Is your car an ROW '79 or a U.S. model? What makes you lean toward thinking that the engine doesn't belong to the chassis?

It would be helpful if you could provide all the numbers (VIN, engine serial number and type designation, which I know you've provided, and the transaxle number and type designation) for experts to see in one place. What other paperwork do you have on your car? The transaxle of the 3.1s, according to the Excellence article were fitted with a taller fifth gear.

I apologize if you've answered these questions elsewhere. I have tried to read the related threads and posts.

Brian

Hey Brian, the car is a US model and it is a '79 vin# 9119201601. The engine is an '80 euro spec. 930/09. I don't have the transaxle number and type. How would i go about finding that? I'm not sure it would make a difference though since it is a US VIN. I have absolutely no paperwork on the car aside from a title. I purchased it from a gentleman that repoed it on a bad loan.

Hey, Peter.

Thanks for the info. The transaxle numbers are located on the bottom of the unit. It would be worth taking a look and seeing what you've got there. More info at the beginning here.

Brian

You would only need to check the cylinders, the pistons would be a given if the cylinders are correct. The 97mm turbo cylinders that were used on the 3.1 only have cooling fins on the bottom side of the engine. You might be able to check by removing one of the heating ducts from the rear of the motor. These ducts are on either side of the big cooling fan you see when you open the lid.

Bummer about the holley... I toyed with that idea for a short while.

So how many people went to look at their engine after reading this thread?

Brian and 78SCRSMAN, great info, I will have to check both of those just as soon as I'm able to get back under there. I will post my findings just as soon as I do

Peter, if you can confirm that you've got the correct cylinders that go with the 3.1 930/09, then you've got to do some strategic thinking.

You would have a spectacularly rare short block engine. Does that equate to value? I'm not sure, since a buyer would need to have a correct chassis and paperwork connecting it to a 3.1. It's possible there are people in Europe seeking such engines.

If it were me, I would be tempted to pull the 3.1 and pickle it for safe long-term storage. In the meantime, look for a complete running SC engine that you can install in your car. Eventually, you can sell the 3.1 to a good home, which would offset buying the other engine.

Brian

Recently got an email from Exotic Classics advertising a 3.1L car that made me think of this thread. Not sure if its of any help to you but in the interest of consolidating information here you go;

the ad;
1980 Used Porsche 911 SC-L 3.1 PROTOTYPE at Exotic Classics, LLC Serving New York,Manhattan, NY, IID 8204305

link to Excellence article;
Excellence :: Point One : The Forgotten 911 SC-L 3.1

Cool find. Never heard of the 3.1 before. Get it back to original :)

I am actually toying with the idea of selling this 1980 3.1 engine to someone with a desire to do a proper rebuild on it. It is currently not running and needs a new fuel system(the one provided with it is not stock and should probably be replaced).

I happened on a link to a 1980 that may have a 3.1 engine in it. If someone is interested in following up, please contact me.

From my investigation, the car still has the correct engine serial # installed. No idea how original the engine still is.

Looking at 'The Essential Companion 911sc' the 3.1 liter was the 930-03....displacement of 3122 cc/190.5 Cu in.
9.5:1 compression ratio
210 hp @ 5800 rpm
torque 206 ft lbs @ 4700 rpm
7k max rpm
Pretty much what Porsche did with the 930-10 ROW minus the slight cc bump.

that is a very low torque value for some reason.
It appears these engines were built in 1979 and 1980.

1980 Porsche 911 SC-L 3.1 -

Here is a car in NY state....

6* retarded cam timing to boost upper end. 206 ft/lbs. is actually pretty good and due to the higher comp ratio.

Find a ROW CIS
 

If you can just get it running to evaluate the rings & valves, a used ROW(big runner) CIS may be a good answer to your fuel system dilemma. There are a few big runner used CIS systems(from running motors, not cores) for sale from track racers and it is not a huge expense to purchase. Your SC came with CIS so CIS may be a low pain & low $$ retrofit. I run a stock 83 930-10 and my canyon runner buddy runs a heavily modified 930-10 on CIS too :cool:. The Euro CIS did not change almost every year like the US CIS so a 78-83 ROW or 76-77 C3 CIS might just be the ticket. If the motor has been sitting a long time pull the plugs and lube the cylinders with MMO(Marvel Mystery Oil) and rotate the crank by hand to free things up. Very old school but the MMO works like PB Blaster. M2CW Make it live at a reasonable cost before you decide to sell. Besides a running motor is worth a lot more than a core. :)

another thread with performance chart showing much better torque:

http://forums.pelicanparts.com/porsche-911-technical-forum/281573-911-sc-3-1-a.html

If you're referring to the factory power curve chart, it's showing about 275 Nm, wich equates to about 203 ft/lbs.

What a great find!