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Is it worth changing to 964 cams?
I'm soon to be pulling my motor apart for a top end job. It's done 79k, has excellent compression test results but is smoking like a chimney & sure enough there's a hell of a lot of play in the guides. Whilst I'm doing the valves/guides/rings, I was considering the possibility of 964 cams (seems to be a popular conversion). My motor is a 930/25 US spec version (Swiss market) so has the low comp pistons. I've already replaced the cat with Euro pre/s and plan on having it custom chipped once all back together.
Will I see much of a performance gain moving to 964 cams and staying with the low comp pistons? Will the additional power be only at the top of the rpm range or does midrange also improve? (don't want to end up with it "peaky") Is the cam change a straight swap or are there other things I should also change? A local Porsche breakers sells them for £125 each. Is this around the going rate? Any advice appreciated.
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3.2 Coupe |
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09-09-2003, 04:04 AM
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Location: Las Cruces, NM
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It is an upgrade, but with the really low comp you might have a problem. A gentleman i worked with when i lived in jersey had an early 930 with the 3.0 in it, which is the 6.5:1 comp car. He installed 964 cams and upgraded the k27, his car wouldn't begin to boost until roughly 4k rpm or more but when it did, good god. The thing would break the 335 rubber in the rear totally loose in first gear. He ended up going with sc330 cams which was a good compromise between evil top end and moderate lag.
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2007 Mazda 3 hatch 1972 Porsche 914 roller with plenty of holes to fix 
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09-09-2003, 06:53 AM
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Irrationally exuberant
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I wouldn't say it makes a huge difference. Most people get a 964 grind. Actual 964 cams have a gear on the end of one of the cams to run a power steering pump that you need to cut off.
-Chris
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'80 911 Nogaro blue Phoenix! '07 BMW 328i 245K miles! http://members.rennlist.org/messinwith911s/ |
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09-09-2003, 08:19 AM
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My car is standard US spec 3.2, which has 9.5/1 comp (ish I think?!)
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3.2 Coupe |
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09-09-2003, 10:12 AM
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OOOHHHHH, when you said 930, i didn't see the #code afterwards, so i thought you were talking about a turbo, sorry
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2007 Mazda 3 hatch 1972 Porsche 914 roller with plenty of holes to fix
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09-09-2003, 10:44 AM
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Since you have a motronics car, why not get something a little more radical like s cams and then a chip that is suitible for the new profile.
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2007 Mazda 3 hatch 1972 Porsche 914 roller with plenty of holes to fix
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09-09-2003, 10:46 AM
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Join Date: Sep 2001
Location: East of Eden, West of the Sun
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While you're in there it may be worth going the whole hog and doing the pistons as well.
But then where do you draw the line and stop? Backdated exhaust? MAF?
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Where once the giants walked now Mickey Mouse is king. My other car is also a Porsche. |
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09-09-2003, 12:48 PM
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1989 Porsche 911 Carrera 3.2
The Blue Pheonix
