Backside valve adjustment tool question

[Don LaVance]

I am ready to do the backside valve adjustment procedure and have everything I need except the "No Go" feeler gauge.
I have seen it identified so many different way's as to cause me to not be sure what size to order. I have the Starrett .0025 gauge for the go measurement.
What is the correct one to order for the no go.
1. .0030
2. .030
3. .003
4. 0.003
5. 0.3mm
I have seen it written in all the above ways on the various forums regarding this priocedure . Which should I use? Are some of the ones listed (1 through 5) the same?

Or can I simply use a .07mm as a go gauge
and
.08 for the no go gauge.
Thanks for your help and advice.
Don

[Targalid]

Two and a half thousandths for the go gauge, 3 thousandths for the no go gauge. They are very thin. Buy a feeler gauge set and take it apart. Wrap different colored tape around the ends of the 2.5 and the 3 thousandths pieces to identify them and use them separately. One guy here has used them taped end to end to keep the package together. That seems like a good idea to me. Once you are set up this method goes very quickly.

[Ronnie's.930]

The Pelican article on the "backside method" answers your questions regarding which feeler gauges to use:

Pelican Technical Article: 911 Valve Adjustment - The Backside Method



BTW: .0025 = .063mm and .003 = .076mm

I have always been able to find feeler gauge sets with these sizes at Autozone, Pepboys, NAPA, etc.

[Ronnie's.930]

#s 1, 3, 4 in your list are the same measurement and #s 2 & 5 have nothing to do with this process . . .

[kodioneill]

Recently there was a post where a Pelican used two Popsicle sticks taped together with the gauge in between to give some support for the gauges. I think this is a great help to get the proper feel.

[Don LaVance]

Thank you for the response,
I feel more comfortable with which to buy and use for this.
Don

[K Sykes]

On the popsicle stick idea - put "go" on one end "no go" on the other, marked in some way so you don't have to read the gauge to know which is which. I used green and red shrink wrap to make it real easy.

Took a while, but got to a good result using backside. Will be much quicker next time

[diy83sc]

I used a green tie wrap for the the go and ... red for the no-go.