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V8MGBV8 Avatar
V8MGBV8 Carl Floyd
Kinggsport, TN, USA   USA
In reply to # 3535730 by scott68B

What did Mike Moor use? His has worked perfectly for about 80K and still going strong.

Mike switched to a clutch fork & Nissan 3/4" slave cylinder three years ago, Scott. He likes his new setup much better. "Wow! I should have done this years ago. Lighter pedal with way smoother engagement."

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Jim Blackwood Avatar
Jim Blackwood * BlownMGB-V8
Gunpowder Rd., USA   USA
I'm just wondering about that Astro-van clutch that is 11". Does it use the HTOB? Maybe that pressure plate is short enough to work. If I have to redrill the flywheel I would rather go larger than smaller.

At this point I don't even know if the Howe is short enough. I would have to sort of think it has to be, but this is the sort of thinking that has led me into this mess to begin with. But, I have to come up with some kind of solution.

OK, as to the measurements, the reason I measured the fingers without a clutch disc in place is that when the clutch is fully used up that is about where the fingers will be. So the measurement makes sense in terms of wear. And wear is something that concerns me.I suppose the thing to do is to bolt it back up with the clutch disc in place and measure the difference. I suspect it will be more than the 1/2" throw of the Howe HTOB. So it looks like more measurements are in order.

The OEM HTOB has about an inch of travel. That is enough for disengagement and wear both. But it is too long to work with the PPs I have. Unless I cut down the clutch disc and redrill the flywheel. Much as I appreciate the offer of the other htob's Bob, maybe it's best to wait and think some more. Maybe try to get a look at the Astro-van pressure plate. If it used the same HTOB as the Camaro that combination could work. I'd be buying another clutch kit, but at least it'd be a larger one.

Jim

260mgb Jim Nichols
Sequim,WA, USA   USA
Jim, The Astro 11" clutch was 80's and used a conventional TOB. Maybe see if it used the longer one.

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Jim Blackwood Avatar
Jim Blackwood * BlownMGB-V8
Gunpowder Rd., USA   USA
More hopes dashed. Undoubtedly it will use the bent finger PP.

Now, there is one other possibility here, the Borg & Beck. I prefer a diaphragm design as they are easier to hold in, but the B&B does have lower fingers and uses the evenly spaced bolt pattern. They do tend to be more expensive, but by now I'm becoming a little less concerned with that and more concerned with finding something that works. Seems to me the finger height on the B&B might be adjustable too.

Jim

Jim Blackwood Avatar
Jim Blackwood * BlownMGB-V8
Gunpowder Rd., USA   USA
More info. I only have 1-3/4" total space for the pressure plate with the OEM HTOB. That's with a 1.1" thick aluminum flywheel. Obviously this isn't going to work.

I've been trying to find a 1986 Skylark clutch fork and pivot ball (cable actuated). I can add a boss to the bellhousing to mount the pivot. That allows the use of an external push slave cylinder.

Alternatively, If I could find a double or triple disc 7-1/4" clutch assembly that fits a 1" x 14 spline that could work. Kinda $pendy but light.

Jim

260mgb Jim Nichols
Sequim,WA, USA   USA
75-80 3.8 (231) V6 Buick Skyhawk, Chevy Monza, Olds Starfire and Pontiac Sunfire H body have the cable bellhousing. That is what Chris and Mike used. Mike used the S10 arm. Chris had to remove all the shims for his aftermarket HTOB and machine down the thickness of the flywheel a little to use the bent finger diaphram pressure plate.



Edited 2 time(s). Last edit at 2017-06-20 12:03 PM by 260mgb.

Jim Blackwood Avatar
Jim Blackwood * BlownMGB-V8
Gunpowder Rd., USA   USA
Thanks. I just ordered the S10 clutch fork and TOB. I'll modify the bell to accept it and use an external push slave. Might even have one in spares. Should get here in a week or so.

A hardened pivot bolt would be nice, I don't think I have a tap to match the old one and it might not be the right length anyway. Maybe I'll just wait until the other parts get hear and see what length I need. I can position the pivot so the arm comes out in the usual place. I think I do have some long hardened 1/2" square headed jack screws, grinding a radius on the head should work, along with a couple of flats on the other end for a wrench. It should come through somewhere between the T5's mounting ears. As long as I'm doing all this I might as well add a mounting pad for the slave cylinder.

Any idea what bore was used with the S10 arm?

Jim

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260mgb Jim Nichols
Sequim,WA, USA   USA
Jim, Same as Ford setup, 3/4" Nissan slave.

http://forum.britishv8.org/read.php?2,44728,page=2



Edited 1 time(s). Last edit at 2017-06-20 01:18 PM by 260mgb.

260mgb Jim Nichols
Sequim,WA, USA   USA
Jim, pivot is above upper mounting ear. Look at Mike's in BritishV8 thread I posted. Here is an adjustable pivot ball.

http://www.speedwaymotors.com/Adjustable-GM-Bellhousing-Clutch-Fork-Pivot,712.html?sku=5503855&utm_medium=CSEGoogle&utm_source=CSE&utm_campaign=CSEGOOGLE&gclid=CKC9-a2GzdQCFdNyfgodDq0FWg



Edited 1 time(s). Last edit at 2017-06-20 01:30 PM by 260mgb.

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Jim Blackwood Avatar
Jim Blackwood * BlownMGB-V8
Gunpowder Rd., USA   USA
Thanks Jim, I saw that. But I figured I'd just let it come out the existing large side opening unless it hits the tunnel (it might, and then I'll get to move the opening.) Since I've already welded on the bell I figure I can't hurt it much. I had patched the Olds starter bulge location, but maybe that would be better. If I do that maybe I'll patch the old opening. OTOH it would be convenient to be able to adjust the pivot with the transmission installed. Found the hardened jack bolts, it should be easy to modify one.

This S10 fork is the cable operated type in case there was any confusion. ~1990 or near thereabouts. Seemed very common, cost about $13 + shipping.

Of course, finding the Buick 3.8v6 cable operated bell and bits would have been simpler, but they seem to be somewhat scarce. Maybe more common in the Chevy line with the Buick engine.

Jim

Jim Blackwood Avatar
Jim Blackwood * BlownMGB-V8
Gunpowder Rd., USA   USA
Here are some photos of the S10 clutch fork and pivot. I built up some metal inside the bellhousing to fill between the existing rib and the curve at the side then added a little more thickness. It's around 5/8"-3/4" there now. Then I drilled and tapped it for 1/2"-NC. The hole comes out just below the top mounting ear on the T5. Close enough that I had to use a spacer tube below the lock nut. I rounded the head of a square headed hardened jack-screw which is probably about 4" long. it turned out to be a pretty nice fit with the spring clip on the back of the clutch fork so the only other thing I did there was to grind a hex on the opposite end (by hand on the sanding disc) so that it could be adjusted with a standard 3/8" wrench.

The clutch fork is a pretty good fit as you can see, however the opening will need a bit of a notch to clear the actuating rod. That isn't any problem, but since the Nissan slave I ordered is upside down (has the bleeder on the bottom when mounted on the left side) I am going to look for a flange mounted slave. By welding a tab at the rear of the opening it should make a very simple and effective attachment, so I just need to find the right slave cylinder to work there. May need a couple of gussets.

Does anyone have a link to an "Illustrated Buyer's Guide" for clutch slave cylinders?

Jim


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ex-tyke Avatar
ex-tyke Graham Creswick
Chatham, Ontario, Canada   CAN
1976 MG MGB
If you're concerned with clutch bleeding with the lower port on the Nissan slave, I've never had a problem bleeding it. ..I don't think that'll be an issue!
FWIW, last year I switched to another slave with a slightly bigger bore (13/16" bore ...."85 Toyota Pathfinder)....this one has the top bleed port.
Photo shows original 3/4" bore Nissan (Dorman #CS37498) vs lower 13/16" bore Toyota (Dorman product # CS37700) with fitting adaptation to my hosing.



Edited 2 time(s). Last edit at 2017-06-25 12:47 PM by ex-tyke.


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ex-tyke Avatar
ex-tyke Graham Creswick
Chatham, Ontario, Canada   CAN
1976 MG MGB
260mgb Jim Nichols
Sequim,WA, USA   USA
Jim,Looks Good! I would use the Nissan slave. Simple mount and everyone that has one seems in agreement that it bleeds OK. The stock application uses a 5/8" master cylinder. I was thinking a .700 Tilton or Wilwood master cylinder might give an easier pedal. Graham, is the pedal a little easier with the 13/16" slave cylinder?

ex-tyke Avatar
ex-tyke Graham Creswick
Chatham, Ontario, Canada   CAN
1976 MG MGB
Quote: Graham, is the pedal a little easier with the 13/16" slave cylinder?
Essentially!......My thought process was to provide a longer pedal feel or "modulation" through the pedal travel....rather than having an "off/on" engagement...personally, I think I achieved that!

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