Valve seat concentricity and dead pilots

[jcisworthy]

What machine are you using and how concentric are your seats?

Also, anyone using dead pilots, what pilots are you using? HSS, carbide, who did you get them from?

I got my HSS pilots from Goodson and I noticed when I install them in the guide they do not install straight in relation to the guide bore. I have seen as much as .004"runout.

Anyone know of dead pilots that install true to the guide bore?

[mag2555]

Are we taking new guides or used?
I use Goodson adjustable pilots a lot on used guides.
I also have a separate set of guides just for usage of 60 degree or steeper cuts and or Hogging out bowls.

[zums]

What machine are you using and how concentric are your seats?

Also, anyone using dead pilots, what pilots are you using? HSS, carbide, who did you get them from?

I got my HSS pilots from Goodson and I noticed when I install them in the guide they do not install straight in relation to the guide bore. I have seen as much as .004"runout.

Anyone know of dead pilots that install true to the guide bore?

if using inserts ive used the VGS-20 some people swear by the live pilot serdi, i hate em, you need carbide pilots, my r/o tool is set for the .389 pilot so im stuck getting hit with sunnens price for pilots, light feed and lube i get .0005-.0007 on a 2.02 and a little less on smaller valves, if you are using stones check out donc on here he has stone holders that keep it tight also
Tom

[jcisworthy]

New bronze guides diamond honed to finish.

The tapered pilot only has a tenth of runout in it so the pilot is straight but when I insert it in the guide it has .004 runout where the ball head tool holder rides.

I am using a vertical mill with a rollover fixture. I indicated the guide with a last word then used a coaxial dial indicator to center and verify the indicated guide hole. I inserted the pilot with spring and ball head tool holder, rand the quill down and the tool holder deflected.

I ran the coaxial on the top of the pilot and it is .004 out. I tried taking the pilot in and out a few times and it repeats .004 out. I stuck an old split pilot I got with my valve grinder and it is better but .002 out.

Anyone make pilots that go in straight?

[gofaster]

used a coaxial dial indicator to center and verify

Haimer Centro? Blake? Or import?

Those can be questionable. I like the Haimer Centro, but an Interapid on a spindle mounted indicol is the most certain way to check for center. Anything else can have you chasing your tail.

Just my 2¢

[vortecpro]

What machine are you using and how concentric are your seats?

Also, anyone using dead pilots, what pilots are you using? HSS, carbide, who did you get them from?

I got my HSS pilots from Goodson and I noticed when I install them in the guide they do not install straight in relation to the guide bore. I have seen as much as .004"runout.

Anyone know of dead pilots that install true to the guide bore?

"how concentric are your seats"

Well, that all depends on the valve guide, if the guide is perfectly round and strait, tenths. A live pilot comes in play on a guide bottom cut at a 45 degree angle, thats where I carbon relief. Blue printed VGS 20 with carbide pilots.

[cpmotors]

New bronze guides diamond honed to finish.

The tapered pilot only has a tenth of runout in it so the pilot is straight but when I insert it in the guide it has .004 runout where the ball head tool holder rides.

I am using a vertical mill with a rollover fixture. I indicated the guide with a last word then used a coaxial dial indicator to center and verify the indicated guide hole. I inserted the pilot with spring and ball head tool holder, rand the quill down and the tool holder deflected.

I ran the coaxial on the top of the pilot and it is .004 out. I tried taking the pilot in and out a few times and it repeats .004 out. I stuck an old split pilot I got with my valve grinder and it is better but .002 out.

Anyone make pilots that go in straight?

The pilot doesn't have runout, the guide isn't vertical/parallel axis to the quill axis. This is why I don't use a coax to center on pilots, you need to stroke the quill along the sides of the pilot in Y and X and see which way its leaning. Very few guides are actually perpendicular to the deck or parallel to each other. Trying to center off of the guide then inserting a pilot is just compounding the problem.

I can use a HSS Goodson tapered pilot, my own custom carbide pilots or Rottler pilots and get the same result. I do prefer the Rottler style with straight lower shank and the fast taper near the top vs the straight taper.

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

[jcisworthy]

"This is why I don't use a coax to center on pilots, you need to stroke the quill along the sides of the pilot in Y and X and see which way its leaning"

I have a last word dial indicator with a 1.5" probe and stroked the guide with that on the X and Y first.

After that I set up my import coaxial dial indicator to center and stroke the hole with that to see if it maintained a zero from top to bottom and it did.

When the hole was verified and centered I had deflection in on the ball head.

One thing I did not do which I can for another check is, after aligning and centering I can install an 11/32 valve stem I have in a collet and see how it pilots the hole.

The pilot still had .004 runout after installing it in the guide.

I looked at the Rottler pilots and may try them.

[user-9274568]

I have a .342 HHS Sunnen pilot = .3883

I have a .342 Carbide Sunnen pilot = .3889

[jcisworthy]

I will run the quill down with a valve stem in a collet after alignment and see if it engages the guide smoothly,

This will verify whether or not the pilot does not aling straight to the guide when I install it.

[jake197000]

x2 on cp motorworks

[cpmotors]

I will run the quill down with a valve stem in a collet after alignment and see if it engages the guide smoothly,

This will verify whether or not the pilot does not aling straight to the guide when I install it.

Your making this more complicated than you need too honestly. Cut the seat, check the runout/deflection direction, offset equal to runout, cut again and check. Put an indicator on the pilot and push it with your finger, it flexes all over the place. It's essentially just locating the bottom of the tool body.

[Dave Koehler]

One thing I found was not to wring in dead pilots too much.
Most guides are not supported all the way around and that makes the pilot push to one side if one uses too much force.

[Brian W]

One thing I found was not to wring in dead pilots too much.
Most guides are not supported all the way around and that makes the pilot push to one side if one uses too much force.

I do the same. However I like to touch the guide with a k-liner reamer. I just cut just enough where it touches all the way around, that way when you put the pilot in guide it does not cock to one side.

[jcisworthy]

I will run the quill down with a valve stem in a collet after alignment and see if it engages the guide smoothly,

This will verify whether or not the pilot does not aling straight to the guide when I install it.

Your making this more complicated than you need too honestly. Cut the seat, check the runout/deflection direction, offset equal to runout, cut again and check. Put an indicator on the pilot and push it with your finger, it flexes all over the place. It's essentially just locating the bottom of the tool body.

I am going through all of this because when you get this retarded on set up and some seats still come in better than others I want to know why.

I am performing at least two checks to verify each particular operation so I can go through a methodical process of elimination to try to see something that will help consistency.

I was told to use a bubble level like Goodson VGL 100 to level the quill and head like you set up a Sunnen VGS machine and forget about it. I am starting to think he may be right.

Ill bet pilots are not going in the guide true everywhere people just do not know it because they nevel checked.

Set up on the pilot however it goes in the guide and cut a seat. That is how the floating seat and guide machines work.