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Join Date: Nov 2004
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Porsche Crest 2.7 RS Mods Approved?

A few weeks ago I posetd some questions on upgrading the power of my 2.7 RS spec motor.

After a review of the replies and conversation with my shop I decided on a piston swap.
My mechanic is recomending 10.5-1 with J&E

After reading a few posts this week I see that there may be more of a concern for valve placemnet ect.

Is there less of a chance with a 9.5-1 set?

Are the Mahle's I have been reading about worth the extra $ on top of the J&E (Which will be about 1600)

I have also decided to get rid of the points and go with a crankfire type system.

This along with a nice reseal of the motor.

I was looking forward to that being a noticable improvmnet and a long lasting set up. Some posts seem to think otherwise as far as the life of the motor.

What are we talking about 10-20K or 5-10 DE events with some street driving here and there?

I realize that any hot rodding has risks.

Thanks for any advice in advance

Old 12-13-2004, 04:02 PM
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Hi

If you are doing this I'd strongly suggest you twin plug, As for Valve to Piston clearance this should be catered for by JE (or who ever supplys the pistons) If you tell them the Cam you are using, You'll check this in assembly anyway. The twin plugging will give you more HP (by reducing the required advance) than the comp increase

HTH
Neven
Old 12-14-2004, 08:30 AM
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Re: 2.7 RS Mods Approved?

Quote:
Originally posted by JScaramella
I was looking forward to that being a noticable improvmnet and a long lasting set up. Some posts seem to think otherwise as far as the life of the motor.
I respect Steve Weiner's opinion, and he has stated that the JEs cannot compete with the Mahles on longevity. It is up to you whether the $1600 margin in cost is worth it, according to your intended use of the car. For a mostly street engine, with maximum reliability expected, I would get the Mahle set.

TT
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Old 12-14-2004, 03:52 PM
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I talked to both Bruce Anderson and Jerry Woods today, and they both had very poor things to say about JE pistons. However, they are coming from a position of using them in high performance race motors under very harsh conditions. I have many customers who have used them in street cars for many miles with not a single problem.

So, for cutting edge race performance, make sure you go with Mahle. For the street, JEs should work okay.

You may want to go with the 2.8 pistons and cylinders. I forget what compression they are, but they are a bolt-in.

Also 10.5:1 is too high to run on pump gas reliably without twin-plugging. Keep it to about 9.8:1 and cc the heads...

-Wayne
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Old 12-14-2004, 11:59 PM
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Wayne

Who sells the Mahle 2.8 P&C and what do they cost?

Neven
Old 12-15-2004, 12:05 AM
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2.7 Approved but can I 2.8 with a 7R

Thanks for all the advice.

I see that the Mahles are probably $ well spent.

With the current case 7R do I have th ability to 2.8 or will the case not handle it? With a 2.8 Do you have to twin plug?
I have seen some $ around 500 with is not bad but I emagine the labor and of course the other 6 wires plugs and crankfire or dist. system add to that upgrade. It looks like the hot set up/

What would be the CR of a 2.8 as opposed to a higher 10.5-1 2.7 set up?

I plan to call Andial to see whats avalible in Mahle set up.


Would you guys use a crank fire type system or stick with a dist.?
I'd like to rid the motor of points.

Is my old Dist. worth anything?
Old 12-15-2004, 02:07 AM
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Quote:
Originally posted by NevenM
Wayne

Who sells the Mahle 2.8 P&C and what do they cost?

Neven
These are readily available. I think we can probably special order the 2.8 and 2.9 kits...

They run in the $2500-$2900 range...

-Wayne
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101 Projects for Your BMW 3-Series 101 Projects for Your Porsche 911 How to Rebuild & Modify Porsche 911 Engines 101 Projects for Your Porsche Boxster & Cayman 101 Projects for Your Porsche 996 / 997
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Old 12-15-2004, 04:11 PM
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