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Perkins 4 Cylinder diesel model no 4107 or 4108..
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vtsteam:
Matt you got to try this thing. Any chance of visiting? Be happy to put you up -- and the engine is as good an excuse as any for a good visit!

Now imagine your BMW with a 6 inch piston, diesel level of compression, and 250 pounds of 24" flywheels attached. Maybe more than 300 pounds of moving mass with the crankshaft con rod and piston. And on a very long stroke.

The ratchet isn't the problem. The muscles are.

The hand crank is ratcheted, btw. But you pull it off the shaft (about 2" dia. as I remember it) when it kicks, because well it would spin around anyway, and besides, these ratchets aren't fool proof. I know it could be done better, as on your motorcycle, but, again, it's heartbreaking to do more than three start attempts in a row. Like real heartbreaking.
mattinker:
I'd love to visit, might just stop in between Montreal and Cutty Hunk if I make it across the Atlantic in Jan/Feb. I was thinking along the lines of a starter motor driving through a ratchet. I thought the engine had a decompresser, nothing wrong with a starter motor to spin up to speed dropping the decompresser when fast enough to start.

It was a hopefully helpful beginning thought rather than a  packaged al thought out solution!

regards, Matthew
vtsteam:
Oh okay, yes a starter motor! That's what I want to do!
vintageandclassicrepairs:
Hi vtsteam,
How about finding a ring gear from something like a truck the correct diamater to fit to the flywheel ?
I have a friend who made a ring gear by cutting and reshaping to the correct diamater then welding the joints  :scratch:
Alternatively, cutting teeth into the flywheel rim if facilities are available to do so
A decently sized starter motor should spin the engine , maybe adding a solenoid to operate the decompressor for a few seconds while sthe starter is spinning the engine up to speed could be added ?

Regards
John
vtsteam:
I'm sure that would work vintage. But probably I'll go with a friction drive and a simple lever to press it against the flywheel and withdraw it when it starts. Kind of like Simon's bicycle drive.
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