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the4ork · Joined: 17 Dec 2009 Posts: 68 Location: lemoore California

took the valve cover off today and adjusted all the valves to about 4 thousandths, and noticed i have a smashed/flattened looking lobe on the exh side of #1

what could have caused that? all other lobes and lifters appear fine, the lifter on the messed up lobe looks a little chewed up. is it possible something made its way between the lobe and the lifter? something metal?

i just had the head rebuilt during a headgasket change so this is a suprise to me.

anyways, im in the market for a new used cam and lifter :/

its my girlfriends daily so i dont need anything fancy, although a cheap performance cam would be nice

Min · Posted: Tue Mar 30, 2010 3:39 pm Post subject:

Oil without enough ZDDP content. And/or it was just time for it to fail. Unfortunately hardened parts like lifters and camshafts do not last forever, they are designed to fail eventually. But first make sure your running the correct oil, which is the most common cause of this problem.

Min
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Custom means it didn't come from a box.
1980 n/a with EDIS and Megasquirt II Injection. 7 different colors and counting.

Rich H · Posted: Tue Mar 30, 2010 5:18 pm Post subject:

As above - it's just life-ex it happens.

It is accelerated if the oil flow is interrupted but once the harded skin is worn through then they wear flat in no time at all.
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1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

the4ork · Joined: 17 Dec 2009 Posts: 68 Location: lemoore California

yeah she has let it get low on oil a few times... to the point the light was coming on.

ive been trying to figure out where its coming from. it looks like it drips down out of the cap, across the valve cover via the fins to the back of the sprocket, and then down the block. only when it runs.

changed the cap and it still does it, so it must be the valve cover gasket, which unfortunately is only like 3 months old

im running 20w50 shell oil in it

Rich H · Posted: Tue Mar 30, 2010 6:29 pm Post subject:

check all the crank case breather hoses are still intact, they heal over or rot in time.
_________________
1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

Min · Posted: Tue Mar 30, 2010 11:23 pm Post subject:

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

The other big cause of this is a failed cam oiler tube, or more frequently, the little plastic elbow that connects it to the first cam bearing cap. If the elbow develops a crack, it will bleed pressure from the oiler tube, which in turn results in improper oil flow across the cam and lifters. You should carefully inspect your other lifters and cam lobes for any signs of wear. I would strongly recommend replacing the elbow at a minimum ($12.50 from yours truly), and verifying that the tube itself isn't clogged or otherwise compromised. It's also time for a new cam and lifter in that bore. If you don't want to buy new, I have secondhand OEM cams and lifters available (but not listed in my used parts bin...contact me via PM if interested).
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erstwhile owner of just about every 924 variant ever made

gla924sem · Joined: 08 Nov 2002 Posts: 405 Location: Taylor, Michigan

Have a stock cam with about 12K on it. Replace it with an Intergal Race cam.

Does not have the cam gear.

Will let go for $75 plus shipping from 48180

Can send pics

Slam · Posted: Wed Mar 31, 2010 1:31 am Post subject:

I agree about the cam oiler elbow, but when that fails, doesn't the wear usually show up on lifters 7 & 8? Having a failure that close to the elbow is rare.
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'88 944 Auto - may or may not resurrect

ideola · Joined: 01 Oct 2004 Posts: 15550 Location: Spring Lake MI

I had the exact same lifter and lobe damaged on the 941, although in my case I don't believe it was due to the elbow. In my case, it appeared that the coily retainer thingy on the valve guide seal let go and got loose in the head. Although some here doubted it caused the problem, and hypothesized that it was due to one of the aforementioned causes.

Still, the elbow is easy to check, easy to replace, and cheap.
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erstwhile owner of just about every 924 variant ever made

the4ork · Joined: 17 Dec 2009 Posts: 68 Location: lemoore California

I know it's not the elbow, oil flows prettywell in the tube, thy was my first guess.

I think it's from low oil pressure from runnin the oil level too low or foreign debris

anyone got a free cam and I'll pay shipping?

ithink there is a 924 at the yard, cams are like 15 bux I think

Joes924Racer · Posted: Sun Apr 04, 2010 7:54 pm Post subject:

You could for 150 bucks send it to schnieder racing cams and theyll
weld and gring up a new hotter gringd on the one you have. Ited be best to give them a cam that hasnt lost its hardness if thats the issue. Ask if you go that route. theyll maybe reharden it for you dont know if thats an issue.
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1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo.