Parts Catalog Accessories Catalog Tech Info Tech Forums
 
  Search our site:    
 Cart  | Project List | Order Status | Help    
  Join us November 1st for Casino Night at the Pelican Parts Open House!
Benefiting LuMind - Research and Treatment for individuals with Down Syndrome
Go Back   Pelican Parts Technical BBS > 1- Porsche Technical Forums > 911 Engine Rebuilding Forum

Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered User
 
f3nr15's Avatar
 
Join Date: Sep 2006
Location: Auckland NZ & Newcastle AU
Posts: 483
High compression 90mm pistons for 2.7?

Hi all,

Am toying with the idea of 9.5:1 pistons for my 2.7 rebuild.

Do Mahle have these available, or is JE my only choice?

Do any other makers besides Mahle provide the CIS specific domes?

Many thanks in advance...

EDIT: Do the CIS specific domes still matter if the cams are going to be reground to a 964 profile?
__________________
Regards,
Peter

1992 928 GTS
1993 964 Carrera 2 Coupé

Last edited by f3nr15; 02-27-2007 at 05:47 PM..
Old 02-27-2007, 05:34 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #1 (permalink)
Registered User
 
Join Date: Jul 2001
Location: Portland Oregon
Posts: 5,986
Hi:

Mahle does a small run of 9.3:1 90mm P/C's when they get enough orders to make them. Availability is scattered but I'd check on that with several suppliers to see what is in stock.

JE's are always available in any CR you wish but they certainly do not last anywhere near as long.

Mahle is the only maker of the CIS-specific piston dome configuration. If you use CIS, this is the best way to go, by far. If you switch to carbs, EFI, MFI or whatever, the double valve relief pistons are recommended. Your 964 cams will clear either piston design,...
__________________
Steve Weiner
Rennsport Systems
Portland Oregon
(503) 244-0990
porsche@rennsportsystems.com
www.rennsportsystems.com
Old 02-28-2007, 12:16 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #2 (permalink)
Registered User
 
f3nr15's Avatar
 
Join Date: Sep 2006
Location: Auckland NZ & Newcastle AU
Posts: 483
Thanks Steve!

Quote:
Originally posted by Steve@Rennsport
Mahle does a small run of 9.3:1 90mm P/C's when they get enough orders to make them...
Arrgghh!

Where do I even begin to look for a set of these HC Mahle 90mm sets?

I'd better start emailing some online stores...
__________________
Regards,
Peter

1992 928 GTS
1993 964 Carrera 2 Coupé
Old 02-28-2007, 01:49 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #3 (permalink)
Registered User
 
Join Date: Jul 2000
Location: So. Calif.
Posts: 16,952
There's a "normal" set of 2.7 Mahles at Rennlist classifieds, item 28, I believe.

The 9.5:1 versions were only imported by Andial who are now in the parts business. Give them a call ..... sitting down.

Sherwood
Old 02-28-2007, 10:16 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #4 (permalink)
Registered User
 
klaucke's Avatar
 
Join Date: Mar 2004
Location: Middle of Out There
Posts: 1,620
There are definately 2 stock versions of Mahle's that were used for CIS 2.7's. The dome shape is different, and I assume the CR is also different but I don't know for sure. This may be the difference b/w S and Normal pistons, as there is a modest difference in CR.
Old 03-01-2007, 06:23 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #5 (permalink)
Registered User
 
Join Date: Jul 2000
Location: So. Calif.
Posts: 16,952
Sorry, I didn't realize you were initially looking for CIS-type replacement parts, but if you're going to replace your CIS pistons/cyl. and cams anyway, I'd seriously consider switching to carbs unless emissions compliance, modest power gains and factory-stock is high up on the list.

With that decision, it's the same cost to replace what's there with a complimentary set of RS P/C I mentioned earlier + more aggressive cams to make a real difference in the arc of your smile.

MHO,
Sherwood
Old 03-01-2007, 09:38 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #6 (permalink)
 
Now Available for Ordering:   101 Projects For Your BMW 3 Series 1982-2000  [more info]
Registered User
 
10zz964's Avatar
 
Join Date: Jun 2004
Location: Bkk Thailand
Posts: 425
hi,
really good info here.
http://www.pelicanparts.com/techarticles/911_engine_rebuild/911_engine_rebuild2.htm
cheers
__________________
instagram @tennster
Old 03-01-2007, 11:12 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #7 (permalink)
Registered User
 
Grady Clay's Avatar
 
Join Date: Dec 2003
Location: Arapahoe County, Colorado, USA
Posts: 9,032
Listen to Steve.

Best,
Grady
__________________
ANSWER PRICE LIST (as seen in someone's shop)
Answers - - - - - - - - - - - - - - - - $0.75
Answers (requiring thought) - - - - $1.25
Answers (correct) - - - - - - - - - - $12.50
Old 03-01-2007, 11:51 AM
  Recommend this thread for the PelicanWiki    Reply With Quote #8 (permalink)
Registered User
 
f3nr15's Avatar
 
Join Date: Sep 2006
Location: Auckland NZ & Newcastle AU
Posts: 483
Quote:
Originally posted by 911pcars ...it's the same cost to replace what's there with a complimentary set of RS P/C I mentioned earlier...
Thanks Sherwood.

(Although it might come back to bite me in the rear,) I've decided to try to maintain a more-or-less stock 2.7L CIS.

Bearing that in mind, I guess the standard P&Cs are prob the best way to go;

I've considered the RS spec P&Cs you mention above, but my understanding is that the CIS domes on the stock pistons will burn cleaner than the RS domes.

I'll prob stick with simply installing SSIs/sports exhaust +/- a cam regrind to SC profile for a mild performance upgrade.
__________________
Regards,
Peter

1992 928 GTS
1993 964 Carrera 2 Coupé
Old 03-01-2007, 03:37 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #9 (permalink)
Registered User
 
Fidalgo911S's Avatar
 
Join Date: Jun 2003
Location: PNW
Posts: 663
If you flycut the heads, won't CR increase slightly? Would it be close to 9.0:1?
__________________
Nate
Old 03-04-2007, 04:23 PM
  Recommend this thread for the PelicanWiki    Reply With Quote #10 (permalink)
Old 03-04-2007, 04:23 PM
Reply

Thread Tools
Rate This Thread
Rate This Thread:

 



All times are GMT -8. The time now is 04:41 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2011 Pelican Parts - Posts may be archived for display on the Pelican Parts Website -    DMCA Registered Agent Contact Page
 

DTO Garage Plus vBulletin Plugins by Drive Thru Online, Inc.