Engine Options????
 

Hey all-

I'm new to this forum and relatively new to the Porsche world as well. Although new to it all, I'm jumping in head first. I'm in the process of buying Geof33's half finished project - an 82 SC backdated to 73 RSR. It has no engine and I've been trying to figure out what to put into it. I recently posted a question looking for advice on what to put into it - got some great info. Now, a little more educated, I've narrowed down my choice and that's why I'm reposting a similiar question.

I've narrowed down the choice to a either a 3.0 or 3.2. I want to buy an engine with some miles on it and rebuild (and modify) it myself with the occasional help from a pro. This will be my first 911 engine rebuild (I've rebuilt three 2.0L type 4 VW engines from the bearings out). While there may be more cost effective solutions to rebuilding, I'm really eager to learn how to rebuild one of these engines.

Any help with direction would be greatly appreciated. I'll list the application below:

-Set up for track and street
-82 SC w/ no sunroof
-Rebuilt 1973 915
-9&11" rims and tires
-FG hood, fenders, bumbers, doors, rear flares and valances
-OG bolt in rollcage
-Want heat
-No ac
-On a diet
-Needs to pass CA smog but I will swap out exhaust and/or intake after test if needed
-I'd like to keep the engine budget under $15k - fully dressed
-I'd like to keep the rebuild simply since it will be my first

Should I start with 3.0 or 3.2?
What year engine?
Oversize P/C?
Twin Plug?
Cams, intake and exhaust?
Comp. ratio?

I've ordered the following books:
-How To Rebuild and Modify Your Porsche 911 Engine
-101 Projects for Your Porsche 911 Engine
-Porsche 911 Performance Handbook
-Porsche 911 Story

While I'm sure I can find the info I need in these books (when I get them), I was hoping to get started sooner shopping for an engine.

Thanks for the help to date-
Craig Backer

Craig,
My 1973 Targa has a totally stock 87 3.2L with stock HE's, cat & all. Certified and able to pass smog in CA as a 87 911. You will need something like this to pass with your car, I think...
If you go this way, it would be pretty easy to swap in exhaust & a chip for track use, etc.
The nice part is I get 20 city /30+ hiway in this car, and it has PLENTY of power, throught the range, no temperamentals...:)

3.2 definitely. Search and read about larger bore/compression/California octane/twin-plugging. You could build as nice a motor as your wallet will allow.

Search carrera3.5L and jeremyD for their exploits, among others.

You may also consider a 3.6 transplant for "instant" HP.

I'm considering a 3.2 Motronic w/ 3.4 P/C and 9.8:1 CR - twin plugged with 20/21's using CA 91 octane gas.

Can a twin plug system be swapped out with a standard one for a smog check easily (having spare distributer, wires and chip)? Would it pass CA smog with the higher compression ratio and cams?

The real question is the second one. Doubtful whether you will be able to pass a CA smog test with those piston/cyls and single ignition.

I think in CA that if you upgrade to newer engine, you have to meet the specs for that model year - visual & emission

So, a Motronic 3.2 bumped up to a 3.4 (98mm p/c) with 9.8:1cr and 20/21 cams running single plug ignition with all the stock smog equipment and new chip won't pass CA emmisions?

Craig Backer

If your combustion is incomplete due to the higher compression and only one operating spark plug, emissions will probably rise. Plus, you have made the engine larger, so more gases will be present as well..
It could pass, esp if the readings are well below the required limits to begin with. But what are you going to do if it doesn't pass? With your mods, there is no easy way back, IMO.
Hopefully you will get some expert opinions here, not just mine :):cool:

Just an observation: aren't you outlining pretty much the most-expensive route possible for putting a motor in that chassis?

I mean, either you're buying a blown motor that needs a rebuild (with lots of potentially-expensive unknowns inside it), or you're buying a motor that doesn't need a rebuild (for 4-8K?), and then sinking rebuild money into it (another 6-10K?) -- so that you're 10-18K into the project (plus whatever it costs to install the motor and upgrade the rest of the drivetrain, brakes, oil cooling, etc.) with only a 3.2+ to show for it?

Why not just get a buy a healthy 3.2 and save money -- or, if more power is a must, put in a healthy 3.6?

You're probably right: although, it could maybe be done fairly cost effectively if I were to get a 3.2 (lowish miles needing head work) and just redo the top end (w/ 98mm p/c's), do the cams and ace the twin plug idea. I don't know, I'm FAR from an expert.

I called Andial this morning and was informed the above mentioned engine would not need to be twin plugged and could pass CA emmisions. Once again, I'd don't know.


Thanks-
Craig

Craig, Andial would know. They've built more of these types of engines than anyone else over the years;) I would trust their opinion more than speculating on an internet board.

My 3.5L with 20/21 cams passed CA emissions in May with little fanfare. You shouldn't have any issues as long as all emissions equipment is hooked up and functioning correctly.

I would just consider twin-plugging both for the larger 98mm bore as someone else suggested & for increased protection against the less than stellar 91 octane that we Californians are blessed with. If you go the 3.2L>3.4L route, you can simply twin-plug the heads only while the motor is apart and simply add the rest of the components at a later date as your budget dictates or if it turns out the motor does have detonation issues.

Rebuilding a 3.2L is not that expensive for parts, it's all of the performance parts that one wants to add "while they're in there" that really makes things add up. If considering 3.4L, try finding a core 3.2L that needs a rebuild, you should be able to save some money off the motor purchase that can help offset the rebuild costs a bit. No sense on paying top dollar for a perfect 3.2L just to tear it down and make a 3.4L out of it.

Ralph