2.7 CIS Upgrades?
Thread Starter
7th Gear
Joined: Jun 2003
Posts: 7
Likes: 0
From: Mountain View/Los Altos, CA
2.7 CIS Upgrades?
Ok I guess my question about supercharging or turboing a 2.7 is a just the wrong thing in performance to look for... sounds as if i will blow myself up. <img border="0" title="" alt="[Eek!]" src="eek.gif" /> 
<img border="0" alt="[grrrrrrr]" title="" src="graemlins/cussing.gif" /> <img border="0" title="" alt="[Eek!]" src="eek.gif" />
What can I do to my '74 2.7 w/CIS to make it get-up-n-go faster?
I meanits fast and all but I want to be able to own these ricers around me.
<img border="0" alt="[bigbye]" title="" src="graemlins/xyxwave.gif" /> <img border="0" alt="[byebye]" title="" src="graemlins/wave.gif" />
So far to date my car has :
-upgraded chain tensioners
-11 blade fan
-Pop off valve
-pertronix electronic dstributor (no points)
-various upgrades to suspension for autoXing
Please, isnt there anything I can do that will make me kick *** (without NOS)? It doesnt necessarily have to horsies, it could be upgrades for max torque. (i always like to squeal my wheels from a stop sign)
<img border="0" alt="[grrrrrrr]" title="" src="graemlins/cussing.gif" /> <img border="0" title="" alt="[Eek!]" src="eek.gif" /> What can I do to my '74 2.7 w/CIS to make it get-up-n-go faster?
I meanits fast and all but I want to be able to own these ricers around me.<img border="0" alt="[bigbye]" title="" src="graemlins/xyxwave.gif" /> <img border="0" alt="[byebye]" title="" src="graemlins/wave.gif" />
So far to date my car has :
-upgraded chain tensioners
-11 blade fan
-Pop off valve
-pertronix electronic dstributor (no points)
-various upgrades to suspension for autoXing
Please, isnt there anything I can do that will make me kick *** (without NOS)? It doesnt necessarily have to horsies, it could be upgrades for max torque. (i always like to squeal my wheels from a stop sign)
Instructor
Joined: May 2002
Posts: 231
Likes: 6
From: Northbrook, IL
I have a 2.7 with 9.5:1 RS pistons and Bosch Mechanical Fuel Injection and S cams. At least 210 hp. Check Bruce Anderson's book as there are really only two options, mine and the 8.5:1 pistons, E cams and Webers.
Instructor
Joined: May 2002
Posts: 231
Likes: 6
From: Northbrook, IL
I have a 2.7 with 9.5:1 RS pistons and Bosch Mechanical Fuel Injection and S cams. At least 210 hp. Check Bruce Anderson's book as there are really only two options, mine and the 8.5:1 pistons, E cams and Webers.
Track Day
Joined: Nov 2002
Posts: 18
Likes: 0
From: Sydney
I recently rebuilt my 2.7.
Changes from stock include:
Recoating my Alsusil barrels in Nikasil to suit the 9.5 J&E Pistons.
SC cams, but would probably go 964 if I did it again.
Timecerted (spelling?) the crankcase to ensure it doesn't pull the studs.
Turbo lower rocker covers to minimise the leaks.
I already had the early style exhaust, the tensioner upgrade and the 11 blade fan.
I also changed the clutch while I was at it and put in a lighter aftermarket one, cannot remember the details.
No idea how much horsepower but it feels like a completely different car. I was planning on ditching the CIS but I am happy with the way it runs. When I floor it at about 2700rpm, it will wheelspin the admitedly old and not very sticky Monarch 245 tyres before it launches.
The 2.7 engine is rather underated in my view. It has smaller and thus lighter valves than the later 3.0 and therefore can rev higher before valve float. I beleive it is lighter than the later engines as it is made of a magnesium alloy.
Changes from stock include:
Recoating my Alsusil barrels in Nikasil to suit the 9.5 J&E Pistons.
SC cams, but would probably go 964 if I did it again.
Timecerted (spelling?) the crankcase to ensure it doesn't pull the studs.
Turbo lower rocker covers to minimise the leaks.
I already had the early style exhaust, the tensioner upgrade and the 11 blade fan.
I also changed the clutch while I was at it and put in a lighter aftermarket one, cannot remember the details.
No idea how much horsepower but it feels like a completely different car. I was planning on ditching the CIS but I am happy with the way it runs. When I floor it at about 2700rpm, it will wheelspin the admitedly old and not very sticky Monarch 245 tyres before it launches.
The 2.7 engine is rather underated in my view. It has smaller and thus lighter valves than the later 3.0 and therefore can rev higher before valve float. I beleive it is lighter than the later engines as it is made of a magnesium alloy.
Advanced
Joined: Feb 2003
Posts: 76
Likes: 0
From: Winnipeg Canada
I wouldn't write off the turbo charger...yet. A modest turbo system will not impose unacceptable forces on your engine. I think that the reasons not to do it include the increased heat and the tremendous cost of a proper, custom designed turbo system. If you are looking for the most cost-effective way to substantially increase horsepower, I'd do an engine swap with a 3.0 or 3.2. And if you decide to modify further from there, you've got a better base to work from.
Advanced
Joined: Nov 2001
Posts: 93
Likes: 1
From: Oswego, IL
SSI's are pretty, but the power gained to cost ratio is not great...
Why not drop in a larger motor? A 3.0 is very fun in a mid-year car and a 3.6.. <img border="0" title="" alt="[Eek!]" src="eek.gif" />
It all depends on home much money you have I guess. If you are out gunning for ricers, go buy a turbo or a turbo motor...a 911 is not a drag car.
My 3.0 and lightened (soon to be lighter)mid-year can give the ricers a good run for their money ( when I've had enough of them buzzing me).
Why not drop in a larger motor? A 3.0 is very fun in a mid-year car and a 3.6.. <img border="0" title="" alt="[Eek!]" src="eek.gif" />
It all depends on home much money you have I guess. If you are out gunning for ricers, go buy a turbo or a turbo motor...a 911 is not a drag car.
My 3.0 and lightened (soon to be lighter)mid-year can give the ricers a good run for their money ( when I've had enough of them buzzing me).
