Tophat settings and an idea, kiss the shims goodbye

All right as i’ve been reading and speaking with others it has come to my attention that the talon valve stem seems to be lacking in threads in which allow a guy to set his tophat less then .070. Which to me is critical, why you ask, i’ll tell you. If you can’t test it you’ll never know, so here is some interesting info.
Tophat set at .071 and tophat set at .067 and everywhere in between. This is from a stock TSS in all regards. Testing done with 16g JSBs and 10 shot strings. The two mentioned settings yielded the same amount energy avg. fps= 794.5 and the same FPE as they relate to each other 22.43fpe. The difference i noted was that the .071 had a shot spread of 17.7fps and the .067 had a spread of only 8.6fps which would you prefer? Thats a loss of less then 1fps per shot, turn them tophats in.

This tophat setting becomes even more critical if one does any modding of the valve to gain velocity, such as drilling out the stem boring out the retainer, adding a lighter return spring. At .070 alot of air is wasted and a setting in the .065-.068 range is going to yield you a tighter shot string.

What are our options for this:
1. shims, easy
2. cutting some more threads on the stem harder, especially by hand.
3. my new idea. Its theoretical but i will be testing it out soon. The idea is simple. Back off the valve spring retainer. That is loosen it up a bit. I’m going to turn the tophat in all the way. and spin it back 2.5-3 revolutions (7 revolutions and it is off) this is to allow for plenty of adjustment in the future. Now on to the retainer, unscrew it till i have a spacing of .070 between the brass base and bottom of tophat. Take careful note of where this is on the retainer i will use a mic or the feeler gauges and write down the distance from base of valve to base of retainer nut. Now we have the potential for a loose retainer nut. I will use blue thread locker to secure the retainer in predetermined position. Some teflon tape would do just as well i would think. Now you have a funtional adjustable tophat as your tophat is set at .070 and you have 2.5-3 revolutions to gain you the optimum tophat spacing for your individual rig.

A guy could also grind a coil off the spring as well i suppose, or use a shorter spring to get the same results. Shims wear out, and its very time consumiong finding hte right setting. Black ops is experimenting with this as of now. I will direct him to this and see what he thinks. This little adjustment will allow to to get some numbers much more consistent then you thought possible. I know i’ve seen it with my own TSS. The same could be done with the condor valve as well. Anyone beats me to this and trys it soon please post some results. I believe it will gain you some incrediable consistency. Thanks go to Black ops, Paul and RiffRaff for their posts which got me thinking about solutions to this adjustable tophat deal and how it can be made to work as it should.

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Adam, Clint,
I don’t want to mess up this thread. There are several sub subjects here we could get into such as.
Setting the spring retainer a couple different ways looking for a response.
To mention a few.
Good subject mater and discussion possibilities. I like the shim idea as well. It’s been mentioned often over the years and could benefit from materials experiments and design. Sort of like the idea one can sort of drop in a durable spacer and not have to mess with a top hat adjustment so to speak. 😉


Owwww….my head hurts from reading your post 😛

Now chances are a few reasons you can not turn the top hat down far enough. 1. they did not cut the threads on the stem far enough 2. the stem is longer then normal 3. they did not drill the seat for the stem in the valve deep enough.

All of those will make the Top hat unable to adjust far enough down. The way I would remedy that is either drill out the valve seat a hair to seat the stem further or grind down the stem a hair to get the same result.

I set my spring retaining screw as Mike describes and it works fine. Blue loctite completely dried out will work fine.

And as for shims, I am all for them. It is a quick easy way to monkey with the velocity with out having to take out the valve.

Keep up the good work and let us know what you come up with.

Thread is getting a bit strung out in spots so good another was started. There seems to be a question about setting the valve spring retainer re hex head. In my Talon Valve Modification Report located in the Quick Reference section this is suggested.

“Now push the valve stem down into valve seat by slowly turning the hex nut, the top hat will start to rise, the second the top hat stops going up stop turning. Put a drop of thread lock or similar locking material on threads, turn down a minute amount and stop turning. Put the valve assembly back into the bottle. You might use some silicone grease on the threads and O ring.â€

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