Barrel not fitting

[duTch]

 Funny that this should occur, given that the cases for A7/10 are the same.....aren't they....?

 Richard I had in mind the breather gallery, but you headed me off... I believe the dowel should be there, with sealer, as without it provides more potential for oil to leak out the breather pipe...as sometimes comes up in topic...?

 Another thing to keep in mind is ensuring the nut on the stud above it is tight- I had to open mine up at least twice to check, even though right before I did it first times was completely focused on task....out of sight-out of mind...(yes Bill), but at least a barrel off is not as bad as a case splitting.....
 (reason for 'twice+' was because there was a noise I had to isolate- hence stripdown)

   cheers

[RichardL]

I didn't think about the oil leakage possibility through the breather, so sealer at that part of the joint is haphazard. We'll see about breather oil leakage. I'm sure as hell not parting it again for that. Anyway, the original design was not intended to include sealer on that joint, as I understand it.

The cases are the same, but my understanding is that Nourish bought A10 barrels to go on his A7 case.. Interesting to note that the cutaway in the crossmember is only on one side, and the same side, in both of the examples shown. A matter, I think, of "easier to trim the case than fix the mold pattern."

Richard L.

[muskrat]

The A7 and A10 cases are the same. Some do, some don't problem is due to the way the virgin castings are machined. A rough surface is fixed to the machine table and a face of the casting is cleaned up. Then most of the machining is done relative to that. So if in the original set up there is a bit of sand or irregular lump on the casting the end result will be slightly different to the next casting.
 My first job after apprenticeship was machining gearbox castings for elevators.
Cheers

[Rocket Racer]

I found my two thick flange barrels had slightly different overhang at the back, with the one I had shortened by 1/2" (for short rods) interfering with the magneto  so that over hang got milled off, so my mag now fits.
My road rocket cases also had inadequate clearance in the cam shaft trough to run a 357 cam without minor milling.
As soon as you start mixing and matching you can never guarantee its simply a matter of bolting on. and don't get me started on fitting a Joe hunt mag   

[BSA_54A10]

back in "the day" every thing was made using auto lathes & mills that machined between stops or against a cam.
Production tooling was high carbon steel which as all you who machine knows dulls or picks up alloy ( some times both ).
Thus no two parts would be machined identical.
The trick was to measure every thing using go-no go gauges and fit the best available part.
This is why you see all those strange little marks, numbers or letters stamped all over the place.
If the "f" gauge went into the hole, it got "f" stamped into it so the assembler took a shaft out of the "f" box and fitted it to the motor.

[duTch]

 

If the "f" gauge went into the hole, it got "f" stamped into it so the assembler took a shaft out of the "f" box and fitted it to the motor.

 gotta love them 'F' gauges and shafts...

 I must've got lucky, the 357 fits my plunger cases ok, though there is a barrel overhang that I wondered about but causing no grief at this stage...!

 

[shuswapkev]

 had to do the same with mine..i am using 51 cases and found a set of big fin barrels...
   had t get out the big file...and cut just as in all the pictures