costpenn

Update:

Took my car to our Olds Zone Show (finished engine pics shown here - it's the Orange 72 vert) https://classicoldsmobile.com/forums...12-14-a-3.html

Had some CO'ers who came give the motor a listen. A couple of guys suggested trying replacing everything else in the ignition system before tearing into the motor, so I changed out the coil, rotor, and installed Delco Unipoints (man they have become EXPENSIVE).

No change, so I'm starting to take front of motor off. Will report cam degree findings

costpenn

Chris, should have more to report this weekend.

Joe

hullinger

I'll tell you why I'm so interested in how this is going. I've got a '66 Toro that has a near identical problem as you. Low vacuum in the 12" range, low power, poor idle and so on. I replaced everything in the ignition system and had the Qjet rebuild and still no improvement. I've concluded one of three issues: late valve timing, wrong cam following a long ago rebuild by the prior owner or valve issues in the heads. Because it's a Toro the only way to get to the timing chain is the remove the engine. So I don't want to go through that effort if the cam or cam phasing isn't the issue.

Chris

oldcutlass

Joe, I'm sorry to hear that the simple things did not produce a cure. I'm curious to see what you find.

costpenn

Eric, it was worth a try. Actually, it's not going to be a big problem doing the tear down. All that work cleaning those bolts and chasing those threads has made disassembly go really quick, and being a non A/C car makes it that much better. Thanks again for your help - it was great meeting you and your cool car.

Dd you get your award?

Joe

oldcutlass

My award????

I hate these kind of problems and having to tear back into a fresh engine. I am really curious to what corrects your problem.

costpenn

Yes, your car won an award. I'll make sure someone gets it to you.

I'm pretty sure it is the cam being too advanced in relation to the crankshaft.

oldcutlass

- Who'd a thunk it.

costpenn

Well, the issue is solved.

Wish I could blame it on the parts, but operator error is the main culprit. Pulled the timing cover off with Chris, and immediately noticed that when - what I thought were timing marks on the sprockets - were aligned at 6 to 12 o'clock, the balancer keyway at approx. 12 o'clock on the crank snout. Looking at the new single row Avon set I have, and what Chris remembered from memory, the keyway with the sprocket marks lined up should be more around the 1:30 position.

I thought it had an improperly indexed lower sprocket, but my error was to line up the lower sprocket on the 0 degree keyway. It had a dot mark there I assumed was the timing mark, and the two others were marked -4 and +4. The actual sprocket aligning mark was on the outer part of the gear, and marked as a 0 - not as the usual dot as I've always seen.

Reassembled everything with the new set and did the #4 pushrod height CSM test. Differential reading is supposed to be anywhere from .170 to .200 - measured right at .178. The reading before replacing the timing set was .075.

I really dont know how that motor was running at all.

dc2x4drvr

Good detective work)

MDchanic

Glad you got it fixed, but sorry you had to pull it apart again.

It's annoying when it turns out to be something you knew had been done right.

- Eric

hullinger

Glad you got her running right and thanks for the update. It seems so many times someone talks about having a problem but than never gives an update on the final solution.

Is the engine running noticeably smoother now? Any improvement in power?

Chris

442rocketdave

Thought I would add something to all this also, the timing chains of lately have been terrible, a friend of mine brought me his 70 455 running like crap and he has everything done to it, edelbrock intake heads cam, 3 inch exhaust msd ignition, distribitor everything. Problem his timing gears were off 20 degrees, I had him by a cloyes true roller and I checked every cam lobe and degreed his cam and it ran great. It had symptoms like yours but no flat cam or lobes but his cam was off from the card!! alot off in mo, anyway I hope you find the source of the problem and if its the cam think about a good Lunati cam for your motor they have always performed well in Olds.

442rocketdave

Sorry I missed your post that you found it and it was the timing mark off, Glad you found it and fixed it!!!

oldcutlass

Well, seems like your hunch was correct. Glad it's fixed and now you can get to the enjoyment phase of your build.

pogo69

The w31 cam does tend to make vacuum readings jump around a bit

I see you found the prob i didnt read the whole thread

garys 68

Glad you got it figured out. Sorry you had to disassemble, but better than changing cams or getting a musroomed lifter out.

gearheads78

Great news Joe!!! Glad you found it. So does it run like a bat outta hell now?

costpenn

Well, funny you should ask.

Don't know whether to start a new thread, but after putting it togther last night a new problem seems to have arisen:

Started right up after reassembly. It idled so nice, the exhaust is much quieter than before, motor wasn't shaking, and had nice snap to it. About three minutes of idling, the choke stared to come off and after it was down to about 800 rpm for a minute it started to stumble, then was barely running. I guess the choke kicked back in, because the idle speed went back up and it smoothed out. As it began to come back down it again began to stumble. Pressing the accelerator almost had no effect some times, then pressing it again made the rpms climb a little.

I tried adjusting the idle mixture screws - both at all the way in and 4 turns out and it didn't seem to make much difference. I adjusted the choke 3 notches lean, again no effect it seems. I pushed the choke open all the way and it seemed to help a little, but not back to the way it was when it first started.

What is really confusing was the motor had none of these issues with the cam to crank timing being so far off before I fixed it. It has (as noted above) all new ignition parts and again, last week before fixing the cam to crank timing, I wasn't having any of these type problems. I going to jack with it a little more tonight - maybe it is leaning out too much when it gets warm? Keith Sauls offered to get me in touch with a CO'er in San Antonio to make sure the carb is et up properly to work with this cam/piston/cyl head combo. I might have to take him up on it!!

Thanks again to all those who have been helping with this project.

costpenn

Chris, use that #4 pushrod height measurement test in the CSM to verify if you do have a cam to crank timing problem. It worked like a champ for me.

442rocketdave

Certainly sounds like a fuel issue this time, do you have a rochester?

oldcutlass

Check the simple things first, manifold vacuum leak or a vacuum line off or misrouted, dwell, timing and then adjust your carb. Make sure your idle speed is not outside the limits of the idle rpm range. You've come this far, your almost there.

garys 68

Stupid question, did you reset your timing?

70Wcars

Hey Joe
I am the guy Keith was talking about. I would still like to look at the calibration of your carb. Let me know which W-31 cam you are running. I'll be happy to check the idle circuit and the primary power circuit.

Danny

costpenn

Danny - thanks so much for the offer. Yesterday evening, the thing again went throught the same issue ( stumbling/stalling after warm up), I just kept letting it do it for awhile, and then the problem went away. Ran it around the block a few times, no issues. So it appears that something is happening between the time the choke steps down (it doesnt seem to me like it is disengaing too early) and when the motor is fully warmed up - at least it behaved like that yesterday, Anyway, I'll check it out some more today and see if it does it again.

The carb on the car is a '70 442 M/T model 7040253 and the cam is the 402194 (308 474/474). Distributor is a '69 1111933 with no work to it at all. Has the big valve E heads and the 8.5 to 1 pistons. Provided the carb is built to it's original standards, should it be close to OK to work with the rest of the components?

I'll probably wind up taking it off and sending it to you anyway, but I'm trying to get it ready to to a few local events here in Dallas at the end of May.

70Wcars

Joe:

You have a PM

costpenn

Last update to this thread, since the car is finally running right.

Still having a quivering vacuum reading, and only getting about 12 inches now at idle, but it's running great. Turns out the main reason for the lack of power is - wait for it- the throttle not fully opening!

I noticed I could get the secondaries to open when snapping the throttle by hand at the carb, but no matter how I tried, the secondaries would not open up when road testing. I thought it might of had something to do with the low vacuum, but it finally dawned on me to check pedal travel. Turns out the pedal, when fully depressed, was only opening the throttle about halfway. Took the pedal crank out, bent it about 15 degrees and reinstalled - Hello frying those Wide Ovals!

Thanks to everyone for their help of this.

Joe

oldcutlass

Finally, can't wait to get my eyeballs on it again.

gs72

Great news, glad you finally got it sorted out.
Enjoy!!!