Author Topic: This looks interesting but does it run?  (Read 394 times)

Online Greybeard

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This looks interesting but does it run?
« on: 06.03. 2020 16:05 »
Four Triumph engines?
Greybeard (Neil)
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A Distinguished Gentleman Riding his 1955 Plunger Golden Flash

Offline RDfella

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Re: This looks interesting but does it run?
« Reply #1 on: 06.03. 2020 17:41 »
Does it run you ask. Probably, but not for long as cylinders would seize for lack of cooling and with the exhausts all different lengths power wouldn't be great either. Nice show piece though.
'49 B31, '49 M21, '53 DOT, '58 Flash, '62 Flash special, '00 Firestorm, Weslake sprint bike.

Online Kickaha

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Re: This looks interesting but does it run?
« Reply #2 on: 08.03. 2020 02:15 »
Yes it did run and it was raced

https://www.jalopyjournal.com/forum/threads/the-mcmahon-air-cooled-v8-mechanical-craziness.1005180/?fbclid=IwAR2qB4eVr7rBBGMhDsc0WfdcbXYZKWS4BrKSwkLcWBUKbebIgHfWcOsWGQM

This was posted on a thread over on the British NSRA board, the information came from Steve Witt at The Smith Collection Museum of American Speed..

The engine was built in the late 40's by Australian Jim McMahan. It uses a Ford V8 (60) crankshaft and rods held in a sheet steel block that supports four Triumph/BSA cylinders and heads with two pistons each. Because the heads are of the hemi-combustion chamber design with valves on each side, there are three camshafts. One is located as a conventional Ford V8 operating the intake valves. The other two cams are on the outer sides and operate the exhaust valves. All of the cams are chain operated inside front mounted large case. Mounted to the front of the chain case in an oil pump and magneto drive. Intake manifolds are hand fabricated and mount two Stromberg Model 97 carbs.

Jim raced his hand built midget engine at Southern California and San Joaqin Valley race tracks and experienced some good success for a few races. However, an accident claimed his life the wonderful engine was forgotten about for a long time. The remnats resided in LA junk yard until it was discovered by a friend of Bill Smith, founder of Speedway Motors and The Smith Collection Museum of American Speed. After many man hours of pains taking labor it has been restored to its former wonderful example of hand made engineering and is now housed in the midget race car display area of the Smith Collection. It is another illustration of how this great facility is preserving the racing heritage of years gone by."
1956 BSA Gold Flash
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