rebuild without teardown

[HemiMG]

I have a 2.2 in my '70 911. I have a 2.7 in pieces to go in it, with 10:1 pistons, ge40 cams and a electromotive distributerless ignition system. I'm wondering how difficult it would be to put this thing together using Wayne's book. I was previously scared of making the attempt without the benefit have having taken the thing apart because a porsche engine is a bit different from an American V8 (which is where my experience lies) I don't want to end up with extra pieces in my rebuild kit when I am done!
Any opinions on how difficult the job would be for a porsche engine newbie armed only with the book would be welcomed. As well as what sort of power difference I can expect between that motor and my 2.2.

[Wayne 962]

The book is crystal clear, especially with the 2.7, which is the engine documented in the book. With the parts diagrams and pics, you should have absolutely no problems armed with the book...

-Wayne

[HemiMG]

Thanks, the relatively low cost of the book will save me alot of money over what the local porsche shop would charge!
I'm pretty anxious to get the new motor in it, but having gotten used to a 99 neon while the porsche was awaiting other repairs, the stock 2.2 litre motor is plenty fun right now.

[snowman]

The biggest difference between an american v8 and a Porsche is that the Porsche has good parts to start with. Also the Porsche uses some one time bolts, like the connecting rods and flywheel ones, that really means ONE time. Once you tighten them up they are history. You can get around this by using Raceware or ARP bolts but you will pay for it.

The other big differance is Porsche uses 10 parts for every one in a american v8. There are parts, more parts, and more parts, you will not beleive how many parts they could put in a 6 banger. No magic, just keep track of where they go. The book is a great help.

I would also strongly recommend Bruce Andersons book on Porsches as well as the factory manual. Take plenty of pictures yourself as you take it apart, you will not regret it.

The basics are exactly the same, american v8 or porsche. Measure everything. The tolerances for Porsches may be tighter than american ones, thats why they get more power per cube. The materials are like typical racing parts for american v8s, no need to improve on them. Unless you go for over 400 HP you will not need things like Carillo rods, the factory ones are good.

By the way DO NOT GO FOR over 400 HP. Porsche engines are air cooled, that limits them to about 320 HP for a reliable engine. There are people getting over 600 HP out of air cooled Porsche engines, they all have a nice, pretty coating on the exhaust system, thats consists of melted piston material. You can do this to, but not for long. Thats the scoop from a PORSCHE ENGINEER that worked on the design. Water cooled heads are needed for more power. I am just repeating what he told me, and I beleive it as I have personally seen the results.

[HemiMG]

Well, I have to disagree about about American engines, my roadrunner sat for 3 years and fired right up running much smoother than the Porsche did after setting for 10 months or so. I would hardly consider bolts that break after one use a quality improvement.
Also I have a '73 ford truck with over 300,000 miles that still runs fine. People like to make fun of American cars, especially the type of snobbish people that give Porsche owners a bad name, but if the cars are properly maintained they will do fine.
I'm not saying you are all wrong, I wanted to slap the idiot who suggested that I put a chevy 350 in my 911, or that his v8 monza could outhandle my Porsche because he added sway bars. Kinda reminds me of the honda civic owners that think they can out drag my roadrunner becuase they've added stickers and a dryer vent for an exhaust pipe.
Although after working on a 33 year old 911 I want to slap the guy who decided to use Allen head bolts for everything even more.

[ChrisBennet]

Originally posted by HemiMG
I would hardly consider bolts that break after one use a quality improvement.

There are just a few highly stressed bolts (flywheel and rod) that are one-time-use only bolts. These fasteners are required to do things that aren't generally required of domestic engine fasteners.
-Chris

[Wayne 962]

The 935 used an aluminum case and output about 800HP. These 930/935 cases can tolerate very high HP, and can be built up to almost anything. For a street car, I would say that you will be getting wear problems at figures over 350 HP or so...

-Wayne

[ChrisBennet]

Originally posted by Wayne at Pelican Parts
The 930 used an aluminum case and output about 800HP
-Wayne

Did you mean 935, 300hp or something else?

[Wayne 962]

Yes, I did mean 935...

-Wayne

[TimT]

Porsche engines are air cooled, that limits them to about 320 HP for a reliable engine. There are people getting over 600 HP out of air cooled Porsche engines, they all have a nice, pretty coating on the exhaust system, thats consists of melted piston material.

I dont buy into that statement at all.

I have built or helped build some pretty powerful engines:

3.8 Turbo approx 900 hp (racecar, 935 clone)
3.3 Turbo approx 600 hp ( this is a street 930)
3.4 NA 374 rwhp (racecar)

even my humble 2.2 puts out some good hp for a small displacement motor just about 200hp ( in a 1800# racecar)


on all of the above engines EGT and operating temps are closely monitored, and mixtures are set to keep combustion temps reasonable. You can make some serious power with the porsche engines if you keep track of mixture, timing and oil temps.

Most of the failures I have seen on high output engines are mixture or rev related. That 12000rpm downshift makes a bunch of schrapnel pretty quickly

[TimT]

Forgot to mention in the above post the engines mentioned above are dead reliable. That 600hp motor is going on 4 years and mucho miles..

[HemiMG]

Originally posted by Wayne at Pelican Parts
The 935 used an aluminum case and output about 800HP.

-Wayne

Correct me if I'm wrong, but didn't the 935 also have a massive oil cooler mounted in a big front air dam? I think the original point is semi-valid if you have to start looking for non-factory ways to cool the thing. I say semi valid becuase I'm sure any serious engine builder would consider the coolant system part of the build.

[HemiMG]

Originally posted by TimT

even my humble 2.2 puts out some good hp for a small displacement motor just about 200hp ( in a 1800# racecar)

hi tim. I'm assuming that we have the same generation 911, how did you manage to get it down to 1800#s? Mines going to stay on the street so I'm sure alot of it I can't do, but I've already swapped out the heavy factory seats for DAD seats which feels as though it saved me a ton. Man those factory seats are heavy! and swapped to the lightweight door panels which realistically speaking probably didn't save me alot.
Granted the car starts at what...like 2250#s?

[snowman]

There is a very simple way to sort out the good cars from the bad ones.

10 laps at Willow springs. Straight off the showroom, no aftermarket anything. Not racing, just driver school driving at 9/10 ths.

Any Porsche or BMW will live thru this and go on to many more happy weekends. ALmost any, and I include the Corvett and Viper, american car will break something. If it isn't the Corvett or Viper it will probably trash the engine, completely. Least that my take on it from owning over 35 american POS over the years.

Don't get me wrong though, if you put enouth aftermarket parts in these they can kick some serious butt. But stock, no way.

[ChrisBennet]

Some years ago Brumos took a new stock 993, put some safety
equipment in it and changed the break-in oil - then ran (and finished!) the 24 hours Daytona. None of the Ferrari 333SP's finished that one if I recall.
Sadly, I don't think we'll see any 996's trying that stunt.
Anyone remember any more details of that story?
-Chris

[Wayne 962]

Gosh, my sister in-law's Toyota Camry could probably run for 24 hours, though...

-Wayne

[snowman]

Not at 9/10ths though. IF you do not beleive it try it.

[ChrisBennet]

Originally posted by Wayne at Pelican Parts
Gosh, my sister in-law's Toyota Camry could probably run for 24 hours, though...

-Wayne

I bet that high banking would be tough on the ole' Camry...
-Chris

[HemiMG]

Sorry snowman, but I have to disagree with you. In fact I think you are just needlessly being a porsche snob now. Vipers and Corvettes are put through the paces at race levels every time a new model comes out by every magazine out there. It's not very often that they break in the process. Maybe you just need to learn how to drive?