Valve adjust: .004 blade thickness.

[felix_browne]

damn. that/s hardcore adjusting them by the feel of the rocker movement!!you must be either really good or like you said completely insane. either way you get two thumbs up from me for guts.

[Nine9six]

Originally posted by JohnJL
Ok, I guess it just seems to me the art of bending that guage in there and the gradual wear on the feeler would lead to some changes over time. I can get consistent, repeatable results with the dial indicator bolted to the housing. I've verified it periodically by positioning the gauge and making a measurement, then loosening and moving the guage out of the way, making no changes to the valve, and repositioning the gauge. I get the same measurement every time.
This is with the engine out of the car though, I've not attempted to use the dial indicator with the engine in situ.

JohnJL,
You are proving nothing relating to "accuracy of measurement" by moving the indicator, and bringing it back into position. The only time you are proving accuracy, is when you are comparing to a "known standard", of higher resolution. This process is called calibration.
All you are doing, is showing that any adjustment you made is repeatable to itself, and that the gage is capable of repeating in that specific area of travel. Therefore, I defer to my previous post.
If you believe that in the use of a feeler gage, you are wearing the gage, I would beg to differ.
The feeler gage through use, get to the point of being no longer useable, WAY before it experiences wear.
Thats why the speciality tools as sold by Island come with a roll of shim stock (mine did).
While I do not profess to be an expert, after 15 years of auditing aircraft and aerospace calibrations labs, I have managed to pick up a tidbit of knowledge here and there. I was a journeyman machinist for 12 yrs prior to auditing.

[Nine9six]

[QUOTE]Originally posted by oneblueyedog
[B]

Originally posted by Hendog
Does the feeler Gage risk sratching the lobes of the cam?

No, one metal is harder than the other.

[Nine9six]

Originally posted by Wil Ferch
Seeing the valve adjustment bolt is 8mm x 1mm pitch...too bad we can't get a device that precisely opens the adjustment nut 36 degrees ( or so) from closed.

Target is 0.1 mm gap. One complete 360 degree rotation is 1mm. We want 1/10 this or 1/10 of a full "rotation" .

Too bad it wasn't 45 degrees !!!

- Wil

Hmmm,
What Wil is describing is the mechanics of a micrometer.

[JohnJL]

Nine9Six,

I am aware of the difference between accuracy and calibration. I described my repeatability exercise in response to the earlier claim the dial indicator couldn't provide repeatable results.

Just trying to learning something here, nothing at stake by "winning" with the dial indicator.

[Nine9six]

Originally posted by JohnJL
Nine9Six,

I am aware of the difference between accuracy and calibration. I described my repeatability exercise in response to the earlier claim the dial indicator couldn't provide repeatable results.

Just trying to learning something here, nothing at stake by "winning" with the dial indicator.

John,
I am only trying to help you understand.
No one is trying to win anything. You promoted the use of a dial indicator, and I said for the cost, and measurement accuracy, a feeler gage has it beat...Simple.

Again, repeatable results do NOT prove accuracy.
Accuracy can ONLY be proven when comparing to a "known standard".

Accuracy is what you are looking for when setting your valve clearances.

I can try to prove this by asking two questions:

Are you looking to achieve a specific setting for your valve clearances?

Or, are you looking to prove that your dial indicator is capable of repeating?

Sorry, but regardless of how you try to rationalize this in your mind, the two are NOT related.
Nuff said.

[JohnJL]

I was just trying to understand if it would work...I already have the indicator so I wasn't asking about the economics of one or the other.

>>>>>>>>>>>>>>>>
Besides, even the .0001" graduated indicators have a repeatibility of .0002.
In the hands of someone who has some mechanical ability and done a few valve adjusts, I'd put my money on the feeler gage adjusted valves for repeatability.
>>>>>>>>>>>>>>>>

I am seeing better repeatability than that with a dial gauge, do you think a person using a bent feeler gauge with an engine in situ has better repeatibility than .0002 +/-?

Is it true then that using a dial indicator is an acceptable substitute or a backup/verification of the feeler gauge method?

thanks all

[captainrb]

Ok now.. I use a dial indicator to adjust my valves. I have adjusted them with a feeler gauge many times.('73 coupe 2.7 w/carbs. owned sence '77) And was happy with the results. But I could hear an slight auditable difference in valve noise not they sounded loose but slightly difference in sound. When I switched to the dial indicator system ,I could adjust each valve 'exactly' the same. No variables or +/- crap. and when the engine is warm up.. ALL the valve sound exactly the same. Its may take more time but for me it perfect. Enjoy Captain R.B.

[Rick Lee]

Excellent thread, but it's a week late for me. I've done abotu 10 valve adjustments, only two of which were with the engine in the car. I used to use two if the Island911 tools - one with .004 and one with .005 stock to double check my work. I always worry about getting them too tight, but then every time I do it on my or someone else's engine, the engine sounds perfect when we fire it up. Still, I always have this nagging worry about burning a valve.

BTW, for those with the Island911 tool, invest in stainless steel feeler gauge stock. You can probably get it at McMaster. I forget where I got my last batch, but I sure wish I had it with me last week when I broke at least 10 pieces of stock while adjusting my valves. The SS stuff is far less brittle.

[2.7RACER]

Captainrb,
Using a .003" feeler as a no go gauge and a .0025" feeler as a go gauge will check how well you did with the dial indicator.
The gap at the rocker/cam is .00285" when the gap at the elephant foot is .004"
Thus a .003" feeler will not slip in between the rocker and the base circle of the cam.
A .0025" feeler will slip into the gap, unless the gap is less than .0035" That's five ten thousandths under .004"
The idea here is to be able to identify which valves need adjustment by checking first.
Once a rocker has been found in need of a adjustment, use a dial if you like to. Or use a feeler.
I use a .0025" at the rocker and cam. Then check with a .003" to make sure I'm not loose (over .0042").
The radius of the rocker and cam guide the feeler very nicely. No square edges at an angle to contend with.
If you think you are OK, don't be afraid to check yourself.
If you want to save time, check for over and under first. Then adjust.
No special "tools" required. Just an ordinary set of feeler gauges.
No broken or bent feelers, no lost feelers or screws.
Just correctly adjusted valves.

[Wil Ferch]

Listen to Doug...he's posted on this method before.....we're talking about using the BACKSIDE measurement where it is ( ta da ! ) EASY ( or at least easier) than under the elephant's foot.

This is one of these epiphanies that comes along only once ina while...we should heed this advice. Imagine...using normal feeler gauges without contortionist access..and you can use the "go" or "no go" gauge to see if you even NEED to do it in the first place.....

- Wil

[JohnJL]

Thanks guys.