CAS drive play

[bobbrown]

New camshaft! does assume you can get one they are listed on a couple of US sites for around £225.00 ish
May be a call to Lotus as they may well have one they are willing to sell at a reasonable price.
The inlet cams were on the after sales list 2 off for £55.00 + vat to give an idea of what the price could be IF they have one.

As a note the drive slot does have a max width of 5mm

[norman lovie]

imagination time
lets say - some time in the past, the bush was loose on the shaft - worn locating pin etc
you go to bolt up the CAS assembly onto the head, but the bush key isn,t quite located into the cam - it's sitting at a slight angle / droop cause the bush is loose on the shaft
As you make up the flange bolts - the key will force into the cam slot, but being at a slight angle to the slot - it causes ( broozes) this taper on the lead in to the slot

ok - due to timing issues because of the loose bush, you haven,t fixed it - you go fit a new assembly, leaving the damaged cam - which is where I am at now

[madbilly]

FYI I've got maybe 3-4 degrees play in my CAS drive, but I'm measuring this on the sensor wheel and not further in. I had the assembly out at the weekend and there is a little bit of play at the camshaft end of the assembly and whilst I considered changing the peg I decided not to for now. The key on the assembly for mating into the exhaust camshaft does have some scoring on it so perhaps it has been worn down and there is some play there. I can't particularly see any wear on the camshaft end though, but if I take it out again I'll have a look, maybe measure stuff, and let you know what I find.

When I first took the assembly out a few weeks ago the peg had been pushed out past the spring and there was a some swarf in the area. I put the peg back in and it dramatically reduced the play in the sensor wheel and cured my intermittent misfire issue.

[norman lovie]

OK thanks good ( and bad - sorry) to see that it might not be a one off

[madbilly]

I've not measured it yet but the service manual says that if the slot is >5mm then the camshaft should be replaced. It's the engine section, removing the camshaft I think. Actually it talks about distributor drive not CAS drive but I assume it's the same for NA and turbo.