BritishV8 Forum

Ah, but the real question: Are the newly tapped holes in the deck blind holes? Or are they open to the water jacket?

Jim

He says blind.

Just to throw in a thought - could it be that this was built for supercharging? Hence the low cr.
The cam spec might give a clue.

Ivor

Is it possible that this was done at the factory due to a shortage of Olds blocks?

As I recall, the flywheels were slightly different from the Olds to the Buick. Looking at the balancing pins pressed into the flywheel might help clarify which factory this came from. Likewise, Buick varied its pistons, so if there's a dished piston under the heads, that will imply a Buick short block.

"Is it possible that this was done at the factory due to a shortage of Olds blocks?

As I recall, the flywheels were slightly different from the Olds to the Buick. Looking at the balancing pins pressed into the flywheel might help clarify which factory this came from. Likewise, Buick varied its pistons, so if there's a dished piston under the heads, that will imply a Buick short block."

The block castings are dimensionally the same between Olds and Buick 215s.  The only difference is whether or not the sixth bolt holes were drilled and tapped.  

The Olds and Buick FLEXPLATES are different due to the differences between the RH5 trans and the Dynaflow.  The Olds RH5 used a fluid coupling internal to the trans, not a conventional torque converter.  The front of the RH5 simply has a splined input shaft, similar to that on a manual trans.  The Olds "flexplate" really looks like an MT flywheel with a separate hub plate with springs that looks like the center of a clutch disk.  This is to make up for the lack of a torque converter on the RH5.

The Buick and Olds MT flywheels are the same, except that Buick used a flywheel with an additional inertia ring outboard of the clutch area to increase rotational inertia on certain heavier models (like wagons) to make for a smoother clutch engagement from a stop.  The Buick and Olds flywheels can be swapped.

Do you take apprentices, Joe?

You're like an encyclopedia.

Olds and Buick castings are identical is my understanding, only the machine work is different.

It seems this could be true. The outline of the lug is there and it would make sense to eliminate it if you were eliminating the metal the stud screws into. So I'm inclined to agree that the old statements that there was no support under the deck for the top row of studs may have been an uninformed guess by someone who was not an engineer.

Still just a theory until someone drills one out though.

Jim

QuoteOlds and Buick castings are identical is my understanding, only the machine work is different.

That and the casting numbers.