What can be done on a 2.7 engine

Uondi · 10-29-2006, 01:00 PM

What can be done on a 2.7 75 Carrera engine to make it stronger?

With a 1k (only parts) what can i expect (HP and Torque numbers) and With 2K and With 5k?

I will use the car on track-days only. The car can be loud (but i wouldn't like TO LOUD) don't need heat and don't need to pass smog regulations!

please simple formulas without compromising to much durability.

CARRERIC · 10-29-2006, 01:30 PM

Uondi,

I have a 1975 Carrera 2.7 US

Motor was professionally rebuilt. But here are "some" of the mods.

SC cam grind
Fly cut heads
SSI heat exchangers
RS Pistons

You can look for a european 2.7 fuel distributor.

randywebb · 10-29-2006, 02:15 PM

1st - make it last (and that is more than $1k)

2nd - SSIs

3rd - more noise with a muffler change but no add'l power
a factory sport muffler will be a LOT louder but w/CIS cams I dunno if it will add any power - with aggro cams it will

So, save the extra $$ for a repair

Zeke · 10-29-2006, 04:36 PM

I think the money spent on exhaust will be well spent. And, it can be used regardless, in the future, no matter what you decide ultimately to do.

1000, 2000 and 5000 are not really good numbers to talk about. 1k buys the exhaust. Or forget the exhaust and 2K buys a valve job. No big performance gain there. 5K will likely put you in a posiition that you won't like, that is having to spend more. And that is because you will be deeper in the motor and discover things that need to be done. Sometimes, it's better to not know.

OR, you could buy another used motor for 5K. Make that a 3.0 and you will see a bigger change in HP and torque than you can buy for twice that on the 2.7. Just my .02. Not facts.

CARRERIC · 10-29-2006, 05:36 PM

1975 was the first year of heavy emissons. Not sure if you have a CA car or not. Removing the polution device amd installing SSI's made a big differnce for me. Brought the operating temps down and allowed engine to breat better. Increases the HP as well.

Regarding the cam. SC grind changed the car completely. Best mod I have done.

gtu935 · gtu935's Garage

Here in NY 1975 cars no longer need to meet any emission standards. The last 2.7 we did turned into a 2.8. with weber carbs, time certed case, J&E pistons etc. Final price was somwhere around 10,500 but, the customer supplied the carbs.

stlrj · 12:58 PM

If you have the 49 state exhaust you're in luck and not too much to be gained with SSI for the money IMHO.

I had the 78 3.0 that I went back and forth with a 74 exhaust and the only difference I noticed was more noise with the 74 system.

Cheers,

Joe

jjrowe · 03:20 PM

Quote:

Originally posted by CARRERIC
1975 was the first year of heavy emissons. Not sure if you have a CA car or not. Removing the polution device amd installing SSI's made a big differnce for me. Brought the operating temps down and allowed engine to breat better. Increases the HP as well.

Regarding the cam. SC grind changed the car completely. Best mod I have done.

Crap... wish you hadn't said that last part about the SC cam grind. I've been debating this mod while putting my 2.7 back together since I am now using RS spec pistons. Can you be more specific on how it changed the car from a daily driver perspective.

Thanks,
Jesse
76' 911S

azasadny · azasadny's Garage

External (front-mounted) oil cooler?

kach22i · kach22i's Garage

Quote:

Originally posted by azasadny
External (front-mounted) oil cooler?

I think that's a good one Art.

Lukesportsman · 10-30-2006, 03:36 PM

This will require you to do the work and good shopping for near $5k.

*RS pistons or JE (are smog engines Alusil?), need valve reliefs
*I personally like my E cams or something custom from camgrinder. I don't know why you'd stop at SC cams for a track car (obviously if keeping CIS but how about some 20/21s).
*$250 used headers loose a little weight and less heat with M&K muffler
*used PMO's or Webbers if your brave
*thoughts about head work or swap

If she doesn't full the studs out of the case this should get you near 200hp.

CARRERIC · 10-30-2006, 03:41 PM

Quote:

Originally posted by jjrowe
Crap... wish you hadn't said that last part about the SC cam grind. I've been debating this mod while putting my 2.7 back together since I am now using RS spec pistons. Can you be more specific on how it changed the car from a daily driver perspective.

Thanks,
Jesse
76' 911S

It really woke the car up! 2.7. with SC cam grind pulls hard from a stop straight up to redline. I researched alot of options including 964 grind when I began the rebuild. I am very happy I went with the SC grind.

Also I understand this was a popular mod for the 2.7 in the late 70's when the SC was introduced. The 2.7 is a great engine when properly sorted. Some people will tell you otherwise...

I also installed a new set of RS pistons and cylinders. They are forged instead of cast. Very stong piston.

Any reason you decided to use them? If you had two make the choice between the two I would recommend using the CIS pistons and doing the SC cam grind.

jjrowe · 10-30-2006, 04:32 PM

I had a damaged piston and ordered new ones. I ended up with RS spec pistons instead of the high domed CIS pistons. From what I understand it shouldn't make much difference and it would allow me to do more engine mods in the future if I wanted to ditch CIS.

CARRERIC · 10-30-2006, 04:42 PM

My CIS pistons were fine. But I decided to switch to the RS for the same reasons - for future mod possibility. Also I feel they run stronger.

However the CIS pistons burn cleaner. The shape of the dome is specially designed to swirl the gas for the CIS. If you don't plan on future mods I would stick with the CIS. Just my opinion.

One mod you might consider is the RS spec ditributor. Has a real nice curve. You can by the new replacement at a reasonable price.

dd74 · 10-30-2006, 05:16 PM

Attentively study the Classified section of the Pelican board. In the last couple of weeks, much of what is needed to build up a 2.7 engine with at least RS specs has been available.

Webers - $800

RS pistons and cylinders - $875

'74 or earlier exhaust - $350

Cam choice will invariably depend on your end goal about your engine and its compression. I wouldn't limit myself to just an SC or 964 cam.

Set a horsepower or a compression goal first, then work around that. Considering some of the prices in classifieds lately, I don't see why you shouldn't have a very good engine for $5K.

PorschePilot · 10-30-2006, 05:27 PM

Mine is a 74 2.7.

I used the following parts for the rebuild.

RS pistons and cylinders
"S" Cams
"S" Heads
CIS off a Euro 3.0
Stock exhaust manifolds
Dansk muffler

My engine is so sweet and strong in the 3K to 6K RPM range.