Hi
I am assessing a late three bearing engine, which I thought had had an easy life since it was only at +0.020. But it turns out to have been sleeved so it has done a few more miles than I originally thought!

Everything seems okay except the end float on the camshaft is about 10 thou - quite noticeable. This seems a bit high? Can it be corrected without stipping the engine? (I have seen the advice from Ruairidh elsewhere on the site about dealing with the square bolthead, which I can do if necessary.)
However, I wondered if building up the front end of the camshaft with a bit of solder might help correct the problem without further dismantling?

Regards
Colin

Colin

The end float is adjusted by lapping the gear onto the shaft. I presume this might be do-able in situ if you remove the 2 timing gears and lock up the camshaft? Personally the idea of lapping paste any were near a built up engine worrys me so I would remove it first, at least that way it can be well cleaned afterwards.

Steve.

I bow to wiser councils, of course, but I would say 2 thou endfloat is what you're aiming at. I think the only way to achieve this is to remove the camshaft and lap the gear in out of the engine. It is a bit tedious because when you wash off the grinding paste and tighten up the nut onto the gear it all goes up some more! Some experimental grinds are necessary and beware, it goes quicker than you think. I have been known to do it wrong and end up by taking a thou or two off the back of the boss on the gear.
As the cam floats back and forward it varies the valve timing. You might care to decide how significant 10 thou is in this context.

Regards, Stuart

Hi Steve and Stuart
Thank you for the advice and warnings. I will proceed with caution.
Regards
Colin

I suppose that you could always use a shim washer to take up end float if you didn't want to strip the cam and bearing out

Charles

Hi
Have just placed a couple of homemade shims between the cam bearing and the timing wheel and these have taken up most the slack, leaving a couple of thou movement. Seemed the simplest thing to do under the circumstances.
Thanks to all for the advice.
Regards
Colin

Old post, I know, but with the same problem and reluctant to strip the engine down, how did you get the timing gear off the camshaft in situ, Colin, so that you could fit shim washers?
John

Hi John
The engine was out of the car at the time. I used a friend's three leg puller, possibly aided by a hide or rubber mallet? However, I imagine there are others here who have their own methods when a puller is not available?

If the engine had been the car, I think it would have been necessary to remove the radiator, at least...
Regards
Colin

Hi John,
As said above - you shouldn't fit shims between moving and stationary parts - it'll eventually graunch and cause a lot of problems. If the clearance is only a little out you could try tightening the nut to drive the gear further up the taper. You need some clearance but anything that has noticable clunking movement will hammer against the front cam bearing retaining bolt giving more movement and an oil leak. I don't use the square headed peg bolt but tap down 5/16"BSF through the crankcase right into the cam bearing to really anchor it - an Allen headed bolt sealed by a fibre washer then allows retightening insitu.

Depending on how long the cam and gear have been initimate and how tight the taper has been driven up (as above!) I find a long drift just onto the centre of the gear over the taper is often successful. Don't try levering off the crankcase - the lip there is quite thin and fragile.

So; if the engine is in the car and running and the clearance isn't desparately big, less than 10thou-ish? I'd try tightening and add to the list of things to fix the next time the engine comes out.

Dave

Colin - suggestion from here is that the desirable figure to aim for is 4 thou. Good Luck, Cheers, Bill in Oz

Location: Euroa,Victoria

I find that a gap of 12 thou with the gear not tightened usually gives an acceptable 3 to4 thou when tight. You still have to do some final adjustment but it saves taking the thing apart several times while setting the gap. The

Thanks everybody for your help.

Bit annoying as not anticipated.

I'm going to check the bearing peg bolt first, reducing the head in situ (the bolt is quite loose), and then try your method, Dave, of tapping 5/16" BSF right through and into the bearing. I may then include a nut and Dowty seal on the Allen screw, as described on the Cornwall club site.

Thanks again

John

Does the hole in the camshaft bearing go right through the bearing wall?

The reason I ask is that having removed the peg bolt, I can shine a torch down through the hole. Is what I see the bottom of a blind hole in the bearing, or is it the camshaft itself? Whichever it is, it moves when I work the timing gear back and forth.

The hole should go right through. You can see the camshaft.

Thanks, Alan