josephsc

In the honor of my 944th post, I guess I should talk about my 944

I had a 968 engine put in my 87na last year when I ate my motor. Here's the old thread. I had a mechanic do it (and it took "only" 30hours of labor -- and I was already in it for 10hours for engine R&R, and but this included a clutch change). It was his third 968 swap, and at the time he mentioned that doing it from an NA was a little more involved (due to the engine wiring) but not too hard to figure out. Overall, cost was not cheap -- but the point of the project is not to reproduce a 968 (hell, you can buy a complete 968 for around $10K these day). Just for reference, another 968 engine swap sold earlier this year in Massachussetts for $9500 (this was a 88 944S, pretty clean, even had 968 door panels)

A couple of other things to keep in mind.
* You'll need to go to a cone filter -- there's just not enough space in there. I'm actually moving towards an S2 airbox to make it less conspicuous as soon as I gather all the parts.
* Definitely lose the rubber-centered clutch if you haven't done so already.
* You can keep the original bellhousing, torque tube, etc -- just need the flywheel, and everything infront of it.
* The original exhaust will mount up, but requires some machining to get the bolts to line up.
* May want: larger radiator and an oil cooler to match -- or move to a colder climate.

As for drivability -- holy cow! Two things make significant differences:
* Short gearings: it's really fun on the street, especially at red lights. The 1st gear on the 944 is like 14:0 total ratio, compared to the 968 box which is like 12.0 -- so you're out of there like bat outta hell! I actually stop at yellow now to wait for the red to turn green
But in general, it's a little too short: : in some AutoX courses, you'll be looking at shifting to 3rd more often than with a 968 tranny. Looking at various trannies, the S2 tranny might be a better match for street/autoX setup. I've been looking for a S2 tranny with LSD for awhile now, but they're very hard to come by - and not cheap. It's been a year with the original tranny and it is still intact -- can't wait until I get an excuse to change that out....
* Weight: Porsche puts the dry weight of the 944 2.5L engine at 166kg and that of 968 engine at 172 kg (I know, doesn't seem right...). So you're not adding much weight. But the curve weight of 87 944 is 8% less than of a 968 coupe. My 968 cab is even porkier. One problem with the 944 is that my interior is very tired compared to the 968. There's something about the build quality of later cars.... That's okay, though, more excuses to rip things out... (rear seats? we don't need to stinking rear seats....)

There are other things you'll have to think about down the line. Personally, my suspension system was not as tight as the 968 to begin with. And it's old and tired, and need to be reworked... That's going to be more $$$. The brakes just doesn't match. The exterior has been well driven in... In hindsight, it would definitely have been cheaper to have junked the car and bough something else -- but then that wouldn't have been very sporty now, would it?

If you're ever in SoCal, drop by for a test run. Heck, you can even come and sample a 951 and a 968 for comparison!

Ken

Everything I know about the 968->944 flywheel bell housing issue:
The 944S, S2, and 968 all use one combined speed/reference sensor on the flywheel. The 944 and 951 use two.
The 968 also has a dual mass flywheel to help smooth the engine out. This was thicker than the previous flywheels, so it needed a larger bellhousing. Since they couldn't move the tranny back any further, they shortened the torque tube to make it all fit.
So you've got two options:
1. Use the 968 flywheel, bell housing, and torque tube.
2. Use a 944S or S2 flywheel. I believe the stock bell housing will work. And the stock torque tube will definately work. This seems like the wisest option. You could even get an aftermarket lightened flywheel when you do this.

More info I found was to make sure you get both the DME and the variocam computer with the engine. It's apparently a seperate unit and some places won't include it.

tifosiman

Cool, thanks for the input Joe .

My car has enough room under the header panel for the S2 filter set up. My brakes and suspension have been beefed up to beyond 968 M030 spec. And, my car is very light. So that means it should be even more of a blast if I do the swap. Awesome!

So, to clarify, I DO NOT need a different bell-housing? That would certainly make things easier.

I have the spring centered clutch in my car that has less than 11K miles on it. Will the same clutch work with the different flywheel?

Thanks again..........

EDIT: Thanks Ken, you were posting while I was typing.

Jeremy

josephsc

Sounds like an ideal candidate for a 968 engine swap -- rather than my old beater that I was refusing to let die! You do NOT need to change the bell housing -- but I don't know about the clutch -- I just ordered a S2 clutch (I *think* they're the same, but don't quote me on it....)

You know, I heard there's a guy out in the UK who's gone one step further after the 968 engine swap in a light-weight 944 chassis: he supercharged it!

Lead Foot 944

You guys just keep talking.....Im taking notes if you know what I mean....


DAmian

Matt Marks

Tifo,

Car runs great. Goes like stink! The car was a 944S, so I'm still using the S transmission. No major issues after 2 years of street use with the 968 engine in, and 30+ track days including 4 944 Cup races.

The tranny has about 100k miles and the syncro's are starting to get a little crunchy and have some pinion bearing whine, but this was present before I did the engine swap. Over the winter I'll either rebuild this one or replace with an S2 trans as mine does not have limited slip.

Dmitry S.

Tifo - PET states that the 944 n/a and the 944S used different flywheels - but the same clutch disc. It also states that the pressure plate was different between the n/a and S models. So it looks like your clutch disc will work with the 944S flywheel - but you need to buy a new pressure plate. The bellhousing from your n/a will then bolt up to the 968 engine.

Like Ken said - you can use the 2 piece 968 torque tube and dual mass flywheel, along with the bellhousing as well - but this is more parts to buy, along with having to buy a new clutch. The good thing about doing this setup is that you can change the clutch without dropping the tranny.

Dmitry S.

Hmm - something a bit odd - looking at the Tweeks catalog, it has the 944 and 944S flywheel as the same part - but the S2 flywheel being different.

josephsc

Would a 968 bell-housing even fit? I recall there being some fitment issues.

I also would recommend against going with the dual-mass flywheel. A lot of us in the 968 world have been reducing weight and getting better throttle response by going back to a single-mass setup, but this comes at a cost of increased vibrations. Strangely enough, there is no vibration with the S2 flywheel setup -- might have something to do with the spring-centered clutch (I'm not aware of a spring-centered clutch for the 968 setup).

That Tweeks catalog must be in error. The S even used a different DME: http://frwilk.com/944dme/math.htm

Mongo

Wouldn't installing a 968 engine be stressful on a 944 drivetrain? Unless you go with a turbo or S2 tranny thats the only thing I can think of to take the stress off of it since NA trannies are so porcelain. BTW, would you have to change the torque tube if you swap engines?

Andy

Tom Carson

with a meter or a test lamp if Matt has +12 volts on the skinny black ignition coil wire and also on the green/black wire to the fuel pump (DME relay term 87c & 15 amp fuse 34) while he is trying to start the engine - the alarm should not be the problem. Matt's real close...

Dmitry S.

Beautiful, looks like this answers the question on the flywheel.

As for the bellhousing, this is what the PET says.

944 116 043 02 944 -86
944 116 043 04 944 87

Looks like the bellhousing was slightly changed for the 87 model year. Must be something very small, because I know you can bolt up early model engines to the later bellhousing.

So I guess these are the things you can carry over onto the S3 motor
Clutch disc (Assuming you already have a spring centered one)
Bellhousing
Torque tube

These are needed for the swap:
944S or S2 flywheel $500ish (new)
944S or S2 pressure plate $230ish

Just noticed this in the Performance Products catalog

944 n/a clutch disc - 215mm
944S/S2 clutch disc - 225 mm

The PET says that the 944S and S2 have the same clutch disc as the n/a, so they should swap out.

tifosiman

[QUOTE=TheStig]Wouldn't installing a 968 engine be stressful on a 944 drivetrain? Unless you go with a turbo or S2 tranny thats the only thing I can think of to take the stress off of it since NA trannies are so porcelain.
QUOTE]

Hence the reason why I stated in my post that I would start looking for an S2 trans after the swap.

tifosiman

Excellent! Thanks for all of the help and feedback guys. It's good to hear from people who have actually done this. It really does not appear to be as involved and scary as it initially seemed. Time to start funnelling cash into my "Car goodies" fund. That's the one that does not go toward home improvement, landscaping, yadda yadda yadda .

It would be nice to get a check-in from Matt Olde regarding his motor/progress..........Matt, you around?!

Take care,

Jeremy

Fishey

S2 tranny will be very hard to find with LSD. (Most factory LSD's would be worn out anyways) So a aftermarket LSD would be a good thing to look into if you plan to really put the tq down out of tight corners in autoX.