Canadian Heads

[jjk]

Doing some work with a buddy and came across a pair of mismatched heads. Can anyone give me the rundown on what the difference could be between the two?

[Newc]

C8BA Ford, C8CM-B Merc; Merc heads were supposed to have a larger combustion chamber in the USA. Compensating for the extra stroke. Canada ?? Newc

[petehoovie]

Originally Posted by jjk

Doing some work with a buddy and came across a pair of mismatched heads. Can anyone give me the rundown on what the difference could be between the two?

[tubman]

Those look pretty good from what I can see (no combustion chamber pics). They can be made functionally the same with a little milling and grinder work to bring the "squish" (over the piston clearance) and chamber size to consistency. You could also "clean up" the markings, but that would be a personal choice.

[jjk]

great , so there's two different combustion chambers?

[38 coupe]

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Originally Posted by jjk

great , so there's two different combustion chambers?

Yes. The shape of the combustion chambers will be very similar, the Mercury head (the one with the "M" in the part number) will have a larger volume in the combustion chambers.


What is the motor going into and what do you want from the motor? Depending no application we can guide you to either the correct head for the vehicle (preserving originality) or the smallest combustion chamber commonly available (maximizing cheap performance).

[tubman]

Since it can't be seen and has a major effect on both performance and fuel economy. I believe that optimizing the combustion chamber is the single most effective thing you can to to a Ford flathead.

There is simply no downside.

[Tim Ayers]

If you flip the heads over and compare them, I'll bet you'll be able to see some differences.

[tubman]

Pictures of the bottoms of the heads would be useful for a number of reasons. I think that the differences might be difficult to see, but could probably be measured.

[Ol' Ron]

Why does everybody send pics of the wrong side of the heads when they want to know sone thing about them. But Aesthetics are important too????
Gramps

[51504bat]

Find a set of EBA heads. Not as pretty but problem solved. IMO

[Tim Ayers]

Originally Posted by 51504bat

Find a set of EBA heads. Not as pretty but problem solved. IMO

Agreed. Anyone know if there was a Canadian version of the EAB's?

[tubman]

Originally Posted by 51504bat

Find a set of EBA heads. Not as pretty but problem solved. IMO

I would respectively disagree with this. It assumes that the Ford factory specs are gospel and the heads are right on. I have found that every set of heads I have used required work to get them to where I wanted them to be. Also, who knows what might have been done to a set of heads in the 70 years (yep, it's been that long) since the heads were cast and machined? In my opinion. any one that just slaps a set of heads on an engine without checking clearances is not doing the project justice. I will tell you from experience that aluminum heads are easier to work with than stock iron units.

Anyone concerned with flathead performance should have at least a passing familiarity with the works of Sir Harry Ricardo

[Ziggster]

Thanks for posting about Sir Harry Ricardo. Had never heard of him until now. Read his wiki page. It just amazes me that all these folks just started designing and building all kinds of engines seemingly out of the blue. There are only a handfull of folks today that repeat such fears, even with all the marvels of our modern technology.

[Tim Ayers]

Originally Posted by tubman

I would respectively disagree with this. It assumes that the Ford factory specs are gospel and the heads are right on. I have found that every set of heads I have used required work to get them to where I wanted them to be. Also, who knows what might have been done to a set of heads in the 70 years (yep, it's been that long) since the heads were cast and machined? In my opinion. any one that just slaps a set of heads on an engine without checking clearances is not doing the project justice. I will tell you from experience that aluminum heads are easier to work with than stock iron units.

Anyone concerned with flathead performance should have at least a passing familiarity with the works of Sir Harry Ricardo

I guess a lot of us assume that someone would check the clearances, but you know what they say about assuming

[Newc]

Thought that C8BA was an EAB??? Just aluminum and prettier. Newc

[jjk]

FORD ON THE LEFT
MERC ON THE RIGH

Both come in around 40CC

[petehoovie]

Originally Posted by jjk

FORD ON THE LEFT
MERC ON THE RIGH

Both come in around 40CC

[tubman]

Thanks for the picture. 40 CC seems kinda low, but it depends on how you measure them. They look pretty good from what I can see. I have seem them milled so much that the "step" behind the water outlet is hardly visible. (I'm not much of an expert as I have only one set of C8BA's.)

[Tim Ayers]

Originally Posted by jjk

FORD ON THE LEFT
MERC ON THE RIGH

Both come in around 40CC

Did you use plexiglass so the water can fill the entire chamber? As Tubman mentioned, 40CC is quite low.