Clearance on Valve Seat Grinder Stone Holder?

[Unmarked Bill]

This seems like a long shot, but I know theres a lot of clever and experienced people on this board with a lot of varied expertise, so I thought I'd ask.

Getting set up to grind some valve seats with an old Blue Point machine, I am feeling what seems like excessive slop when I slide the stone holder over the pilot. is this going to cause a lot of runout or is this how they normally are used? I don't have a dial bore gauge for valve guides, so I can't provide a clearance spec, but can anyone tell me what kind of fit is required for this operation?

thanks in advance for any insight!

 

[bmwpowere36m3]

Valve seat or valve? Like this:

I'd get a neway seat cutter instead... pilot should be centered and steady in the valve guide. Or send it to a machine shop, for a one or two time job.

 

[Unmarked Bill]

it is a seat grinder like the one you pictured, yes. I'd like to use this machine if possible, just wondering what clearance is typical on something like this?

 

[bmwpowere36m3]

What are you grinding the seats on? Honestly I wouldn't use that tool. Seats generally don't need much cutting or grinding. If you're reusing valves, then just lightly lap them in.

 

[txvwnut]

The stone holder should fit the pilots with a snug slip fit, at least my Sioux set up does.

Are the pilots the ones that came with the grinder? I want to say Blue Point used Black and Decker pilots on their early stuff and then later switch to either KwikWay or Sioux.

 

[VDubJoe]

Should be no slop in the holder on the guide pilot. Stones are still a great way to
cut seats. Just takes practice like anything. Only takes a second to go to far.
Been used for a long time.

joe

 

[Unmarked Bill]

thanks for the responses, guys. I have always just lapped valves and seats, but I wanted to play with this and see what I can get out of it.

It feels like there's probably about .005" clearance, comparing to how i remember valve guides I've checked in the past felt. I'm guessing it shouldnt be more than .002" but I guess the obvious answer is to give it a spin and check runout.

 

[txvwnut]

Might I recommend painting the seat with layout fluid before grinding. I do that every time I build a set of heads.

 

[Unmarked Bill]

thanks, yes I have dykem on some shelf I was going to throw on them.

 

[rsanter]

Much of the blue point valve grinding stuff was made by black and decker.
So you have the ball bearing stone holder or the one with the bushing in it?
If you have the bushing type stone holder they do get worn out, you can drill them out and install new bushings and ream to size to recondition them.

Grinding seats with a stone is still a good way to do it and I have been doing them for years in street and in race engines.
There are rough and fine stones. You also need a stone dresser in order to get a good finish as you need a good flat true grinding face on that stone

If you need more info you can message me an I will give you my phone number

Bob

 

[Unmarked Bill]

Bob, I sent you a message, not sure if it went through.

 

[Unmarked Bill]

This is the machine I have. Without a runout gauge I can't tell how concentric I am, but marking the valves and slapping them in, it looks pretty good. There's some attachments for flatheads and whatnot, I got this from the estate of an old farmer in Wisconsin, so it was probably just for tractors.

I'm noticing some things, the stones don't stay tight on the holder unless I really crank them on tight, makes them very hard to get off. Is that typical?

Also, on the dressing stand the bronze bushing in the stone holder rides the stand's pilot and that contact takes a little material off the bush after a while. Am I just pushing down too hard on the holder?

This is all just for fun, I won't be making this my life's work or putting any weight on the results besides just wanting to be able to grind nice seats.

<a href="http://s19.photobucket.com/user/picturedlife/media/20160304_112858_zpsmry5zl7n.jpg.html" target="_blank"><img src="http://i19.photobucket.com/albums/b168/picturedlife/th_20160304_112858_zpsmry5zl7n.jpg" border="0" alt=" photo 20160304_112858_zpsmry5zl7n.jpg" style=""></a>

<a href="http://s19.photobucket.com/user/picturedlife/media/20160304_112920_zpsiqmpkely.jpg.html" target="_blank"><img src="http://i19.photobucket.com/albums/b168/picturedlife/th_20160304_112920_zpsiqmpkely.jpg" border="0" alt=" photo 20160304_112920_zpsiqmpkely.jpg" style=""></a>

 

[Wine-o1]

I have a Kwik-way setup and as far as the stones on the holder, they don't need to be that tight to stay put. My stone adapters have ball bearings as opposed to a bushing so I don't know if some bronze material should show during use. It also shouldn't take to much time to grind the stone unless you are changing an angle of a stone or starting with a fresh one. You basically just want to freshen it up to keep it true by taking a few light passes. Based on your description, it sounds like your holder is worn causing the slop between it and the pilot. As stated previously there should be minimal clearance (like 0.001") between the pilot and holder otherwise it will not make proper seat.

 

[Wine-o1]

I also forgot to add that my stone holder has a paper washer that gets sandwiched between the holder and the stone;if your not using it maybe the stone will want to vibrate loose? Just a thought.

 

[Packard V8]

What are you grinding the seats on? Honestly I wouldn't use that tool. Seats generally don't need much cutting or grinding. If you're reusing valves, then just lightly lap them in.

I'd disagree. Most rebuilds require both seat and valve grinding. Many we see, the seats are so trashed, they have to be cut out and replaced with new hard seats. New valves are so inexpensive these days, nearly every rebuild gets new valves as a normal procedure.

Bottom line - hand lapping valves just isn't done much any more, for good reason.

FWIW, it's impossible to grind good seats using worn guides as a pilot. Have you first replaced and honed/reamed the guides to the finished size?

 

[Unmarked Bill]

I have a Kwik-way setup and as far as the stones on the holder, they don't need to be that tight to stay put. My stone adapters have ball bearings as opposed to a bushing so I don't know if some bronze material should show during use. It also shouldn't take to much time to grind the stone unless you are changing an angle of a stone or starting with a fresh one. You basically just want to freshen it up to keep it true by taking a few light passes. Based on your description, it sounds like your holder is worn causing the slop between it and the pilot. As stated previously there should be minimal clearance (like 0.001") between the pilot and holder otherwise it will not make proper seat.

Thanks for that about the fiber washer, that seems like something worth trying.

 

[Unmarked Bill]

I'd disagree. Most rebuilds require both seat and valve grinding. Many we see, the seats are so trashed, they have to be cut out and replaced with new hard seats. New valves are so inexpensive these days, nearly every rebuild gets new valves as a normal procedure.

Bottom line - hand lapping valves just isn't done much any more, for good reason.

FWIW, it's impossible to grind good seats using worn guides as a pilot. Have you first replaced and honed/reamed the guides to the finished size?

I'm messing with a 455 Buick, probably going to end up getting SS valves (and size up the intakes) anyways but i got the runout on the valves to 2 tenths so I was happy about that. I could have just lapped them in but I have this seat machine and I wanted to play with the seats. I have two sets of heads, one to sacrifice if need be, the other hopefully I will nail it. The guides are great, but the bushes in the stone holders are wobbly so I might have to rebush them or get new ones.

It's all a little here and a little there, as money and time allows. I am not dying to hear the engine run tonight, I've killed myself over too many of those already. This really is just for the fun of learning and playing with toys, so all the info you guys are sharing is dynamite.

 

[Poodlehead]

...This really is just for the fun of learning and playing with toys, so all the info you guys are sharing is dynamite.

I inherited one of these tools that I will put up for sale once I get enough posts... Trying to post pictures but not sure if I'm smart enough yet...