I have a stock (well, it is chipped) 3.2l 911 motor. Other then the engine tin removed and 914-6 engine tin installed...it has everything still on it as I took it out of the 911. I will be keeping the factory fuel injection and it will be bolted up to my 901 tranny. So, what can I safely remove from it and/or plug for it running in my 914?

Thanks,

Jim

Wow it has been a long time coming hasnt it. Been a couple of years since you stopped over.
I wouldnt be able to tell you off hand what I unplugged and capped off by I know there was a couple of things.
An FYI she will not start if there are too many vacuum leaks BTDT.
ARe you wiring it yourself , thats what I did, or are you buying a conversion kit.
If you need help let me know I am just down the road.
The Bently manual is also a big help.

..

When I do them, I start out by removing all the oil tank vacuum lines leading to the rubber elbow intake. I plug all the holes where lines were connected. I usually simply vent the oil tank to atmosphere.

I also plug the nipples on the air cleaner housing (if you plan on using the stock paper filter and filter housing).

Click to view attachment

Will the 901 be able to handle that 3.2?



Brett

I would hook up the oil tank vents like the factory did.


You will need a conversion flywheel, that one won't work unless you are using a 70-71 911 pull type clutch setup on your 901.

You will need to notch the bell housing on the transmission to accomodate the DME sensors.

You need to convert the transmission to handle the 914/6 throttle linkage.

Did you install the 914/6 motor mount in the chassis yet?

You will need some kind of exhaust system.


Will your brakes handle the extra horsepower?



We need a slippery slope smiley....

Keep the info coming! Here is what I have done so far and/or plan on doing:

1. Bought the Patrick Motorsports Clutch/Flywheel Conversion Package
2. Notched Transmission for all sensors
3. Installed the Rick Johnson Motor Mount (completely welded in, no bolting)
4. Bought the GHL Stainless Steel headers with heat & GHL dual SS muffler
5. Installed 84 Carrera front end...and have the matching rear brakes (next summer I plan on putting on 911 rear brakes and parking brakes..have them from the 84 donor car...and have 72 911 parking brake components)
6. I have the throttle components from the 84 including the transmission side...I'm guessing I can tap the boss and install similiar to a 914-6?
7. I also have Patrick Motorsports 3.2l wiring conversion harness...I plan on NOT using the 914 relay board?
8. Purchased a DWDesign oil tank, cut out the holes using the AA template

I'm painting the engine compartment today! I haven't had the oil cooler mod done yet nor have I purchased any oil lines. The engine does have the 911 hard line on it...can it be to use it in a 914 can I simply mod it by moving the curved connection piece to face the side facing the oil tank? Can one use the factory air filter?

Finally getting the time to try and finish this project!

PMS wire harness conversion if you don't feel like figuring out the wiring yourself.

Oil tank, lines and fittings.

911 fuel pump

911 Tach\

911 oil cooler mod

Patrick also makes an (overpriced) throttle cable with a tab to mount on a tranny stud which eliminates all the slack you would otherwise get with the bell crank and its 5 mile long cable.

If you're talkin' 911 ebrakes it sounds like you've got a project worthy of a 915/wevo or one of those 916 kits.

brp986....I actually have the 915 tranny that came with the donor car...I'm saving that for sometime in the future.

Why would you even think about venting the tank to the atmosphere? It's a passive emissions system, takes/robs no power, keeps the atmosphere cleaner, and has been part of federal law since 1965.

The Cap'n

Why?

The main reason is to eliminate the oil mist from reaching the intake. These hoses always have some amount of oil residue inside them.

Tell me it's better to attempt to burn the oil vapor and create more greenhouse gasses.

So, tell me that all the 911's running around with carbs or now individual throttle bodies vent their oil tanks into the intake.


You should be more concerned with telling the original poster that the whole thing will be illegal since the exhaust will all have to be altered and should have a CAT on it.




Give me a break mr crusty.

How about dumping the 9lb 6oz boat anchors for these?





It''s a current project we're working on... JKH widened the slot for the 24mm Carrera rotor and the pads will be the stock Carrera pads now.

It should ...

I've been running my stock 901 behind my 3.6L for the last 4 years or so. So far, so good.


Just don't do any 1st gear burnouts, and you'll be fine ...
Andy

Here's my free advice........


A 901 can survive, but it depends upon a few factors:

1. How is the car to be driven?
2. What is the condition of the transmission?
3. Is the transmission improved or modified?


In my experience, if the car is a street car and driven with some form of prudence (no burnouts, no pounding through the gears, no sudden loading/unloading of the transmission (sudden slip then sudden grip)), then the transmission should last a good long time as long as the transmission starts out in good to great shape.

If using for track work, the 901 may find that it is up for a challenge. Sudden loading / unloading of the transmission (like driving on the alligator strips, rumble strips, or curbing) will shorten the life of the gears. The torque of the 3.2 will eventually wear out the transmission.

If the transmission is improved/modified (billet intermediate plate or steel reinforced intermediate plate) and all new components are used in a good 901 box, the transmission can be made to survive. Spray bars can be used to help with lubrication and coolers can be used to remove heat build-up. The transmission will still require periodic rebuilding depending on how it is used.

The failure we saw was with gears. We broke teeth off of at least 4-5 sets of 4th gears before converting over to a 915 transmission. Since converting, the only failure was an improperly set ring/pinion that caused erosion of the ring/pinion set (thanks PMS).

A 915 box can be made to work as well and will offer some more durability, but they too have some limitations and are all getting older as well. The 915 is more expensive to convert and to rebuild (and they will all require rebuilds as well). Recall that the factory changed to the g50 with the 3.2 in 1987 and there was reason to do so.



My street car (84 euro 3.2) is using a 901 with a billet intermediate plate. The trans was fresh when I installed it 4 years ago and I have no problems with it. I don't baby it, but 1st is only to get rolling.

How does a billet intermediate plate strengthen the gears?

Our belief is that part of the problem with breaking the teeth off of gear sets is that the two shafts (the pinion shaft and the input shaft) were not being constrained properly or the two shafts were bending (elastically). If the shafts were getting further apart, the mesh of the gears would change creating more stress on the roots of the gear. Over time, fatigue failure would cause the teeth to fracture right at the root.

The billet intermediate plate (being newer than the original plate) would hold the intermediate plate bearings tighter than the magnesium intermediate plate. Most of the original intermediate plates that I have seen do not hold the bearings tight. This would allow the two shafts to move with respect to each other.

Many years ago, I spoke with a builder who told me that back in the day, they used to machine the intermediate plate in order to make room for a steel plate reinforcement that would hold these bearings tightly. They experienced issues with the intermediate plates a long time ago. He warned me of breaking gear teeth long before we ever did.


again, just my free advice

Seen it many times. In fact, many 915 transmissions also suffer from this.

Andy

4 years+ with a 3.2 and a 901. No problemo.

Yes, particularly the later solid silumin cases. The early mag cases have a cast-in steel bearing retainer like the 901, which are more stable. If you had bought a 3.2/901 converted car then I could see just running as-is until it broke. But you are at a crossroads where you have the opportunity to get it right from the get-go. Doing the 915 now means taking your car off the jackstands once and for all, versus putting it back up for popped cv's or some other 901 foible, which ofcourse will happen at the worst possible moment.

It IS better, and cars serviced/modified in my shop have it attached to the air cleaner(s). As these motors burn substantially cleaner than their 70's counterparts, I suppose you could have a legitimate excuse for not running a cat, although it would be nice to do so. Kinda complex, but it could be done.

The Cap'n

John,

I am still learning and am curious about exactly in which situations the billet intermediate plate is worth the money and when it is snake oil. I think that the days of harvesting X number of core transmissions to find good used replacement intermediate plates are numbered and while I don't even know if Porsche still provides replacement intermediate plates, I suspect that in the future (not sure how far in the future) many people will end up moving to billet intermediate plates due to cost alone if their current intermediate plate is fubar.

With that being said, I have so far been surprised as to the number of intermediate plates I have seen so far (customer and core transmissions pulled apart for parts) that have issues with problematic bearing bores in the intermediate plate. The issue being a lack of proper interference fit for the bearing (malformed bores due to shafts attempting to push apart) which results in bearing that spin in the bores and shaft alignment issues.

California Motorsports (http://www.californiamotorsports.net/901.htm) makes an interesting bearing retainer plate that is different than the OEM version. It's unfortunate that due to the design of the 901 (proximity of the cover and reverse idler gear) it probably makes it difficult or impossible to make a bolt on bearing retainer plate much like the one that WEVO makes for the 915 in which it completely wraps around both bearings. I can see how you could machine the intermediate plate and press in a wrap around reinforcement, but that is probably relatively expensive. I could see that as being an option as part of a the creation of a billet intermediate plate.

Regarding your problem with 4th gear breaking teeth, I wonder if it is more an issue with shaft flex than intermediate plate issues? 3rd and 4th are in the middle of that shaft (more prone to alignment issues due to flex due to distance from bearing suppport?) and 4th is not close to the intermediate plate. With the known issue of 1st gear being twisted off the input shaft, I wonder if part of the issue is that the input shaft is just not large enough in general. That it is a weak link?

Richard

Richard,

One of our original thoughts was that either the input shaft or the pinion shaft were flexing (elastic deformation) under load that caused the gear mesh to change and eventually break gears. The other thought was bearings not holding the shafts correctly.

I rebuilt all the transmissions that we went through. The first few I wondered about but in the back of my mind I had wondered if it had been something that I had done incorrectly. Experience told me otherwise. As time went on we would always break teeth off of 4th gear. The only thing that seemed to follow along with the failed 4th gears was a looseness of the races in the intermediate plate. One case had loose races in the case, but mostly it seemed like the races in the intermediate plate were no longer press fit.

On a whim (and out of desperation), I bought one of the billet intermediate plates and tried it. The quality was nice and more importantly, the fit of the races required heating the plate and dropping in the races. This box has yet to fail on me, but it is now relinquished to serve out the rest of it's life in my street car. I had it apart to check on it and all is well. No wear to speak of, the bearings look good, the races are still tight. I'm sold on it (and no, I don't sell them or even know the source any longer).

For a high torque application, I believe that they help.

Are the shafts too small to take the torque? Long term, I would probably say yes. For track use? I would say that the 901 can survive for a while on the track, but the abuse of a higher torque/higher horsepower motor, it will have a shortened life. For track use, I will stick with 915 gearboxes. I have learned how to make them work for what I need them to.

(just my free advice. your mileage may vary)

My first 3.2 conversion was in 1990, and it ran with 901 gearboxes until 2002 when we went with a 915.

Thanks John. It's always good to hear the details from someone who has hands on experience.

Richard