Another Valve post

[70spider]

Ok, I just finished measuring the gap of my valves and here is what I got:
EX CYL IN
0.011 #4 0.019

0.016 #3 0.017

0.012 #2 0.018

0.013 #1 0.018

From the data my exhaust are way off. I would have removed the shims and measured them but the tool I have, which came with the car, is a bit off and will not hold the bucket down (prongs are to wide) to allow access to the shim. I did have a brand new one from AR but gave it away to a fellow forum member.
Also a bit of a concern was that the exhaust cam lob for the #1 cylinder is little rounded off, this can't be good huh?
When I was measuring the gaps I noticed no lobes were in sync, I thought two lobes were suppose to be in sync, are my cams out of sync?
Any thoughts on how to proceed? First I'll try to get the tool to work to get the shims measured on the exhaust side.

[azruss]

your exhausts are way too tight. need to get a tool so you can change your shims.

[So Cal Mark]

if the lobe is rounded off, that cam has failed. At this point it can be welded and reground. If you run it until it's completely flat it becomes scrap metal

[Jon124]

You don't actually need the tool to remove the valve shim. I wrote up an instructional a while back with another way to do it, check this link.

http://www.fiatspider.com/f08/viewtopic ... al#p236174

[70spider]

Thanks for the suggestions. I went back out and took some pictures of the cam.
This is the lobe for #3 piston, looks good.

Here is the rounded off lobe on piston #1, not so good.

So I think I may need to replace the exhaust cam, what do the experts think? I have a couple, a new one and one that has about 100k on it but it looks good (got it from Csaba). I was saving the new one for my 1608 rebuild. I guess I have to PM Beek.

You don't actually need the tool to remove the valve shim. I wrote up an instructional a while back with another way to do it, check this link.

I'll check out the link, thanks.
Just one more question, is it possible to replace the exhaust cam without removing the head?

[131]

is it possible to replace the exhaust cam without removing the head?

Yep. Remove the timing belt, unbolt the cambox, remove camgear (Bolt should be very tight), remove rear plate and withdraw cam. Clean it all up, might as well replace the front seal, refit with new gaskets and adjust clearances. If the old replacement cam is in good nick, I'd use it, coat the lobes with assembly lube before you get too carried away.

[So Cal Mark]

that cam has failed. I'd suggest you start using oil with zinc in it

[70spider]

My thoughts on the failed lobe are the cam failed a long time ago and the mechanic who did the head work prior to me purchasing the car simply put the old failed cam back in. My reasoning behind this is that the gap is extremely tight and consistent with the other exhaust gaps, if it failed in my use wouldn't the gap be a lot greater?

I'd suggest you start using oil with zinc in it

Since getting the car I have run Castrol GTX 20W/50, I couldn't find the zinc values but found some other information saying that Castrol GTX High Millage and Quaker State Defy have higher zinc levels than their standard oils. Here is a link for those interested in some brands zinc levels: http://speedtalk.com/forum/viewtopic.php?f=1&t=35836

It looks like I will need to replace the cam. I will be doing a lot of reading, my mechanical endeavors so far have been auxiliary (intake manifold, carburetor, water pump) not internal so I am a bit nervous.

I had a thought, I have all the parts for a new head to be built maybe I should have a real mechanic rebuild it and then simply swap the new head for the old head.

[70spider]

Well I think I'll try to replace the cam. I have a few questions, seeing how both my manuals do not go into detail on how to do this.
1. Should I rotate the engine to align the camwheels to the pointers before starting?
2. What is the best way to remove old gasket material from the head and cam box?

[131]

1. Should I rotate the engine to align the camwheels to the pointers before starting?
2. What is the best way to remove old gasket material from the head and cam box?

1. Yes, always. Before doing anything involving timing belt removal, line them up.

2. This is painful, you need something sharp and hard enough to remove the old gasket, but you need to avoid damaging the aluminium. Put a small piece of cloth or similar into the oil drain galleries in the head after you remove the cam box, you don't want to drop bits of gasket down there and block anything.

The cam lobe is worn/damaged on the high point. The base circle, where the clearance is measured is not damaged.

[70spider]

131 thanks for the confirmation. When I get the cambox off tommorrow I can measurre the shims. Would it be safe to assume I could use my old measurements on the gap as reference point to determine which shims I need to use to achieve 0.020" gap, or do I need to start over once the new cam is in?

[azruss]

I never liked the idea of removing cams and valves with 2 of the pistons at TDC. I do mine at 90 degrees so all pistons are at half mast. Do the rotation with the timing belt on and document where everything is. Once you have everything close, you can move to TDC to make sure everything is on the money.

[70spider]

azruss, that makes since. I have a feeling that my cams are not properly aligned as you said

never liked the idea of removing cams and valves with 2 of the pistons at TDC

. Like I said earlier

When I was measuring the gaps I noticed no lobes were in sync,

. If two pistons, #1 and #4, are at TDC at the same time then it would be safe to assume that the lobes on the intake and exhaust should be in the same positions, mine never were. So the question is how do I get the cams to sync up with the pistons?
When I got the car the first thing I did was change the timing belt. I had noticed then that the cam wheels didn't line up with the pointers exactly, they were close, and in my naivety left it that way.

[aj81spider]

I'm not sure what you mean by "lobes in sync." However, although 1 and 4 are at top dead center at the same time they are not in the same stroke (one is compression and one is exhaust) so the cams won't line up.

[70spider]

aj81spider, thanks for the clarification. My stupidity strikes again