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-   -   Rusty cam gear sprockets (https://rennlist.com/forums/928-forum/686629-rusty-cam-gear-sprockets.html)

Leon Speed 03-18-2012 05:20 PM

Rusty cam gear sprockets
 
Are these excessively rusted or is this normal? Reusable or garbage?

http://i560.photobucket.com/albums/s.../DSC_04342.jpg

http://i560.photobucket.com/albums/s.../DSC_04332.jpg

http://i560.photobucket.com/albums/s.../DSC_04322.jpg

http://i560.photobucket.com/albums/s.../DSC_04312.jpg

ammonman 03-18-2012 06:53 PM

How well do they fit on the ends of the camshaft? If the are very snug and have to go on straight to fit then i would say they are fine. If there is any noticeable wobble or tilt to the fit as they slide along the cam end I would say change them.

Mike

Herman K 03-18-2012 06:55 PM

UnusuaL to see that kind of pitting but if they still fit snug coat the inside with a Molykote G-n Metal Assembly Paste (Dow Corning) and use them again

Dave928S 03-18-2012 07:17 PM


Originally Posted by Herman K (Post 9371757)
UnusuaL to see that kind of pitting but if they still fit snug coat the inside with a Molykote G-n Metal Assembly Paste (Dow Corning) and use them again

Maybe there was a leaky water pump sometime in the cars history giving a steamy environment inside the covers, with condensation on cool down?

I would be concerned with the possible lubricating effects of the assembly paste both on the inside and, more critically, on the stepped end of the cam face. The consequences of a lubricating effect might mean premature loosening of that cam sprocket hub, and then hammering of the keyway and everything else that goes with the slight rotational movement. I think I'd just be using them clean and dry if they're still dimensionally OK.

Leon Speed 03-18-2012 07:25 PM

They fit very snug. In fact, I had to use a puller to get them off. I guess these haven't been off since new.

ZEUS+ 03-18-2012 07:27 PM

1 Attachment(s)
Not really worth taking the chance. They are only about 30 bucks each. Mine looked alot worse when I had to replace them.

Mrmerlin 03-19-2012 12:00 AM

I would replace these parts and install them dry,
any lubricant will reduce the clamping effect given by the cam bolt,
and thus cause possibly catastrophic damage.

It is common for these parts to crack along one of their shanks, with the corrosion on the inside of the spider bore it may have a place to happen.

These are critical to cam timing

SeanR 03-19-2012 11:02 AM

Agree with the above, get new ones and install dry.

Leon Speed 03-19-2012 05:11 PM

Hey, not a bad price for a Porsche part. For the price of new it makes sense to replace it. I do have some discoloration on the cam noses as well, but noting to be done about that unfortunately.

Mrmerlin 03-19-2012 08:02 PM

for the cams dress the surface with some 600 grit and oil ,
clean with acetone when your ready to fit the new parts,
be careful with the front seals so they dont get acetone on them

Mark Anderson 03-19-2012 08:18 PM

I would NEVER consider using them. When they fail it's big $$$$$$$$

RKD in OKC 03-19-2012 08:20 PM

REPLACE THEM. Mine were rusty that broke when the end of the cam shaft broke off on the drivers side and am currently replacing all the valves on that side.

Leon Speed 03-20-2012 05:55 PM

I'm convinced! I'll replace them.



Originally Posted by Mrmerlin (Post 9374780)
for the cams dress the surface with some 600 grit and oil ,
clean with acetone when your ready to fit the new parts,
be careful with the front seals so they dont get acetone on them

Mrmerlin any special reason for acetone? Will denatured alcohol work? I have that at hand. Front seals will be replaced.

Mrmerlin 03-20-2012 08:10 PM

acetone will evaporate the quickest and leave the surface grease free,
alcohol may not cut the oil from the metal as well

Podguy 03-21-2012 03:54 AM

They look normal to me

Glass bead blast them and spray on some black paint.


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