Enfield 1996 frame reinforcements

[Sphere]

Is it necessary to add reinforcements to the Enfield frame if you want to mount a diesel? There's nasty stories about frame cracks, but I'm not sure about their validity/cause. It would be nice to do welding to the frame before powdercoating

[Sphere]

On the German Enfield wiki there is a mention of using an Audi absorber in the frame mounted to the cylinder head:

http://www.enfield-wiki.de/index.php/Flatterd%E4mpfer

[Diesel Dave]

Cool idea,

A bit of overkill on the shocker size!

An old Enfield rear with the spring removed might be more descreet.

Dave

[Anorak_ian]

I thought it was only the rocking motion of twin engines that caused this problem?

Maybe this is a bit of hysteria.

The bike in the pic has a single cylinder engine, a bit like yours Dave, how many miles have you done and have you spotted any frame problems?

For twins, I'm wondering if welding a thick steel plate running from the underneath of the backbone, back of the head stock, and down the down tube would do the job?

[arnaud]

As you might recall, i wrote here some stuff about it.
Be sure that the subframe is capable of giving the same rigidness as the engine original does.
I made the mistake to forget about the connection of the 2 lower plates under the gearbox which originally are bolted to the rear of the engine. The frame was bending and solely supporting onto the bracket between the 2 rear frame tubes.
I mentioned this so others do not have to make the same mistake!

[Diesel Dave]

I've had no frame issues in 92,000 miles apart from wearing out 2 centre stands and 3 sets of bottom engine plates and 2 sets of top ones.

Over time the holes get enlarged and the studs get a wear groove that allows the engine to move more.

This might have been due to not using a head steady until 2007, so the engine could rock.

At rebuild time I'll ream out the mounting holes in the frame to an accurate round size and turn up interference fit studs. I'm considering adding an additional set of lower engine plates so I'll have a 4 bar ladder and doubling up the triangular top plates. This will create a much stiffer connection and 'lock' up the frame better.

Dave

[Sphere]

I've studied pics on the web of the altmann conversion and andrew's conversion, and it would seem their subframe is *not* bolted to the frame (at the back), just to the gearbox. I can't imagine cast aluminium (of the gearbox) is strong enough for that.

[Diesel Dave]

The gearbox does carry most of the strain of the engine.

Even on the Mighty 700cc Interceptors the system was the same albeit with a strengthening plate behind the gearbox but this was on the open Brit frames that did not have the upper gearbox mountings (triangular plates)

Dave

[Sphere]

So you are saying, don't worry...

The gearbox does carry most of the strain of the engine.

Even on the Mighty 700cc Interceptors the system was the same albeit with a strengthening plate behind the gearbox but this was on the open Brit frames that did not have the upper gearbox mountings (triangular plates)

But, what is the "top one"? Top engine plate? What does your subframe look like It surprises me you haven't experienced wear at the gearbox, but I don't mind

I've had no frame issues in 92,000 miles apart from wearing out 2 centre stands and 3 sets of bottom engine plates and 2 sets of top ones.

[Diesel Dave]

Here's the top plates I was trying to describe - the triangular ones:



This is the later brit frame, there is no 'down tube' to the top of the gearbox as on the earlier frame used by the Indian factory.



Dave