Universal valve opening fixture?

[bruce]

Let me reword this if someone was building a fixture what would be the dimensions on the alum bars that are used.

Is it 1/2 x 1 or 1/2 x 3/4?



Edited By bruce on 1222560022

[stevenford]

I was looking at Darin Morgans wet flow page and there is a pic about 7 pics down with a fixture

[106-1194218389]

The one thing that I found out with my testing is that your opening fixture needs to give you repeatability. I found that in some instances a difference of .002" - .003" can skew your results.

I use a 1/2" fine thread bolt because then one turn is .050". I machined the head and the threaded end perfectly flat in a valve facer. The flat end on the threaded side goes against the valve stem and my dial indicator goes against the flat side of the head of the bolt. I have found that I need to make sure the center line of the dial indicator plunger is parallel with the center line of my bolt to make sure I have a one to one ratio that my dial indicator is reading with the actual valve opening

Somethings I want to implement when I build a new valve opening fixture:
1. Some sort of a guide that will go down the valve guide or valve stem or something so I can be sure the dial indicator is following the exact path of the valve when it is opening.

2. I want to machine a dimple on the end of the opening device, i.e. my 1/2" bolt, so I can silver solder or glue a small ball bearing on the end of the opening device so I have a round end to push against the valve tip. Would be more effecient when turning my bolt to open valve.

John

[bruce]

I've accumulated a bunch of pictures just thought the "forum" might like to make a project out of making one cost effectively.

I personally do not flow automotive heads so it's something I need to make if and when I do start flowing automotive heads. As of right now I do not even have a head stand for my bench although that's a Winter Project for me to accomplish.

[49-1183904562]

Bruce;

Don't think you will need one then either, as you should start slow, a nice B model Flathead in a HiBoy would work just fine fo ryou and the wife

Rick



Edited By 1960FL on 1237124589

[bruce]

Trust me that thought has been on my mind!!

Been giving some thought's to selling out all my pulling tractor stuff and getting into a car, sure would be ALOT cheaper considering what it cost to build one of these single cylinder engines!!

[106-1194218389]

Well now that we have brought the subject up here is a spot where I have a body spotted. It looks like a Cobra site and that it is but if you scroll all the way to the bottom left you will see the 32 Body they offer. It looks really good to me especially for the price:

John

[Half-Inch Stud]

Belt-sand//Mill-Bolt that Bolt-end flat.
Drill into that Bolt end.
JB-Weld that BB onto the Bolt end.

[Half-Inch Stud]

The Darinmorgan site showed good florescent tracks.

[slracer]

A friend sent me some shots of what he is using for his 90cc single cylinder Honda head. His note is below and an overall pic is attached. A detail pic is in the next post. I think the adjusting mech and the measuring system are pretty "trick" and might be of interest for a universal fixture. The 1/4 - 20 machine screw gives .050 inches per turn which is convenient! The bent plate is tapped so the assembly moves there.

"Here are the pictures of the attachments for opening valves. The spacers that hold the plate up are .5" round, the overall height is 1.500" , the step which locates in the stud hole accounts for .200" of the total height and is also .5" round. The long pointer on the indicator is .078" or 5/64 drill rod and is 4.250" in length. The 1/4 20 screw is 2.00" long and the hole in the center of it is .173" or 11/64 or #17 drill. The plate is .187" or 3/16" thick. If you have any questions shoot me an email or call. Hope this helps!"

See next post for part 2. -- Doug

[slracer]

Part 2 of the images. Part 1 is the previous post. This shows the measuring "end" of the fixture. The assy shown here replaces the short tip on the dial indicator and the double nut (the lower is also secured with a set screw, but that probably isn't necessary) is used to turn the 1/4-20. Food for thought!

Doug

PS - I'm guessing that a machine screw was used as a 1/4 bolt 2 inches long isn't threaded all the way to the head?

[bruce]

I floated this topic a few months ago and would like to revisit it again . . . I spent the better part of this afternoon working up a design for a universal valve opening fixture that looks like the ones you see on a couple of websites (blue in color and I prefer not to post a direct link)

How much interest would there be for me to finalize the drawing once I have a working model? I'm ordering the raw materials and will make one as soon as I can work on it in my shop. It will probably be a project that I work on when I just wanna do something different so it might be a month of two before it's finished.

If there is enough interest I might think about building some to sell as the design does require some machine work.

[bruce]

I took some "my time" today to work on this fixture and am pleased with my results. Not to sure on some of the sizes of the parts though and think they might be a tad to small for the utmost rigidity.

But it's a start . . .

[bruce]

Disregard the crappy mill job on the slot! I was to lazy to setup my mister to blow the chips away.



Edited By bruce on 1237069310

[bruce]

The arm holding the indicator is only 1/2", the rails are 3/4"x3/8", the main body is 1-1/2" x 1" and the handles are 1/4-20.

I think the next one I do will have a larger arm and attaching parts.