Different clutch cover types - 5 speed

[promotor]

I have two different clutch covers that look the same on initial inspection but have some relevant differences when looking a bit more closely.
I appreciate they aren't for the 4 speed gearboxes due to not having the platen for the release bearing. That's not a concern as a different release bearing and carrier would be used.

The one on the left seems to be the odd one out to Lotus Twincams - it has a different paint colour code on it to those I usually have - this has got a white / faded yellow paint mark, whereas the original type on the right has a green paint mark, as do my other clutch cover units.

Also, although both clutches are designated "8 - 8 1/2" ie for the drive face, the major difference between the two is the location of the riveted pivots, with the one in question having the pivots in a place that gives less leverage advantage, providing all else in the clutch is similar to the other unit.
The overall depth of the fingers to the mounting face of the flywheel is shallower on the odd one out, suggesting possibly a different thickness of friction disc to be used.

Without clamping the clutch covers up to a flywheel with a friction disc and making an adaptor to test the break-away / clamping torque of either unit is there any experience on here to provide an insight into whether the clutch is or isn't for the Twincam engine? I'm wondering if there is another use for his clutch. All bolt and dowel holes are in the correct place.

As an aside, what kind of power / torque are people managing to use on their Elan clutches without slippage?

Any help would be much appreciated as I don't want to use this to find out it's not suitable and have to take it out of the car!

[webbslinger]

I used a clutch similar to the ones in your pictures for seven or eight years. The whole time I had it it made a racket on startup, like a lathe was in the bellhousing. My opinion is that the bull-nosed throw-out bearing doesn't ride on the fingers as well as the flat bearing rides on the platten in the center type.
Last winter I switched to a Borg & Beck with the platten and it is so much smoother, quieter, and easier to modulate. I haven't stalled the car once since making the switch.
I was sold the "finger type" clutch as being high performance but it did slip a coupe of times on sticky tires. My car has limited slip and a little over 125 hp at the ground. So far I haven't slipped the Borg and Beck and I can't recomend it enough.

[promotor]

I used a clutch similar to the ones in your pictures for seven or eight years. The whole time I had it it made a racket on startup, like a lathe was in the bellhousing. My opinion is that the bull-nosed throw-out bearing doesn't ride on the fingers as well as the flat bearing rides on the platten in the center type.
Last winter I switched to a Borg & Beck with the platten and it is so much smoother, quieter, and easier to modulate. I haven't stalled the car once since making the switch.
I was sold the "finger type" clutch as being high performance but it did slip a coupe of times on sticky tires. My car has limited slip and a little over 125 hp at the ground. So far I haven't slipped the Borg and Beck and I can't recomend it enough.

Thanks for the info - was the one you used previously a Borg & Beck one, or a known brand?

I'm not too concerned about the lack of platen as the style has been used in the Lotus 5 speed as well as numerous other cars with hydraulic and cable operated clutches. I used the same type with a cable operated clutch successfully: granted, the hydraulic type clutch in a Lotus Elan does require free play in the adjustment of the clutch pushrod, so maybe this is amplified the noise in your case?

It would be interesting to hear the thoughts of 5 speed owners also.

[nmauduit]

fwiw I've installed a "heavy duty" Helix supplied by QED (no affiliation) when I refreshed my setup upon 5 speed conversion (installation of a Saab concentric slave, too) and it has performed flawlessly since (some friends consider the action a bit "binary" rather than progressive, but I cant say whether this comes from the non stock slave or the clutch - this does not bother me, I suppose I'm used to it) engine is only moderately tuned though, ~130hp

[webbslinger]

I don't know the manufacturer of my first clutch. There were no markings to identify it. I should add that I don't have any reason to think the B & B will handle any more power (abuse?) than the old one, it's just so much smoother. I have a little hill out of my driveway and I can feather it and keep the revs just right even when the engine is still cold. Getting out of the driveway when cold was the only time the old clutch made a racket, but it was always unforgiving starting on hills. I won't go back to a clutch without the center platen.

[ericbushby]

Hi All,
First I have to say that I know very little about clutches, however on my car the previous owner had fitted a clutch with fingers but a flat faced thrust bearing for the platten type. This meant that the spacing and alignment was wrong and the clutch was grabby and erratic. The clutch cover and plate appeared to be new, With guidance from members of this forum I fitted a round nose bearing for a Ford Capri 1.3 and mounted it on a stepped tubular spacer to make up for the thickness of the missing platten.
The clutch was then as smooth and sweet as any I have had on other cars.
So it may not be lack of a platten that is causing the trouble, just the way it is being used.
Hope this helps
Eric in Burnley
1967 S3SE DHC

[MACCA.GLM]

Have to agree with webslinger

I fitted the Genuine standard Borg Beck to my sprint which was bought online for £169 quid including vat and delivery. Very smooth easy on the pedal and does the job a treat. Just could not bring myself to pay for an upgraded clutch for £500 when its not needed for road use.

cheers G

[RichardHawkins]

Eric,

I had a conversation with LUK about clutch release bearings and the advice, for a platten use a flat faced bearing, for fingers use a rounded face bearing. To my surprise, when I took my old clutch out it had a carbon/graphite release bearing.

Richard Hawkins

[ericbushby]

Hi Richard
That is fascinating. How can that happen? The one they took out should have told them what to use. Maybe they could not get the correct one or were just desperate. It must have worked, at least for a while.
Cheers
Eric

[promotor]

Hello all, many thanks for the responses, some food for thought.

To clarify, both of the clutches in the photo are Borg & Beck, and I will be using a round nosed bearing together with a bearing carrier originally used on a Mk1 Escort Twincam / RS1600 with a 4 speed gearbox similar to the Elan one (except for the gear lever position). I will be using the clutch with a 4 speed Elan type gearbox.

The bearing carrier I will use is slightly longer than the Elan type to account for the space made available due to the missing platen so I will hopefully get the clutch geometry close to how it should be, depending on clutch friction disc thickness as this affects how high or low the fingers sit once the clutch cover is tightened down. I have in the past used a Lotus clutch cover with spacers between it and the flywheel to have the fingers sat at the right height / orientation where a thicker disc made the fingers sit down towards the flywheel - having the fingers facing toward the flywheel even before actuation makes the clutch action inefficient / heavier than need be: they need to be sat level or fractionally away from the flywheel at rest.

I had the option of fitting an original type Borg & Beck clutch cover but they are used and wanted to use a new one so have chosen to fit the unusual type shown above. If the clutch ends up too heavy I have the option of fitting a larger slave cylinder for the clutch to help out.

[mark030358]

Hi,
This is an interesting topic.

I wanted to put a five speed box in my Elan to do a european tour, so I bought one and duly installed it. I used the QED Helix clutch kit too. First thing right off the bat was the clutch slave cylinder adjustment was at the end of its travel. I had to get a new carrier made, so if you can check the clutch slave cylinder adjustment before fitting I would do.

After a bit more faff, I bought the last original 5 speed cover that Chris Neils had. I can get this out and take a few pictures/measurements etc, but will be in a week or so's time as I'm off the Scotland, hope thats OK.

cheers
Mark

[promotor]

Hi,
This is an interesting topic.

I wanted to put a five speed box in my Elan to do a european tour, so I bought one and duly installed it. I used the QED Helix clutch kit too. First thing right off the bat was the clutch slave cylinder adjustment was at the end of its travel. I had to get a new carrier made, so if you can check the clutch slave cylinder adjustment before fitting I would do.

After a bit more faff, I bought the last original 5 speed cover that Chris Neils had. I can get this out and take a few pictures/measurements etc, but will be in a week or so's time as I'm off the Scotland, hope thats OK.

cheers
Mark

Thanks Mark. Am I right in thinking that the original 5 speed cover from Chris Neil is the same as the one on the right in my above photo?

Was the spacer you had made that was suitable for the Helix clutch then not quite suitable for the original cover? I presume the original 5 speed release bearing carrier is the same as the ones that SJ Sportscars supply? I know that's not suitable to my application but it's interesting to know for future reference.

[mark030358]

Hi,
Still in Scotland, back on Sunday so I’ll take a look at the cover.

The sleeve I bought from SJ and with the helix clutch and cover resulted in the rod being almost fully extended. So the carrier I had made was for the helix clutch. The 5 speed plate from CNs came after I had refitted everything and a chance conversation with Paul who said he had one left. Soo bought it as a spare.

Anyway, will get the pictures when I return

Thanks
Mark

[mark030358]

Hi see my post on 14 July 21 re the carrier dimensions. In fact the whole topic is about 5 speed clutch covers. Hope it helps till I get you the photos

Thanks
Mark

viewtopic.php?f=37&t=49179&start=15

[mark030358]

As promised…

If you need measurements let me know
Cheers
Mark