Lotus Elan and Lotus Elan Plus 2 Forums

Well I know, originality counts on old cars. But there is allways a but..

I have a project car, totally without drivetrain. But the car should go back in the streets as reliable well used car.

My intention is to swap the not existing engine with a Zetec-SE (Sigma) engine. Due to regulation, I am not allowed to modify the chassis and I have to stay with the original chassis as well.

So the well documented half moon modification is not possilbe. Spyder isn't a option als well

In thread elan-mods-f31/zetec-engine-lotus-chassis-t24502.html Bud mentioned the possability to move the transmission backwards.

So my first few questions:
- how far can I move the transmission backwards without interfering the chassis?
- how far goes the pulley of the zetec engine 'into' the crossmembre?
- the picture from Bud shows the MVH-engie. Which is the 'normal' Zetec engine. It says the lenght of the enigne overall is close to 490 mm. I found a few infos about the Zetec-SE engine, which says this engine is just 470mm long. Where can I find any futher infos on the SE enginge?

Sorry about my rough english, it my 4th foreign language.

Regards,
Piple

PS: Picutres will follow

What you're hoping to do will be complicated.
The half moon cut out in the cross member provides the necessary space for the front pulley/damper.
The engine even when fitted into a chassis with this modification has the back of the cylinder head/crankcase very close to the bodywork bulkhead. A special adapter for the engine thermostat, located on the back of the cylinder head is necessary under "normal" circumstances.
The route you are thinking about will need the bulkhead removed locally to get the engine in.
Access to the bell housing mounting bolts etc. will then be very restricted.
I'm not certain about space in the chassis for the Lotus gearbox; maybe it will work out, but I think that using an MT75 / 5 Speed gearbox would be almost impossible.

The authorities would not notice that 1/2 moon cutout, surely?
After all do they have any idea of what an original chassis looks like anyway

Cheers
John

Very close means within a few mm?
If this is the only way, so I have to find a solution with the bulkhead.
My hope is, that the SE-engine is a few 20-30mm smaller thant the normal Zetec.
As I saw on the pics just the pulley is intrudes not to far in the 1/2 moon cut. Can someone tell me more?
According to a technical pic, the pulley is only 44 mm. But this is the info of an normal Zetec.

Gearbox:
I have allready found infos, that the Type9 is not as wide as the MT75. May the original will help me here further.
So it has enough space to move 20-30 mm back.

The responsible expert pointed me especially on the chassis thing. I guess, he used Google to find infos about the engine swap on a Elan

If nothing works, I have to go the original route, but than the +2 can't be used for what i wanted.

Is it possible to use a smaller diameter pulley on the Zetec and avoid the chassis cut? I run a 75 mm pulley on my racing twin cams to cut the pump and alternator revs at 8000 rpm engine speeds so a smaller pulley on a Zetec should be possible if it helps with chassis clearance.

cheers
Rohan

rgh0 wrote:Is it possible to use a smaller diameter pulley on the Zetec and avoid the chassis cut? I run a 75 mm pulley on my racing twin cams to cut the pump and alternator revs at 8000 rpm engine speeds so a smaller pulley on a Zetec should be possible if it helps with chassis clearance.

cheers
Rohan

Not a safe area to play around with.
Apart from its torsional vibration damper function both of its clamping faces are vital.
The front one for the central crankshaft bolt & the rear one for clamping on to the toothed belt pulley for the cam timing.

Cheers
John

May someone with the conversion has the posability to measure the distance between the bellhouse and the crossmember. this would help me a lot.

thanks in advance
Piple

GrUmPyBoDgEr wrote:

rgh0 wrote:Is it possible to use a smaller diameter pulley on the Zetec and avoid the chassis cut? I run a 75 mm pulley on my racing twin cams to cut the pump and alternator revs at 8000 rpm engine speeds so a smaller pulley on a Zetec should be possible if it helps with chassis clearance.

cheers
Rohan

Not a safe area to play around with.
Apart from its torsional vibration damper function both of its clamping faces are vital.
The front one for the central crankshaft bolt & the rear one for clamping on to the toothed belt pulley for the cam timing.

John

Hi John
Torsional damping in a 4 cylinder engine should not be critical most don't ever have it. The clamping faces for bolt and tooth belt pulley should be much smaller is diameter than the v belt itself so should be able to reduce the v belt pulley diameter I would have thought?

No practical Zetec experience though so just suggesting

Cheers
Rohan

rgh0 wrote:

GrUmPyBoDgEr wrote:

rgh0 wrote:Is it possible to use a smaller diameter pulley on the Zetec and avoid the chassis cut? I run a 75 mm pulley on my racing twin cams to cut the pump and alternator revs at 8000 rpm engine speeds so a smaller pulley on a Zetec should be possible if it helps with chassis clearance.

cheers
Rohan

Not a safe area to play around with.
Apart from its torsional vibration damper function both of its clamping faces are vital.
The front one for the central crankshaft bolt & the rear one for clamping on to the toothed belt pulley for the cam timing.

John

Hi John
Torsional damping in a 4 cylinder engine should not be critical most don't ever have it. The clamping faces for bolt and tooth belt pulley should be much smaller is diameter than the v belt itself so should be able to reduce the v belt pulley diameter I would have thought?

No practical Zetec experience though so just suggesting

Cheers
Rohan

I agree but my only worries would be about the quality of a "different" pulley. The surface finish & run-out of the surfaces is so important, as is the hardness value of the material being used.
Not every machine shop has that knowledge or experience, hence my word of warning.

Cheers
John

Hi Piple

To be honest in your situation I would use a mildly tuned crossflow unit, these will bolt pretty much straight in and can give similar power output to a Twincam but a really easy install.

Regards
John

Wise words indeed

Cheers
John

c42 wrote:Hi Piple

To be honest in your situation I would use a mildly tuned crossflow unit, these will bolt pretty much straight in and can give similar power output to a Twincam but a really easy install.

Regards
John

A wise decision would be to buy a running car.

Before I install an xflow, I'll stay original. But I have allready a car with a engine from the 60s. I want to build the +2 to a daily driver to bring the joy and design to new glory.

And thats the car:



Pic 'borrowed' from the seller thread

Hi
If you go with Xflow you can get a running car quickly and sort the rest of the systems.
Later on get the bits needed to turn it into a twin cam.
Jon the Chief

Hi all,

May someone with the conversion has the posability to measure the distance between the bellhouse and the crossmember. This would help me a lot, to make a my mind, what happens to the engine project.

thanks in advance
Piple

A quick measurement with a steel tape shows 18 1/4" from the engine block/bell housing split to the flat rear face of the front cross member. Actually that's the rear face of the block because I was measuring from the Intermediate plate. Even for the twin cam, the cross member has a half moon cut. If you can't make that bigger by regulation, you probably can't trim the frame bulkhead at the front of the tunnel to move everything back. Hindsight being 20/20, I wouldn't have made my relief cut quite as big and I would have kept it half moon shaped.

Thank you, this helps to investigate further.

Regards,
Piple