8BA vs 59AB dimensions

[Ralph Moore]

I've been told the 8BA is dimensionally bigger(outside) , but I've got both engines sitting in my garage and I don't see it. I put a tape from ****** to water pump mounting surface and they seem the same.
What are the outside block size differences?

 

[Ol' Ron]

For the exception of the early cast on bell housing. NONE.

 

[Mart]

As Ole Ron says, except for the bellhousing there is no difference in the size of the block.
What is different, though, is the pulleys at the front of the engine, plus the extra length required for the fan. The generator is also mounted further forward. So a fully built up 8BA will occupy more space in an engine bay than a 59A for example, and that is why you see threads on here saying what a tight fit an 8BA is in a '34 for example.

The extra length is probably what people were referring to when they said it is "bigger".

Mart.

 

[38 coupe]

Mart has it. The pulleys moved forward to allow the belts to clear the new post distributor.

 

[rotorwrench]

The extra pulley/fan length is approximately 2 inches longer (slightly less on 49 to early 51 Mercury) from the transmission mounting surface half bell (Mercury & Truck) to the front of the fan. The belts had to clear the Holley Load-A-Matic distributor.

Kerby

 

[52merc]

so i take it the 8ba with the adapter on it is the same length as 59a ??

 

[Ralph Moore]

I measured a 1946 59 block and a 52 Merc block and they are the same.

 

[Bruce Lancaster]

Here's an article I posted on the HAMB: http://www.jalopyjournal.com/forum/showthread.php?t=35029&highlight=flathead+dimensional&showall=1

I need to get back and come up with more 8BA dimensions and more of the combinations possible with early parts.