I have a question for you FE gurus.

I have a stock 352 with a four barrel cast iron intake and Holley, headers, 3" stainless exhaust and electronic ignition. It runs well and I drive it as much as possible.

My question is this.
I read that the 360 heads are the same as the 390 heads. I was given a set of heads off of a 360 it pretty good shape.
Would these heads have bigger valves than the 352 and would it be worth my time and effort to install them on the 352?
I am working on getting gas mileage.

Thanks in advance

jd

 

For best gas mileage sounds like you have done alot of the best improvements already. Small intake ports with small valves would have the highest flow velocity, which should be best torque meaning better gas mileage. I don't know about valve sizes, but you might be best off with the heads you have. Give them a fresh valve job with pocket porting and some smoothing work on the exhaust ports should help. Set the piston to cylinder head quench distance at about 0.035-0.040 and dynamic compression at about 8.0:1 would make the engine most efficient.
Have you looked at the rear axle ratio? A cluth type fan driven by the water pump has been said to reduce the work load on the engine. Use one of those oxygen sensors on your exhaust to set the fuel air mixture the best it can be. Just some ideas.

 

Nope. They all have the same size valves. 2.02" intake, 1.55" exhaust.

For the record, for mileage, you want smaller valves, not bigger. Bigger gives you more power.

 

If all you did was slap on a set of 360/390 heads to your 352, you would actually lower your compression. Think about it for a minute. You have a smaller piston trying to compress a now larger quench area (I don't know if I used the term quench correctly). The head has a larger cylinder diameter and would create more wasted combustion space.

 

Most standard 352 / 360 / 390 heads had the same combustion chamber volume. There were quite a few part numbers, but most are pretty close in combustion chamber volume. High performace heads are where it gets interesting. For the most part, ford controlled the compression with the pistons. In stock form, 352 pistons will usually be closer to the deck at TDC, and lack a dish.

OBTW, quench = space between piston and cylinder head surface at TDC.

Edit:
Check this out-
C4AE-G heads, used on 352's and 390's, 71.2 - 74.2cc chambers.
D2TE-AA heads, used on late 360's and 390's, 68.1 - 71.1cc chambers.

In this case, the 360/390 heads would actually give you 352 more compression! Not a whole lot, but an increase.

 

The cylinder diameter of the 352 was smaller than the 360 as I have come to understand, right? If so, the 360/390 head would have a larger diameter thus increasing the combustion space. Straighten me out if I am wrong. It just seems to me that one would end up with lower compression, lower ci and lower hp.

The physics would seem no different than when I bored out my 360 block by .030 and gained about .3 or so compression because the pistons were able to compress the gasses into the (now) smaller head by just a little bit. This is all a matter of thousandths....

Why not bore out the 352 to the same diameter as a 360 or 390 and take full advantage of the ci?

 

Cylinder heads dont have a diameter. That is in the cylinder block.

 

my .02 cents, if the 352 has the older big port heads, keep them and don't worry about the chamber size. Throw, in a shim gasket and call it good.

 

WOW
Great information. After taking it all in, I think I am staying with the stock heads. They were rebuilt about 50,000 miles ago and I just replced the seals so they are tight.
FEmtnmax:
I have also bumped up the rearend gears to 3.00 from 3.50. I might have to concider the fan conversion, as I am running just a normal flex fan.

You guys are a wealth of information I have just been schooled on heads. I will check to see if I can find some casting numbers so I can determine if the valve size is the same. If they are I may just do as you guys said and polish and port the 360 heads for a little better flow.

Thanks again guys..

This place has been one of the best learning tools I have ever had. There is no replacement for good old hard knocks knowledge.

jd

 

Another question for you gurus.


I have heard you guys talking alot about intakes.
I believe My father got this manifold from a 410.
The casting numbers are as follow....first number 3H9: second number C4SE9425A
Is this any kind of special four barrel manifold or just your plan old run of the mill manifold?

Is this a good manifold to keep on my stock 352?

Thanks guys

jd

 

Got me stumped on that one. Does it have a large "S" cast into the runner, before the part number?

 

It's a plain old run of the mill iron 4bbl lowriser intake. Found on the 352 and 390's so it will be fine on your stock 352. 3H9 is the casting date of 63/Aug/9th. It's pretty common to see a earlier date code on a later casting number part back then. The intake has a 64 casting number and a 63 date code if you noticed. The "S" intake castings were 66 and later.

G.

 

Ok Thanks guys.
That also tells me it didn't come off of the 410 my Dad had.

jd

 

Where can you get a listing of the FE heads with the casting numbers and what the differences are? The heads on my block are stamped 6E25 right in the middle.

 

Those are the date codes. 66/May/25. Most head casting numbers are between the center 2 spark plugs. Date codes are either between the center two valve seats or by the casting numbers. Look for a C6AE-6090-R type of number. That number is just an example and yours might differ. Woody's Fairlane site has a list of FE head castings www.woodyg.com

G.