Yet another valve adjustment thread (dial indicator method)
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From: Indianapolis, IN
Back side method pictures
I just finished a valve adjustment on my 90 C4, using the back-side method plus 9-Meister Tool method. Here are some pictures that may help show what it's all about. I use 0.0025" for "go" and 0.003" for "no-go" on the cam face. I found 7 of the valves slightly tight, 1 loose, and 4 good. When I had to adjust one, I used the 9M tool as a check and a guide for micro adjustments. It still takes a fair amount of time (I'm slow). And, I still went back an rotated the engine a full 2 turns and checked again (found a few that I wanted to tweak a bit). Hope these pictures help.
Have Fun, Be Safe
Have Fun, Be Safe
Thread Starter
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From: Bay Area, CA
Definitely going around again on the crankshaft and checking each one with the feeler gages is definitely something I will do next time. Thanks for the clear photos. I will be doing my new C2 in March.
Rennlist Member
Joined: Nov 2005
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From: san jose california
I just did mine over the weekend. Anyone else notice that the little thick washers for the valve cover nuts tend to break. I bought all new ones.
Last edited by stevepaa; Sep 17, 2012 at 03:56 PM.
Thread Starter
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From: Bay Area, CA
I just finished my second valve adjustment (or my third if you count fixing the mistake on my first one). Here is what I learned.
1)The dial indicator is a pain to use but it did really help me at first as a learning tool. I don't think its needed for first timers (now that I understand and use the backside method as a check).
2)The backside method is a super quick confirmation check of your adjustment, and totally aligned with the dial indicator and using the Pelican shim tool.
3)Going forward my valve toolset is as follows
- 13mm wrench
- flat blade screwdriver (I didn't use the special screwdriver)
- Pelican shim tool
- .0025" and 0.0030" long shims from McMaster (I got the 12" long ones and the thickness is marked on them, less than $2 each, I ordered 3 of each size)
- my gorilla torch flashlight
- and the Pelican valve adjustment kit with all the hardware and gaskets (including for the Cat)
- torque wrench that goes as low as 7in-lbs for the valve cover nuts
Its all in the feel of the shim which shouldn't slide in easy or move around with little friction, it should fit where if it was any tighter it wouldn't really move. Using the backside method will help you dial in the feel. I would unlock the valve adjustment and actual tighten down onto the shim until I got the feel I wanted and then locked the valve adjustment nut. Then I would confirm my adjustment was ok with the backside 0.0025" go gauge and the 0.0030" no-go feeler gage. Whenever I got the right shim feel with the pelican tool the go / no-go gages would work exactly.
Oh and doing an adjustment with the engine out of the car is super easy!
1)The dial indicator is a pain to use but it did really help me at first as a learning tool. I don't think its needed for first timers (now that I understand and use the backside method as a check).
2)The backside method is a super quick confirmation check of your adjustment, and totally aligned with the dial indicator and using the Pelican shim tool.
3)Going forward my valve toolset is as follows
- 13mm wrench
- flat blade screwdriver (I didn't use the special screwdriver)
- Pelican shim tool
- .0025" and 0.0030" long shims from McMaster (I got the 12" long ones and the thickness is marked on them, less than $2 each, I ordered 3 of each size)
- my gorilla torch flashlight
- and the Pelican valve adjustment kit with all the hardware and gaskets (including for the Cat)
- torque wrench that goes as low as 7in-lbs for the valve cover nuts
Its all in the feel of the shim which shouldn't slide in easy or move around with little friction, it should fit where if it was any tighter it wouldn't really move. Using the backside method will help you dial in the feel. I would unlock the valve adjustment and actual tighten down onto the shim until I got the feel I wanted and then locked the valve adjustment nut. Then I would confirm my adjustment was ok with the backside 0.0025" go gauge and the 0.0030" no-go feeler gage. Whenever I got the right shim feel with the pelican tool the go / no-go gages would work exactly.
Oh and doing an adjustment with the engine out of the car is super easy!
Last edited by RicardoD; Sep 16, 2012 at 01:39 PM.
Racer
Joined: Jun 2012
Posts: 341
Likes: 27
From: UK
Just read all the way through this thread as I'm part way through my first time valve adjustment. I've kind of stumbled into Ricardo's final method; I'm tightening the adjusters (gently) down on to the feeler gauge then backing off until I can just get smooth movement. My only worry in doing this is that I may be distorting the feeler with the elephant's foot - am I OK proceeding or do I need to revise my technique?
Cheers,
Z
Cheers,
Z
Thread Starter
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From: Bay Area, CA
As long as you are not super cranking down on the feeler you should be fine. I had the same reaction as you and took out my micrometer and confirmed I didn't smash my feeler gage any thinner.
Burning Brakes
Joined: Aug 2012
Posts: 841
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From: Raleigh, NC
I am about to finally start working on the 964. It has been waiting on me for 3-months in the garage while I was out of the country.
Can someone please share the link on pelican to this tool?
- Pelican shim tool
Thanks in advance,
Steve
Can someone please share the link on pelican to this tool?
- Pelican shim tool
Thanks in advance,
Steve
Thread Starter
Rennlist Member
Joined: Oct 2003
Posts: 1,861
Likes: 225
From: Bay Area, CA
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If you are interested in an alternative valveadjustment method, this 3 min. animation shows how and why SNAPGAP works. https://snapgap.us/pages/how-and-why-snapgap-works-1
And, in this video https://snapgap.us/pages/snapgap-installed-on-911, you can watch the installation of SNAPGAP in a 911 and the confirmation of the resulting valvelash with a dial gauge.
Some advantages of SNAPGAP over other methods:
We have extensively road tested this system (running it in a '78SC for more than a year) and have never had any parts get loose. This is because the stainless steel screw that folds the spring steel collar against the valveadjustment screw threads is held in place by back pressure from the spring steel once it is locked down. Further, the collar screw has a pre-applied high temp nylon threadlocker patch that is good up to 500 degrees F to prevent the screw from rotating. Finally, unlike the OEM jam nut, the collar itself is locked to the valveadjustment screw and, of course, the valveadjustment screw with the elephant’s foot on it is not able to be removed from the rocker arm without taking the entire rocker arm out of the engine.
More information can be found at the SNAPGAP site https://snapgap.us/ , including several articles about valve adjustments and valveadjustment systems.
And, in this video https://snapgap.us/pages/snapgap-installed-on-911, you can watch the installation of SNAPGAP in a 911 and the confirmation of the resulting valvelash with a dial gauge.
Some advantages of SNAPGAP over other methods:
- Precise - as confirmed by dial gauge testing.
- Fast - 2 to 3 minutes per valve as shown in the video.
- Replicable over all 12 valves - and no need to "confirm gap" by trying to reinsert feeler.
- Accurate - no inaccuracy introduced by rotation of valve adjustment screw on final tightening of jam nut or bent feelers.
- Easy - can be done with one hand.
- Can Be Done With Engine In -- the tools are designed to work in the tight confines of most 911 engines. However, for example and as with other methods, depending on your engine, you may need to remove the CAT or, alternatively, use a standard torque wrench to get behind the CAT or past lines and hoses.
- Accounts for "cupping" or other misshapen wear features of valve stem and elephant's foot - unlike with a flat feeler.
We have extensively road tested this system (running it in a '78SC for more than a year) and have never had any parts get loose. This is because the stainless steel screw that folds the spring steel collar against the valveadjustment screw threads is held in place by back pressure from the spring steel once it is locked down. Further, the collar screw has a pre-applied high temp nylon threadlocker patch that is good up to 500 degrees F to prevent the screw from rotating. Finally, unlike the OEM jam nut, the collar itself is locked to the valveadjustment screw and, of course, the valveadjustment screw with the elephant’s foot on it is not able to be removed from the rocker arm without taking the entire rocker arm out of the engine.
More information can be found at the SNAPGAP site https://snapgap.us/ , including several articles about valve adjustments and valveadjustment systems.
