I've just taken possesion of my 63 1/2 Z code, 4 speed Galaxie, and I noticed the motor has C3AE heads. I assume these are the standard heads for a 63 390. Are these heads any good for a performance street motor? The motor has a 6V intake set up, and I have a set of the 390/406 hipo exhaust manifolds. Would it be worth spending some money on these heads to fit 2.09/1.65 valves and have them ported? Are they the heads with the 2.34" tall intake ports?
These heads have a smaller combustion chamber and a higher compression than some other heads, if the exhaust valve is 1.66" and the valve spring seats are machined you might find these heads on a 406. Similar combustion chamber to C1AE 6090 A heads. I am sure there is much more info on these heads but this is all I have.
They are similar to the C1AE head which is also a good head. The low risers are all pretty much the same heads with small improvements except when your talking about the J head. The J head was the best of the low risers. Your C heads would be good for a nice street engine. I'd keep them and use them if thats the way your going to go.
Yes if you want 10.5cr. I'd skip the hard seats though.
November 18 2008, 7:10 AM
The C3AE-C is listed as a "hi altitude" etc option for the 390/"300"hp, which was really closer to 280hp with the more common C1AE-A heads giving about 9.5cr on the ones I've measured.
The C3AE-C intake and exhaust ports are identical, near as I can tell, to the B9AE-B, C1AE-A, and C4AE-G heads, but smaller chambers so they will kick that 9.5cr up to at least 10.5cr and give nearly an honest "300" hp. So I'd guess you have about 10.6cr right now. Does it knock badly on regular gas? I bet it does....
The C3AE-C are a good head to add 209x165 valves, but the exhaust seat is not fully supported all the way around like the 1968 and later heads and several of us (me too) have had hard seats pop out later on, perhaps for this reason. What you might do is just clean up the exhaust ports, and leave the 203x156 valves in there. Then, if the seats pound in, which I doubt with limited use, just enlarge the seats and add the 209x165 valves later.
The thing about that 10.6cr or so on a big 4100 lb Galaxie with iron heads and cast pistons is it will likely knock, maybe even on premium - a bigger cam with wider centers might help, and with a 3.50 or steeper gear you could get away with it even in that heavy car. The factory grinds, c8ax-c at 216-228-116, or c3az-aa at 228-228-114, or c3az-k at 245-245-114 would run good with a 3.50 or 3.89 gear, the 6v intake, and those 406 iron exhausts and avoid knock if you made a practice of keeping the carbon out of the cylinders, always a fun activity and healthy for your engine, too!
Those heads were run both on 390 high altitude and with machined spring seats on 406 motors. I had a set that I ran on a .060 390 with tri power and it pinged pretty bad. The combustion chambers were 61cc. I had to go to a Comp 280h cam to get the pinging down to a reasonable level even though it still pinged if I had the initial timing at 16. I ran the timing at 12 to get away from the pinging which lost a little power. I had 427 long cast headers on it and it did run pretty decent.
61cc, that is VERY small, I think mine were about 66cc
November 18 2008, 10:07 AM
I cc-d them but cant find where I wrote it down so just a guess. Todd should measure his then, because 61cc would probably give over 11.0cr, an unhappy combo, 10.5 might be liveable with a big cam.
Ok I did some calculating and now whether Todd's combo will be ok on the street or not is going to be a function of kinda everything, so Todd you better measure everything - cc those heads, the piston dish, deck clearance. Also figure what cam and rear you want to run, a cam like the 427-8v style c3az-k will be the most forgiving but will want 3.89 gears to work right. Block the heat riser, that will help a bit and is of course essential anyway, don't run crappy exhaust gas thru that 6v intake!
guys, as always, this site is a great source of useful info. I've only just picked up the car last week, it is not running at the moment and requires a full rebuild. I will be concentrating on finishing my Thunderbolt clone first, the Galaxie will go into storage for a while. But it's always nice to know what parts you have to work with and come up with a good plan for the future.
