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Registered
Join Date: Oct 2004
Location: Bremerton
Posts: 166
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2.2 L Use 90mm Mahle Pistons & Cylinders?
I have a 1971 911 T with its original engine. Can I use a set of 90 mm Mahle pistons and cylinders on it. They are adertised at fitting a 2.0-2.7 engine. I beleive that the head bolt spacing is the same on all there motors so they should bolt up. What other parts would be required? Can I use the same rods and heads? What would the resulting compression ratio be? The add did not mention what compression the pistons were rated for. I've often thought about this uprade/conversion since 90 mm 2.7 pistons are easily available but have never heard of it mentioned any where. Any feed back is appreciated.
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1971 Porsche 911 T Targa |
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I would rather be driving
Join Date: Apr 2000
Location: Austin, TX
Posts: 9,108
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yes, you can use these on a 2.2. They will fit the head and bolt/stud pattern. they are not a bolt on. YOu will have to have your case spigots cut to fit the new cylinders which are a larger diameter. The new 90mm bore will give you a short stroke 2.5 which is a great little engine. The resulting CR will be lower since the crank is a 66mm for a 2.2, not 70.4 as in the 2.4/2.7. The RS P/C set has a CR of 8.5:1 on the longer crank. I think this works out to around 8:1 on the short crank. A better way to do this is to use the Mahle nikasil cylinders with custom JEs to up the CR.
Do a serch for "2.5" and you will find more information.
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Jamie - I can explain it to you. But I can not understand it for you. 71 911T SWT - Sun and Fun Mobile 72 911T project car. "Minne" - A tangy version of tangerine #projectminne classicautowerks.com - EFI conversion parts and suspension setups. IG Classicautowerks |
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Old Member
Join Date: Feb 2004
Posts: 1,317
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Kevin
You'll need to bore out the spigots, use 2.7 heads and CIS cams if the pistons are CIS. Should give you 2.5L. There are probably other issue someone else can add.
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Clifton Brown https://www.mancalamarketing.com |
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Join Date: Oct 2004
Location: Bremerton
Posts: 166
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Thanks for the replies. I was aware that any cylinder bore over 87.5 mm would require macining the case spigots. I did not realize that I'd have to change cams, thanks for the heads up. But, do I really have to get different heads or can my 2.2 heads be machined? I'd love to go for Nickies and JE's but the cost is prohibitive, especially since I've seen a set of brand new Mahle cylinders and pistons for $950.00.
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1971 Porsche 911 T Targa |
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Registered
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Where did you see new Mahle p/c's for $950?
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Bill G. '68 911 Ossi Blue coupe |
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Registered
Join Date: Oct 2004
Location: Bremerton
Posts: 166
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I knew I shouldn't have put that out there. It was on Pay Pal, Good luck.
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1971 Porsche 911 T Targa |
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