Help.Stuck valve shim bucket 86 VR Valve adjustment

[dvuch1]

Guys I need some advice

I started adjusting Cylinder #1 exhaust valves...used the shim tool replace the shim...remeasured clearance and it has a LARGE clearance and now can see that the bucket is not completely risen to original height. I can depress the bucket with a screwdriver. I can "spin" the bucket with a screwdriver and soft taps. I cant pry the bucket up. When cranking the engine by hand the cam lobe will push the shim and bucket down.

My thoughts. #1.The shim tool was off center and burred the bucket not allowing it to rise fully. #2 the valve is stuck somehow( should spring back up) #3 what was I thinking?

 

Any thoughts....and the last resort would be to start the engine. I dont want to mess with the cams at all as I'm already in over my head.

[RandyR]

what was the size of the old shim, and what is the size of the new shim?

 

Have you tried removing and replacing the new shim? (no good reason, just that I prefer to do simple things first).

 

Did you mic the shims? perhaps one was mis-labeled?

[Flyinfool]

The buckets are very hard, they would break off a piece before they would raise a burr.

 

Does that cylinder have compression? Take out all of the spark plugs except that one and turn the engine over to see if that cylinder has some compression.

 

If it has compression then the valve is just that far out of adjustment. If it does not have compression then there is some kind of debris holding that valve open.

[dvuch1]

no the bucket that holds the shim is not rising up. Its does go down but wont rise like the other 3 in the cylinder. Yes plenty of compression. I like the debris idea, but I don't have a reason to believe that theory when I just used a shim tool and the engine has run fine

Edited July 13, 2014 by dvuch1

[Neil86]

Was the engine rotated without a shim in that bucket?

[dvuch1]

Hi Neil..

Is this a yes no answer or are there extenuating circumstances? No. Initially low clearance --replaced with smaller shim---rechecked AFter spinning cam to seat new shim. High clearance ... on inspection bucket too low... took shim out and realized bucket is now the problem. I spun the cam with no shim AFTER the fact and thought it might have been the shim tool off center Etc.

[jasonm.]

Need some clarity here.....you should never spin the cams w/o a shim in place. Did you do this before you replaced the shim? What was the shim size before and what was the clearance measured

[dvuch1]

I'm sure I did not spin the cam on an empty bucket before it was stuck.

I did spin it later as the clearance was so great I was curious if the cam lobe would contact the bucket without a shim. It did, but didnt make it any worse.

 

The measured clearance was .06 (exhaust) I took out a 285 shim and replaced with a 275 (per the chart) I spun the cam to seat the shim and then remeasured and noticed the large gap and realized my problem was a stuck bucket. Not too small a shim..I can get alot of shims in that space.

 

I have done everthing to the bucket to get the bucket to come up without success.

 

Thoughts?

[Kirby]

Can you take a pair if needle nose pliers and turn the bucket? If so, see if you can lift the bucket with the pliers by wiggling it back and forth. If the bucket will turn and you can lift it, I suspect you may have a bent valve or just a valve stuck in the valve guide since the valve and its' spring is what pushes the bucket back up. This is just a guess. Are you sure you haven't dropped anything into the sparkplug hole that may be keeping the valve from closing?

[Kirby]

Ok, I reread you OP and you said you could turn it with screwdriver. Try to keep turning it all the way around and see it it begins to rise at all. If you somehow burred the outside of the bucket the spring pressue may be enough to overcome the burr or debris that's got it in a bind. You said you could push it down. Try to examine the bucket hole with it depressed to see if someting is between the bucket and the hole. I'd do this before trying to spin it out.

[dvuch1]

Thanks kirby---

 

I'm trying everything I know how to do...There shouldn't be any debris and the bucket spins and without the shim in... there is a small groove on the inside lip of the bucket...I have tried a small blade long handle screwdriver in there to pry it without success.

Ive lubes it as well....and Iv'm going out now to get a dental mirror to see if there is any lip,burr or issue there,,,,Thanks keep giving me suggestions....I really want to get this going again! Dave

[Neil86]

Just a guess, but I would think since the bucket just sits over the valve stem that if the bucket was physically holding the valve from rising you would have valve spring pressure acting on underside of bucket and you couldn't rotate it.

[dvuch1]

I agree but the bucket has those handle depressions to turn it and it does turn despite being too low...But I just don't know the anatomy and physiology well enough to assume that ...make sense?

[Neil86]

As I said, the bucket just sits on top (like an inverted bucket...)

[jasonm.]

With 275 shim in...WHAT'S the clearance ? With the shim in and do a compression test...I know ...sounds odd. But do it UNLESS you think the piston will hit the valve. Turn crank by hand 1st

[dvuch1]

if that is so.... I just bought long handled pliers with an angle on the end to pull up while I pry with a screwdriver as well as a dental mirror....this is it...wish me luck.. Dave

[dvuch1]

With a 275 shim the clearance ... I can put the 3/4 of the feeler gauge in there!! Because the bucket is so low. I have cranked by hand it's not that low that the valve will hit the piston

[dvuch1]

Ok I got it up a ways but not safe enough to run....Question...my intake buckets spin freely...my exhaust buckets I have to tap to spin with a screwdriver and hammer. Why are these buckets in there so much tighter on the exhaust side?

[Kirby]

If the cam lobes are pushing down on the shims it's gonna be hard if not impossible to turn the buckets.

[Neil86]

Normally with clearance between shim and lobe, the buckets will rotate easily with fingertip with the tool not in place.

 

Are the ones that barely move ones you previously depressed with the tool?

[dvuch1]

Yes Neil...these are the ones that I used the shim tool on ,,, the ones that are hard to turn...have to tap with screwdriver and hammer...the intake buckets spin easy.

[Flyinfool]

The only other option that I can think of is that you ran the tool into the aluminum head real hard. It is theoretically possible that with all of the leverage that you have by turning the crank, that you put a dent in the aluminum of the head and squeezed the bucket bore.

Look at the area in between the two buckets to see if there are any marks on the aluminum?

[djh3]

If you buggered the bore there you may be able to use a angled pick to clear the crushed aluminum out of the way. If it is not wrecked to bad.

[dvuch1]

I bought a dental mirror and it appears that there may have been some damage but its a bit hard to discern...scraping aluminum sounds like fun but that is my same thought I have right now. I initially was hoping to find a dremel but it would never fit in there.

 

 

On a side note, I can't figure out why the intake buckets spin easily and the exhaust one have to be tapped?

[Neil86]

The only ones the tool was used on are now tight to rotate.