924Board.org

[koolkarateguy]

Well, I finally did a compression check tonight on my engine and it's not good. # 1 #2 and #4 cylinder are around 120 psi each. #3 is 0 , I checked it twice and it came back at 0 both times. I'm pulling the head this week . So what do you guys think ? Hole in the piston ? I'm kinda nervous about what I'm gonna find
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1979 N/A 924

[PORSCHEV]

Could be a many things..... let us know if you need any help.
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1976 924
5 lug conversion, 17'C2 wheels,custom body work,327 vette engine.

1978-#53 "D" track racer.

[koolkarateguy]

Thanks man, hopefully it'll be one of the "many things" and not a hole. One way or another tho it'll get fixed. Shouldn't be all that hard to replace a piston in this thing.
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1979 N/A 924

[Mike924]

My money's on a valve stuck open.

You can check for this quite easily just by taking the camshaft out; fixing it will mean removing the head, though.
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1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org

[Ozzie]

I'm with Mike924- a valve not sealing or stuck open
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Porsche 924 1984 (UK import) NA
Its AUTO and its BLACK
Montego Black on black/red
Engineer of Electro/Mechanical Systems Maintenance

[PORSCHEV]

I was thinking it might be a bad cam lobe as well. If you had a hole in the piston they wil usually get alot of base pan pressure and blow out the dip stick and make a mess under the hood. Since you didn't desribe that...I dought thats the problem.


If you need another motor....I talked to a guy just outside halifax last night. You could get some parts cars for $2500.00. I would in on them with ya!
I know one looks like a trubo...but it's just the hood and nose panel vents.


http://halifax.kijiji.ca/c-cars-vehicles-cars-under-5K-1979-Porsche-924-Florida-car-W0QQAdIdZ12954043
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1976 924
5 lug conversion, 17'C2 wheels,custom body work,327 vette engine.

1978-#53 "D" track racer.

[fiat22turbo]

I'm not sure about the cam lobe causing the lack of compression as it would have to be completely wiped out and you'd have other issues with that much metal floating in the engine.

Now, I had a lack of compression on the number one cylinder. I had concerns about that cylinder when I initially bought the car and saw that number one was missing the exhaust studs. I of course heard it running on three cylinders before popping the hood.

http://www.924board.org/viewtopic.php?t=17911&start=15

Take a look at the pictures and you'll see why there was no compression on that cylinder.

[Mike924]

Any idea why the ex valve went like that, fiat22turbo? (And where did the missing bits go?...)
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1985 Porsche 924 'Lux', Kalahari Beige (my ex)
1993 Porsche 968 Coupe, Midnight Blue, 6 spd

'There is no substitute for a little grease under your fingernails.' - Chrenan, 924board.org

[fiat22turbo]

Nope, wish I did. I'm changing the exhaust out as well as the intake solution, so I'm not too concerned there. The pistons look fine at first glance, but I'll clean them up a bit before reassembly begins.

I really think it was cold air (it was raining that day) hitting a hot exhaust valve. Luckily the uber-huge valve stems are what saved the head of the valve from falling completely off.

[koolkarateguy]

I'm having a feeling after reading your post that I'm gonna find the same thing. Almost got the head off , just never had the right hex socket. I'm hoping to get it into the machine shop this week. Hey Fiat ? How bout some photos when she's all back together ?
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1979 N/A 924

[Rasta Monsta]