A Quiet Boom

Well took the plunge and bought a 3.0SC engine and 915 trans for my '66 912. The car currently has a 2.0E 6cyl in it so I've got the oil tank etc. already. Just a few questions while I wait for my motor to arrive from the west coast;

1)Do I need a front mounted cooler right away or can I put it off until I can put a really nice one in?

2)Can I use the speedo drive from an earlier 915 to operate my mechanical speedo?

3)Will the trans mount from a 901 bolt up to a 915?

4)I'm going from carburation to injection, any fuel system upgrades or parts I may need?

5)Since it's mechanical injection do I need to use the stock "brain" or can I untilize an MSD 6al box I have lying around?

6)Any known sources for adapters for the 915 flanges to the 901 axle shafts? (other than milling them myself)

7)Can I use the 901 shifter and linkage?

8)Bruce Anderson's book recommennds early style exhaust for a 10-20hp increase, any problems with using the Triad headers an sport muffler from my 2.0?

9)And last, I'm planning on eventually turbo charging this engine, does anyone know if I can run 3.3 turbo P&Cs on a 30SC? I know the rod length is shorter on the turbo is this how the factory reduced the compression or are the pistons dished as well?

Thanks in advance for any help

Bill Gregory

[quote]<strong>1)Do I need a front mounted cooler right away or can I put it off until I can put a really nice one in?</strong><hr></blockquote>

The original SC engine had a loop cooler, really nothing more than alot of metal piping to add cooling capacity. However, you may find without auxilliary cooling of some sort that temps heat up more than you want.

[quote]<strong>4)I'm going from carburation to injection, any fuel system upgrades or parts I may need?</strong><hr></blockquote>

CIS injection used higher pressure than the earlier systems, so you'll need to splice an SC fuel pump in. You may want to consider the SC accumulator and certainly the SC engine compartment fuel filter. Don't know if the SC fuel tank filter is substantially different than the earlier fuel tank filters, but you may want to check on that.

[quote]<strong>5)Since it's mechanical injection do I need to use the stock "brain" or can I untilize an MSD 6al box I have lying around?</strong><hr></blockquote>

For clarity, CIS, while mostly mechanical until 1980, is not the same as the earlier mechanical injection. After 1980 it picked up some additional electronic sensors (lambda sensor, etc). Many people use MSD 6AL's in lieu of the Bosch CD box.

[quote]<strong>8)Bruce Anderson's book recommennds early style exhaust for a 10-20hp increase, any problems with using the Triad headers an sport muffler from my 2.0?</strong><hr></blockquote>

I'd expect the pipe size for a 2.0L would suboptimize that needed for a 3.0L, but I'm sure someone who has done this will let you know.

A Quiet Boom

Thanks for the replies, I thought that would be the case for cooling, since I'm not racing or sitting in heavy traffic I'll probably wait and do it right. As for the electronics the motor is an '82 so I assume it's got all those sensors. As for the fuel system any idea on what pressure it runs? I plan on EFI in the near future (SDS standalone) and would prefer to buy an EFI pump most likely the Bosch unit SDS sells. As far as the headers go, my brother bought them for a 2.7 he never installed in a car before selling to buy a 3.2 for his Carrera (still not in the car LOL) he gave them to me with my purchase of this car from him and I installed them at a glance I'd say pipe size is 1.5" OD I really just enjoy the sound these headers produce and they'll only be on the car until I finish assembling the parts I need to turbo the car (you know that money thing LOL) My main concern right now is just getting the motor running in the car so I can sell my 2.0E and trans.

CamB

You know headers = no heat exchangers = no heat?? Just checking. Otherwise they sound fine. I think the std headers are 1 5/8 (I forget). Look here: <a href="http://www.europroducts.net/main/cars/por/spec/ssi/ssi.htm" target="_blank">http://www.europroducts.net/main/cars/por/spec/ssi/ssi.htm</a>

and make sure you have the right oil lines etc too.

I don't know what the SDS recommended Bosch fuel pump is (or what pressure you need), but a second hand 911 one probably doesn't cost much. The std 911 pump should work with the SDS. You may need a mounting bracket for the pump to replicate the std setup (carbed cars have a different placement). You will also need to plumb a return line to the gas tank, as your car probably doesn't have one (my '69T with Webers didn't).

That is the only stuff I think I can answer and be sort of right rather than really wrong.

A Quiet Boom

Yeah the headers I have are the Triad type, there's a picture of them in Bruce Anderson's book, anyway they have small heat exchangers on them. As far as the fuel system goes, I bought the engine from a Porsche dismantler, I'll call them tommorrow and see if I can just purchase the parts from them. My main concern ATM is adapting the trans to my car. What I know so far is that I cannot put later wheel flanges into the short wheelbase car so I need to buy or make adapters for the transmission flanges. Not a big deal but I don't know anyone that sells them so I guess either I or my machinist friend will have to make them. Another thought I had as a temporary fix would be to put my Zenith carbs on the motor and jet them accordingly, but this is probably more work than just installing the correct fuel system.

A Quiet Boom

I measured my existing headers and the primarys are 1 5/8" ID. Since I'm going to install them and remove the stock exhaust (where I assume the lambda sensor is located) can I just remove the emmisions related electronics without harming the engines performance, in other words use the CIS like it was in prior years before the elcetronics where added? So far I have tracked down a used fuel pump, used speedo, and bought a new clutch cable and fuel filter, it also turns out my 901 trans crossmember will bolt on to the 915 so I think I'm ok there. I also tracked down a source for a decent front oil cooler (I have the RSR front spoiler so I'll mount it there, I'd like to run -12 AN fittings for the oil lines to the front of the car, where can I get adapters to adapt the AN lines to the Porsche lines?

emcon5

[quote]Originally posted by A Quiet Boom:
<strong>put my Zenith carbs on the motor and jet them accordingly, but this is probably more work than just installing the correct fuel system.</strong><hr></blockquote>

My guess is this would be easiest, if the jets are available.

The CIS-Lamda system will work without an O2 sensor, but all the other parts of the system need to be working, including the "brain" under the passenger seat, and the frequency valve. In fact, there are a number of people who advocate unhooking the O2 sensor on 80-83 911s except when it needs to pass smog.

There are a couple threads over on the Pelican 911 board about this.

Tom

A Quiet Boom

Thanks for the idea about the carbs, I contacted Motor Meister, a Rennlist sponsor, and Lee was very helpful. I think I'm gonna go that direction. If anyone is interested in selling a stock 2.0 exhaust and Zenith carb setup let me know, since I'd prefer to sell my 2.0 as a complete engine.

The only question I have not yet figured out is where I can get adapters for the 915 flanges to the 901 CV joints, I suppose I could machine my own or have them done by a friend, but it would be quicker just to buy them.

emcon5

[quote]Originally posted by A Quiet Boom:
<strong>Thanks for the idea about the carbs, I contacted Motor Meister, a Rennlist sponsor, and </strong><hr></blockquote>

Links to threads about the "M" word submitted without comment:
<a href="http://forums.pelicanparts.com/showthread.php?s=&threadid=52202" target="_blank">Link One</a>

<a href="http://forums.pelicanparts.com/showthread.php?s=&threadid=70160" target="_blank">Link Two</a>

There are plenty more if you search the archives.

Before you start spending a ton of money, you may want to buy <a href="http://www.911handbook.com" target="_blank">Bruce Anderson's 911 Performance Handbook.</a> If you plan on buying carbs anyway, you may want to look for a pair of Webers. With slightly higher compression pistons, early style exhaust, a more agressive Cam and Webers, you can probably get 250HP on pump gas pretty easily. Doesn't seem like much by 10 second drag car standards, but in a lightweight 2200lb chasis, it would be a lot of fun.

Tom

Edit: Just reread your post, looks like you have Bruce Anderson's book already. Something else, you should be able to use the 901 tranny with the 3 litre engine. I understand the 914 V8 Hybrid guys use the stock tranny, which is essentially the same as yours with a lot more torque going through it than from a 3.0. You will have the bonus of the shorter 7:31 ring & pinion, which according to BA "feels like 50 HP" compared to the later 8:31. I don't know what else you will need to make it work though, maybe Steve Weiner can shed some light on that.

Tom

A Quiet Boom

I hadn't heard much about MM before but thank you for the links, anyway I'm only planning on buying the carb parts to set up my current Zeniths for the 3.0. As for purchasing another set, I'm debating that one. I need to sell the 2.0 and it is a good running engine, I just think I stand a much better chance of selling for a decent price if it's in running order. My thoughts where to just pickup a set of Zeniths and modify them for the 3.0, install a stock exhaust on the 2.0 and sell it as a complete running engine (with good documentation) My eventual plans involve reducing the compression on the 3.0 and installing a turbo with an SDS EFI system, I'm not gonna further mod the engine for NA power. With that in mind however I'm gonna need to install that 915 sooner or later.

Roland Kunz

Hello

Sorry about the dealy most had been covered now

1)Do I need a front mounted cooler right away or can I put it off until I can put a really nice one in?

You can use the engine without cooler for basic transportation. If you like to demand the new power you will rush into hot oil problems and need a external cooler.

2)Can I use the speedo drive from an earlier 915 to operate my mechanical speedo?

Yes you can retroswap the pre 77 nosecone with speedodrive.
It´s maybe simpler to use the electric pickup and swap to a newer speedo.

3)Will the trans mount from a 901 bolt up to a 915?

Yes you only have to clear the rearseatportion to makes space for the upper nosecone area.

4)I'm going from carburation to injection, any fuel system upgrades or parts I may need?

Best is to get a complete system from a CIS car.
The CIS system will also need some brainwork on the electric side.
Don´t save on the high pressure fuelside as any mistake will let you strand somewhere or can lead to even worser trouble. The CIS pump will run over 7 bar fuelpressure.

5)Since it's mechanical injection do I need to use the stock "brain" or can I untilize an MSD 6al box I have lying around?

Now CIS isn´t MFI and CIS normaly don´t need a brain. The brain is for the rev limiter and for the Smog circuits.
The Ignition is seperate and has a own module.
I think you can use the MSD if you can adopt it to the hall trigger signal from the distributor.

6)Any known sources for adapters for the 915 flanges to the 901 axle shafts? (other than milling them myself)

I think the early 925 axles have the same bolt pattern.
Must verfiy that one day when a early 925 comes in

7)Can I use the 901 shifter and linkage?

Linkage yes, shifter has the reverse lockout on the wrong side.

8)Bruce Anderson's book recommennds early style exhaust for a 10-20hp increase, any problems with using the Triad headers an sport muffler from my 2.0?

No, you have to fit your early oilines anyway.
You also have to adjust the CIS a bit more to rich.

9)And last, I'm planning on eventually turbo charging this engine, does anyone know if I can run 3.3 turbo P&Cs on a 30SC? I know the rod length is shorter on the turbo is this how the factory reduced the compression or are the pistons dished as well?[/b]

Forget it, why not picking a Turbo ?

Now you also will run into several problems:

Your oilines depend from the used engine type, cooler and oiltank. You have to match them to one version or makes something to mix them togehter.

As you base is a 912 be prepared to upgrade the brakes and the suspension to keep the new power behind you.

If you only need the power to do 1/4 mls runs then get a NOX kit and a parchute

--------------------------

Now using the Zenits as interim is possible but you will have problems to jet them correct. Webers have cahngeable venturys and are easier to tune to a bigger engine.

Most EFI´s need up to 4 bar on the fuelpump and can be operatet with a CIS pump. CIS will not work with EFI pumps.

The 911 CIS O2 system is piggybacked to the system and can be removed.

Grüsse

A Quiet Boom

Thanks for the info, as it stands I'm going to most likely use the 901 gearbox in the interim as well as the Zenith carbs, I have found a place to get 36mm venturies and the correct jets for the car. I'll use the MSD system and install a front cooler. The car already has S brakes and I'm switch to 17" wheels and tires, also looking at various swaybars. I think I'll address the 915 issue over the winter when I pull the motor for the EFI system. This will give me some time to possibly modify the CIS manifolds to accept EFI parts including injectors and a throttle body.