nimrod239

[nimrod239]

I just joined in Florida to try to gather some information on a McColloch supercharger I own. I was told by the previous owner that it was for a WWII
B 29 bombers' hydraulic system(?) fitting on a Briggs and Stratton engine (unknown HP). It has a hang tag that states it passed government inspection. There is a plate on it that gives this info;
SUPERCHARGER
MANUFACTURED BY
McCOLLOCH
ENGINE COMPANY
MILWAUKEE WISCONSIN
2502 19757

Possibly one of the members may have knowlege on this item and help me out. MANY THANKS IN ADVANCE

[Michael]

Hi and welcome to the site.

It sounds to me like you have an extremely early McCulloch supercharger, before the company became Paxton. This is very intriguing...

Can you post some pictures? I'd really like to see this supercharger.

[nimrod239]

I WILL TAKE SOME PICS TOMORROW AND POST IF I CAN FIGURE HOW TO DO IT

[vinces427bb]

welcome to the site;
do you have anything to put that unit on??

[nimrod239]

No I don't. I haven't had the time to research what Briggs and Stratton motor was installed in the B 29 bomber. I would guess that it was designed for this wartime use but I don't have a clue.

[nimrod239]

SUPERCHARGER 011.jpgSUPERCHARGER 010.jpgSUPERCHARGER 009.jpgSUPERCHARGER 008.jpgSUPERCHARGER 007.jpgSUPERCHARGER 006.jpgSUPERCHARGER 005.jpgSUPERCHARGER 004.jpgSUPERCHARGER 003.jpgSUPERCHARGER 002.jpgSUPERCHARGER 001.jpg
These are the pictures of the supercharger in original box missing one board.

[Michael]

Nice pictures, thanks for posting them.

I did some research on this topic, and there is some very interesting history here indeed.

If this did come off a Briggs & Stratton engine, then it didn't power a B29. The B29 Superfortress used Write Cyclone 18BA (R3350BA) Series radial piston engines. These engines used a massive centrifugal supercharging system, not a roots-type of blower like the one pictured by nimrod239.

I believe, however, the B29 did use a Briggs & Stratton engine as it's APU (Auxiliary Power Unit) located somewhere onboard the aircraft (typically the tail section). If that's the case, then I could certainly see this blower being used on such an engine as the B29 was capable of extremely high altitude flight. Superchargers were commonly used on piston-driven aircraft of the time in order to pressurize the engine's incoming air thus maintaining power output at high altitudes.

The interesting part of this is that Robert P. McCulloch - founder of McCulloch Motors Corporation, which later became Paxton Superchargers - was married to Barbra Ann Briggs, daughter of Stephen Foster Briggs of the Briggs & Stratton company.

Unfortunately, because this item was used for military purposes, it don't think it'll be easy finding information on it's specific use or it's performance specifications. You might want to start your research by visiting the closest aviation museum. I'm sure someone there might be able to help set you off in the right direction.

Where did you buy this unit? And more importantly, what are you plans for it? I'm sure there would be a few people interested in an item like this, especially if there's a museum restoring a B29...

[nimrod239]

In my initial post, I stated that it was used for a hydraulic system(?) with a question mark. That was a long time ago I received the blower and the info (my memory) gets corrupted over time. It would make more sence to be for an APU. Some measurements I forgot to include are; 1 13/16" spacing of the carb intake studs, 1" intake diameter bore, and a 1" radius triangular bolt pattern on the drive coupling. These measurements are close. My plans are to sell this supercharger in the original box. I believe it is about a 1942 model. Please inform me if someone has an interest.