Pelican Parts
Parts Catalog Accessories Catalog How To Articles Tech Forums
Call Pelican Parts at 888-280-7799
Shopping Cart Cart | Project List | Order Status | Help



Go Back   Pelican Parts Forums > Porsche Forums > 911 Engine Rebuilding Forum


Reply
 
LinkBack Thread Tools Rate Thread
Author
Thread Post New Thread    Reply
Registered
 
joetiii's Avatar
 
Join Date: Apr 2006
Location: Western Mass.
Posts: 1,218
Garage
Need your educated guess

What percentage horsepower gain is acheived with the 3.2 heads versus the smaller SC intake heads?

__________________
joe
------------------
'69 911 E Targa - aka "RoxiE"
Old 12-29-2007, 03:44 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #1 (permalink)
Registered
 
Join Date: Jul 2001
Location: Portland Oregon
Posts: 7,007
Joe:

It all depends on the rest of the engine; in other words, what state of tune that its in.

For a stock 3.0 SC engine, the difference is very small due to its relatively low compression and modest cams.

For a 3.0 with "S" cams, PMO's (or ITB's), 10:1 CR or more, the large-port SC heads make a very significant difference and those will support up to 325-335 HP.
__________________
Steve Weiner
Rennsport Systems
Portland Oregon
(503) 244-0990
porsche@rennsportsystems.com
www.rennsportsystems.com
Old 12-29-2007, 04:01 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #2 (permalink)
Registered
 
joetiii's Avatar
 
Join Date: Apr 2006
Location: Western Mass.
Posts: 1,218
Garage
ok.... so we're going from stock SC to a mod S cam at std 9.3:1 compression

and then if we were to twin plug it at say 10.5:1????
__________________
joe
------------------
'69 911 E Targa - aka "RoxiE"
Old 12-29-2007, 05:54 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #3 (permalink)
Registered
 
Join Date: Jul 2001
Location: Portland Oregon
Posts: 7,007
If you want power over 6000RPM, you need the early SC or Carrera heads.
__________________
Steve Weiner
Rennsport Systems
Portland Oregon
(503) 244-0990
porsche@rennsportsystems.com
www.rennsportsystems.com
Old 12-29-2007, 09:08 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #4 (permalink)
Registered
 
joetiii's Avatar
 
Join Date: Apr 2006
Location: Western Mass.
Posts: 1,218
Garage
Can the later 3.0s be ported with good results, or is it best to find a decent set of 3.2 heads?
__________________
joe
------------------
'69 911 E Targa - aka "RoxiE"
Old 12-30-2007, 05:51 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #5 (permalink)
Registered
 
Join Date: May 2003
Posts: 3,346
Joe,

The early heads can be ported to 39mm (intake). A friend of mine did this himself with an air grinder. It was a very crude job but effective. He has just as much power as the rest of the cars in our class. You can also find a set of used 78-79 SC heads or go with 3.2 heads.

-Andy
__________________
72 Carrera RS replica, Spec 911 racer
Old 12-30-2007, 09:41 AM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #6 (permalink)
 
Try not, Do or Do not
 
Henry Schmidt's Avatar
 
Join Date: Apr 2004
Location: Fallbrook, Ca. 92028
Posts: 14,067
Garage
Steve is absolutely correct. Port size is a function of a complete engine package.
In general larger port sizes only offer positive flow enhancement at higher RPMs. We are currently involved in research that involves small ports with enhanced configurations that seem to offer vast improvements in lower RPM transition and still sustain higher RPM flow.

Stay tuned. The results so far seem impressive.


__________________
Henry Schmidt
SUPERTEC PERFORMANCE
Ph: 760-728-3062
Email: supertec1@earthlink.net
Old 12-30-2007, 12:08 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #7 (permalink)
Registered
 
Join Date: Oct 2006
Location: Scotland
Posts: 262
When do you expect these results?
What are the main 'enhanced configurations' which you are finding work well with smaller ports, in particular at low rpm's?

Thanks

Regards
Mike
__________________
RS #1551 (Sold)
67S
Old 12-30-2007, 12:14 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #8 (permalink)
Registered
 
joetiii's Avatar
 
Join Date: Apr 2006
Location: Western Mass.
Posts: 1,218
Garage
On paper, the size doesn't seem like much, but that first pic looks like a huge difference.

Henry, I'm assuming the second shot is of your new concept?

__________________
joe
------------------
'69 911 E Targa - aka "RoxiE"
Old 12-30-2007, 01:00 PM
  Pelican Parts Catalog | Tech Articles | Promos & Specials    Reply With Quote #9 (permalink)
Reply


 


All times are GMT -8. The time now is 12:00 AM.


 
Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2025, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2025 Pelican Parts, LLC - 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.