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Discussion Starter #1
Yes, test driving car that dropped valve yesterday. And this guy was in Las Vegas about a month ago and didn't gamble. What a waste.

No idea why the valve dropped. It doesn't seem like rocker rails had rode the retainer, no clear wear marks. How easily the keepers pop up if rails are riding retainer?

So, replacing just keepers got the engine going on again. We drove about 5 miles to warm the engine. Slight knacking noise, but my friend can't remember how the engine sounded last autumn (also he took 56 Caddy out of hibernation earlier and spoiled his ears with that smooth sound). Next step, checking all valve clearances and rocker rail-retainer clearances. If knacking sound still there, then what? Connecting rod bearing?

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I may be missing something, but if you dropped a valve, hodya get the keeperes on again? Usually the valve falls into the cylinder and tears stuff up pretty badly. The only thing I can think of , is that, the vavle was hit by the piston and got bent keeping it from falling in all the way. In any event I'd at least pull the head off and check things out. I think you'll find more damage than you think!

Tom
You can do anything you want to......ONCE!
aka "my 66 coupe"
 

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Did you compression test the cyl? or leak test? The klacking might be bent valve that does not close. Do like the previous poster said and remove head. Maybe test first.

John


[color:blue]66 coupe 289 2v C4 needs restore</font color=blue>
[color:blue]70 coupe 351W 2v c4 almost done (?)</font color=blue>
[color:red]71 coupe 302 2v C4
 

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No popping out the carb?? You might have gotten lucky....

Did you run a leakdown on that hole yet?

Make sure the stem is contacting the flat part of the rocker and that the rails aren't hitting the retainer.

Can you run the engine with the valve cover off?

That might help isolate the noise...

If it's a topical tick, tick at half crank speed, then it's likely valvetrain or an exhaust leak...if it's a deeper knock, knock that seems a bit fast, then it's probably crank related...

Oil pressure good??

If you can't hold preload on the bad valve, either it's sticking again or the cam lobe is going flat....

What fun, eh?? *G*

Pat
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Discussion Starter #5
The previous post (Dropped valve I) was surprised that valve didn't seem to break or bend. Oh, keepers on, very easy. Take a piece of ally, drill a hole, put it on stud, nut on. Then you can wedge the retainer plate down with some proper tool like handles of pliers or like and then drop keepers into valve grooves.

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Discussion Starter #6
Compression and leakdown test are on the cards. This friend was thinking that if there is problem he might as well try driving first, which we did.

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Discussion Starter #7
No popping at all. And this noise I was describing, my 289 makes more noises than this, so it is hard to say if this "noise" is remarkable or not. Compression test tonight, leakdown later on.
Very knowledgeable shop owner said that rocker seems fine and by visual inspection rails didn't seem to be near the retainer when rotating engine.
We did run the engine without valve cover, nothing strange was evident, except this slight sound. We might try to do that again and put stethoscope on stud. Also to see if the rocker moves as much as others to verify that lifter and cam lobe are ok.
I am sorry I can't say whether this noise is halfspeed or crank speed, I haven't heard either before, my ear isn't calibrated. Might try to observe valves when idling.
We didn't do proper preload stuff. Approximated with other valves and how they felt. That will be done next.

Door handle first when cornering
 
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