679526 Valve work cont. from "valve job"

Maddy’s XK journey continues with replacing the tappets after a mis-step in the process. I am holding off on the tappet replacement to examine a couple other things that Nick has recommended. These include, bore scope the pistons, use a magnet to swab out the cylinder for metallic debris, put stoppers in the spark plug holes, hand turn to see if the stoppers pop put in order 1-5-3-6-2-4. When all that is done he suggested to use a vacuum with an improvised tool to suck out the cylinder.

I have done the magnet sweep and got nothing. I have put the stoppers in the spark plug holes tightly so no air escapes. The stoppers did not pop out as expected and maybe because I cannot turn the engine by hand very quickly. There is a lot of pressure compressing and I find it difficult to turn the engine. if I hold pressure in the turning process I can feel the pressure ease. Once it does then I can go to the next compression and so it repeats for all 6 cylinders. I did the bore scope the cylinders today here are the results.






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The pictures of cylinders are from #1 through #6 are shown in that order.

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Good idea, but not likely ‘poppable’ only by hand cranking.

Cylinders look reasonably clean; your method of determining compression is sound, and it appears you’ve solved your issues.

next test I suggest Maddy, will once valve train all hooked up, cams to sprockets (not safety wired yet) , cam bearing caps torqued, cams aligned via tool…at #6TDC compression verified…and all that done and double checked…: then you can be sure timing abyss is clear, no debris in cam oil galleys, (a little new cam lube on all the cam lobes)…will be the compression test…all plugs still out, coil to distributor wire disconnected, throttle wide open…using solenoiid button do 5-6 spins as you watch the gauge peak…(fuel pump disconnected…battery charger so that all spins are at the same spin rate.) Report results…will then determine if to do a “wet” comp test, …or any leak-down.
Nick

At this point in time I am dealing with shims that do not want to come out with proper measurements .006 intake and .008 exhaust. Although Nick says to proceed with the turning of the engine via remote start button I don’t think the measurements are close enough and I do not want to cause damage. So listed below are the measurements for the third time around. I am looking for comments as to how the next shims that get put in (sometime) will give the desired final measurement of .006 intake and .008 exhaust. Like Nick said to me (paraphrasing) you would think that it is simple, you calculate the right shim and voila the .006 and .008 appear! what can change every time a shim goes in?

INTAKE Spec: 0.006
Cylinder Initial Gap Diff from Spec Installed Shim Thickness New Shim Thickness New Shim Installed Final Measurement
1 0.003 0.003 0.085 0.082
2 0.004 0.002 0.096 0.094
3 0.002 0.004 0.097 0.093
4 0.005 0.001 0.095 0.094
5 0.006 0 0.122 0.122 0 0.006
6 0.002 0.004 0.1 0.096
EXHAUST Spec: 0.008
Cylinder Initial Gap Diff from Spec Installed Shim Thickness New Shim Thickness New Shim Installed Final Measurement
1 0.006 0.002 0.113 0.111
2 0.017 -0.009 0.099 0.108
3 0.008 0 0.115 0.115 0 0.008
4 0.009 -0.001 0.123 0.124
5 0.006 0.002 0.123 0.121
6 0.006 0.002 0.116 0.114

I hope the charting is legible.

Intake #6 installed shim thickness is .114 not .1
my misprint apologies.

Don’t get too wrapped up in the idea of making it exactly 6 thou or 8 thou: if you’re off 1 thou either side of that, you’re fine.

Paul,

Some are not within that 1 thou. either side. That is what concerns me. When I figure out what shim to bring that within the 1 thou. range and it is still off by more than 1 thou. do I just keep replacing those or is there something else I should be looking at?

Intake 1,2, 3 and 6 are more than 1 thousands off. The exhaust 1, 2, 5 and 6 are also off more than 1 thousands.

Maddy, it looks like yo have a good base to order the shims and go ahead and see what you end up with and if there is any major variation then just try swapping shims again. As Wiggs states .001” either way will not harm.

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…so…what i said Maddy was that you would think mechanical metal to metal valve adjustment would be accurate…I continued…that oddly it never is…at least never the first time…even tho you measure all with micrometer and select correct shim…it just never comes out…as I said…and others…within 1/1000 is good enuf…you will chase 1/1000 many times over…BUT…you have some odd descrepancies in your clearances, I will need to go over my past notes on all to be able to list them…but initial measurment showed zero clearance on one…so a guess to select a shim…and it already had a thinnest shim, so you ground one down. Later…you had some where you replaced with a thinner shim…and instead of more clearance you got the same, or less. And so on…so this is the reason…along with that you spun the engine with one cam all attached, the other in place but off the sprocket…that as long as you have some clearance on all…even if off by 3-4 thousandths…I suggest not chasing it…until you run the compression test to see what you have…the step prior that I suggested…you have done…the by mouth blow test, the compressed air blow test.both with cams out all valves closed…, the rubber stopper test, the bore scope to look for debris, the magnet and vacuum again for debris…verifying cam alignment…and finally to do the compression test…IF…the comp test is OK…anywhere close to OK…then you can do another valve shim adjust to get all to within the 1/1000 of spec. From what I have seen of your clearance measeurments…please don’t chart as above…all we need to know now…is what shim is in there now…and what is the clerance now. I will deal with the issue …that you did put in some odd sized shims, and had some confusing results…and the why of that…later, below…I suggested that a shim may have been not rocking a little…so on the keeper…so measurements come out the same…or that a shim was cocked and not flat…has slipped sideways…

OK now for the anomolies of what you did and measured: example: example…intake #4 had a .099 shim in it…(was the replacement from your prior work-) your recent clearance check for intake #4 showed .003…very odd…it was .004 to begin with and you went from a .101 existing to a .099…to get more clearance…yet is tested less…, and now you say you replaced the 099 with a .109…a much thicker shim, ten thousandths thicker, …which would give you ten thousandths LESS clearance than the .003 that you had, not more clearance, : , but you say you re checked the clearance and it is now …008. . I sent you this…
Let’s start with this: which is stated over and over in the Adjust Document instructions…The RULE:
A Thinner replacement shim gives more clearance by the amount it is thinner.
A Thicker replacement shim gives less clearance by the amount it is thicker.
Think of shims
as Pringles in the tube. Make the pringle stack thinner (by removing some) and the clearance
at the top of the tube becomes more. Add some pringles to the tube (a thicker stack of Pringles)
and the clearance to the tube top will be less. )

so this is what you say you did …(copy of your email…my notes added.
Intake side
intake #1 shim size .082 with final measurement of .008 Replaced with .076 final measurement .005.

(nick says: intake spec is 006, it measured .008 so it was 002 too much clearance, so to reduce clearance a 002 THICKER shim is the correct replacement, thus a replacement of the existing 082
with a .084 would have been the correct adjustment. Somehow you put in a 076 which is 006 THINNER…should have made MORE clearance…yet you measure .005. Something is rotten in
Denmark.

intake #4 shim size .99 with final measurement of .003. Replaced with .098 final measurement .003

(nick says…for the 003, initial, it would require 003 MORE clearance, so a thinner shim by that
same amount…003 thinner than the 099. so it would be a .096. --not a 098. It is possible
to put in a different shim size that is only 1/1000 different and have the measurable clearance stay the same. The correct shim should have been the .096, to gain .003 more clearance and achieve
the spec. 006.

Exhaust
exhaust #2 shim size was.108 with final measurement of (?) too tight for thinnest feeler.
Replaced with .092 final measurement is .015.

(Nick says: needed to have Exhaust spec of 008 and had zero.none…lets guess you needed .009 thinner
than the .108. (thinner gives more clearance),
so that would be a 099, say even a 098. But you went much further.thinner, by.006- thinner
than you needed…so ended up with clearance of .015, which is 003 too much clearance)

exhaust #4 shim size was .124 with a final measurement of .015. Replaced with .109 with a final measurement of .015. Not sure why.

(nick says: exhaust spec is 008. it initially measured .015. it was say 003 too much clearance
at 015
so the replacement shim would be .003 THICKER than the 124 to reduce clearance by that much.
The new replacement shim would then be .127. Why did you go THINNER from a .124 to a .109.
that is the wrong direction…and not only that, but a difference of fifteen thousandths…when it only needed three thousandths?, by .003 THICKER…not thinner. Needed to reduce clearance.
Now to the issue with this one…you changed shims b a lot…and clearance stayed the same.
Did that shim rock on the valve stem? Likely not…it seems the stem is so low that
the shim is not contacting the inside of the tappet. That is the ONLY way a shim size can
change a lot but not change the clearance…the tappet is not riding on the shim.
You said you were able to push on each stem and they moved.
You said no air escaped on the blow test. It seems it has to be one of a few things.
stem ground too short by prior work, stem bent and not fully returning to closed valve
position (but air would escape the open valve), valve edge damage-bent, where valve
does not fully close thus stem is not fully released…again…air would escape.

so…not only the wrong shims installed, but also the problem of exhaust #4 to figure out. If this all were going well…I’d adjust again…including the ones that are 1/1000 off…once in there, why not. But Exhaust 4 needs a close look…and it really needs to get to a compression test to see if it passes or not…could be chasing will-o-the-wisps if there is a compression problem and the head has to come off. So…that is reason for the bore scope look first, a magnet sweep, even a flash lite look…and then after all that to try to be sure there are no “bits” in there…the blow out the 6 stoppers test…
Nick

True dat: it happens all the time!

What I’d do to minimize it, was to tap on the tappet, cams installed, on the base circle, then measure: that gave a few less whacko ones.

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so…for Maddy.in short…just want your current clearances…please post them. Then…if…not so far out as to be a mechanical problem…ie will be ok for the engine to turn, run…: verify that that your cams are correctly in and aligned, then time for the compression tests. I would do a normal one…and a wet one while at it. record numbers.
see what it says…then decide what is next. Nick

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Nick,
Should I presume when putting the numbers in the shim calculating sheet the gray column give me the replacement shim size does it not? That is how I have been calculating new shim sizes. I am setting aside the the shim project right now to focus on the compression test. If need be I will turn my attention to the shims at a later time.

Nick,

The post of the chart earlier the column entitled “Installed Shim Thickness” are the current shim sizes.

in your case…because of the oddities…the full history of what clearances were initially measured, and then what shim was in there, what shim was put in as replacement, what was then the new measured clearance…will show up some of the issues…more complicated because you did it all again…so will need that work history as well, because that will show the oddities…of odd clearances after your first work…and then odd replacment shim choices…with still even more odd results…it is very muddy now…but can be charted with some careful work. But…as I said…for NOW…just want the clearances you have right now…to be close enough to go ahead with compression test…without extremely off spec, or no, clearance affecting the comp test…so that…along with being absolutely certain of the cam alignment, and certain no visible-audible-felt damage from the engine spin with one cam on, one not attached.
the need now is to find out if your valves, cyl head are of a condition to proceed without removal…Nick

Yes… plus twenty yes’s!

Hi maddy…iv only just picked up on this thread…“how can the measurements not be acurate”…ensure that you always use the correct bearing cap…also dont swap the cam followers around…and vital to always tighten the bearing caps down to the correct " low" torque…just tightening by hand will give you different clearances…also ensure your shims are flat…used shims often have a worn area where they sit on the valve, so measureing across the flat and re useing will give wrong gaps…Steve

Steve H.

Hi and thank you for your words. All that you mentioned has been accomplished. There is no mixing up of the bearing caps or followers. The shims are new so no worn spots. The bearing caps are torqued to 145 inch pounds. It is a matter of finding the right shim is all. Thank you again.

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Nick Requested the history of shim replacement to be posted.

April/2021

Intake

Installed Shim

#1 .086

#2 .097

#3 .096

#4 .100

#5 .100

#6 .101

Exhaust

Installed Shim

#1 .114

#2 .101

#3 .115

#4 .126

#5 .124

#6 .116

New Shim Replacement

Intake

Installed Shim

#1 .082

#2 .097

#3 .096

#4 .099

#5 .099

#6 .099

Exhaust

Installed Shim

#1 .113

#2 .108

#3 .115

#4 .124

#5 .123

#6 .116

July/2021

From Nick’s notes

Intake

Installed Shim

#1 .101

#2 .101

#3 .101

#4 .097

#5 .097

#6 .086

Exhaust

Installed Shim

#1 .117

#2 .124

#3 .126

#4 .115

#5 .118

#6 .112 or .114

New Shim Replacement

Intake

Installed Shim

#1 .099

#2 .099

#3 .099

#4 .093

#5 .095

#6 .080

Exhaust

Installed Shim

#1 .117

#2 .123

#3 .124

#4 .115

#5 .117

#6 .?

July/2021

Intake

Installed Shim

#1 .082

#2 .097

#3 .096

#4 .099

#5 .099

#6 .099

Exhaust

Installed Shim

#1 .113

#2 .108

#3 .115

#4 .124

#5 .123

#6 .116

*New Shim Replacement

Intake

Installed Shim

#1 .074

#2 .097

#3 .096

#4 .098

#5 .091

#6 .099

Exhaust

Installed Shim

#1 .113

#2 .092

#3 .115

#4 .109

#5 .123

#6 .116

  • These numbers are the shims that currently reside under the followers.
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Maddy…what is needed, for anyone to understand what is going on, is more than that list. It is the initial measured clearance, the existing shim, the replacement shim: and the new measured clearance , for each position. And then…and this is the puzzling part…same for your 2nd pass…of doing it…and 3rd, when you changed shims again…some in odd selections, and came up again with some odd clearances…I don’t have time today…but I will go back over the notes you sent me on your work and try to piece it together…for those following…it is not now just a matter of current clearance: what shim is in…and what shim needed, BECAUSE of the wierd results of prior shim replacements that had odd effects…so knowing that history may give clues. As I have said, I suspect one or more of: errors, shim on keeper, shim cocked under tappet. And Maddy, I said that inorder to proceed to a compression test…clearances needed to be within reason…no zero clearances, verified no debris in chamber, verified no visible piston damage, verified cams in proper alignment via tool at #6 TDC compression, and I wanted a by hand via the crank turn to blow out 6 rubber stoppers in correct firing order: …all BEFORE proceeding with a comp test. For now…it is not just what shim is in now, and I am not sure of that as I really don’t understand your list, but also what are your current clearances. Let’s go back to the clearance chart…and lay it all out…first adjust, second adjust, third adjust…each on a new chart page. I will help to get that done. Meanwhile I suggest do nothing further. For those following…Maddy has and has had…a very detailed document of procedures…step by step, with all the cautions and what ifs, edited by me…of Paul Saltwicks article, Tom Harmons good article, and forum posts from many of you (Charles, Rob, Lee, and more) that helped me when I did a clearance adjustment…that by the way, turned out perfect–on second pass. But do remember, Maddy spun the engine with the solenoid while one cam was fully in place…and the other in place but with both cam sprocket bolts removed…one cam turning…the other not. Muddy waters.
Nick