T9 gearbox conversion

[alaric]

Thanks Brian.

Alan has used a concentric clutch actuation set up, which does away with the level arm and external hydraulic slave cylinder - very neat. The front face of this actuator is currently the standard 4 speed thrust bearing (I believe).

I could modify the front face of this actuator set up to allow me to retain my beloved clutch plate as is i.e. fit the rounded 5 speed thrust bearing - I have a brand new one. I'll have a poke around this evening to see how possible it is. The concentric actuator is a standard ford part, so there's probably guidance on how to use it somewhere. There may even be a part that suits the 5 speed thrust bearing.

All the best.

Sean.

[lotusanglia1965]

Hi Sean,
been busy last few days, looks like you are getting there! If you find a way to fit rounded bearing to release mechanism from mondeo(as supplied by alan) I'd like to do one for my car. I don't think it's possible, but would be handy, then I could use my paddle clutch,which needs rounded bearing.
good luck,
Martin

[alaric]

Hi all.

Following up from last week, I now have a 4 speed clutch cover from QED. It's the heavy duty item from Helix Autosport if I remember correctly.

It fits the flywheel etc fine.

I've measured the distance from the engine block dirt cover to the front face of the pressure pad on the clutch cover and it's 111mm.

The concentric actuator used in the gearbox kit requires that this distance is between 97 and 99mm, so I now have an assembly that's 12mm over.

QED tell me that the clutch cover has the same dimensions as the standard 4 speed one, but with stronger springs.

Alan Voigts tells me that the QED supplied clutch cover is the problem.

At the same time QED are telling me I could have used a Tritan concentric actuator with the original 5 speed clutch cover i.e. with the rounded thrust bearing, and that they've never heard of the ford item that Alan has supplied.

Could somebody please please please measure the standard 4 speed clutch cover, and verify the distance between the flywheel and the face of the pressure pad. This would then allow me to identify where the problem is and work out how to proceed; do I get the standard 4 speed clutch cover, or do I get the tritan actuator, or go to the pub and forget it all.

Thanks.

[M100]

Just measured a brand new 1980's sourced 4 speed clutch cover (Borg & Beck HE2846) at 57.8mm from release face to flywheel mounting face.

According to the AP catalogue the AP uprated clutch cover (CP2246-71) which is supposed to be a "bolt on" has a set up height (flywheel face to the top of the fingers) of 46.91mm.

This seems a lot of pissing about to get what should be a simple upgrade to work!

[alaric]

My sentiments exactly about the so called simple upgrade. If I could start again I'd spec it all up myself and buy the correct parts - requesting measurements before purchase...

Thanks for the info. I'll check the measurement that I made on the QED cover on my return home.

All the best.

Sean.

[rgh0]

My spare engine and 4 speed clutch measures 109 mm from the rear of the block to the thrust face of the clutch cover. The clutch cover is a B&B 8/816 which is to my knowledge a dimensionally identical later model cover than the original HE2846.

I would expect the possible range of this measurement to be approximately 105 mm to 115 mm dependent on clutch driven plate wear and orginal thickness and assembly tolerances on the clutch cover components and with the crank / flywheel / thrust bearing / engine block. This sort of range is what is built into the adjuster on the standard slave cylinder lever arm push rod arrangement.

The spec range of 97 to 99mm for the concentric slave cylinder assembly seems to be to low and also unacceptably tight at a 2mm range, as it will need to accomodate a reasonable range given the wear and assembly tolerances.

Rohan

[alaric]

Rohan,

That's great, thanks. My measurement is 111mm.

The QED clutch cover measures 57.88mm, which is the same as the measurement that Paul Matty's gave me yesterday, and M100s post that appeared following my request.

So my engine and flywheel assembly would appear to be completely standard.

Alan is supposed to be phoning me today with his measurement. If there is not a clear explanation / way forwards that does not involve me spending more money, then I think a refund is in order; this would appear to be a problem with this kit that would be seen with all elans.

I'm planning to look more closely at my lotus 5 speed over christmas, as that's actually fine apart from no retention in 1st and 2nd.

Thanks again for all your help. This really is an invaluable resource. I hope to be able to put some more cheery posts in soon; the new year should see the postman bringing bits and pieces of my car up the drive...

Sean.

[john.p.clegg]

No retention in first and second?
That sounds like a rotated thingy shaft,the one with two notches that the ball detents lock into....
Sorry if i get too technical at times but it is Christmas

John

[rgh0]

Sean

I measured the free height of another spare clutch cover I had at 57.8 mm consistent with your other data. The assembled clutch cover height with the driven plate in place is 52 mm for the cover on my spare angine with a partially worn driven plate. This combines with a measurement of 57mm from block rear face to flywheel face to give an overall measurement of 109mm.

Rohan

[alaric]

John,

Apparently there are ball bearings in the selector shaft and in the baulk rings. The latter can be assembled incorrectly, with the slot not lined up with the ball bearing, or something like that, and the former can get hydraulic lock.

I will probably just get the box re-built. A freind has use this bunch in the past: www.gearlink.ukf.net and they're just down the road, so I could pop up with both boxes and see if they have experience that'll help.

Happy Christmas to you all.

Sean.

[alaric]

Hi all,

I've managed to spend some time out with the car over the last few days - sad actually, it's been -7 outside, and I've been sat in the garage surrounded by heaters...

Referring back to earlier posts: After some thought, I re-measured the height of the clutch pressure pad, but with the clutch plate fitted this time. It was not having the clutch plate fitted that was the problem. The measurement now comes out at ~99mm, which is spot on what it should be.

So it was my mistake - I wanted to clear that up, as now that I've been able to spend some time at it, I've managed to get the gearbox fitted and test the clutch operation - needed three hands, a foot and the pedal box from the car, but it definately works. So the kit, at the moment, looks great. I've measured the prop shaft length based on the distance between the engine mount and the output spline, and it matches that for the standard 4 speed prop shaft. Also, the gear lever is within a few mm of the original position.

The gear selection is really nice. I've cranked the engine on the bench with the starter motor, and all the gears are really sweet. The selection feels very precise.

This evening I've put helical inserts into the starter motor threads on the bell housing, and spent an eternity carefully filing the speedo gear to accept the speedo cable drive and altering the clamp arrangement, but it's finally together.

Next job is to offer the whole assembly up to the chassis, and work out where to attack with the angle grinder.

The most difficult part of this conversion has been getting concrete information about how to procede. I guess that's par for the course with these cars though, and maybe it'll make it all the more satisfying once the car's on the road.

All the best.

Sean.

[tower of strength]

I'm sorry it's six months or so late, but just wanted to add my two penny worth to this thread;
Regarding the gearbox types, the Type 9 (5 speed) was developed from the Type N (4 speed)
there are two types of 'box, heavy duty (long input shaft) and std (short input shaft) the heavy duty type was fitted to diesel sierra and Granada/scorpio's and P100s, V6 Capri, sierra and Granada/scorpio2.3/ 2.8 engines (inc 4x4s)
the standard 'box was fitted to Sierra, Granada and Capri 4 cylinder cars.

The Transit had a wierd set up, with the long (heavy duty) input shaft and the selector on the side of the cast iron part of the gearbox.
the input shafts (memory fails me on numbers) have the same number of splines as the type N 4 speed (2litre and2.3/ 2.8 petrol, 2.4 and 1.8 diesel) and the spigot bearings are also the same.

My findings are that the ratios are all over the place, but the diesel gear set in the 1.8 turbo diesel Sierra are, from memory, the closest set ones. A good source of info on this would be Autodata/Glasses technical data manuals from the late 80's if any one has a set.

The clutch diameter and depths of pressure plate will vary from engine to engine, but the 4cylinder petrol ones are the same (capri, sierra and granada), the V6 one is larger diameter, the transit larger still.

The bellhousing from any 5speed petrol 4cylinder car will fit the twincam, however they are designed for a cable clutch.

after market concentric hydraulic release bearing conversions are available from the rally/performance outlets, as are various alloy belhousings (original MK1 Escort RS 2000 would be Ideal!!

2.4/2.9 and twin cam Sierra/Granada/Scorpios had the MT75 type Gearbox as per the Spyder Zetec conversion.

with regards to changing the input shaft from long to short, the output shaft also needs to be changed as they are matched pairs (from memory)

In my opinion,for what its worth, the std duty Type 9, in good condition or properly reconditioned will handle all of the torque and power that a Twin Cam can throw at it. In my distant youth I ran a 170 bhp Pinto through a 1.8 cvh sierra gearbox for 40,000 miles with no problems, bear in mind that this was a 2nd hand gearbox, in a Capri and I thought I was Nigel Mansell (only 23 at the time so give me a break!!)

I'm going to try and create a "budget" 5 speed conversion, with both the twin cam and Zetec or Duratec engine for the Elan and Plus two in the not too distant future and if there is sufficient interest, I'll keep you all posted of my progress.
My aim is to modify my plus 2 so that I have an unleaded tolerant, useable,daily driver, bearing in mind the actual value of the car concerned (?3-4500), without destroying its classic/period feel and outward appearance.

How did the Voight conversion work out finally? Sadly its beyond my budget (Just aquired a ready made family) and my Enginuity gland has just kicked off

regards

Mark

[alaric]

Hi

The Voigts conversion turned out to be ok on my car. I haven't finished the restoration yet so have not driven it on the road. However, I have run the engine with the box, tested the clutch, and gone up and down the gears. From what I've read, the box is really easy to rebuild, so I can't see there being an issue with it. The conversion wasn't really designed for fitting to a 5 speed Elan, that was the main problem. I now know of two other +2 owners that have fitted the box having seen mine in the garage. One is having hassle getting the speedo drive to work. The other has just placed the order so is awaiting delivery. I think the speedo issue is actually because the drive wheel Alan supplies is intended for the 4 speed box coupling. I spent a lot of time carefully filing mine to get it to fit, so I think it'll work ok.

I'm happy with my Voigts box.

You mentioned a Duratec engine. That's not the 6 cylinder Mazda one that I have in my Mondeo I take it. If it is, that'd be a fantastic conversion. And I have a donor car which even has the same concentric clutch actuator as in the Voigts box.

Sean.

[tower of strength]

Hi sean,

the V6 in a mondeo is actually a ford engine ( almost half a Vanquish V12!!), The old Probe used Mazda engines,
The Duratec is the current alloy block chain driven cam engine as found in Mondeos etc, I have one in my company car and its a super engine, just lacking the "coming on the cam " surge you get with the standard twincam. As a rally car building friend of mine has informed me that the Duratec is only marginaly lighter than the zetec, he recons it wont be worth the effort. I'll just have to see whats lurking at my local breakers yard (they are my inlaws tenants so they are pretty tame and helpfull).
What ever I eventually do to the car will be reversible as I dont want to change its fundamental nature and may get the originality bug later!!

Regards

Mark

[GrUmPyBoDgEr]

Hi,
the thread seems to have diversified a bit & has reached a point in the discussion where I think my earlier investigations may be of some interest.
with ref. to MT 75 G/boxes; I believe that most British derivatives, that is right hand drive, have the mounting for the starter motor on the left hand side. This would get very badly in the way of any sensible exhaust manifold.
According to Wiggy at Spyder, left hand drive variants have the starter motor on the right hand side as per normal RHD Elans. One or two variants also have a hydraulic concentric clutch actuation as standard. This info' also from the Spyder "Oracle".
Having built a Zetec into an Elan, I have also had a look at the newer 4 Cyl. Duratec. No measurements or weights but subjectively it looks a bigger lump than the Zetec.
One thing that put me off was the reversed (European LHD) cylinder head configuration that puts the exhaust manifold where the carbs (or fuel injectors ) should normally be. That would mean on RHD Elans, the exhaust manifold would have to be woven around the steering column.
Just thought I'd sort of mention it.
Are there any more Christmas cards in the shops?
John