C3AE-6090-C Heads

[The Real McCoy]

I have recently come across a set of C3AE-6090-C heads that I am considering purchasing for my 63 Galaxie.  My understanding is these heads would have originally been on a 63 406 engine.  The heads have been in storage for many years and do not appear to have been on a running engine prior, i.e. every thing is clean including the exhaust ports and combustion chamber.  The heads do have valve spring cups which I have seen mentioned for 406 engines.  I poked around the Internet to see what was out there on this particular head and noted there was some discussion regarding the small combustion chambers and they can potentially bump the compression up to a point that with today's pump gasoline that it can be difficult to control the pinging and detonation. 

My intent is to collect period correct high performance parts and assemble an engine to replace the original stock 390 Z Code that is currently in the car. At this point I would like to leave the original engine intact and not cannibalize it.  I'm in the early stages of collecting so do not have any information on block, pistons, crankshaft.  The goal would be to start with a 428 block or 360/390 if a 428 does not surface and then put a stroker kit in whatever block I end up with.

I have 2 questions on the heads.

1.  Where do these heads fall in the FE hierarchy as far as performance?  (I understand the Edelbrock heads would be easy and not that much dollars, just rather stick with period correct cast iron heads)

2.   Is the Internet chatter about pinging and detonation with pump gas due to the small combustion chamber a real concern, or can it be addressed during the engine build?

I do have some pictures I was going to post but the file size is to large and am not sure how to crunch them down to the allowable limit.

Thanks for any feedback you can give me.

[BH107]

That casting number is very common for 63 1/2 Galaxie 390s, as well as a very short run with smaller combustion chambers for the 406. Only way to know for sure is to measure the combustion chamber volume.

I've had about a dozen sets and only 2 had small chambers. One was just under 60cc, but looked like it had been cut quite a bit. Another set I have now has never been cut and is 64cc with stock valves. They are also cut for valve spring seats, and 2.02"X1.65" valves.

On the other hand, I've had 2 sets that looked right, but were "clone" heads with 72cc chambers.

As far as performance, they are a low riser style head like the rest from that era, and with Oversized valves and a good valve job they can work very well.

Compression ratio is based on many factors, not just the combustion chamber volume. It can be worked around, and depending on the build and purpose shouldn't be a problem.

[blykins]

You are correct that all of your aftermarket heads will be head and shoulders above the C3 heads, right out of the box.  However, I have respect for the guys who want to use the old factory pieces.

I did a 427 for a UK guy, an FIA piece for his Galaxie.  I used the C3 heads and a C3 intake.  It made 510 hp and carried it to 6500.  The caveat is that the heads and intake were pretty heavily modified and flowed almost 300 cfm. 

So, you can get some numbers out of the old stuff, it just takes a little work.  That may or may not be in your budget.

As for the chamber size, you just address that during the build.  The machine work and piston selection will address the compression ratio.

[JimNolan]

I run a set of those on my 63 Galaxie, 65cc chambers with 1.65 " exhaust valves, The guy I bought them from sold me a aluminum intake for a 63 B code as well and said they came off a 406. Someone else told me the 406 head had 53cc chambers and what I had was a 390 head that was made for mountain areas of the country to increase hp on the 390's. He said they call them mountain heads. I use my car for show and travel so I don't really get into the performance part of it.  I had the new type valve seals put in it when I had them rebuilt, wish I hadn't done that, didn't need them.

[The Real McCoy]

Thanks for the quick overnight responses.

That casting number is very common for 63 1/2 Galaxie 390s, as well as a very short run with smaller combustion chambers for the 406. Only way to know for sure is to measure the combustion chamber volume.

I've had about a dozen sets and only 2 had small chambers. One was just under 60cc, but looked like it had been cut quite a bit. Another set I have now has never been cut and is 64cc with stock valves. They are also cut for valve spring seats, and 2.02"X1.65" valves.

BH107, I read this to mean all 6090C's are not created with the same size chambers...., some 406's have smaller chambers even with the same casting number.   Is that correct?  BTW, looked at my 390 heads this morning, they are 6090C's too.   So in a sense the heads I am looking at buying are probably nothing special other than through initial appearance they look as if the are virtually brand new.  I understand there is some risk in assuming all is well based off outward appearance.  If anyone has some visual tips on what to look for, good or bad, I would like to hear what they might be.  If I spring for them I will have them checked out completely but I doubt I will be able to pull them apart prior to me owning them.

Brent, the budget really hasn't been determined other than when it is done I expect will be well over the limit.  That's how it works, right?  The goal would be to have the characteristic and sound of the 406/427 instead of the typical sewing machine 390.  I am past the racing stage so it probably will rarely be pushed to the limit.  I just want it be capable of what they were back in the day.  In my meager collection to date I have managed to collect the full length iron headers and R code air cleaner, now I just need to fill in the gaps between them.....

[BH107]

Thanks for the quick overnight responses.


BH107, I read this to mean all 6090C's are not created with the same size chambers...., some 406's have smaller chambers even with the same casting number.   Is that correct?  BTW, looked at my 390 heads this morning, they are 6090C's too.   So in a sense the heads I am looking at buying are probably nothing special other than through initial appearance they look as if the are virtually brand new.  I understand there is some risk in assuming all is well based off outward appearance.  If anyone has some visual tips on what to look for, good or bad, I would like to hear what they might be.  If I spring for them I will have them checked out completely but I doubt I will be able to pull them apart prior to me owning them.

Yes, there are at least 2 different combustion chamber sizes with the same casting number. Lots of people out there think or advertise that they have 406 heads, when in fact they are normal 63 390 heads.

The real 406 C3AE-C seem to have been made in a very short time period, and I've only documented 2 production cars that had them, both special order cars built in the spring. Our Nov built G code has C2SE-C cast in October, and I've seen the C2SE-C cast as late as November. I've also seen a reference to the C3AE-C 406 head being used after 12-25-62, which would be a real small window for 406 cars as the 427 was starting into production about the same time. Rick Kirk told me that most of the 406 version were sold over the counter, and that there wasn't a continuous run of those heads.

Of course none of this is really relevant unless you are restoring a 406 car. Just have the combustion chambers measured and plan your build accordingly. If it were me I would only buy them if the price was really good, as while they might look nice you don't really know how good the work was or if the spring package will work with the cam you choose.

[chris401]

I have the C3AE-C 390 heads. No spring cups and the combustion chambers match the D2 and C8 heads I have. Below is a link with some measurements. I have seen both of the true 406 and the smaller chamber "Denver" head. They are easy to tell apart looking at the combustion chambers side by side. A dished piston with good quench will work well in the iron head.


http://www.mustangtek.com/heads/Heads.html