1974 engine setup in newer SC

Porsche_911s · Porsche_911s's Garage

I am in the middle of my restore and have started seeing rollers that are in better condition than my 1974. Mechanically my 74 is done. But body & paint wise I am about to get started.

Question: What would I need to do to get my 74 2.7 setup working & legal in a 76 or newer car?

Edited to add useful info:

1974 coupe weight ~ 2370 lbs
1978 targa weight ~ 2700 lbs

'74 CIS 2.7 ~ 150 HP (with carbs & "S" CAM ~ 170 HP)
'78 CIS 3.0 ~ 180 HP

2.7 engine weight ~ 401 lbs

Modification needed:

- 6 plug CDI to 3 plug CDI
- 14 PIN engine connector rewired correctly
- Speedometer changed out & cable ran ('74 915)
- Tach changed out
- temp gauge changed out (recommended upgrade on '78 anyway)
- Going to carbs, CIS mods not needed, fuel system removed for carb fuel system

jmz · jmz's Garage

putting an 81 based engine in my '74 was a piece of cake. I suppose the opposite is true.

Porsche_911s · Porsche_911s's Garage

I think the Houston smog test will probably kill me.

jmz · jmz's Garage

I guess it depends on how clean your engine runs.

ianc · 10-31-2005, 08:19 PM

Put a 2.7 in an SC? Forget it. Dump the motor and the whole car and just get something newer if that's the way you want to go,

ianc

Porsche_911s · Porsche_911s's Garage

hhhmmmm... get a divorse because I dumped lot of cash in a 2.7 motor before joining this site.... OR, keep the motor & the hot wife and just get a 74 or 75 roller... I think I will just look for the 74 ot 75 roller. The lack of response makes me think it's more trouble than it's worth.

jmz · jmz's Garage

OK, here's my advice:

IF your LIme Green '74 is really a P.O.S. then don't waste your time. IF it is a rust free car then go after it by yourself just don't pay somebody to do the body work and you will be $$OK that is if you just want a fun car.

If this is some way a financial investment for you then you have other problems. You will almost NEVER make any money on these cars. I suppose the salvage title would make it that much harder though. If the salvage title bothers you AND you 2.7 is fully sorted and running well just find any old roller with a clean title. A pre-74 will prove to be the best investment (again hard to make money on these cars) but any roller will do. You've got everything you need on the '74 to transfer to whatever roller you end up with to make that 2.7 fit and function. Go and buy the factory manuals if you need to they are really helpful.

JZ

s2per · s2per's Garage

You mentioned that the smog test would kill you on an '81. I'd go with the newest roller that would work with your area's smog laws. Definitely get a '76 or later and be sure to swap your shorter-geared '74 915 trans into the newer car. An early SC roller with limited options and your freshened drivetrain would still be a fun car.

ianc · 11-01-2005, 08:24 AM

Quote:

get a divorse because I dumped lot of cash in a 2.7 motor before joining this site.... OR, keep the motor & the hot wife and just get a 74 or 75 roller

I think putting it in a mid year would be fine if you can find a decent one. The earlier post about it being an investment is correct; you won't make any money on the motor. But, if you chose to sell it, you might get enough out of it to finance a new project.

I just don't think a 2.7 in an SC or Carrera is the way to go. Something earlier and lighter,

ianc

Rich76_911s · Rich76_911s's Garage

I do not completely understand. If you want to put it into a 76 or 77 that would be the correct engine, 78 and up you would have an underpowered SC. I recently saw a post from a Texan whos car is now smog exempt because it is more than 25 years old. Is this only a law out in the country and not in Houston? Do you have family that lives outside of the city where you could register the car to avoid city requirements? I am not sure about the laws in Texas, but the exhaust system on a 74 is not as clean as the 75 -77 mid years. I think you could swap out the hear exchangers from a 75 - 77 fairly easily. But I feel like there might be more than just the heat exchangers. It probably wouldn't be that hard to locate used parts to get you to a 75 and up middy as a lot of people backdate to the 74 style exhaust. I guess it really depends on the year car that you would end up with and what the laws are where you have the car registered. Can you register it as a collector car, antique ect ect? Some states do not require emissions testing on cars that go under 5000 miles a year too. Look up the texas DMV and see what your options are.

Rich

Porsche_911s · Porsche_911s's Garage

I was WRONG and mis informed! Just checked and any car over 24 years old DOES NOT need the smog test. Thanks for correcting me!!!!

I am not looking at this as an investment by any means but at the same time I am at a point where I can make a body switch and get a clean title. I want the car for cruising and coastal driving. After the switch I can sell mine off cheap as a track car.

Hhhmmmm so I should probably take a look at the weight of my 74 -vs- the weight of a newer car.

Thanks guys!

Porsche_911s · Porsche_911s's Garage

Do these weights sound correct??

1974 911s 2380 LBS

1978 911sc 2470 LBS

1981 911sc 2558 LBS

I plan on flaring out the 74 & running 16x6 & 16x8. That will probably increase my weight some.

Also, could anyone tell me the weight difference a 2.7 setup and the 3.0 setup?

Thanks!

ianc · 11-01-2005, 12:26 PM

Not sure about those weights. I think SC's are weighing in closer to 27-2800 lbs. Lot of variables there though, AC, coupe or targa, fuel load, etc. If you do a search here, you'll probably find more info. For two similarly equipped motors, both CIS equipped etc., I think the weight diff between a 2.7 and a 3.0 is negligible,

ianc

Porsche_911s · Porsche_911s's Garage

Those were kerb weights.

I'll see what type of rollers come across the classfied section.

jmz · jmz's Garage

The aluminum 3.0 engines do weigh more than the magnesium 2.7 engines. By how much, I am not sure.

pjv911 · pjv911's Garage

I disagree with the above post which states that with a 2.7 the sc would be underpowered . Power to the seat of the pants would be indistingquishable (wow thats a long word).
Furthermore a fresh 2.7 would be more powerful than a worn 3.0 anyday . And 40lbs lighter too . I see no problems with this guys intensions . And its a direct fit . Swap the flywheel and bolt it in .

Kurt Williams

ianc · 11-01-2005, 05:44 PM

Quote:

I disagree with the above post which states that with a 2.7 the sc would be underpowered . Power to the seat of the pants would be indistingquishable (wow thats a long word).

2.7 ~ 150 HP; 3.0 ~ 180 HP. Not a good idea if you're ever thinking of selling the car again either.

ianc

pjv911 · pjv911's Garage

150hp yes but thats if his 2.7 had the thermal reacters bolted back on (doughtful) .
175hp with 74` type exhaust . Factory hp for 74 was 175hp .

5hp/40lbs you decide which is right and which is an elusion .

Kurt Williams

Porsche_911s · Porsche_911s's Garage

I'm running strait headers into Supertrapps... I think I have 7 rings on the Trapps. Had 9 but it was very very loud.

ianc · 11-01-2005, 09:59 PM

Quote:

Factory hp for 74 was 175hp

According to the factory workshop manuals for the 74 model year, the claims were 143/167 SAE HP for the 2.7/2.7 S Carrera with 8 and 8.5:1 comp ratios respectively. Neither will equal the torque of a 3.0, and the SC is heavier than a middie. As I said before, what buyer will look twice at an SC or Carrera with a 2.7?

ianc