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Motorcycle Discussions => British Bikes => Topic started by: Suzee on October 26, 2007, 12:08:29 AM

Title: Triumph engine!!
Post by: Suzee on October 26, 2007, 12:08:29 AM

Any clues??
I recently visited my mates garage to take a peep at his nice vintage morgan cars, he advised me that he has part of a triumph motorcycle engine in a box up the corner. unfortunateley there are no crank cases, the engine is a twin & around 500-600cc's built around the 1930's.the conrods (alloy) don't split & the flywheel sits between the conrods.he also advises me there are two tank badges that are a tear drop shape,sorry it's not much to go by but does anyone have any ideas??

Title: Re: Triumph engine!!
Post by: 33d6 on October 27, 2007, 08:03:13 PM

If the conrods don't split I would assume the crankshaft comes apart so as to mount them. If that is so and the cylinders and head are cast iron I think it is probably a 350cc 3T engine from the 1940's.
This is not an engine that Triumph enthusiasts like to brag about. Being a 350 it had nowhere near the power of the rest of the range so it got thrashed hard to maintain the image. Unfortunately it didn't have the stamina to take it so many 3T's died a sad death.

Cheers, Bob

Title: Re: Triumph engine!!
Post by: Suzee on October 27, 2007, 10:42:37 PM

Thanks for that Bob, unfortunately its not a 3T, ive been advised it has 650cc on the timing cover!! Ho well, ile keep hunting, thanks again.

Title: Re: Triumph engine!!
Post by: L.A.B. on October 28, 2007, 12:27:32 AM

Quote

Thanks for that Bob, unfortunately its not a 3T, ive been advised it has 650cc on the timing cover!!

But as there are no crankcases, can you be sure that the timing cover actually belongs with any of the other parts?

'650' as far as I know was never used on an original Triumph timing cover?

I would expect the Triumph timing cover to have a triangular 'patent plate' (or at least the three small rivet holes if the plate is gone)?


I must agree with Bob 33d6 from the description of the crankshaft arrangement you have given that it is most likely to be a 3T 350 if it is actually a Triumph engine?

Even the pre-war model 6/1 650 Triumph twin had split big ends and (steel rods?) with a different flywheel arrangement I think?


This is where some photos of the parts would be very useful. Is there any chance that you can either post some up, or email them to Vintagebike?    

Title: Re: Triumph engine!!
Post by: Suzee on October 28, 2007, 06:23:05 PM

Cheers mate ile get sum pics for you to have a gander at.

Title: Re: Triumph engine!!
Post by: 33d6 on October 29, 2007, 07:17:34 PM

Is the rocker box integral with the head? The rocker box was cast in one with the head on the 3T and instead of the usual Triumph separate circular screw in access caps above each valve for tappet adjustment, the 3T sported two long covers across the head front and rear so you removed one cover to access both inlets or the other cover to access both exhausts.
You could also measure the bore and stroke. The 40's 500 twins were 63X80 and the 650's were 71x82. The 3T would obviously be smaller.
Whatever the case, pictures would be good.
Cheers, Bob

Title: Re: Triumph engine!!
Post by: L.A.B. on November 15, 2007, 03:10:58 AM

One other Triumph that apparently had a built-up crankshaft and one piece conrods is the 500cc military TRW model.