spigot main shaft engine 1968 with pre-66 gearbox

[lotusbzz]

Buongiorno all the Elan?s folks

I have a problem to fit together the twincam engine prod-year 1968 with the pre-66 gearbox .

The car has been bought dismantled and this is the another surprise that pops up ? and probably not the last one .

Anyway the pre-66 gearbox doesn?t fit with the engine LP11970LBA that I assume to be made in 1968 for my S4.

The problem comes from the main drive spigot that fit in the housing of the crankshaft since it?s 21 mm diam, but it doesn?t in the main drive shaft of the pre-66 gearbox because this shaft is 17 mm diam, not 15mm as the inner diameter of the spigot requires

My questions are the following :

1. Is there any spigot that can fit with 17mm inside diam and 21 out diam?

2. Which kind of spigot fits with the pre-66 gearbox? ? I could adapt the hole/housing in the crankshaft making the hole a bit larger ? using a boring/lathe machine of course.

3. What about replacing the needles-spigot with a sintered bush made to size

4. I could make the main shaft smaller in diameter for the parts where the spigot fits, but it means that I have to dismantle the gearbox that is just assembled.
Furthermore this modification it means that I have to harden again the end tip of the main shaft and then fine grinding to make the surface smooth for the needles.

I?ve seen similar topic at lotus-twincam-f39/spigot-bearing-t26454.html?hilit=spigot#p175053 , how do they solve the problem?

Gentlemen , your advice is higly apreciated!!!

[wotsisname]

Hi
I have a similar setup.

This might help....

elan-racing-f12/bullet-box-input-shaft-t24397.html

[lotusbzz]

Great!!!
thanks a lot

Paolo

[vstibbard]

Ive just used early boxes with later engines and always make up sintered bronze bushes.

V

[elansprint]

Did the early gearbox not use a sintered bronze bush fitted in the centre of the flywheel to support the gearbox input shaft
Ian

[rgh0]

The standard early 4 bolt crank arrangement was a bronze bush with a 17 mm dia shaft and 40 mm hole in the crank for the bush . The standard later 6 bolt crank arrangement was a needle roller bearing with a 15 mm shaft with a 21 mm hole in the crank for the needle roller bearing.

The challenges come when you mix the engine and gearbox later with earlier or visa versa - the Dave Bean manual shows all the 4 possible combinations and the various possible solutions.

The 5 speed gear boxes used a bush mounted in the flywheel to carry the needle roller for the gearbox shaft which was shorter than the 4 speed in relation to the bell housing

cheers
Rohan

[englishmaninwales]

I had always wondered why there was a strange noise when changing gear, discovered why this year with the engine / gearbox out - 40/17mm bearing and a 15mm spigot (2000E gearbox). I bet the culprit thought the engine and gearbox went together easily!
Sorry, I know this doesn't help !
Malcolm,

[denicholls2]

40/17mm bearing and a 15mm spigot

Sure minimizes wear on the bearing or bushing, though.