Problems with 16 valve engines?

[Harp]

My question is really geared toward the S2 since I plan to buy one some day. I have an 8 valve 944 at the moment. I've had a few mechanics tell me that the 16 valve engines were poorly designed in terms of reliability (at least the top half of them) and require overhauls much sooner and costlier than the 8 valve engines. Does anyone know to what degree this is true?

[Pilot_951S]

From my own experience I can tell you that I had a 91 944S2 and it was strong all the way to 103,000 miles (totaled it at 103k ). The only engine work it received was a new head gasket at 91,000 miles.

I have heard that there is a possibility of major damage if the cam chain guide wears out and gets dislodged and stuck between the cam sprocket and the chain. This can cause the head to crack, and at the very least will cause valvetrain destruction, and possibily piston damage.

I should note that I found my S2 to be in the shop much less than my previous 87' 944T or my current 88' 944TS. In my experience the S2 motor was much more reliable than any other 944 engine.

IMO the S2 motor was the best of the bunch because of its combination of low end torque and high RPM power. Basically the motor is a gem, it also warms up faster than the older cars because it has much less coolant volume and a more efficient cooling system and it maintains temperature better thanb the older cars. In addition on long highway trips I oftensaw 26-28 MPG so it can be a frugal motor as well.

Good luck finding one though, they made fewer S2s than they made 968s.

EDIT: You should find yourself a 944 specialist and see what they have to say about the S2.

[This message has been edited by Pilot_951S (edited 04-20-2000).]

[Harp]

Thanks Pilot for the helpful reply,

I really could use the horsepower of the S2 (212 HP I think) compared to the 158 HP of my 1988 944.

[Pilot_951S]

208 bhp, and 211 lb/ft of torque for the S2

It is a gem of a motor

Good luck in your search, oh and if you happen to find a car with an M030 suspension then you are REALLY lucky.

[1.2gees]

I agree with Pilot on the S2 being a generally better car, and a lot easier to drive, however can they push 300 without internal engine work? I'm a bit skeptical about performance capability of the NA engines in the 944 range. How about say 350 with internal engine work, but without spending 10000$...I'm just curious (though I think I know the answer, hope to be proven wrong) no offense.

[Pilot_951S]

1.2gees,

Curious where your commentary is coming form, am I missing a post here or something?

I didn't see any discussion of building up an S2 motor. (not that I haven't thought about it)

Anyway I figure the only way to get 300 or more posines out of an S2 motor is to do the following (and it will be big $):

Knife edged stroker crank (3.2 liters)
Major flow work (radiused valves, port , plish, extrudehone etc, redesign air intake snorkus for Ram Air effect, exhuast sytem redesign)
New cams (lumpy idle, but hey you want the juice you have to pay the price)
Stiffer valve springs etc to go with the cams
Increase compression (new pistons, deck the head etc)
Beef up all internal parts so they don't break when runnign all this power.

Like I said major bucks.

However I can see say 250 horsepower with maybe the flow work by itself. I've seen a blueprinted S2 motor running 230 horse at the flywheel.

[1.2gees]

You're not missing anything, I've wondered which was the more suitable car and have come up with ultimately the best car for me: a turbo!

The reason being although the S2 has no lag, and a pretty flat torque curve, its the 951with which you can achieve say 370+hp though without a bottom end (upgraded for higher hp) rebuild this engine wouldn't last very long. Besides that you can almost eliminate the lag by changing chips, getting a different pop off, and if that's not enough one of those new turbo's that are much lighter and spin up faster, huntley's got one that produces boost at idle... I just thought I'd ask since you owned both the 951 and the S2.
Ahmet

[1.2gees]

Maybe I should add, if you plan to keep your car stock, and about 210hp is enough for ya, than sure the S2 is the better car, both more drivable, and more reliable.
Ahmet

[Pilot_951S]

1.2gees

Intersting question, in my opinion the S2 makes a much better street/autoX car than the 951. I found it much more livable in the day to day trafic grind than the 951. Ultimately however I am now back to the 951 because it is easier to make more power, and I am planning on taking the car to the track where lag is not a problem.

Also during my buildup when it is time to really get into the motor my goal isn't going to be super power but usable power. A lot of flow work is going to help me bring down the RPM that the car begins to make boost. I haven't mapped out all the details yet cause I still have a long way to go with the chassis improvements.

I am thinking seriously about Huntley Racing's MAF and pipe kit, but I don't like the way they plumb the air to the filter. I may end up desiging a custom setup with my shop (Fairfield County Motorsport, Fairfield CT.)But it is a long way down the road, hell I still have a full interior in the car.

[1.2gees]

I've heard a lot of good stuff about the Huntley kit, but don't have any first hand experiance, I suppose I could recommend them based on what I hear, but, I've also heard that the air filter rubbed on the hood in a couple of cars, and huntley is saying they're working on that, good luck with your project, and keep us updated :-)
Ahmet

[Pilot_951S]

I'll keep you updated, don't expect quick updates though as I have gone back to school and I don't have much spare cash for the car.