Engine rebuilding

[rideaway]

Hello

I was wondering if you have more info on the hill climb at Ollon as I would love to bring my sprint down for a go.

https://www.ollon-villars.com/en/the-race/

It sure is a small world as 666 said he has a place in la toumaz.I also have palace in Crans Montana and regularly drive down past Bex on the motorway

There are quite a few English people who enjoy the sun and snow of the Valais.
Villars-sur-Ollon is a meeting place for F1 drivers: Sir Jacky Stewart, Greg Pollock, Jacques Villeneuve, David Coulthard.

Anyone who comes to my house with a Lotus Elan will be offered a beer.

Regards

Stéphane

[MACCA.GLM]

If I come down in it I will look forward to that beer
G

[rideaway]

Hello,
About Ollon-Villars Race

I found this photo which could look like a 26R

[rgh0]

I had a look at Stephanes engine while i was in Europe in June. The engine needs a lot of machining work to rebuild.

i.e.
head and block face skimming
possible rebore or at least a hone for new rings on existing pistions
follower sleeves reboring for oversize followers to be fitted
crank bigend journal grind

The challenge for Stephane is to find someone in France todo this sort of machine shop work at a reasonable price. it appears no one does this work in Switzerland except Bruno Schaffner Racing at ridiculous prices and lead times. The UK seems to hard given brexit and the language communication barriers.

Do any of the French members know of suitable machine shops in France for this sort of work ?

cheers
Rohan

[HCA]

The jobs you outline can easily be done in France by any engineering shop specialising in engine re-builds. What might be more tricky is finding a shop that has intimate knowledge on Twinks. And what is the definition of a reasonable price!

As you know, I am using Accel Moteurs in Pau. By all means call them. The owner is ex Cosworth who is the shop of choice for FF and historic Ford in SW France. But I imagine you might find him expensive.

What town in France would suit you best? I can ask in the Lotus club for you.

I have your PM on my engine. Will return when I have some more ideas.

[rideaway]

Thanks for your help, guys,

I'm starting by contacting workshops in Switzerland, then near Switzerland. I'm gradually widening the circle.
Then, as far as the price is concerned, the work to be done requires tools and precision, and that comes at a price! I myself have a mechanical business. It's more a question of budget for me!
But when the machining work alone is billed at twice the price of a new cylinder head, I think that's a lot.

I don't despair of finding a workshop capable of doing it at a fair price. I've found workshops capable of doing all the machining required on the engine at decent prices, even in Switzerland, except for the problem of replacing the follower sleeves !
You don't need to be a Lotus specialist to make the bores to the specified dimensions.
I don't know why it's so complicated, the answer is usually : not the tools!

Hal, thanks for the address, I'd prefer something closer, but I'll keep it in a corner.

Does anyone know how much material needs to be removed to fit the followers in new sleeves?

To take my mind off things, this weekend I'm going to work on the gearbox, which is in pretty good condition.

Best regards

Stéphane

[rideaway]

Hello everyone,

Still looking for solutions for my head, I was interested in the 1,400 inch oversize camshaft followers from J. Exley in Bicester, but I have no reply to my emails and phone calls are going nowhere.

Does this company still exist?

If not, do you know the source for 1,400 inch oversize followers ?

Best Regards

Stéphane

[rgh0]

Hi Stephane
I dont know of any other source of Twincam oversize followers that I can find. but I would try Tony Ingram at Lotus7.com to see what he knows

However I do know that Alfa Romeo followers (from the 60's to 80;s I presume) have been used as oversize followers in Twin cam heads so research into the options there may be useful ?

cheers
Rohan

[promotor]

Hello everyone,

Still looking for solutions for my head, I was interested in the 1,400 inch oversize camshaft followers from J. Exley in Bicester, but I have no reply to my emails and phone calls are going nowhere.

Does this company still exist?

If not, do you know the source for 1,400 inch oversize followers ?

Best Regards

Stéphane

I have some 1.4" followers from Newman Cams which are for Jaguar engines (Lotus Twincam valvetrain is similar in design to Jaguar) but the pad underneath is wider and does not stand as proud as original Lotus followers - although still 0.220" deep face-to-face - so they need some careful setting up by way of having the valve adjustment shims sitting proud of the retainers. The pad is almost as wide as the bore for the shim in the retainer. Perhaps you could widen the retainer bore at the top but I don't think they'd allow much modification to retain their strength.

http://www.newman-cams.com/wp-content/u ... E-2023.pdf

[2cams70]

https://www.burtonpower.com/steel-cam-f ... 13-os.html

[rideaway]

Hello everyone,

Thank you for your help.

The Alfa followers could do the job but in o/s for the diameter but I have not yet managed to find out their lengths. And they look as rare as the oversized Lotus followers.
The Jaguar followers I've found are 24.89mm long instead of 22.23mm, which should be a problem with higher lift camshafts.
Burton and Arrows have 34.97mm o/s lifters that would be fine for the intake, but not good enough for the exhaust wear. I ordered 4 from Burton that arrived but they were wrong at over 38mm diameter and too long . I made a complaint on Thursday, but no reply to date.

The hunt for parts continues!

Best Regards

Stéphane Mamin

[promotor]

Hello everyone,

Thank you for your help.

The Jaguar followers I've found are 24.89mm long instead of 22.23mm, which should be a problem with higher lift camshafts.

Best Regards

Stéphane Mamin

They only need shortening, no big drama.
However, you may want to question shortening them too much / at all anyway - higher lift cams benefit from longer than standard followers and/or follower sleeves to support the additional loads that higher lift cams and their buckets have to deal with.

[rgh0]

The "long" followers that people sell are about 22.9 mm long compared to the "standard" length. You cant go much longer as you get to close to the bottom of the follower hitting the spring seat or the ridge at the bottom of the pocket.

cheers
Rohan

[promotor]

The "long" followers that people sell are about 22.9 mm long compared to the "standard" length. You cant go much longer as you get to close to the bottom of the follower hitting the spring seat or the ridge at the bottom of the pocket.

cheers
Rohan

These are the 1.4" Jaguar followers.
I must have got lucky - this is an early head, with 420 cams and I've got a fair bit of room to the followers clashing with the head. Q55 spring pack fits at slightly longer than the 1.150" suggested figure so there's a fair bit of room to make it all work.
The followers in the photo are 1.000" deep give or take a few thou.
Notice the size of the pad in the follower - requires shims to sit higher than the retainer top otherwise the pad acts directly on the retainer top and not the shim. Some careful set-up required to make these work but it is doable.

Cheers.
Al

[rideaway]

Hi everyone,

I'm back to work on my engine.
I found the 0.05 mm oversized followers at Burton for the intake without sleeves and little worn. (I received them false and exchanged them free of charge, very good service).
For the 1.40'' oversized followers I give up, I replaced the sleeves myself, which is easier than expected.

Following Rohan's precious advice, I bought an ultrasonic thickness gauge to check the remaining thickness of my block.
How far apart should the measuring points be?
Which points are particularly critical?

I couldn't find the recommended remaining thickness for road use on the forum.

Best regards

Stéphane Mamin