My 968 engine build

[968 GUY]

Speedy, not exactly sure how you checked your timing, but you seem to know what you are doing. I read that you had checked for TDC before putting the head on, which in my opinion is the most accurate way.
The way I have done it before is to have a degree wheel on the crank...a positive stop device bolted over #1 cylinder, rotate crank and mark on the degree wheel, reverse rotate and mark where it stops, divide by 2 and that should be TDC.
Having the stop directly over the center of the piston should eliminate most play.
I would think that belt elasticity and thermal expansion would have more effect than a small amount of piston rock, which if you can determine that amount, then it can be compensated for.

[speedysprocket]

That's essentially what I did. Found where the piston just started to move on either side of TDC, and split the difference to mark TDC.

[speedysprocket]

Got the engine in the car last night!
What's recommended break in oil and process?

[johnjcos]

I was just watching Ass Monkey Garage the other day and they ruined two completely different rebuilt motors by following improper engine break in protocol. Lesson learned from those 2 episodes; do not use break in additive, purchase expensive break in oil with as high a zinc content as you can find.

[mattdavis11]

Fill with 20W50 and let it rip tater chip.

[speedysprocket]

Any particular brand…? Non detergent or standard oil with zinc?

[Lear35A]

These aren't air-cooled airplane engines. You don't need straight mineral oil or anything like that. When I did my 968 rebuild break in earlier this year, I used standard multweight oil (I used Valvoline 10W-40 Premium) . I ran it an easy 500 miles. I drained the oil through a paint filter to see if anything was in the oil. I also cut open the oil filter to inspect the paper element. I expect you will see some tiny pieces of debris. This is normal.
Then refill with whatever oil you plan to run normally and as said earlier, let 'er rip.

[speedysprocket]

Got it started yesterday afternoon! Time to finish bleeding the brakes, fix a little water leak, and get an alignment!

[kwikt 911]

Congrats on the build! Keep us posted.

[speedysprocket]

If you have questions on converting a 944S to a 968 driveline, let me know. Pretty sure I figured it all out; it's not rocket science!

[speedysprocket]

Just an update- I played with my G-Tech Pro a little...
The last time I used it in this car with the original S engine, I got about 125hp.
New engine read 200hp... I put a new O2 sensor on the car after that too, since my gas mileage has not been what I expected, so I'll see if that made a difference soon.

[arominus]

The 968 motor gets significantly worse mileage than the S motor, I do 16/25 in my swapped s2. Your S will likely do worse since the gearing is a little shorter. My S gets 19/28.

[speedysprocket]

I used to get 27ish on the highway with my S, but was down in the low 20s before the head went... I was looking for better out of the 968 between it's better engine management with the 944's lighter weight...

[BikePilot]

Nice work! Weight won't make much diff on highway mpgs. My 968 does 24.x mpg all the time (mixed driving). I've never done a full tank of lowish speed highway though. Speed limits here are 70 and traffic flows around 80...

[speedysprocket]

And I've heard others claim 30 or close to it in there 968s...

[flash968]

it really depends on speed. at 55, you can get over 30 in a 968. at 65 you'll get about 27. at 75 it's down to 25.