How can I put an 8" Clutch on TC

[bgthomas@earthlink.net]

Hello everyone

I am continuing to work on getting my xpeg 1500 engine into my TC and getting very close. One issue has come up that I could use some help on. I was planning on using a TF starter and 8" clutch but discovered that my TC bell housing makes contact with the clutch. When I turn the the crank over by hand I can here a slight scraping sound. I looked at a TF bell housing and I see the clutch shaft is recessed deeper into the bell housing. It is also a 3/4" diameter where the TC shaft is 5/8".

Here are the problems as I see them

In order to use the TF bell housing ( with a 3/4" shaft) I need to change the clutch lever to a TC style, which is designed to fit 5/8" shaft. Do I need to pull the TF 3/4" shaft and turn the end to fit the TC lever?

The TF bell housing has a different register where it mates up to the gear box. I assume I would machine that off and just have a flat face and rely on the bolts alone. Is this correct??

Is there some way to modify the TC bell housing to fit the 8" clutch??

Or should I just use the 7.250" clutch?

Any help or advice would be much appreciated. I know several of you have the 1500 in a TC. What did you do and why?

Thanks!!!!
Bob
TC 7388 EXU

[Peter & Rachel Ross]

Bob,

I did this once, way back, and hit the same problem as you. I simply put three large flat washers on each bolt between the bell housing and the engine thus moving the engine forwards by 3/16 inch so the cover plate missed the release shaft boss.

Nowadays, especially if I had my own machining capability, I would probably make an aluminum spacer to go between engine and bell housing.

In order to use the TF bell housing ( with a 3/4" shaft) I need to change the clutch lever to a TC style, which is designed to fit 5/8" shaft. Do I need to pull the TF 3/4" shaft and turn the end to fit the TC lever?

Not a bad idea. You could also bore out the actuator lever to 3/4" but that would be more difficult to return to standard than fitting a new shaft back in the TF b/h.

The TF bell housing has a different register where it mates up to the gear box. I assume I would machine that off and just have a flat face and rely on the bolts alone. Is this correct??

I think this is a BAD idea. The register is there to centrally locate the gearbox first motion shaft bearing and just the bolts would not ensure that. Compare to the pins between engine and bell housing. My spare gearboxes have the bell housings on them, but I seem to remember the gearbox bearing stands proud and fits into the recess in the bell housing to ensure the correct end float. The TD/TF gearbox had a smaller gearbox bearing

You could make an adapter plate to go between gearbox and bell housing.

Or should I just use the 7.250" clutch?

I've been racing a fairly powerful 1466cc engine on a standard 7 1/4" clutch for the last 3 seasons and upon recent disassembly (It was a semi automatic disassembly) could not see any signs of overheating. I could have done with more bite on aggressive hill climb starts and I only occasionally felt it might be slipping in 4th when pulling hard up hills.

If all you are doing is fitting an XPEG with no power enhancement, then a 7 1/4" clutch will suffice, in my opinion. Isn't the TF heavier than TC?

Bob Grunau talks of a Ford Escort clutch being fittable to TC flywheel so expect to hear something from him.

Good luck
Peter,
TC8892

[Dean Jensen]

Hi Bob
I have more info at home but the way to do it is to take your TF flywheel, and have it turned down so that it will take the ring gear that is used on the TC, of course you have to use the TC starter also, then you have to have the flywheel turned down on the clutch surface, it seems to me you need to take off about 5/16", I can check on this later, you then use the clutch plate and clutch use on a late TD, TF and/or I think early MGA, make sure you have enought clearance and you are all set, like he said, if the engine is not tuned, the standard clutch should be okay.

Cheers
Dean

[PADDY WILLMER]

Peter and Dean have said enough on the technical aspects of this conversion, but my experience of racing powerful XPAGs soon disabused me in using a 7-25 clutch, as after about 70bhp is attained they slipped wildly. I went over to an MGA 8" clutch on a TF flywheel-I ground a flat in each shaft boss for clearance- and this was ok up to about 100 bhp, before slippage occurred. I now run a 7-5" Ford Escort Mk1 or 2, clutch on a spoked , lightened flywheel. No problems any more. To Dean. Alconbury was the biggest USAF base in Huntingdonshire, and the closest to Huntingdon. From the 1950s Beer`s Garage in Houghton , nearby, was a franchised M.G.dealer and could well have second-handed your TA. Happy New Century to you all.
Paddy.

[info@roofcarriersystems.com.au]

My TC9507 uses Ford 7.5" diaphragm clutch with no problems with 100 hp XPEG. If using 8" clutch the MGB diaphragm clutch is said to be better than MGA spring type.

" To fit XPEG with 8" clutch to TC gearbox the cross shaft must be ground down on the side nearest the pressure plate to a depth of about 3/16 " for about four inches on either side of the carbon thrust throw-out ring. The other points of interference are the cross shaft bosses. Bevel these on the inside forward sections. "

Richard Townley
TC9507

[MIKEFRAN@aol.com]

BOB

I RUN AN XPEG WITH THE TC CLUTCH AND HAVE HAD NO PROBLEMS. BEFORE I INSTALLED THE XPEG I WAS RUNNING THE XPAG WITH A SHORROCK SUPERCHARGER LIKEWISE WITH NO PROBLEMS. I JUST WENT THE EASY ROUTE AND USED THE TC FLYWHEEL AND STARTER.

IF I WERE TO GO AND CHANGE THINGS I WOULD LOOK INTO CONVERTING TO A DIAPHRAGM CLUTCH IN THE 7 1/2" TO 8" RANGE. I USE A NISSAN CLUTCH BEHIND THE 1275 IN MY MORRIS MINOR AND NO SLIPPAGE YET LIGHTER PEDAL.

MIKE

[Skip Kelsey]

Bob:

Just grind the bosses inside the bell housing, and when you get clearence, all will work fine. I have done it several times. I believe its spelled out in either the stage tune manual, or Woody Woods book.

Cheers:
Skip................

[Dean Jensen]

Hi Bob

Getting back to you on the clutch, I see that you have plenty of replyes. To expand on what I wrote, it is about 5/16 that needs to be removed, it is not any exact amount, but 5/16 worked okay for me. Thinking about it more I am not sure a TC starter will bolt up to a TF engine, if it does this is the way to go, I think. If not you would have to use the ring gear from an early TD flywheel, instead of the TC ring gear. If you go this way (TC), which I have done you only need two cuts on the fly wheel, you do not have to do alot of redrilling and retaping, all parts can be obtained from you MG supplier, not knowing what you have, you may need only the ring gear.

I would not grind on the TC bell housing unless cost is the most most important consideration, as the bell housing is already weak, and is subject to breaking, as I can a attest to. The total weight of the flywheel will still be about the same, and this will have little effect, if any it will be positive. I believe another consideration, is what gear box you are using, If you are using a TC, you almost have to use the TC bell housing. In closing, I change mine, I had no problem doing it, and I have not had any problems since, it was easy to do.

Cheers
Dean

[bgthomas@earthlink.net]

Thanks to everyone for all their responses. If you'll recall when I had the block and bell housing up on the workbench I could easily turn the crank by hand and detect a slight rubbing sound and associated drag. After reading all of your thoughts I decided to try the easy fix first and see where that took me. I brought the bell housing to a local machine shop where they milled down the front of the cast aluminum bosses for the clutch shaft. I asked them go down to where they did not break through to the shaft. I also increased the outside radius of the existing cut back by an .125" or so. It would seem this would still leave plenty of material structuraly, particularly as it would seem all the loading would be on the rear side of the bosses.

It seems to be just fine. The clutch works and the drag is gone. I now have my XPEG engine with 8" competion clutch and TC trans back in the car and am awaitng the head to come back from the machine shop and I can finish up the assembly process.

As a final note I decided to go with a lightened TF flywheel and starter. This will give me enough room to use my derrington header. Now another request: I figured using a TD/TF start switch, but how and where have people mounted it? I thought of getting the bracket that is usesd on the TD/TF but not sure where that would fit. Any ideas??

Thanks again for all your suggestions!!

Bob
TC EXU 7388