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914World.com _ 914World Garage _ 2.7RS Motor

Posted by: Randal Jan 22 2006, 11:19 AM

Dan mentioned that Larry Sharp was running a 2.7RS motor that was previously in a 914. This was in Trekkor's painting thread.

Question for Dan:

What is the specification for a 2.7RS motor and how much power/torque do they put out?

Posted by: ArtechnikA Jan 22 2006, 11:32 AM

QUOTE (Randal @ Jan 22 2006, 01:19 PM)
What is the specification for a 2.7RS motor and how much power/torque do they put out?

210HP @ 6300, 188,4 lbs-ft@5100
MFI

8,5:1 compression, early (2,0) S cams.
46/40 valves, 36/35 ports.

i see lots of engines described as "2,7RS spec" but when you look at the build sheet, you find all it means is 8,5:1 compression.

IMO - no MFI, no ports, no early S cams - no "RS Spec" engine...

Posted by: TimT Jan 22 2006, 11:32 AM

If its a real RS spec engine, with MFI it should put out about 210hp, and 188 lb/ft torque

Posted by: anthony Jan 22 2006, 11:35 AM

I'd recommend that everybody with some interest in 911 parts (six cylinder engines, suspension, transmissions, wheels, etc) get Bruce Anderson's "Porsche 911 Performance Handbook". It's one of the best Porsche resources out there and great reading for motorheads.

To summarize:

first use of Nikasil cylinders on a production Porsche
bore increased to 90mm
retained 70.4mm stroke
case was reinforced internally at the main bearings and the base of the cylinders
diameter of cylinder spigots was increased to 97mm
(this is the famous 7R magnesium case that everybody talks about)
he also goes on to say that the engine was otherwise identical to the 1973 911S engine except for the different cam in the MFI unit.
210 DIN hp at 6,300rpms.

Posted by: trekkor Jan 22 2006, 12:08 PM

OK, I'll take one.

Randal, whatcha doin'?

KT

Posted by: carr914 Jan 22 2006, 01:01 PM

Anybody need a set of 2.7RS pistons & cylinders? Used but very nice shape. Got a set of factory 2.8s, so these will go if my engine guy hasn't already sold them already.

T.C.

Posted by: Headrage Jan 22 2006, 01:16 PM

QUOTE (carr914 @ Jan 22 2006, 11:01 AM)
Anybody need a set of 2.7RS pistons & cylinders? Used but very nice shape. Got a set of factory 2.8s, so these will go if my engine guy hasn't already sold them already.

T.C.

Will these work on a '77 2.7 motor?

I may need them shortly depending on what the rebuilder says about mine when he tears the motor apart.

Posted by: ArtechnikA Jan 22 2006, 01:19 PM

QUOTE (carr914 @ Jan 22 2006, 03:01 PM)
...Got a set of factory 2.8s, so these will go if my engine guy hasn't already sold them already.

do you also have a set of the ultra-rare 2,8 heads?

'cause otherwise, you may have an interesting with compression ratio ...

Posted by: J P Stein Jan 22 2006, 04:16 PM

Mr. Anderson also gives the set up of a lightly modded
2.7L that, according to the dyno chart provided, puts out about the same amount of power "listed" for the RS motor. Many say the RS motor puts out closer to 230hp than 210.

I used "Anderson's hotrod motor" as a starting point for mine...
more cam, more compression and am pleased. Like any hotrod, tuning it is a learning process, but getting there is half the fun....after you're done getting pissed off His jetting set-up for Webers seems spot on....a real plus.