Most-Desirable Heads

[Admiral]

Just curious, what are the most-desirable cast-iron cylinder heads out there? Are there any to keep an eye out for? Which ones offer the most compression? I've read that EAC heads are perhaps the best (depending on application) but what about earlier ones with the center water outlet?

[Seth Swoboda]

I'm a simple guy, I like the 59A engine and it's 59A or 59AB heads.

[flatheadmurre]

Are we talking factory heads or any cast iron ones ??

[Ol' Ron]

EAC are about the worst head you can uz.

[jimTN]

The 59AB heads have the best comp. and design for 48 and earlier 24 stud blocks in my opinion and from what I have read for specs in the service bulletins.

[Bored&Stroked]

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If you're looking for compression, then usually the early 81A heads are a great head to use. Though, with high-lift cams, you may need to fly-cut the valve pockets. I've heard that the ones marked with a big 'A' are about as good as it gets . . . though there are supposedly some marked with an 'S' for 'Special' - that are even rarer. (Police units?).

I've never built an engine with cast-iron heads, though I've ran a few - so this information is not from building experience!

[Dave/Green Bay]

Ol' Ron:
What about the EAB heads?
Thanks Dave/Green Bay

[rotorwrench]

EAB heads aren't bad heads but they are more suitable for the 8BA family of engines unless you need coolant ports on the front of an early motor for some reason. There were what they sometimes refer to as Denver heads (high altitude). They are relatively rare but there are likely some still out there.

[aonemarine]

But is there really any difference in the eac and eab once you wack .040" off the eac heads?
What is the cc's of the early 59a heads anyway??

[Ol' Ron]

I think alittle measuring is in order here. The EAC has the smallest stock combustion chamber. I remove .040" off of this and use a Dremel to shape the chamber for .045" pston to head clearance. This gives me 8.2 CR with a .050" head gasket. However this will not clear the L-100 cam or any other HI Lift cam. Again you have to do some measuring. But this makes a fine running engine with goo power, throttle response and economy.

[aonemarine]

Ol Ron, did you mean the eab heads you wack .040 off or. ???

[Tim Ayers]

Originally Posted by Ol' Ron

I think alittle measuring is in order here. The EAC has the smallest stock combustion chamber. I remove .040" off of this and use a Dremel to shape the chamber for .045" pston to head clearance. This gives me 8.2 CR with a .050" head gasket. However this will not clear the L-100 cam or any other HI Lift cam. Again you have to do some measuring. But this makes a fine running engine with goo power, throttle response and economy.

This is were grinds by Clay Smith or Winfield could help. Most are under .325" lift, but give you are better lobe profile over stock.

[40 Deluxe]

Originally Posted by Ol' Ron

I think alittle measuring is in order here. The EAC has the smallest stock combustion chamber. I remove .040" off of this and use a Dremel to shape the chamber for .045" pston to head clearance. This gives me 8.2 CR with a .050" head gasket. However this will not clear the L-100 cam or any other HI Lift cam. Again you have to do some measuring. But this makes a fine running engine with goo power, throttle response and economy.

I think Ol' Ron's mention of the EAC head is a misprint/typo. This is a Mercury head with large chambers to keep the compression low enough for regular gas with the longer 4" stroke. I think he meant the EAB head used on Fords of that era being the best head. I remember back in the day if you had a '49-'53 Merc you swapped to the EAB Ford heads for more compression and power.

[flatjack9]

I've got 81A heads on my 276 in engine. I have a Winfield SU1-A cam and they clear the chamber without a problem. Had to radius them a little because of the change in valve location.

[aonemarine]

I thought thats what he meant. Just making shure there isnt some strange difference in the transfer area or something. Looking at the eab next to the eac they look identical except the pocket for the piston isnt cut as deep.

[meric42]

According to the Ford Service Bulletin, sunject No. 6000, dated December 22 1947, the head with the smallest combustion chamber is the 81AS series with a capacity of 60 - 62 CC giving a compression ratio of 8.0 - 1 on a stock 239 engine.

[scooder]

Regular 81A heads have a 80-81cc chamber, as above there are the 81AS head that's got 60 cc, but they are rare.
59AB heads are the easiest heads to find with higher compression,with the center water outlet, they have a 76cc chamber.

Not sure where the 81A head gives you more compression came from, I've cc'd aluminium and iron 81 A heads, they all came in at 80-81cc.
Martin.

[Ol' Ron]

Yes, I made a mistake, I ment the EAB heads have the smallest chamber. When I wrote my book I measured dozens of heads of all types and found them to be all over the place. I even found a set with 115cc. I think they were a set of 8RT's but not sure, that was a long time ago. Yes Clay Smith made some great cams.