My 70 Nova project (Formerly looking at this mustang)

I am messing with but have not run my hyd clutch, do you have a finger clutch, or diaphragm? I am concerned the my finger clutch has no free play, which they need for the fingers to pull back and increase the counter weight clamping force. I have a 1/4" spacer added, but have not tried it yet, . The fingers need .250, but, .185 is considered minimum for the counter weights to work.. I also had, and I'm sure you would have noticed a flywheel surfaced too much, and the clutch hub contacting the fly wheel bolts
 
It is a diaphragm style. Clutch plate definitely clears the flywheel mounting bolts by a mile.

This setup has a spring loaded release bearing and the bearing rides on the fingers all the time. I really don't like that but that's how it was designed. I'd love to have a borg and beck or a long style pressure plate. That was what we ran in anything that had some power in it in the "olden" days. But supposedly the diaphragm style has more even clamping of the disc.

The flywheel looks fine, doesn't look like it's been surfaced. But the LS7 setup uses a different flywheel, and there doesn't seem to be anyone near me that will grind the flywheel, and that decreases the thickness, so just bought a new one that's made to work with the clutch.

Is yours an LS engine?
 
any chance you have a slight misalignment of one of the bearings? So that it's in spec with appropriate clearance when just the shaft is running through the bearing, but when everything is assembled together the slight misalignment causes binding? I've never had a clutch apart so can't really visualise where that problem might occur, but I have experienced it with other "one shaft running through multiple bearings" situations.
 
I do have that release bearing, my engine is a BBC. Matt the bell housings do need to be dialed in for concentricity of the input shaft to crank shaft centerline.
 
I wish there was a way to dial this housing in. Because of the open bell housing design I don't see any way to do that other than making a plate that has the transmission bolt pattern in it with some dowel pins to locate it. But I don't have any info on the bolt pattern. I'm sure the info is out there some place, but I haven't found it. I researched it after extropic mentioned it. It would be pretty easy to make, just a plate with holes in it. I'd program it and run it on the VMC.

But I can't believe I have to make one. As I said it works perfectly for short time. Shifts like a dream. Clutch pedal engagement is high, but I can adjust that. I modified the master cyl push rod and put a heim joint on it. So just have to crawl under the dash and do it. But not going to do it until I get the new clutch in. It may grab at a different point in the pedal travel and no use duplicating the effort. Especially since the seats are in.

And speaking of the seats, it's been 23 days since I dropped the bench seat off to be recovered. They said 3 weeks. This would be the perfect time to put the seat in and see if it clears the shifter. Monday they will get a phone call.
 
@alloy

I looked online for the Coefficient of Thermal Expansion (CTE) for any grade of Oilite (and any other sintered, oil impregnated bearings) and I found nothing. Oilite doesn't publish the number. So I telephoned Beemer Precision who currently owns the Oilite brand (I think) and talked to a technical rep. He gave me 2.09e-5/°C. Ambient OD = 1.090". 1.09" x .0000209 x 100°C = .0022781", rounded to .0023" increase in OD of a cylinder.

The question was, how much clearance is needed to prevent, at elevated temperature, the pilot bushing from squeezing the input shaft and it's not as simple as it may sound. There has been considerable discussion (on the web) about whether a hole, in a part, gets larger or smaller when heated.
My opinion is that it gets larger. In this case the hole we're concerned with is in a part (bushing) and the OD is constrained in a steel housing (crank shaft) which has a much lower CTE. I don't know enough about the effect of the constraint on the hole diameter to calculate a clearance value. My estimation is that, with .003" difference between ID (bushing) and OD (input shaft) you are fine. I don't see how the bushing could be the problem.
 
@mattthemuppet2 has a good point about the possibility of the pilot bushing not being seated squarely in the crank.
I understand you're replacing the bushing so just be sure it's fully seated. For peace of mind, please check the runout before installing the new clutch.

I sure hope the problem evaporates.
 
Good point. The bushing fits deep into the back of the crank, so I'd assume the bore is parallel with the OD of the bushing, but it may not be. The new bushing isn't a bushing it's a roller bearing. So not sure how to check run out in that.

I just found this. I may have to make one of them.

 
@alloy

That video was on the money. Good find.

QuickTime RM-130 Indexing Plate. :clapping:

Were you able to find the mounting bolt/dowel pattern dimensions?
 
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