RWest,

If a shim fell out, it would only be because either a) the collar AND adjustment screw combination that is locked together overcame their torqued down position against the rocker arm enough to rotate several threads so that the shim that is shaped with "bumps" to hug the adjustment screw were able to twist off the adjustment screw and come out; or b) the cap screw that squeezes the folds of the spring steel collar down overcame the pre-applied ND threadlocker patch as well as the back pressure of the spring steel and unscrewed from the collar enough to loosen the collar's grip on the adjustment screw and allow the collar to rotate enough around the adjustment screw to open a gap between the bottom of the collar and the rocker arm to allow the shim to twist past the hugging bumps and escape.

In more than 100 hours of running and multiple on and off heat cycles in my personal 911, neither a nor b has occurred.

IF it did, as explained above, it would be because the collar is lifting off its fixed position against the rocker arm. In scenario (a), plainly that would be opening the valve gap because the collar and adjustment screw are joined together. In scenario (b), I can't see how the adjustment screw would get tighter given the hammering of the valve stem against the elephant's foot -- thus, the adjustment would get looser.

In either case, I think you would hear a very loud tapping coming from the offending tappet as the adjustment got looser and looser.


Hope that helps and make sense.

Brad

Genius little invention. Nice work developing this.

Field tests..........
 

Brad,

It would be great if you could test the Snap-Gap collar in track car/s to demonstrate its stability. The OEM jam nuts are track proven for many years and counting. So being able to demonstrate the stability of this product in engines driven at red line all day is one testimony your product must have.

I believe your new jam nut design is better but without actual field tests, some people would have second thought to use them. While you have used these jam nuts in your motor for sometime now, any track car demonstration would surely give credence to this new product. Keep up the good work.

Tony

Thanks Rxtrom.

Tony -- I agree with you 100%. Unfortunately, neither my car nor I are trackworthy - although I go to redline everytime I drive. That said, since launch in July, kits were purchased by 911 owners in the US, Canada, Germany, Australia, New Zealand, Norway, France, Czechoslovakia, UK and Spain. Hopefully they or others will track their cars and report back to me or on this forum. Thanks for your interest and suggestions.

Of course the extra weight issue would only be seen (as a problem) on very high revving extremes. (not mid range.) Valve springs are going to be chosen (by the engineer) to be just stiff enough for managing the inertial at max RPM. (no float).

Not likely, but it would get looser fast.

edit: woops, didn't see page 2 here. :-/

How about titanium to put it on diet?

hienz,

Titanium expands less quickly than steel and might work well. However, the raw material and tooling costs for titanium are much higher than for steel. Without a sound reason to reduce that amount of weight for the 911 set up operating at 911 revs, the additional cost does not seem justified.

Put another 5 hours on my SC on VT twisty roads yesterday -- hanging between 4000 and 5500 RPM with several redline shifts. Still purring quietly. . .

This looks like a wonderful product that I would like to try. I've seen that general idea used in other applications where it works perfectly. If you trust it enough to test on your personal car that's good enough for me. PM sent.

I subscribed to SnapGap’s website awhile back. Was pleasantly greeted with an email today for $25 off. I’ve have purposely been waiting as I just did an engine rebuild and had planned on making a purchase when I reached 4K. But, I’ll definitely will be ordering his kit tomorrow. Over my life I have adjusted valves on a lot of different makes. And don’t mind trying a new technique. Wishing Brad the best of success. It’s difficult to launch any new product.

ND Patch Hi-Temp - Pre-Applied Threadlocker
 

Thanks Acme911!

RarlyL8 -- besides running it in my car, the following information about the ND Patch pre-applied threadlocker on the cap screw provides me with confidence. The short video makes me wonder how the thin OEM jam nut that is unlocked to the valve adjustment screw stays tight against the top of the rocker arm -- although I have seen reports of it loosening.

https://www.youtube.com/watch?v=Cvq_B43ughg

https://www.ndindustries.com/products/inert-threadlocking/nd-patch-hi-temp/

Lespaul…..if one wanted to reuse the screws what level of high temp thread locker would one use...high or mid strength locker? It seems that the 'pinching' action of that screw would be fine with a mid strength blue type.

Reiver,

If you wanted to reuse the screws, I would recommend Blue 243 -- medium strength, oil resistant, and high temp applications. See below -- actually mentions "rocker adjustment bolts." That said, you get 39 screws in the kit (a few extra than you need for 3 valve adjustments) and if you need more, just PM me and I will send you a pack.

"Loctite 243 Blue Threadlocker is a general-purpose, medium strength threadlocker with improved oil tolerance. For fasteners between 1/4" and 3/4" (6mm to 20mm). Parts can be separated using hand tools. Suggested applications: Rocker studs, rocker adjustment bolts and bolts on valve and cam covers, oil pans, disc brake calipers, intakes and alternators, and pulley assemblies."

I met Brad at Hershey this year and decided to give the system a shot. It worked exactly as designed in the video. I have previously used the Kirk tool, feeler gauges, and an angle measurement screwdriver... Here's my opinion:

* Kirk tool was too complicated for what it does in my opinion. Great piece of engineering, but too fiddly...
* Feeler gauges work, but are a pita and require an acquired "feel" gained with experience.
* Simple screwdriver with angle gauge on it works well with a little practice
* Snapgap method is pretty much foolproof and is consistent.

I did my last valve adjustment a couple of weeks ago using Snapgap with the engine in the car without issue. First couple of valves I went very slow double checked instructions as I went, but the rest were very quick.

What I like best about the system is dealing with older and inconsistent elephant feet. This is where I always ended up with inconsistencies using feeler gauges. With this system, you just finger tighten the adjuster down, lock the special nut in place, back it out, insert shim and tighten - no guessing. My valves are dead nuts on at this point.

I'm not a paid spokesperson and Brad was super helpful with my questions.

Karl

Great to hear feedback. I ordered mine last night. Looks like I will receive it by the weekend.
Andy

Any time something that comes along that can make a task easier especially for those that do not do this everyday is a good thing.

It needs to make sense and it needs to do a good job at whatever task it does. In this case, I have say I guess it does.

Would I buy one? No. But that is only because using a simple feeler shim, I can run through the 12 rocker adjusters in less time than it would take with this system. And, in most instances, we are doing this on an engine building stand.

Seems as though my write up about performing the valve adjustment is used on the vendors web site, so maybe I should be "given" one. If the vendor is up for it, I'll offer my "free one" up for auction on this site with all the money going to a children's hospital pediatric cancer center. I'll match the amount as well.

Looks really cool!

Wait, are you kidding me, that's it? The only thing that might be hard to accomplish is the 270 degree tightening and using the mini suppled torque wrench when engine is in the car.
So, how often do you suggest one should adjust valves using this method after the initial adjustment?
Thx.

Valve adjustment frequency wouldn't change using this method. What's the factory recommendation, 10K miles?

In the question and answer part of this great article, Wayne Dempsey concurs -- 10k or every 2 years.

https://www.pelicanparts.com/techarticles/911_valve_adjust/911_valve_adjust.htm

Note that his book "101 Projects for Your 911" says "every 6,000 miles for pre-1978 cars."

When some trusted wrenches of the community here are giddy about it... I've trusted their judgement for many other things in the past, why wouldn't I trust their judgement now?

I'll certainly give this a try for this year's winter projects since a valve adjustment is in the cards for me.