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Re: Projects are like busses......Enfields

Posted: Wed Oct 31, 2018 8:48 pm
by Capitano
Camden90 wrote:
Wed Oct 31, 2018 8:24 pm
So the Kubota engine was lifted straight from the microcar into the royal enfield? What gearbox does it use?

Apologies if its a stupid question, but i know very little about car mechanics and even less about diesel bikes.
I don't know here but I'll hazard a guess before DD tells us, and that guess is ... a Royal Enfield one.

The Enfields had separate gearboxes until a few years ago. The later ones had a 5 speed LHS gearchange and earlier ones a 4 speed RHS gearchange ... unless I'm completely wrong , which has been known. 8-)

Re: Projects are like busses......Enfields

Posted: Wed Oct 31, 2018 8:50 pm
by wightegi
Enfield gearbox ,like a lot of old bikes they have a separate gearbox.

Re: Projects are like busses......Enfields

Posted: Wed Oct 31, 2018 9:04 pm
by Camden90
Looking at the pics again, its a 5 speed box. Just googled the engine so I now know what it looks like, so I guess it uses a pulley type setup (like some old harleys) to drive the gearbox

Re: Projects are like busses......Enfields

Posted: Thu Nov 01, 2018 12:03 am
by Diesel Dave
Indeed - it's an Enfield 5 speeder converted to right foot shift.

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Primary drive by duplex chain is identical to the original Enfield setup, the engine sprocket is simply an industrial sprocket drilled to fit the flywheel bolt pattern. This is why the build has been so complex as the primary chain cover needs to both keep oil inside for the clutch and chain and also keep oil out of the car type starter motor.

Here it is without the flywheel and clutch - you can see the engine mounting between the gearbox and engine.

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And here is is in an easy mockup with the 4 speed gearbox and clutch with the chain fitted.

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So there are several parts to finish for the primary cover - the backplate will be 5mm alloy cut to fit the engine bolt pattern and also the electric starter and a tensioner for the duplex primary chain. It will also have thinner parts that will protect the back of the clutch from the final drive chain muck - I may also put an oil seal on the clutch mainshaft.

Then there will be the removable outer cover that fits one the clutch and primary chain meeting up with the backplate - this is the part I've started on as I'm still waiting for the sheet of 5mm alloy to arrive.

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Re: Projects are like busses......Enfields

Posted: Tue Nov 20, 2018 9:09 pm
by Diesel Dave
Little progress as I've had to wait ages for the 5mm and 1.5mm alloy sheet - they gave me a full 2x4 metre sheet of each in the end so I have a garage full of the stuff.

So first one has to make a backplate ...

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Welding is not improving much.

So re-install the clutch and flywheel

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Then discover that the 5 speed clutch mainshaft is 4mm shorter than the 4 speeder I used originally for mockup so the chain fouls the flywheel when it's running. If you look closely you can see the chatter marks on the outer edge of the flywheel.

The best solution I could come up with is to lighten the flywheel by taking 4mm off the face and then turn 3mm off the sprocket back.

Voila...

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Chain tensioner is installed now too.

So all I have to do now is make the bit to match the backplate to the 'frontplate', add an oiling system, make up an exhaust, weld in some radiator mounts and another support for the battery plate and then it's off to the MOT station.

Sometimes I get the welding right... but not often.

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Re: Projects are like busses......Enfields

Posted: Tue Nov 20, 2018 9:53 pm
by JOHNBOY
what an engineer good on y dave

Re: Projects are like busses......Enfields

Posted: Sun Dec 09, 2018 2:32 am
by Diesel Dave
It's been a while as friends projects keep demanding my time but I have almost finished the primary case.

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There is still little bulge needed to clear the flywheel drive sprocket.

Also.

1) Oil system for the clutch and primary.
2) Exhaust
3) Crash bar (the covers won't withstand a decking)
4) Extra battery mount tab (it's a 14ah heavy battery)
5) New yellow number plate
6) MOT

Then it's proving time, this is always the interesting part when you find out how it rides, what fails on the road and whether all this hard work is worthwhile.

Re: Projects are like busses......Enfields

Posted: Sun Dec 09, 2018 9:43 am
by Capitano
Good luck with the rest of it, and proving it out, Dave.

It's a fascinating read every time something appears about this one.

What's the intention of use between this one and Sluggy?

Re: Projects are like busses......Enfields

Posted: Sun Dec 09, 2018 12:04 pm
by Diesel Dave
Capitano wrote:
Sun Dec 09, 2018 9:43 am

What's the intention of use between this one and Sluggy?
Now that is a very good question as they are both just under 500cc although this one weighs quite a bit more. I’m hoping it will manage to hold 62 mph plus as this keeps me out of the truck overtaking zone in the U.K. (it’s not a problem on the continent as their top speed for trucks is only 80kph).

With the 5 speed box it allows for a low first without sacrificing the top gear ratio - this will make it easier to tow the trailer and have the missus as pillion. Sluggy 1 has a close ratio 4 speeder so first gear is very tall; great for country lanes as it removes the usual Enfield gearbox chasm between 3 & 4. Think of it as a C90 upgrade between a 3 and 4 speed gearbox, makes little difference to bobbing to the shops but a big difference when loaded up with camping gear and heading for the hills.

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Re: Projects are like busses......Enfields

Posted: Sun Dec 09, 2018 3:54 pm
by Diesel Dave
Let's play spot the C90 part..

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No?

How about now.

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Ok, final give away photo.

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As my old grandpa would say 'Don't throw 'owt away - maybe useful some day'.