Horrible Noise!!

[SGB]

After the car sits for maybe 24 hours, when I start it this is what happens-
whir whir whir CLUNK!!

Heart racing in fear, I try again:
whir whir pause varoom...

The CLUNK is HORRIBLE. It makes my skin crawl. I swear I can feel the whole damn car shake.

It never does it twice in a row. It only does it if the car is totally cold and motionless for a long time.

Sometimes I think I feel/hear a real minor rumbling sound at idle.

Is a cam bearing broken maybe?
Is the crank end play gotten loose?
Could it be a broken piston

This weekend I'll drop the oil screen and see if big pieces fall out. The sound seems big enough to a pretty big chunk of something, but otherwise it is running well.

I have the valves intentionally loose to do a compression test and to be sure I had not somehow caused a valve /piston impact.

What can it be? My trusty mech thinks it may be end-play, and he doesn't have line-boring capability for a type IV, so I may be talking to Jake....

[silver2.0]

Maybe you just have a broken tooth on your flywheel? It could be peeled over against the next tooth, or stuck in it. I have seen it happen, on gearboxes

[SGB]

I'm gonna go out and drain the oil - drop the sreen and look fer things. I started thinking about it... I had the oil pump replaced a while back with a high volume pump. I didn't do it myself, but had it done by someone else. What happens if they DID NOT file down the drive tang? Would it impact something? Could it cause a CLUNK! ?

[SGB]

And the answer is:

.
..
....
......

LOOSE STARTER!!
What a relief. Horrible sounds are banished. Compression test completed, and results are good (135 on cyl I could use screw in fitting, 125 on the two I had to hold the rubber end thing against). Valves are now reset too. I think there is no point in finding TDC, etc to adjust these. I love the "if these are rocking, adjust these" table in the PP guidance article. I have confidence that my valves are properly set for the first time. The screws are all at about the same point also, and the clearances all felt the same amount of resistance. Tomorrow plugs go back in, carbs get rebalanced, then a quick wash before the test run over the mountain.

[WOODPIE]

Great news, Scott. I've been keeping up with this thread, but I had no ideas to suggest to you other than what was already brought up. Glad it was simple.

Ed

[Zeke]

I'm not so sure about your valve adjusting prowness, but if they all sound nice and quiet and it idles smooth, I will defer.

Actually, there is a theory about adjusting the valves anywhere on the base circle of the cam that has the most clearance, but this is a fairly complicated proceedure. Some American V8's could be adjusted with the motor running (if you coud stand the mess) and this is exactly what they were doing.

And again, this does nothing for valve timing, if you really want to get complicated.

[SGB]

So now I'm not as relieved. I understand where you are coming from I guess, but I NEVER had confidence that I was hitting TDC right. I think that the relative improvement psychologically is good enough for me. Truely, how far off could this be? I guess the concern is the duration of the low spot and are you really on it during the adjust. I had really consistent torque required to loosen the lock nuts- I really don't think there was any load on the valves screws I was messing with each time. Also, I have the (insert positive or negative adjective here) hydraulic cam, and the adjust proceedure requires tightening until resistance. In previous adjustments, I was never certain that I was not compressing a spring. This time it was totally apparent when resistance increased., so I got some confidence that it is at least better. A couple of intakes had obviously been too tight (one that reads 135 psi- up from 80 before the adjust). But I wanna know - what is the downside? What are you thinking about Zeke?
PS- Starter siezed this weekend, too. Puttin in another tonight I hope. My wife is getting pretty tired of me doing nothin but 914 stuff.