, 2003

I did the math and if your heads now are 58cc and the E7's are 64cc then you'll get a .6 point reduction in the comp ratio. If your motor has the 54 cc heads, then the drop will be just a hair over 1 point. It's hard to say if you will see a decrease in performance or not, yes the E7's breathe better than the older heads, especially if you port and polish them. If you do then you just may see some gain, just a question of how much, is the question. You have to ask yourself : Is it worth the trouble? Another side benefit will be the hardened seats in the E7's. That's if they haven't been overworked and had the seats ground down so far as to get past the induction hardening. You will also be able to take advantage of a set of "Cobra" 1.7 ratio bolt down type roller rockers ( I bought a used set for $125) for the E7's, that'll net you about 15 hp from the friction reduction.

thumper460 · Dec 14, 2003

totally... get the E7s shaved .030 and the compression will be back up there!! the power loss with the compression will kill ANY benifit of the ported heads!! Back in the 70s I pulled off my ported 289s and put on a set of C90E W heads with the 1.94/1.6 valves... the trick thing in the 70s!! I lost .8 in the qtr!! abd that was shifting at 7500 rpm ( where I did with the 289s) Compression loss will kill almost everything!!

Just me..............................

Thumper

Desert Stallion · Dec 14, 2003

Okay, sayin' I was to have the heads machined down .03", would that cause pistion to valve clearance issues with the stock valves, cam, and pistons? What about those heads on a stock 5.0L motor, assuming stock cam, heads and pistons?

D.Hearne · Dec 14, 2003

You will have no clearance issues. You would have to go to a monster of a cam before worrying about the valves kissing the pistons.

Desert Stallion · Dec 14, 2003

So milling the heads will take the combustion chamber volume from 64 to somewhere around 58-60cc?

Hmm, startin' to sound kindy interestin' all of a sudden.

68GEETEE · Dec 14, 2003

if I am not mistaken the E7 valves are the same size as your older heads 178/146. I think you are gonna need to increase them to really see a worthwhile gain in performance. I think you would be better off with some cast iron Roush heads that are CNC machined and already have the larger 190/160 or 202/160 valves. Just my two cents.

Desert Stallion · Dec 14, 2003

Desert Stallion said:
The idea was that since I had the ported E7's laying around, that they would be a bolt-on upgrade over the stock heads.

If I wanted to spend money on heads, I would, but I've got these already, already ported by me, so buying new heads would defeat the entire purpose of this excercise.

D.Hearne · Dec 14, 2003

Milling them .030 will reduce the chambers about 5 cc's according to Ford.

68GEETEE · Dec 14, 2003

what size valves are in your E7s?

D.Hearne · Dec 14, 2003

The E7's do have the same size valves , but they DO flow better than the old heads, they have hardened seats, and like I posted before, he could take advantage of the bolt down "cobra" roller 1.7 rockers. There's lots of good used sets out there, cheap horsepower!!

68GEETEE · Dec 14, 2003

wouldnt it defeat the purpose of porting and polishing by not upgrading the valves too? Just asking, so I can learn.

fastback brian · Dec 14, 2003

must drill six 1/4 inch coolant holes in block to realign with new head.

D.Hearne · Dec 14, 2003

68GEETEE said:
wouldnt it defeat the purpose of porting and polishing by not upgrading the valves too? Just asking, so I can learn.

No, you will gain SOME flow, just not as much as you would with bigger valves and bowls. Just removing the EGR bumps from the exhaust ports, and blending the bowls, removing any other casting flash and port matching helps a lot. A bigger cam would be a big help too. But the switch in ratio with 1.7 rockers does a little to improve the stock cam's lift #'s, the biggest gain in going to the Cobra roller rockers is the friction loss. I've read that you can see a 10-15 hp gain from the extra lift, the friction reduction, and the equalization of the lift at the valve from the rockers not flexing.

Desert Stallion · Dec 15, 2003

fastback brian said:
must drill six 1/4 inch coolant holes in block to realign with new head.

Really? Why hasn't anyone else mentioned this? Where does the old head have coolant passages that the new ones don't?

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