Technical 8CM swap to 8BA

Hey fellas,

So the my 51 mercs 8CM is shot and needs to be rebuilt, good news is I have a rebuilt 8BA ford flathead in the garage and was thinking about just swapping parts and running it Instead. ( yes I know I should rebuild the 8CM, but I don’t have the money to spend ) with that said I remember reading that the 8CM and the 8BA are the same blocks so everything such as the intake, heads, water pumps, oil pan, bell housing, and crank pulley all from the 8CM should fit the 8BA right?

Any wisdom would be greatly appreciated.

 

I ran 8CM heads on my 8BA with no problems.

 

Right......I swapped a 53 Merc into my shubox ford and all except the flywheel is the same. Merc flywheels are drilled for borg and beck clutch pressure plate and fords are drilled for Long-style plate. Just put your merc flywheel on the ford motor.............done! Oh, and the merc should have a 4 bolt carb....ford uses a 3 bolt carb. I'd use the ford intake and carb on the ford engine.

 

I've been told Merc heads on the Ford engine will lower the compression a little bit? Any truth to that?

Dave

 

^^Have heard the same Dave and also “Doesn’t matter” so would like to get that clarified too.

 

True. But not enough to worry about. Also, IIRC the water pumps are different (mounting pads are at different heights).

 

Thanks guys, anyone else with any incite?

 

Depending upon the type of oil pan you have on the Ford and the fit--you may want the Mercury Oil pan on your "Ford" engine too. Otherwise-I believe all the other stuff has been covered.

 

Cool, I’m just worried about the pulleys and the crank. Looks like the merc and ford crank are a little different.

 

Ok, the pulleys can be swapped. Sometime in the run of the 8BA/CM series, belts moved from the older 5/8” thick belts to the newer 1/2” style. Someone will know what year? Either can work as long as it matches the pulleys on the water pumps and generator

 

When I bought my 51 Merc in 1963 it had 8 BA heads on it and I am sure it was an 8BA engine. It did have the Merc intake and carb and the Merc water pumps. I'd say the Merc intake and carb might make hooking it all back up a lot easier.

 

Just take anything from the Merc engine that looks different on the Ford engine, and swap it to the Ford...then install it........it's really that simple.

 

Anyone know if the 8CM crank pulley will fit on the 8BA? They are different size belts but I wasn’t sure about the inner diameter of the crank pulley itself.

 

Yes, the pulley will fit.