1976 911S 2.7, looking for some engine improvements
 

Hi,
I'm a proud owner of a nice '76 911 with a 2.7 motor which ran 150,000 miles and I'm planning for a rebuild. I'm thinking of all the available options to improve/update this engine, can I swap the mag case with an aluminum 3.0 and retain the internal parts? if its possible, then I can also use 3.0 pistons/cylinders and end up with some extra hps as well. what would you guys do in that matter?

Prices have gone up, but: When I was at this point with my 73.5 2.4 engine, I shopped 2 years looking for a good 3.0 or 3.2....I bought this from a pelican ad and kept my 2.4 in storage:

Recently removed upgraded '81 SC engine and transmission from my '81 SC after car was damaged in front, causing parting out the car. Upgrades include 1) Max Moritz 3.2 liter pistons and cylinders, 2) 964 cams, 3) Raceware hardware, balanced rods, Carrera oil pump. New parts included: intake valve sleeves, rod bearings and rods balanced, and rocker arms. Transmission clutch disk, pilot bearing and fork were replaced. All of the above was performed in 2004 at 120,000 miles approx. and now at 132,000 miles. Transmission has recently installed Quaif LSD. Good solid reliable running engine with no oil leaks. Transmission will need third gear syncro replaced in future depending on how fast you want to change gear. Asking $6,000 for both, or $4,500 for engine and $1,500 for transmission.

Well, I wish I can find a similar deal, that would save me alot of time and money.

Give us more information on why you want to rebuild. These engines can go beyond 150 if maintained.

I have a 2.7 that is at 152k miles myself. I've cleaned and done small improvements, but I also decided that I would find a 3.2 core to sink my money in. I'll keep my 2.7 but I figured if I was going to drop 10-15k, I wanted more displacement.

Tons of ways to improve the performance of your car via adding lightness, exhaust/muffler change or intake.

I rebuilt the CIS on my car, the dizzy, added SSI and custom muffler and have been throwing off 100's of pounds of weight. The car zips along quite nicely for being a low hp California car originally.

What's your budget and timeline?

My main goad is to have a 200hp or more motor with the reliability to use it as a daily driver. In the near future I'm planning to add a small turbo with around 8-10 psi of boost to get the power upto around 260-280 hp.

I can do all the mechanical work by myself in my very well equipped home garage, I can also do some small machining work myself. I'm an engine builder and did countless number of very high hp LS motors, actually I have a 800 hp supercharged LS motor into my daily driver Firebird right now. I just need to know a bit more about these air-cooled Porsches.

My cost budget will be around $6000 for the engine mods, time is not a big deal, it will be a long term project anyways.

I'd recommend against modification. The 2.7 is quite a nice engine when built properly. It can be smooth, strong, and reliable. It revs a little easier than the 3.0, and makes practically the same top end hp, though at the expense of some bottom end torque. Your budget of 6K is probably a little light for a proper rebuild. Assuming you are doing all the labor yourself, you'll probably be in the 10K range for parts and machining.

You can get the power you mention out of a modified engine, but not simply by bolting on a turbo. It would be effectively a track engine at those levels; high compression, twin plug, cams, carbs, exhaust, etc. Great fun, but not so practical or long lived, and even more $. Be aware that some of your $ will be spent on heat management. A factory trombone loop will do fine for your stock engine. If you don't have one already, include the cost of one in your rebuild budget. But every hp you add above stock will require increased cooling.

Sorry if I sound pessimistic. There are some very nice, carefully built, stock cars, that are a complete joy to drive. And there are some very nice, carefully built modified cars that are screaming pleasure to drive. But in between there are a whole lot of crudely modified, jerking, surging, overheating, misery-causing crappy cars.

I’d get and read Bruce Anderson’s book on 911 Performance and Wayne Dempsey’s book on rebuilding the 911 Engine before starting. The case needs to be properly prepared with Case Savers, oiling modifications, etc.. However, properly built the 2.7 can be a great, tractable engine. I just wish someone produced a replacement case in aluminum!

$6000 is nothing, you can spend that just getting rid of the CIS and exhaust. Cash to HP ratio is not in your favor when it comes to the 2.7 or 3.0 motor. Most will tell you it's more feasible to find a 3.2 and mothball your 2.7 if you want that kind of hp increases. However finding a 3.2 for $6000 will probably not happen and that's just a core probably closer to $8000 or higher.

Dave911L makes a good point on the cooling. When I did the above mentioned high compression 3.2, I did add a trombone cooler. It does a fantastic job in my mild climate.

Thats exactly the kind of advice that I need, you are not pessimistic at all, I appreciate your valuable and very sensible advice.

I will shop for these books in Amazon. thanks!

Being in Qatar which closer to Europe than US, I will see if I can find a good deal on a 3.2 engine over there, I remember seeing a bunch of them everytime I go the dismantlers in Stutgart, but that was a while a go.

Mine doesn't have one and I'm planning on getting the largest cooler I could mount in the front to keep the engine cool.

I still need a final answer to my question, though. Is it possible to swap a 3.0 case with the 2.7? are they physically the same?