924Board.org

flosho · Posted: Sat Apr 18, 2009 3:14 am Post subject:

Hey, 4 days after I bought my car, the timing belt broke and I spent my graduation money fixing it! 5 years later, I'm still here lol.
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Paul · Posted: Sat Apr 18, 2009 8:33 am Post subject:

If you had the camshaft lined up and was able to turn the crankshaft a complete 360 degree revolution, valves were already bent.
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White 87 924S "Ghost"
Silver 98 986 3.6l 320 HP "Frank N Stein"
White 01 986 "Christine"
Polar Silver 02 996TT. "Turbo"
Owned and repaired 924s since 1977
Porsche: It's not driving, it's therapy.

Crux Mason · Joined: 08 Apr 2009 Posts: 67 Location: iowa

Stupid question: Would I be able to turn the crankshaft pulley by hand hard enough to do damage to the valves?

I don't think I went all the way around but I don't really want to try it now to see if it will.

alexvex · Posted: Sun Apr 19, 2009 6:29 am Post subject:

GoodCat · Joined: 11 Apr 2009 Posts: 31 Location: Indianapolis, IN

^^
Which is probably exactly what I did.

They did mention the compression was literally almost zero on 3 and 4 and that valves were prolly bent, but there was more than likely more work that needed to be done. If this is the case, should I only be looking to do a valve job, or a whole engine rebuild? If anyone near Indianapolis has a good condition motor for my '80 924 at a good price, I'd rather buy and do a swap personally.
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1980 Porsche 931

alexvex · Posted: Mon Apr 20, 2009 6:23 am Post subject:

If the valves are bent and not making a seal then yes the compression is going to be zero because the cylinder has no seal/pressure....so that's why I'm pretty sure it's just the valves.
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--Alex--
1992 Porsche 968 (VW 2.5L I5 Turbo swap in the works)
1995 Audi 90 Quattro Sport (4.2L V8 Swap)
2010 Touareg TDI
Past Pcars: 80 931, 87 924S, 87 951

GoodCat · Joined: 11 Apr 2009 Posts: 31 Location: Indianapolis, IN

sweet, time for a valve job when I can afford them.

Cheapest price I could find was at http://cgi.ebay.com/ebaymotors/NEW-Stainless-Steel-valves-Porsche-924-Turbo-1980-82_W0QQcmdZViewItemQQ_trksidZp3286Q2em20Q2el1116QQhashZitem120269105490QQitemZ120269105490QQptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

Should I be replacing all of them, or is it safe to only replace bent valves? If so, where can I buy them individually?
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1980 Porsche 931

Crux Mason · Joined: 08 Apr 2009 Posts: 67 Location: iowa

I finally got mine on right by ignoring Z1 and using the marks. I came up against the valves a couple times but I think they are alright.

931Owner · Joined: 14 Feb 2009 Posts: 352 Location: Chicago NW Suburbs

Crux Mason · Joined: 08 Apr 2009 Posts: 67 Location: iowa

I knew about where TDC was so if I had to put any more force into turning it at some other point then I just stopped and went the other way. The biggest thing that screwed me up was looking for Z1, it was no where close to TDC but the notch on the crank pulley did line up. I used the spark plug hole to make sure it was about right. You should stop turning it by hand when when the 1st cylinder is all the way at the top.