Update Bilbo's new race clutch + fitting external Hydraulic slave

[Bilbo]

Hi all

 

Well the engine fired up tonight but it still need a bit more work. ☹️

 

To recap the old AP road one failed massively at the club drag race. I have now fitted a AP race clutch assembly with a CP7381-CE80 SF pressure plate, 311 ft-lbs with a 6 paddle Cerametallic friction plate CP4946-7 and the Caterham external slave and master cylinder.

 

First a big thanks to Norman and Arnie who have been providing offline very helpful advice. *thumbup*

 

Well you find all the bits up to the engine back previously posted that Gram Ford also helped with and Wilcox Engineering. *thumbup*

 

Since my car is 1988 it does not have any knock outs for the master cylinder ☹️. Also Caterham do not have a write up for fitting the external slave ☹️.

 

So as to fitting the master cylinder well I made up a template in thick cardboard. This I fixed to the outside of the peddle box then sprayed the holes yellow. Then as the electric drill would not really fit from the outside, I had to drill from the inside by best guess. That really was fairly easy. So three 8mm holes with increasing drill bit sizes then removed the main part of the big hole for the centre of the master with a round diamond tile cutting hacksaw.

 

Then with a conical grindstone, the type you would use for porting a head, I ground out the rest that took a while and ended up with a near perfect round hole.

 

The two fixing bolt holes I centre drilled from the outside, well 5 drill bits later had 2 x 2mm holes near centre. Those were then drilled out from the inside and finished with a needle file. Fitted the master cylinder bu88er it just touched the brake master cylinder. Well very slightly filed out one side of the top hole the other of the bottom, a bit of easing of the main hole and 3.8 clearance between both master cylinders.

 

Then the hydraulic line for slave stumped me for a while. Till I decided that the threaded hole on the slave was very slightly tapered.

 

Next problem the slave comes with a big rubber dust cover. With this fitted the peddle moves too far for the clutch to work so I added some washers between it and the bellhousing. Pushing the car in gear the bite point was vague and actually changes its position each time. That evening I found an old thread that said basically dump it. More chat to Arnie and Norman.

 

Well currently I have Bu88ered up the air temperature sensor taking the engine out as I failed to pull it off and the wires have detached. Also run out of time to make MIRA tomorrow.

 

Still the engines fired up and the clutch works, car sound crap but the sensors still missing and I have not checked the carbs.

 

The clutch feels very odd and needs more adjustment. I will get more leg room as it only needs to move an inch ❗ Raise me foot say half an inch and full clutch. I do still need to make a stop as its bottoming out at just over an inch.

 

There is about 8 washers between the slave and the bellhousing. I have not checked but I think the clutch assembly is shallower than the old AP road one hence there is more release arm movement. Plus the latest release bearing from Caterham is slightly thinner front to back. That all mounts up by the end of the release arm. The brass adjustment bar that fits on the slave is presently set at half way. Also it really needs an additional nut to lock its position. The two holes in the bar that fixes to the clutch peddle is set on the one that gives max leg room.

 

So no dust cover for the slave well few ideas. One is to get the right position set for the peddle then replace the washers with a spacer. This might fit inside the dust cover, with luck. The second is a hard rubber washer fixed with sealant fiited between the spacer and the slave... the last idea is more oddball err use a condom instead well I said it was an odd idea. Still I wonder how many packets of aspirin I buy first 😬 I will defiantly will get odd looks, if I tell them at 56 its for me slave 😳

 

I will let you know how I get on

 

 

'Can you hear me running' ......... OH YES and its music to my ears 😬 😬 😬

1988 200 bhp, 146 ft lbs, 1700cc Cosworth BD? engineered by Roger King, on Weber's with Brooklands and Clamshell wings, Freestyle Motorsport suspension.

[elie boone]

Bilbo, I don't use the big dust cover and a friends K series thats in my garage does'nt have it eather.

I use an extention on the axe of the slave cil. with at the end a nut witch has been rounded at one side, you will have to take away the sharp edge on the release fork.

U adjust the clutch bite point by simply adjusting the nut on the release fork side.

The set up on both Cat's is the same and works perfect with clutch bite near the middle without spacers.

 

If you need a pic. i could ask my brother to come round and take a pic if that would help you.

 

Pic available tomorrow

 

 

Can you hear my running............. NO ????????? thats because i only have 170 BD power

 

Edited by - elie boone on 5 Aug 2006 10:27:09

 

Edited by - elie boone on 5 Aug 2006 12:42:58

[Bilbo]

elie boone

 

Me

 

If I take up all the slack on brass threaded brass extension the clutch is still engaged. As I said I think the race cover is not as deep as the road one hence the arm has a lot more travel. Plus the race pressure plate sort of has short springs.

 

The old one here

 

New pressure plate hereand here and here

 

The new plate Fiction Plate hereand here

 

Still I will be interested in the photo but mine is as on another owners site here you will note he does not need washers but Arnie did need them.

 

Maybe its just different engine types 🤔

 

EDIT Also I would rather have some form of dust cover it gets very dirty down there.....its not just a track car

 

'Can you hear me running' ......... OH YES and its music to my ears 😬 😬 😬

1988 200 bhp, 146 ft lbs, 1700cc Cosworth BD? engineered by Roger King, on Weber's with Brooklands and Clamshell wings, Freestyle Motorsport suspension.

 

Edited by - Bilbo on 5 Aug 2006 19:13:27

[Bilbo]

Bad news the replacement sensor arrived this morning

 

Why bad news that because it is JUST the sensor and not its connector to the loom ☹️

 

Overnight thoughts as the peddle travel is just an inch in fact could be less why not replace the arm with a solenoid and a foot pressure switch. 😬 None of that messing about with paddles 😬

 

Yep I bored 😬

 

'Can you hear me running' ......... OH YES and its music to my ears 😬 😬 😬

1988 200 bhp, 146 ft lbs, 1700cc Cosworth BD? engineered by Roger King, on Weber's with Brooklands and Clamshell wings, Freestyle Motorsport suspension.

[elie boone]

Bilbo, I have about the same set up for the slave cil. ( BD with ally bell )

 

You can do 2 things : see that u get more thread on the slave cilinder extension.

Or /and try to get a spacer under the release arm where it sits against the bell, bringing the releasearm more forward.

 

In a week or 2 i can tell you if you can put a spacer underneath the releasearm supporting point on a VX without remouving the engine and g.box.

[Bilbo]

Hi elie boone

 

In a week or 2 i can tell you if you can put a spacer underneath the releasearm supporting point on a VX without remouving the engine and g.box.

 

That would seem impossible without a slot at say 2 o'clock in the bellhousing

 

Well the old Clutch Release Bearing was 32.5mm. the new one 31mm so 1.5mm less and the old Pressure )Plate 36.17mm the new 29.88/27.51mm ( both from AP Catalogue). I am not sure why there seems to be a 2.37mm tolerance

 

Anyway using the 29.88mm that's 6.89mm plus 1.5 so the new set ups is 8.39 mm less. Multiply that by the length of the Clutch Release Arm and I think this explains why the arm is so much more forward at the bite point.

 

The peddle bottoms out just after the bite point I need to think why its not that the arm is not hitting the end of the slot.

 

In fact it does need a bit more clearance.

 

There is 3 options for this

 

1. Maybe its just that the thread bar need to move the peddle more down as I am at the limit of the pull on the slave

 

2. I have fitted the Friction Plate the wrong way round and its bottoming on the boss. I will ring AP. I should have done so before fitting it but it was the weekend before me holiday and I did not want to leave the engine sotting on the garage for that time.

 

3. That's the limit of travel on the Pressure Plate springs

 

Hopefully, its just 1 and/or 2.

 

Currently I am leaving it till the sensors fixed.

 

I had a short play driving it away in the driveway today it is VERY in or out and really should not bed any bedding in.

 

'Can you hear me running' ......... OH YES and its music to my ears 😬 😬 😬

1988 200 bhp, 146 ft lbs, 1700cc Cosworth BD? engineered by Roger King, on Weber's with Brooklands and Clamshell wings, Freestyle Motorsport suspension.

[Bilbo]

Hi

 

Well it seems the Friction Plate is the correct way round with the spline boss facing the Pressure Plate. 😬

 

The maximum movement need to release the Friction Plate is 5.5mm which allows for spring wear any more is detrimental as the Clutch Release Bearing can start to hit the pressure plate .

 

Also IF you have an internal Clutch Release Bearing you need 3.5 to 4mm of movement upstream so that it’s not too close and still allows for spring ware. So you could get away with 10mm of travel. These are distances within the Bellhousing and not at the Clutch Peddle or Slave.

 

'Can you hear me running' ......... OH YES and its music to my ears 😬 😬 😬

1988 200 bhp, 146 ft lbs, 1700cc Cosworth BD? engineered by Roger King, on Weber's with Brooklands and Clamshell wings, Freestyle Motorsport suspension.

[elie boone]

I have mounted a lighter flywheel on a VX together with a new pressure plate, it is the new style of shallow pressure plate witch is also shallower.

I need to see if it will work : nock the pin out ( on the opposite ot the slave )in the bell, prepare a threaded bush witch i need to defy the lenght. Source a steel washer and glue it on top of the bush. Position the bush between bell and release fork and bolt it from the outside. It must be possible to do this with a bit of patiance a long magnetic arm and som masking tape.

 

I'll keep you posted on the progress.

[Bilbo]

Hi elie boone

 

Well the must be a lot more room in a VX bellhousing doupt I could even see the pin A slot in the bellhousing where the pin is located might make it possible 🤔 Still you would have needed to do that with the bellhousing out.

 

'Can you hear me running' ......... OH YES and its music to my ears 😬 😬 😬

1988 200 bhp, 146 ft lbs, 1700cc Cosworth BD? engineered by Roger King, on Weber's with Brooklands and Clamshell wings, Freestyle Motorsport suspension.