Best engine for 68 912 to 911 conversion
 

What would be the best engine for my 911 conversion? 2.2, 2.2, 2.4, etc.
Should I only consider a complete engine that has been pulled vs. a short/long block and then sourcing all the missing parts? Seems like that could be a real PIA, but?
My transmission is a 902/02 so all I need is a motor.
I have never built a 911 motor before so I am looking for help. Thanks

Well, anything other than a 2.0 will require a different flywheel to go with your transmission. Though changing flywheels is not a big deal as long as you don't purchase a motor which is later than the 2.7 (last of the 6 bolt flywheels/cranks, exceptions excepted).

I think you are better off purchasing a complete motor. I'm currently building a race motor, and even with my somewhat extensive collection of bits and pieces from othe motors and blown up race motors, I'm always finding something I don't have or can't find, and those costs can add up pretty quickly.

How you find a used motor which still has a fair amount of life in it before rebuild time is something I don't know about.

For the mechanically inclined, rebuilding a 911 engine is not difficult. Time consuming, though.

Walt

Walt, thanks for the advice. I have read about the rebuild and agree, it does not look impossible, as long as you know how to read. As you said, time consuming for a novice first timer, but it is all there in black and white.

What do you think about a 72 2.4T motor. One of the S members here has one for sale and he says it runs well and is a complete unit. Mark

Well, its factory spec 140 HP would be a nice power boost for your 912. These might be as unstressed a 911 motor as Porsche made? But others with more experience in swapping engines around or with this motor may have more valuable opinions.

A 2 liter flywheel will bolt on to the 2.4, so I see no reason to swap a trans. I agree with Walt in sourcing a complete engine. The 2.4T would be a good fit in a short wheelbase car. It's always good when possible, to be able to drive the car that you are buying the motor from so keep an eye out.

Aaron and Walt, would the bump in HP of the 72T be enough to make the car fast? Maybe that is a dumb question, but.... I thought the car had 130 hp, not 140? I realize it is no S or a hopped up motor, but would it make the little SWB fast? As Walt mentioned, the T should be a solid base motor. Aaron, the engine is supposedly still in the car and can be driven, but it is a long way from me. Any idea what a reasonable value a motor like this would be worth? It currently has Webers which are available with the motor. Thanks, Mark

The 912 won't be any faster than a 911 with the same motor. Might benefit you to find someone willing to let you go for a ride to get an idea what you might expect with a 2.2, 2.4, or 2.7. My dad had a '74 Carrera with a modified 2.7 and it was freakishly fast. Keep in mind a large increase in power might require suspension, wheels, and brake upgrades to make handling and stopping safe.

jt912, i understand that, i just meant what motor is best for the SWB cars to not over power them and over weigh them given the size. M

As fast as a 72T ;) It's a subjective question so it's hard to define. It will be a mild ride with decent torque. Definitely good for a base to start with. It's no heavier than a 68 911 2 liter.

Can range from 2500-4500 or more....There are too many variables that determine price. If you cannot get a drive, perhaps another person can help you with that. An independent shop could also provide a PPI on a decent runner and give you feedback on how the engine performs. Keep in mind that a PPI can get expensive so you have to weigh that expense vs risk.

Merb:
I'm in the same boat, just a bit farther up river. 1967 SWB 912. I've gone the pieces parts route. There are times I've sorry I just didn't find an engine, but it really depends on what you want. I'm doing a screaming 2.8, and I would have tossed a lot of stuff anyway from a 'complete engine'. I used nickies, Mahle pistons, a small journal centerlube schrick cam reground to 3.8rsr on 102 LC (thus different trays), Ti rods all on an early aluminum case... so most parts would have been tossed anyway. BTW, 2.8s are freaking expensive FYI.

So if you want big displacement, go with a six. If you just want more power give a call to charles navarro at L&N and discuss his big bore nickes kit for the 616. A LOT has been done since the 912 handbook. You can have 160+ hp for a not unreasonable amount of money. It requires head work (~2-2.5k) and cylinders. Maybe toss in a set of his rods. If this info on the 616 had been there when I started collecting for the six in 2005 I would have gone this route. Toss in a twin plug kit from Wilhot (2k?) with high compression, and I would guess you could stomp an early S in power and still have the inherent handling of the shorter motor. Oh, and an additional cooler isnt even required!

Really worth looking into, IMHO. I do think sometimes about selling my 2.8 parts and doing a monster NASCAR reving 616, but the wife wants the car done so we can go get ice cream again. Any further delay would mean death :D.

tadd

Overpowering an SWB? Not possible. :) A well set up SWB is a great car with any motor, 2 liter to 3.6 and even turbo. Buy a complete running motor, IMO, but don't limit yourself. A 9 bolt 901 flywheel is a fair compromise if you find the right 3 liter. That said, if your tranny has a 6 tooth ring and pinion, any 911 motor has the potential for problems, even a 2.4T.

At this point I am so confused. I keep going back and forth. Value of car vs. building what I want vs. build the 912, sell it, buy a 911 and do it again. This is not something I want to always be working on, I would like to drive it someday. As tadd points out, my wife would like to see a project finished and go for a ride someday. With all my project cars, she already thinks I am crazy.

Merb:
It's tough sometimes. There are too many options with 911s. :D

Build what you want and forget the originally crap. Have a ball. SWB with RS flares? You want it, do it. When your dust 100 years from now someone else can Chang it back :eek:.

Staying 616 will save dealing with all the oil stuff and no cutting engine mounts. I really wanted to rev, so I went six. If I could have anything it would be a late 2.0L twin cam four (type 7xx I think). Ultimate 912 upgrade in my mind.

As many have told me, pick a path and enjoy.

There is no equation for satisfaction (other, perhaps, than >$). If the car is in good shape, and the engine also, maybe the early 912s have held value? Not that many of them around.

So sell it, and buy an SC. All the power you need there, really. Durable motor if maintained and not abused.

Much quicker route to more performance, and probably less expensive.

But its your money, as long as you have it now.

Walt

I have a '67 912. converted to a 3.0 and a 915. serious, serious fun. stock body, 6 inch rims. I love the flat sided look of the SWB caes. FWIW I would be very hesitant to add flares. with decent tires and suspension the handling will be fine. I did a 3.0 because they're strong and cheap to build, relatively. dynoed 250 hp and 2100 lbs surpises a LOT of people. here's some links......

http://forums.pelicanparts.com/porsche-911-technical-forum/502996-3-0-dyno-day-pleasant-surprise.html

http://forums.pelicanparts.com/porsche-911-technical-forum/475180-3-0-915-swb-perfect-combo.html

http://forums.pelicanparts.com/porsche-911-technical-forum/540300-took-my-swb-drag-racing-today.html

FWIW before I built my engine I'd never even rebuilt a lawnmower engine. see above. with resources like pelican I wouldn't hesitate.

I am thinking a built 912 motor making up to 140hp would be faster, handle better, stop faster, and probably hold value better than a putting a T motor in it.

There have been some fun sport oriented 912's built.

I have been thinking about your concerns and challenges and think that this might be a good alternative that meets your goals:

http://forums.pelicanparts.com/porsche-911-technical-forum/216206-1969-912-turbo-project-update-6.html

Not turnkey, but doesn't require 911 engine mounts and has gobs of power.

The mind boggles comparing the effort to build a 912 turbo and that to move two motor mounts and plop in a 911.

Indeed! Still, it's an option. :)

Mark, give me a call. also, FWIW you can put in the 6 and mounts, while leaving the stock 912 engine mounts in place. makes one plug access slightly awkward but not bad.

My youngest son now drives a '68 912 with my old '72 911 T motor in it. We built the car together as his high school senior year project. It's been a wonderful combination, and is certainly faster than his older brother's mildly hot-rodded '79 SC. The car barely cracks 2,000 pounds with gas in it, and combined with that short geared 901 box meant for the 912, the car failry hauls ass. I'm sure it would give most any 3.2 Carrera a run for its money, at least up to 80-90 mph.

This particular motor dyno'd at 135 RWHP and 145 ft lbs or torque. It's dead stock, and has well over 100,000 miles on it. All we did was reseal it a bit before it went in the car. The 2.4 T motor is one of the most trouble-free of the mag case motors, with the cast iron barrels serving to all but eliminate any pulled stud problems (CTE's match more closely than with the biral cylinders). It actually makes more power than the vaunted 2.0 S motor, and gobs more torque. It really is a neat little motor.

The 912 itself is subtantially lighter than a 911 of the same year, even after swapping a 911 motor into one. They simply had less stuff on them, fewer "luxuries" or "creature comforts" and options. I was really astounded just how light his car is and, as a result, just how quick it really is. I would highly recommend this combination, from our personal experience with it.

Well, maybe fewer options, like a Webasto Heater, but other than that, the shells are about the same. From the little white book p. 88:

SWB 912 empty weight 970Kg, max gross 1275
SWB 911T 1080Kg, max gross 1400
SWB 911L same as 911T
SWB 911S 1030Kg, max gross 1400

Well, the 912 motor weighs less, around 130Kg dry vs 184Kg of the 911.

So. . . 970Kg - 130Kg = 840Kg or 1851 pounds without the motor
911S, 1030Kg - 184Kg = 846Kg or 1865 pounds without the motor
911T, 1080Kg - 184Kg - 896Kg or 1975 pounds.

Those are dry weights, the oil tank in a 911 probably weighs 10 pounds, and the five additional liters of oil have a density of, say, 0.8Kg per liter, or 4Kg, that is another 9 pounds, call it 15 by the time you add the additional oil lines. So when you switch to the 911 motor you are adding about 25 pounds, that is in addition to the extra 120 pounds of motor weight, 145 pounds all in.

PCA rule book quotes slightly different weights (including 150 pound driver)- 2333-150 = 2153 pounds = 990kg, not sure where they got that from.

But you get the idea-- the whole 912 mythos is really about the extra 145 pounds situated about six inches further aft in the car. And the missing two gauges, wooden dashboard, webasto heater, front fog lamps, engine electrical panel and the steering wheel!

That's all well and good, but weighed side by side on the same day, on the same scale, my somewhat lightened '72 911 comes in at about 2250 with a tank of gas. My son's '68 912/911, which we have made no attempt to lighten, came in at about 2005 with a tank of gas.

Everything you wanted to know about bang for your buck with a 616.

http://www.lnengineering.com/hotrod356.pdf

t

I have a 912 with a 2.4 conversion and love it.... 68 901 transmission. everything works nice!

http://img.photobucket.com/albums/v468/patpan/BWRear.jpg

I've had 2 '69 912's a targa and then a coupe. Neither had any swaybars and I don't know if the 911T had them or one in front. It was probably an option anyway.

It's already been said and it's true. The 912 and 911T have the same body, suspension and brakes and the 2 instuments to the left of the speedometer were different because there is no oil tank in a 912 and no oil pressure gauge, just a light.
I think the first 901 transaxle was designated a 902. The 912 and 911 transaxle is the same with shorter gear ratios for the 912 and the 911 clutch is also bigger and heavier.

They didn't change much with the 912 because they already had the parts for a 911 and it would cost more to design, build, and stock more special parts for the 912 which had a the same motor that was in the 356 super 90 or something like that. The only difference may be the split shafts in the Solex 40mm 2 barrel downdraft carburators..

Solex 40 P11 comes to mind as the number on them.. but it was 21 years ago when I had my last 912 and I get confused in memory because I had a '72 BMW 2002 Ti with Solex 40 PHH sidedraft carbs.
The Mercedes 190SL also used the same Solex 40 PHH dual sidedraft carbs.
Dual Weber 45DCOE with 38mm venturis, a 300degree BMW motorsport cam and 10:1 compression pistons, intake port matching, and stahl headers were much faster and stayed in tune better!

I drive a 72t with a 3.0 sc conversion and it is adequately quick by modern standards. A new camry V6 is faster as I'm sure is my Tundra p/u. Does anyone know the difference in weight between a 68 and a 69? I'm guessing 200 pounds. No doubt the 911 is more fun to drive. The 3.0 works well in the 72 and no doubt would be a little quicker in a swb if it fits.

Lots of engine choices, I would look for any engine that has documented low mileage, or
rebuilt by someone reputable. The cost to rebuild any 911 engine will put you very deep under water with this project.

I have seen so many nice cars sold recently for 1/2 or 1/3 of build cost, you would probably be better off just selling your car to someone who appreciates the charm of a 912. Not only will you save $1000s of dollars, but you will not waste 100s of hours of your spare time in the garage. Buy someones well done project and be enjoying it the next day.

I of course, did not listen to this advise given to me, and decided to build several cars at the same time.... because its fun... and I have other cars that are done that I can enjoy;)

Think about your needs, look whats for sale, before you get in to deep.

I'm at a loss as to why, exactly, you don't just find yourself a SWB 911....cutting up a 912, that could be worth 15 to 25K or more, if done 'right'...& building this 912 into a "911", that will never be "real" & thus never worth the money you poured into it doesn't pass the sniff test.

I got my 912 when I was a post doc in New Mexico. Rust free, $5.5k, YMMV but usually cheaper than a 911. You have to have a pristine, near show car for 25k and that's a lot of $$$$.

Like haycati mentions above, the only 'non transparent' change is the rear motor mounts which have holes and the 912 do not (assuming one does not cut the sheet metal for a standard oil tank) but mounts an aftermarket. External coolers are considered a wise upgrade just like a 911, so it's a feature not a bug for extra oil cooler plumbing.

Driven one? There slow. Yes they are 'momentum machines' but merging onto a freeway, mine can be scary. The 912 is unloved and under valued and will be since it has 90 hp in a stock fresh motor let alone one that has some miles. In the past three years there has been a lot done with the 912. 160 hp plus is very do able now where 130 was 'hot' then. Porsche should have used the 2000GS twin cam, maybe the 912 wouldn't be as unloved now..... but then it would have pounded the 911S.... :D

The 912 did outsell the 911 in the early days. We all just were used to cars with less oomph.

Bottom line is that for a fixed price a six will get you more zing and a six will go way, way thru the 'power glass ceiling'. Me, I'm going with a 2.8 and shooting for 275 at the rear wheels. Cheap, no... But not even obtainable in the 616 platform. Only diff will be those two rear engine mounts which with the 616 in place you'd be hard pressed to notice I'd bet.


t

I have to agree, the 912 does seem a little unloved in the retail market, but appears to be getting some more love, ie. money paid, these days. I figure it is like anything, when prices rise, all related products tend to rise as well. However, with the recent down turn, it seems that the 912 is becoming a little more popular maybe due to the value. And the fact that some of the prices people are asking for 911's is just stupid. High prices for junk cars. IMO.

Also, I agree with tadd, there are little to no differences in the 912 vs. 911 other than the engine and related hardware. So if a 912 can be had for reasonable money, why not put the motor of your choice in it. As I have said before, it is so ironic that some folks will take a 356 and stuff a 911 in it, take a 911 and stuff a bigger 911 in it, so on and so forth, but when someone mentions putting a 911 motor into a 912, suddenly it is a bastard. Sounds a bit snobish to me. I say do what makes you happy. If you are concerned about value go for it, if you want a hot rod, go for it. I myself have been wrestling with the value thing vs. the fact that the 912 will have small balls with the stock motor. But for now I am sticking with the stock motor. I can always change it later with a couple of motor mounts.

3.2 is the go
 

I've just finished putting a 3.2 in my 912. Fairly straight forward accept for some flange work. Hope you proceed.
Good fun.

912/6
 

"Also, I agree with tadd, there are little to no differences in the 912 vs. 911 other than the engine and related hardware. So if a 912 can be had for reasonable money, why not put the motor of your choice in it. As I have said before, it is so ironic that some folks will take a 356 and stuff a 911 in it, take a 911 and stuff a bigger 911 in it, so on and so forth, but when someone mentions putting a 911 motor into a 912, suddenly it is a bastard. Sounds a bit snobish to me."

merbesfield, i totally agree with you! it's also like turning your regular LWB 911T to an RS, RSR, ST, Turbo look, etc. there's the purist, the outlaws or hot rodders. i belong to the later crowd. why? because life is boring when your car is too original and perfect that you can't even afford to have a non-factory screw hold your radio in place.

bottomline, do what you want and just have fun! after all, it's going to be you sweating bullets trying to catch-up with the cars going 55mph on the freeway, if you don't. my .02