The V8 Owners Forum -

Back to the hydraulic setup ...

My current master cylinder is 19mm internal diameter ...i can get a motorcycle one that 26mm internal diameter ...
Am i going the right way ?

the slave cylinder is 22mm

A larger diameter master cylinder will have less travel but require more effort to operate.

I'd be inclined to find out how it was done for disabled drivers - in the days when they still used clutches, rather than autos.

Motorcycle clutches are nowhere near as strong as car clutches so I doubt that you will find a suitable master cylinder, car master cylinders have a very long stroke compared to a motorbike one so to get the same amount of fluid into the system to operate the clutch you would need a much larger bore size. problem with that is you would need a grip on the hand clutch lever like Atilla the Hun on steroids IE you probably wont be able to operate it.

Have a look at this might be worth considering

www.youtube.com/watch?v=oiXnVl_KZ70

Thanks Dave , i wasnt sure which way it went ...
Spongo ... the trouble is already made sytems are expensive ... (see first post )
As im on disability benefits its going to be home made
The effort required has already been dealt with here = servo
so it looks like orginal master cylinder but cable operated

Aha yes of course sorry I must remember to look at the start of the post as well, should be quite doable with some modification.

Would be interested to see the final set up as well.

Spongo wrote:Aha yes of course sorry I must remember to look at the start of the post as well, should be quite doable with some modification.

Would be interested to see the final set up as well.

... i'll take pictures ) ...lol

What about considering a truck clutch servo? Lots of HGV's have pneumatic clutches and there must be plenty in scrapyards.

Would i need an airpump to run one of those ? )

Would i need an airpump to run one of those ? )

Probably, and the "how" is a different story.
It could be done, like the Land Rovers have for their air suspension.

Back again
Just wondering if a 1.65-1 servo would be enough to make a differance ?
Thanks guys )

Google search for Truck Pneumatic Clutches and you will see the units available. Wabco make some of them, and they do the ABS for Land Rover, among others.
The remote servo idea is still the best one, I think. The Mini had a nice setup with a small unit that you could tuck away in a corner. Some high performance cars even had the units doubled up in tandem for added effect.

If using a remote brake servo to assist your clutch you will need to ensure the slave cylinder remote servo has enough displacement or more displacement than your clutch slave cylinder.


Looking at the AP Lockheed remote servo's the type six it has three different slave cylinder diameters, the larger the dia the less assistance but the more displacement.
slave cylinder size vs displacement;
5/8 = 0.61 cu.ins
0.70 = 0.74 cu.ins
7/8 = 1.20 cu.ins
slave cylinder size vs input/output force
5/8 = 100lbs / 220lbs
0.70 = 100lbs / 200lbs
7/8 = 100lbs / 160lbs

Looks like you 1.6-1 is using a 7/8 slave cylinder dia.
As long as your clutch slave cylinder doesn't displace more than 1.2cu.ins then I think it should work ok.

You say your current clutch slave cylinder is 22mm dia?
So to be less than 1.2cu.ins you'd need less than 894mm travel for your clutch slave cylinder.
1.2cu.ins to cu.mm = 19664 divided by 22mm = 894mm travel.

You could also use a smaller clutch master cylinder or larger clutch slave cylinder to decrease pedal effort but then you also decrease clutch stroke so you might not be able to disengage the clutch.

Tom.

Tom thankyou , thats brill ...
Not sure of the stroke of the slave cylinder ..ill have to have a try to see if i can find out
Probably by laying undermeath the van with a ruler ..lol
the stroke of the mastercylinder is 1. 3/4"

As far as i can gather the whole body is only 110mm long so should be ok