Cam timing marks

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RRoller123
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Re: Cam timing marks

Post by RRoller123 »

just a little more info: if you upgrade a 2L engine to the large valve head, it turns it into an interference engine.
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BigMacDave
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Your car is a: 1978 124 Spider
Location: San Antonio, Texas

Re: Cam timing marks

Post by BigMacDave »

Thank you for those tips.

The manual does talk about slacking, but not in that much detail. Thats a big help.
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phaetn
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Re: Cam timing marks

Post by phaetn »

No problem.

I forgot to add, of course, that after turning it over by hand to make sure everything is still lined up. That's when you can tell if something slipped or not. :)

I had an annoying issue last year when the exhaust cam would always be off by one tooth after I cranked it by hand: everything else was good, but that kept going off. Must have had to do with slack. I kept at it and kept at it, but boy it was frustrating.

More recently I have installed adjustable cam pulleys. The exhaust one slipped in its positioning about a month ago and the engine just lost pull after 4,000 rpm. It was fine up to that point, but then wasn't breathing right and I could feel it wasn't happy. These engines are best between 3,000-5,000 rpm and I could tell it wasn't in its sweet spot. Readjust the synchronization, problem solved. :)

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phaetn
1974 CS1
32/36 DFEV; CompuTronix ign.
9.8:1 c/r; 40/80 intake cam w/ Isky springs
Vicks' SS header & adj. cam pulleys
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BigMacDave
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Joined: Wed Sep 14, 2016 2:41 pm
Your car is a: 1978 124 Spider
Location: San Antonio, Texas

Re: Cam timing marks

Post by BigMacDave »

phaetn wrote:No problem.

I forgot to add, of course, that after turning it over by hand to make sure everything is still lined up. That's when you can tell if something slipped or not. :)

I had an annoying issue last year when the exhaust cam would always be off by one tooth after I cranked it by hand: everything else was good, but that kept going off. Must have had to do with slack. I kept at it and kept at it, but boy it was frustrating.

More recently I have installed adjustable cam pulleys. The exhaust one slipped in its positioning about a month ago and the engine just lost pull after 4,000 rpm. It was fine up to that point, but then wasn't breathing right and I could feel it wasn't happy. These engines are best between 3,000-5,000 rpm and I could tell it wasn't in its sweet spot. Readjust the synchronization, problem solved. :)

Cheers,
phaetn
First, thank you all for your help.

Here it is on. Before i clean everything and button it up, i wanted to make sure this looks right. I don't remember the belt riding on both sides of the aux shaft, but i did turn it 3 full revolutions tdc on the cam marks and everything feels good.

So, is that the way it should be? I don't see any other option, but i just wanted to check.

Thank you as always
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ORFORD2004
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Re: Cam timing marks

Post by ORFORD2004 »

If your crank mark is on 0 yes you are good.
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phaetn
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Re: Cam timing marks

Post by phaetn »

Confirmed.

I thought it was maybe odd that the belt was on both sides of the aux shaft pulley, too. I went out and just checked mine. Hard to see behind the timing belt cover that I have on, but my belt is like that up against the flange on the passenger side of the pulley, too.

I guess I am so used to looking at it from the driver's side that a front aspect threw me. :)

All the best when you go to start it!

Cheers,
phaetn
1974 CS1
32/36 DFEV; CompuTronix ign.
9.8:1 c/r; 40/80 intake cam w/ Isky springs
Vicks' SS header & adj. cam pulleys
A/R's progressive coils, Koni Yellow dampers
205/50-15s on CD-66 style rims
Momo wheel, Corbeau seats w/ 5 pt belt
pics and HD vids
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