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This restoration topic has been epic. That engine bay has such wow-factor now, for sure. You make me miss my 78 so bad, in winter storage, can't stand it. Will definitely revisit this thread and #107's when I go full-bore on #225.
Wow! What a page turner! Absolutely qualifies as a "Dwayne's Garage" award member..How lucky are we to have so many exceptional 928 owners that give the rest of us something to aspire to..
Awesome Guy! Great work and beautiful result. Can't wait to see more pictures. Bring it to show off at the 40th 928 Celebration at the Pittsburgh Vintage Grand Prix this summer - it will e in great company with very special sharks!
Awesome Guy! Great work and beautiful result. Can't wait to see more pictures. Bring it to show off at the 40th 928 Celebration at the Pittsburgh Vintage Grand Prix this summer - it will e in great company with very special sharks!
Now that would be quite a test drive!! Thanks. I have more pics and videos coming! I filmed it at initial start up before the lifters got primed. What a racket!
Originally Posted by marine928
Wow! What a page turner! Absolutely qualifies as a "Dwayne's Garage" award member..How lucky are we to have so many exceptional 928 owners that give the rest of us something to aspire to..
Another victim of the 928 WYAIT curse...
Yes! I describe it as the Boulder running downhill. Once it starts it just picks up steam! Thanks for the kind words, I owe everyone here on the forum for continued guidance
Originally Posted by The Deputy
Guy,
This restoration topic has been epic. That engine bay has such wow-factor now, for sure. You make me miss my 78 so bad, in winter storage, can't stand it. Will definitely revisit this thread and #107's when I go full-bore on #225.
Outstanding work, keep up the good work!
Brian.
Thank you. I have so much left to do but really happy that the mechanical end is sorted. I actually found myself revisiting my own posts to figure out what the heck I did and how I did it!
Start of tuning....... keep in mind that the CiS fuel injection was serviced and calibrated on the old motor. I replated the hardware and lines and switched it over. So today, after fixing a minor weep at the fuel feed line, I decided to do my cold control pressure, system pressure and rest pressure tests.
All hooked up and ready to roll
IR temp at the WUR
Cold control pressure 17.5 psi
System pressure 74 psi
Rest pressure after 30 minutes
I will do my warm tests tomorrow and see where we are at. So far, I am very happy with these results!
Warm control pressure at 45. Idle was fluctuating with low vacuum. 1/8 turn clockwise on mixture screw instantly smoothed it right out! Idle is still a bit high at 900 but I figure I can now run it smoothly enough to fine tune timing and mixture.
I had this CIS set up for my previous engine which had lower compression and a dead cylinder. Makes sense that this engine requires a slightly richer mixture.
Hot start is good, warm start is a little stubborn but nothing to be concerned about until final tuning is done.
It was dark and rainy but a test drive is certainly possible on the next clear day!
Your engine looks excellent, Guy!
You're doing my fav thing right now, tuning. Matter of fact I'll be doing the same thing this Friday, can't wait!
The CIS cars respond well to good vacuum & tune.
You can really dial-back the ignition timing which helps with low-end torque. I've been known to hit 29 degrees while keeping good idle, which is 925rpm for the early ones (IIRC). So your not far off on idle speed.
Your engine looks excellent, Guy!
You're doing my fav thing right now, tuning. Matter of fact I'll be doing the same thing this Friday, can't wait!
The CIS cars respond well to good vacuum & tune.
You can really dial-back the ignition timing which helps with low-end torque. I've been known to hit 29 degrees while keeping good idle, which is 925rpm for the early ones (IIRC). So your not far off on idle speed.
Thanks Jim! It's getting there. I have a lot of detailing to do yet on the engine once it's stable. I want to change out the hoses to the booster and clean up the mess I made so far. I also want to tweak the injector lines a bit to get them nice and neat.
I am going to time it tomorrow and hopefully if the weather cooperates, I will test drive this weekend. Thanks for the reminder on the idle speed. For some reason I had 650 stuck in my head. Your site has been an awesome resource to refresh my memory on CIS.
About a week ago, I tried timing the engine. I got it fairly close but was struggling to get the RPMS steady. I also didn't like the sound or feel of the engine at higher RPM. I pulled the passenger cover to recheck belt tension and found that the belt was tracking forward. See these TWO posts for details https://rennlist.com/forums/928-foru...-opinions.html
Managed to get the timing belt done yesterday using the updated 83 pivot arm and pivot bolt. Belt is tracking straight and car sounds and (my imagination) seems to idle even better. No test drive yet, but any day now!!
So, a brief observation on my timing belt job and what went wrong.......
1.) replace the pivot bolt on the early cars, even if it looks straight and use extreme care on installation. I think I likely tweaked my old bolt while tightening it by allowing the tension arm to travel too far and snag the water pump casting.
2.) Since my seals were done, a straight belt replacement took about 4 hours start to finish including draining oil, coolant and accessories. Not bad but keep in mind that all hardware and components had just been installed. I left the air pump and power steering in place, and left the lower bracket on the alternator.
3.) Check your large crank washers! My belt tracked forward into my washer and my washer had a few nicks on the surface which aided in shredding my belt.
First test drive on the "new" engine, rack etc. Drove only about a mile at most as I was fighting daylight. Made it up to 40mph and third gear. Ran and drove great. Needs alignment but very driveable in the short term.
Rear main is leaking. I don't believe I set the seal in far enough. Going to drop the lower bellhousing and see if I can get between the flywheel and set the seal better.
I am going to do some final tweaking and button a few things up such as the sway bar, splash shields and alternator cooling hose. Then settle in for some test miles to get it fine tuned.
In the past couple weeks I dropped the clutch and replaced the real main seal. Job went well. I ran the car a few times and no signs of leaks.
I took the car out for a 3 mile test drive and it did quite well. Really comes alive at 2200 rpm plus. There is a little idle hunting at low RPMS, I think I am still chasing a vacuum leak or the mixture may be a little off still. Either way, I am really pleased overall as the car drove really well. Shifts great and clutch feels great as well.
I am going to try to time it again in the next few days and then log some more miles.
Tracked down a small vacuum leak at the A/F mixture base gasket. Makes a nice seal now.
I removed the vac line from the decel valve and the car seems to be running better. I have a GUNSON colortune on the way to get the mixture a little closer.
So with ten miles and about four hours of run time, I rechecked the belt tension and found it at the low end of the window. I am going to leave it on the loose side for now since that seems to be the prevailing wisdom with 16v.
02-05-2017, 07:35 AM
