I need to get my flywheel closer to my concentric clutch slave. Do you think I can use a shim from an auto flexplate? Something like this: http://www.rimmerbros.co.uk/Item--i-FRC9203
I can't really adapt my bellhousing without major work - milling current slave seat down, creating a locating bore for an adapter then making an adapter of the correct height for the slave to sit on/in.
It would be much easier to just move the flywheel about 1mm or so - that's not enough to mess up the starter is it?
I'm using an AP concentric slave with an AP 240mm clutch. The clutch needs about 12mm or so to disengage, the slave has 18mm max travel and when retracted the bearing is currently 5mm from the fingers on the clutch cover. That's all a bit close to the limit and ~1mm at the flywheel would make all the difference.
I could possibly shim it on its 3 mountings a little but too much and it won't seat in its recess which keeps it concentric to the gbox input shaft. The slave sits on a raise part of the bellhousing casting which has a recess machined into it.
I've just measured up and the clearance is approx 5.9mm between bearing and clutch when the bearing in fully retracted. So 5.9 + 12.5 = 18.4 - to much!
I think I could shim the slave .5mm and use a 1.25mm shim on the flywheel to get it down to 16.65 ish then I'll be happier.
Next job it to find a master that'll give me enough volume, my current .7" bore at full stroke only gives me 8.4mm slave travel - bugger.
There's a ring on the base of the slave that locates in the recess, the ring sticks out 2mm. If I make some kind of flat shim for the slave from say 1.6mm ally sheet that only leaves .4mm of the locating ring in the recess. That may be enough but it doesn't sound much but it will leave me using 16.8mm out of the 18mm max slave travel.
This all seems a bit precise considering it's me that measured it !!
It's all a bit annoying as I had my bellhousing machined to give 6mm (5.9 as it turned out) clearance for clutch wear as AP told me that was the max distance the cover fingers could move out. Really though the clearance should 4 to 4.5mm to make the rest of my system work
I meant a proper spacer- rather than a shim. Then you can move it any distance you require rather than just the amount of depth you have built in. So I imagine a bit like this:
That would definitely work and would probably be the best solution but I would need my bellhousing machining down again and need a spacer making. It cost me £60 to get the bellhousing machined the last time so it's going to be another £60 + the spacer hence looking at the alternatives.
Why would the bellhousing need to be machined? If the slave fits on there at the moment, the rear of the spacer would be identical to the rear of the slave so no machining necessary
If you wanted to pop your slave/release bearing in the post to me I'd be more than happy to make you a 5mm spacer for it in ally and it wouldn't cost £60!
Without machining the bellhousing the spacer would need to be about 1.5mm thick which is less than the depth of the locating ring on the slave so it wouldn't work.
I think the original machining was £60 because I needed the concentric recess which meant they used a CNC to get it right. If I get the 'platform' for the slave machined flat then it should be possible to make an adaptor like your diagram that locates on the main hole that the input shaft comes through but has the correct recess diameter on the other end for the slave. I'll have a think about it.
I guess I'll be taking the gearbox out again tonight then
Progress.
I had an email waiting for me from the AP technical team. It seems the 240mm clutch cover does NOT need 12mm bearing travel to release it only needs 8mm when used with an organic plate.
That means I have 5.9mm from fully retracted bearing to clutch cover then another 8mm to release the clutch - that's a total of ~14mm well within the max slave travel of 18mm.
All I need now is a .75 master cylinder to make it work (where's the fingers crossed icon?)
Mike
seight wrote:Progress.
I had an email waiting for me from the AP technical team. It seems the 240mm clutch cover does NOT need 12mm bearing travel to release it only needs 8mm when used with an organic plate.
That means I have 5.9mm from fully retracted bearing to clutch cover then another 8mm to release the clutch - that's a total of ~14mm well within the max slave travel of 18mm.
All I need now is a .75 master cylinder to make it work (where's the fingers crossed icon?)
Mike
Owner of an "On the Road" GT40 Replica by DAX powered by 3.9Hotwre Efi, worked over by DJ Motors. EFi Working but still does some kangaroo at low revs (Damn the speed limits) In to paint shop 18/03/08.
Engine back in now, clutch works with the .7 master cylinder but only just so a .75 is on it's way. I had to take part of the steering column mount off to get absolutely all the travel possible from the .7 so .75 should be just right.
Throttle pedal/linkages next
