Airbox crack - did I just find the reason for my 2500 rpm cold idle speed?

[pampadori]

Originally Posted by '76 911S 3.0

The same plug does not necessarily mean it is the correct sensor...you need to verify that this sensor reads correctly via the Infinity. I would hate to see incorrect sensor data and an improperly tuned/running engine over $50 for a critical sensor.

Fair point @'76911s3.0. I found it to cross over to AEM pn 30-2001 on a couple of reference sites. I also found where a few folks had good luck using it with the AEM UEGO controller/gauges.

Would you be able to confirm anything for me on it? I didn't know we had a AEM engineer on the board! Bosch number is 0 258 007 018 and its listed as a LSU 4.2 sensor.
Thanks in advance for any confirmation you could provide.

['76 911S 3.0]

Originally Posted by pampadori

Fair point @'76911s3.0. I found it to cross over to AEM pn 30-2001 on a couple of reference sites. I also found where a few folks had good luck using it with the AEM UEGO controller/gauges.

Would you be able to confirm anything for me on it? I didn't know we had a AEM engineer on the board! Bosch number is 0 258 007 018 and its listed as a LSU 4.2 sensor.
Thanks in advance for any confirmation you could provide.

I'll look into it for you Shaun and let you know!

[pampadori]

Still waiting on a couple little items before i really dive in and begin the install of the ITBs and AEM. Knock sensor, some wiring items and harness wrap, heat shrink.

In the meantime, I've finalized my harness plan after getting some help from a few different folks on this board with way more experience, talent, and functioning brain cells than I have!
I'm going to run starter, alternator, and temp/pressure sensors for the instrument cluster in one harness and keep the 14 pin factory plug as part of the harness.

For the main engine harness, below is my diagram/plan. I'm not sure how to physically wire the fuel pump since I had wanted to use the factory wiring and not have to send new wires down there under the car to the pump. Maybe I can use the factory wire that runs to the air flow sensor and run it to the ECU lowside for the FP relay and just use the factory FP relay up front in the frunk.

[pampadori]

I had wanted to do this whole upgrade without removing the motor from the car but today's discovery changes that. You might recall from post 17 that the motor is a mix-and-match of parts using a 77 930 case/block and likely 83 3.0 heads. Well, I guess when the motor was rebuilt they stuck with divilar head studs.

https://www.youtube.com/watch?v=C_dT2-UmzXM

[zelrik911]

Originally Posted by pampadori

I had wanted to do this whole upgrade without removing the motor from the car but today's discovery changes that. You might recall from post 17 that the motor is a mix-and-match of parts using a 77 930 case/block and likely 83 3.0 heads. Well, I guess when the motor was rebuilt they stuck with divilar head studs.

https://www.youtube.com/watch?v=C_dT2-UmzXM

Very good/clear pictures down the holes - what do you use for that?

Hmmmm - so you may have ALL dilivar studs, not just the bottom row as per usual SC owners. On the positive side it proves you have a real Turbo case, which may be worth more than a whole SC motor in this crazy collectible era.

[pampadori]

Got the motor out saturday morning. Went pretty smoothly since he CIS was already out.
Found a couple of things that need attention, besides the head studs. Oil line from crossover pipe to external t'stat was spinning and leaking at the crimp point and the motor mount bar had some damage on both ends. Looked like it had been repaired at least once before so a nice RSR bar is going to replace it.

[pmax]

Originally Posted by zelrik911

Very good/clear pictures down the holes - what do you use for that?

Had the exact same question !

[pampadori]

Originally Posted by pmax

Had the exact same question !

Sorry fellas, I overlooked that question. I used my smartphone. It has a flash directly next to the camera lens and since it's only about 6mm thick I could maneuver it easily.

Got the studs in the mail. Still need to order a gasket kit but I'm not sure which part numbers I need just yet.

[pampadori]

Engine disassembly has began.
For the life of me, i couldn't get the transmission to separate from the engine. I saw some mention of rotating the throw out bering 90 degrees or something like that. It didn't make sense to what i was seeing though. Finally i gave a call to Al K since he's been so helpful already helping me figure out what case was in my car and general info about running ITBs on these motors. Of course within 30 seconds he had the instruction I needed to hear. "remove the circlip and clutch fork pivot arm completely from the trans and it will come right off. Bingo! Al is on the Xmas card list now!

Clutch didn't look too bad. I need to measure the disc to see if its reusable per the specs but i did notice that the flywheel was very very light. It also had some heat cracks so I think i might be replacing it when I start to reinstall everything. Its a 6 bolt flywheel, from a 77 930 i assume. What should a factory flywheel weigh for that application? It felt like it might be sub 5 pounds or so. not what i'm used to with my other cars. Rear main seal looks good and dry although i'll still probably replace it for good measure.

Got the exhaust off and only snapped about 4 of the studs in the process! ordering new studs and nuts i guess. The price keeps growing here and there but I'm still pretty sure that I made the right call doing this myself instead of farming it out.

Here she is now:



I was surprised to see that none of the lower studs were broken. Just the 3 intake studs I found originally that prompted me to remove the motor.

These were the numbers that I found on the heads. I assume the 7/82 is the date. One head was 3/82 so i guess it was replaced at some point.
The other numbers indicate normal 83 SC heads. What is the other number though, the 9 in a circle? Should that mean anything to me?



Next time i get to turn some wrenches I'll be taking the chains, cams and towers off and removing the heads to inspect. Can't wait!

[boyt911sc]

Shaun,

Nice looking engine yoke. Are you aware that you have it installed on the 1-2-3 side of the engine? The preferred installation by people is the 4-5-6 side. You will find it when you re-assemble the motor.

Tony

[Joe Bob]

Crack proof.....Webb's Machine Design in Clearwater FL

[pampadori]

Originally Posted by boyt911sc

Shaun,

Nice looking engine yoke. Are you aware that you have it installed on the 1-2-3 side of the engine? The preferred installation by people is the 4-5-6 side. You will find it when you re-assemble the motor.

Tony

If it has to do with the exhaust, i couldn't get the yoke connected on either side until i removed it. Is there another source of interference that makes 4-5-6 preferable?

[al lkosmal]

Shaun,
You mount on the 4,5,6 side because the oil pump/intermediate shaft/gear are installed on that side.......so when you remove the 1,2,3 side of the case you are left with this assembly...I.E. ready for dis-assembly.

regards,
al

[pampadori]

oh, i see now! That makes good ol' fashioned sense.

I had not planned to split the case as I was trying to replace the studs, and get back on the road.
Its quite clear looking at the motor that it was rebuilt not that long ago. inside things look pretty spotless. There are some pretty nice looking nuts on the end of the rod caps too. Arp hardware perhaps? Oil pressure was well within spec before i took it off the road.

Should I leave it be and only fix what is confirmed broken and move on or is there always a need to split it?