Rivergate clutch issues, need help

[bugedd]

About six months back I did the conversion to my bugeye with a rebuilt Datsun 5 speed and Rivergate conversion, and have been having clutch issues since. It seems that after 3 bleeds, 2 of them with the CNC slave elevated straight above the master, I can't get the clutch to fully disengage. I have a trace of play between the slave push rod and the clutch fork, and with this as recommended. Its is most notice between 1st and 2nd shift, as well as down shifts. I spoke to someone with Rivergate about this issue, and with using the 7/8" bore master that is in the car, and it was suggested that this may be the issue. But after reading at brakecylinder.com about properties with the pistons, the 7/8" bore will push 36% longer travel than the suggested 3/4" bore that was used on the disc brake cars. As my car is disc brake, I sent the 7/8" in for sleeving both sides to 3/4", but now I am trying to figure out if I should have the clutch side done in 7/8" for greater push rod travel.
Can someone help me out with this, I'd like to get the clutch situation squared away once and for all.

 

[64rocksprite]

bugedd..I will be watching with great interest..I have a 7/8" MC on my set-up but I am still in reassembly, so it's untested. I asked a while back if that would be an issue..consensus was that it should be fine. Rivergate's answer to you has me doubting my set-up again.
Have you been able to verify how much piston travel you are getting from the slave?

 

[Billm]

I know that you adjusted the freeplay at the slave but did you adjust the freeplay up at the master? This is VERY important!
You should have very little peddle travel before you begin to engage the master (just enough that the rod "just" moves freely and NO more)
Bill

 

[bugedd]

I adjusted the freeplay out of the pushrod at the master, but thats it. If there is a different procedure, I'd love to hear it. And Bill, do you have any feedback as to the bore size and that is correct for the application?
Thanks

 

[Billm]

If your car is adjusted properly (both upper and lower links) then either bore is fine.
I found with my setup (with a 5/8" bore common Datsun slave) that the clutch force is high with the 7/8" master and easier with the 3/4" but neither are a real problem.
With Gerrard's kit I would stick with the 7/8" master since he uses the big (original) slave and you need the fluid volume and do NOT need the force multiplication. I don't know what size bore the Rivergate slave is so I don't know which is better. (the bigger diameter the slave the bigger diameter master is a rule)
Bill

 

[bugedd]

I just spoke with Rivergate, and their cnc'ed slave is 7/8" bore. He does recommend that I use a 3/4" bore master or smaller. Perhaps that is for clutch feel or for progressiveness. Right now its pretty strong left leg, and the clutch is very on and off. So perhaps that pedal adjustment is where I am screwed up.

 

[Gerard]

There's no question you should have 3/4" bore on both bores. The clutch action is significantly better, with or without the 5 speed, but especially with. It sounds like you misinterpret the longer travel issue as being a benefit. In reality, the longer travel means you'll you may run out of pedal before the optimum clutch release point. Feedback from others and my own experience is 100% in favor of the 3/4" bore and I've never encountered any problems like you describe. Keep in mind that, of the several dozen installs I have either personal or remote experience with, a Datsun clutch and stock slave cylinder are involved, so there may be other issues in your case.

As a side note, did you measure the distances when installing the modified clutch per the Rivergate instructions when installing the modified clutch and pressure plate. Section VI?

 

[bugedd]

Yes, I did take the measurements and they were within required specifications.
On a side not Gerard, ever come across any decent bonnets, other than they super nice one you have? I am getting ready to do body/paint, and can't find a decent bonnet anywhere.

 

[Gerard]

On a side not Gerard, ever come across any decent bonnets, other than they super nice one you have? I am getting ready to do body/paint, and can't find a decent bonnet anywhere.

A guy in Georgia is considering my bonnet.... how to get it there being the issue. Having two Bugeyes, I'm not that eager to let it go in case there's ever a mishap. The race car has a fiberglass bonnet and I may someday want to put the steel one on, so I need to be 'persuaded' to part with it... :friendly_wink:

So, did you say you sent your MC in to be sleeved?

 

[bugedd]

I sent the MC off yesterday to get sleeved. Its actually a 3/4" that was pretty roached out, so he is doing whatever he needs to do.
So dare I ask, how much $$ persuasion do I need to get that bonnet from you? Right now I am thinking of Speedwell, but if I can find steel.....pm me and let me know.