USA and Canada owners

[Tony K]

Emissions equipment: I've got everything off of the white car except the hub for the pulley on the end of the exhaust camshaft, and the boss behind the hub that the seal fits around.

Question: Can I just remove the hub and the boss and just bolt the thrust washer back in place and put the correct end cover on, or do I have to recheck end play and use a different thrust washer? . . . Or ???

Also, there is a vent line from the fuel tank. What should I do with that?

- T

(Edited for Canada! )

Edited March 26, 2007 by Tony K

[Esprit Aviation]

Tony,

Do it just like you mentioned. I did mine many years ago, and don't recall any trust/end play problems. Not sure about the vent line. Mine is now a fuel cell up front, and I'm wondering the same thing.

Cheers, Lee

[WayneB]

Hi Tony, like Lee, I unbolted the air pump pulley boss and spacer, and ordered and installed a new camshaft housing rear cover plate (and rubber O ring seal).

I think the vent line goes to the charcoal cannister (if its still installed), but Im not that up on S1s!

[Tony K]

Thanks for the replies!

Okay, remove and forget it is! Whew!

So just for the sake of education then, what is the thrust washer's purpose -- to keep the camshaft from creeping forward?

If I go and look at my car later today and the charcoal cannister is gone, what do you suggest I do with the vent hose?

- T

[WayneB]

Its a good job you mentioned that Tony! I answered that question at 7.30 this morning before I had fully woken up.

I remembered I left the thrust washer in, but used a shorter bolt to hold it on the camshaft (but removed the air pump boss)

The washer controls cam shaft endfloat (preventing it from moving back and forwards) , it shouldnt be left out.

[Tony K]

Backwards, too, or just forwards? It seems to me that once I remove the boss there is going to be a space between the thrust washer and end cap, but I suppose the cam sprocket or something else is in a fixed position up at the front so the cam can't slide backwards, and the thrust washer "holds it in place" at the rear?

???

Forgive my needling questioning -- this is how I learn.

Edited March 26, 2007 by Tony K

[WayneB]

Backwards and Forwards.

It bares on the camshaft housing cover plate to prevent it moving backwards.

There is a raised "ridge" machined into the camshaft housing that the thrust washer rides on to prevent it moving forwards.

Edited March 26, 2007 by WayneB

[Tony K]

Wayne: Thanks.

Okay, I feel kind of stupid now -- I looked right at that very page in my workshop manual and right at that diagram, and didn't see the words "THRUST FACES" in big capital letters! :)

So technically, I should check the "depth" of the new end cover to make sure it is the same (or close enough) as the one that's coming off. . . .

- T

[yeller77]

All this begs the question, as the camshaft thrust washers come in different sizes, how does one measure the clearance and/or, with the purchase or installation of new cams, how does one know what size to install, esp. if the old washers are too thick (if that's possible)?

Discuss...

[WayneB]

Eric, to measure the end float of the cams, a dial indicator must be set up to read on a vertical (preferably machined)surface of the camshaft (pulley, pulley mounting , lobe or side of bearing face)

Push the cam all the way back, then zero the gauge and pull or carefully lever it forwards.

The reading on the gauge will be your total end float in thousands of an inch.

If its greater than the 0.001-0.008 in allowed by Lotus, remove the stock shim, measure it with a micrometer and add the amount recorded from the dial gauge to that figure(subtracting 0.001-0.008 in) Then substitite a shim as close to that dimension as posible.

If the washer is too thick, the camshaft will bind up when the camshaft cover plate is installed making it difficult to turn) (substitute smaller shim until clearance is obtained)

[yeller77]

Thanks, Wayne!

E.

[Geeman]

I am now looking at doing this very same thing.  I am hoping to ditch the air pump hub (53), spindle (50) and specific endcap (55) and replace with the fully enclosed endcap (16).  I am not sure how best to check the endfloat with the engine in the car.  How do you lever the camshaft back and forth to measure the endfloat, and without the endcap fitted what is to stop the camshaft pushing forward?

The thrust washers have completely different part numbers one for with air pump, the other without.

 

[EXCEL V8]

Part 8 both stops the cam from moving forward and determines the end float.  End float is measured at the front of the cam using a dial gauge, having fitted part 8 and the end cover (16) and by pushing the cam forwards and backwards.  If end float is too great fit a thicker "part 8" washer, and vice versa.

Pete

[snowrx]

I would try a dial indicator on the back of the cam pully, but given the small measurement range, you might see flex in the pulley if you use it to move the cam back and forth. Back is simple, just a block and prybar between the bulkhead and cam bolt, but moving the cam forward might need a careful pry between the cam carrier and the center of the pully hub as you watch the dial.

I'll confess that when I did this, I assumed the new end cap would have the same depth as the old one and just re-used the existing thrust washer, making a bushing to make up the difference in ID between new bolt (12) and old spindle (50). JAE had the cap in stock.