C8AE-H heads
 

[updated:LAST EDITED ON 01-Jan-03 AT 11:46 PM (EST)]I have seen some folks talk like the C8AE-H heads are desireable. I have read where they can be made into Cobra Jet heads by going to a larger valve size. I have also seen them referred to as GT heads.

I am interested because I have a set of these on my 68 390.

On the other hand, George Reid, in his book, "How to Build Max Performance Ford V-8s on a Budget", does not mention them specifically as a high performance potential head, in fact, they have the same CC, port size, and valve size as the C8AE-A, C8AE-B, or for that matter, the C8OE-A or C8OE-B, which he DOES list as a "high performance" head.

Can anyone straighten me out here?

Thanks!

C8AE-H heads
 

A guy here named econodrag used to race a 1970 F-100 Longbed with a set of unported C8AE-H heads on top of a 9.5:1 390. He ran a 8.65 in the 1/8 mile (equivalent to a 13.0 - 13.5 in the quarter) with 4.56 gears, slicks, 3500 stall and some off the wall erson hydraulic cam. His truck did only weigh 3400 I think. I saw the heads with my own eyes and they looked like regular rebuilt heads. They do not flow as good as CJ heads do even with the bigger valves but it takes very little work to get them that way. There are only minor differences in most all FE heads that came on the 390 and below. I have never heard anyone call a particular casting bad before.

C8AE-H heads
 

>A guy here named econodrag used to race a 1970 F-100 Longbed
>with a set of unported C8AE-H heads on top of a 9.5:1 390.
>He ran a 8.65 in the 1/8 mile (equivalent to a 13.0 - 13.5
>in the quarter) with 4.56 gears, slicks, 3500 stall and some
>off the wall erson hydraulic cam. His truck did only weigh
>3400 I think. I saw the heads with my own eyes and they
>looked like regular rebuilt heads. They do not flow as good
>as CJ heads do even with the bigger valves but it takes very
>little work to get them that way. There are only minor
>differences in most all FE heads that came on the 390 and
>below. I have never heard anyone call a particular casting
>bad before.


Thanks Ratsmoker,

I remember seeing econodrag on the boards, he stopped racing the truck about the time I got on the board, I think. As soon as we get search functionality back, I'll look for his posts.

The info I have from my build sheet data tells me that mine is 8.6:1 compression. When you say his was a 9.5:1, does that mean he built it to that compression, or that it came that way? If he built it, I'm assuming he did so either by milling the heads, decking the block, different pistons, thinner head gasket, or some combination of those factors.. now I'm curious...

So, I can make my heads flow as well as CJ heads with the larger valves and "very little work" - I'm new to this, so I need to know if you are referring to port and polish work or something else. The Reid book I mentioned notes that the C8AE-H heads are Thermactor type, which as I understand it, means they have a hump in the exhaust port that can be ground away as part of the porting work - especially since my engine has an automatic transmission and therefore uses the IMCO system to handle exhaust emissions.

Am I making any sense?

Thanks!

C8AE-H heads
 

When you put in TRW forged pistons, part number L2291F, you'll get about a 9.5:1 compression ratio.

I bought those heads from econodrag. They had seen pretty hard service. I'll be putting in new guides, valves, etc. Stock size valves only, as my machinist advised me that they are more likely to crack the thin area between the valve seats when installing the CJ valves.

--Matt


1972 F250 Custom Sport Camper Special 4x2 360 2v C6 3.73
Some day hope to shorten to a 104" wheelbase as part of a Broncification project
My FTE Website -- http://www.clubfte.com/users/mlf72f250/index.html
My Galleries -- https://www.ford-trucks.com/user_gallery/displaygallery.php?userid=1108

C8AE-H heads
 

Matt, you may need a new machinist. There is no reason to fear putting the 2.09/1.65 valve combination in the C8AE-H heads. We have done several sets and had no trouble. You ARE putting hard seats under the exhaust, aren't you ? DF

C8AE-H heads
 

DF,
Thanks for the comments.
Yes, we will be putting new seats under the exhaust for sure.
The heads had seen some pretty hard service and the intake seats were sunken a little. I think we were leaning towards intake seats, too. Maybe that's where the cracking comment came from -- seats on intake and exhaust and there's not much original materal left between them. Also, my original requirement was that they go 100k miles without trouble.

I guess one reason that swayed me to be more conservative was that the 2.09 intakes gained me only a few percent in Desktop Dyno.

But I'm still open to putting the larger valves in.

--Matt


1972 F250 Custom Sport Camper Special 4x2 360 2v C6 3.73
Some day hope to shorten to a 104" wheelbase as part of a Broncification project
My FTE Website -- http://www.clubfte.com/users/mlf72f250/index.html
My Galleries -- https://www.ford-trucks.com/user_gallery/displaygallery.php?userid=1108

C8AE-H heads
 

First off, I agree with DF completely. No reason in the world bigger valves will hurt the head. I wouldn't wory as much about the 2.09 intake upgrade as I would the 1.66" exhaust. You will get twice as much gain by going to the bigger exhaust as you will the intake. FE's arent starving for air, they just have a little bit of a hard time getting rid of it.

C8AE-H heads
 

[updated:LAST EDITED ON 04-Jan-03 AT 06:36 PM (EST)]I guess I remember trying that.
The exhaust valve diameter had a bigger effect with desktop dyno.
But then I pushed the model and tried 3 inch exhaust valves.
And that had huge improvements. Then I concluded that the model may have bugs in that area.
Maybe I was wrong to conclude that.




1972 F250 Custom Sport Camper Special 4x2 360 2v C6 3.73
Some day hope to shorten to a 104" wheelbase as part of a Broncification project
My FTE Website -- http://www.clubfte.com/users/mlf72f250/index.html
My Galleries -- https://www.ford-trucks.com/user_gallery/displaygallery.php?userid=1108

C8AE-H heads
 

C8AE-H heads
 

3" exhuast valves would be awsome. Except for that one bug of being in the next cylinder to work(for us FE'ers anyway).

C8AE-H heads are very good heads to make into performance heads. hardened seats and 2.09 int & 1.65 exh valving is a must though. But, if you do not run headers the exhaust valve upgrade is all for not. The stock exhuast on these trucks really really restrict airflow. Add a decent cam and carb and you could be well on your way to some real fun, at a low buck price.


Scotty

C8AE-H heads
 

I'm getting ready to put in the 2.09 valves.
Any machining advice?
I need to change the intake seat angle to 30 deg to work with the 29 deg of the valves.

Ijust got a 360 with 390 heads (c8ae) to replace my 300. I'm told I need to make sure that I dont have pasenger car heads or my Hooker super comps wont fit. How do I find that out??

The seat angles are different for a reason. Leave em that way. The different angle creates the seal. And as for your questions about these heads that didn't seem to get answered----there were at least three different C8AE-H heads. First was the std, non thermactor head (the Thermactor bosses aren't drilled and tapped) then the Thermactor version (which are drilled and tapped) then there's the GT version which was used on 68-70 GT390's, these have the 14 bolt exhaust pattern, where the others had an 8 bolt pattern. The C8AE-H heads were carried on as the D2TE heads from 68-76 but had induction hardened exhaust seats. The intake ports are filled in at the bottom vs the earlier heads, that's why many think the port is smaller, it really isn't, as the earlier heads had a sharp jump upwards inside the port where it narrowed down to about the same dimension as the C8AE-H heads. Ford simply raised the port floor as opposed to the earlier heads, they did the same thing with the 427 medium riser heads, so apparently it's not a step backwards.

I will add a little... i am currently running the C8AE-H heads on my 418FE... I had 2.09/1.65 valves installed and did a home port job on these heads. My '66 F100 currently runs mid 12's (12.66 in the 1/4 and 7.94 in the 1/8). that should tell you that these heads can breath just fine, when built right. Currently the truck still spins a little at take off. So i am sure it will run faster as soon as I get back to the track!!

so these heards are the better ones of the bunch? because i have the c8ae-h heads in my truck.
polcat, did you just do the exhaust ports on ur heads when you did this? i herd if you just get rid of that hump"" they flow alot better?
thanks
Mitch