Valve Seat Pilots

[jsmith]

Hi Guys,

Does anyone make their own pilots for valve seat grinding??

I have quite a good selection but I now need an odd-ball size and wondered whether I would get away with turning a bit of 3/8 silver steel to size.

What are your opinions on this and the accuracy required? Will I get it concentric enough in the lathe or is it a cylindrical grinder job?

[Greg]

jsmith,(sorry, dont know your first name)

I've made a few odd sized pilots from silver steel. You are better off using 10mm or so, so that you can machine both diameters simultaniously. It's no problem turning them in a lathe but you are better off turning both diameters at the same time so there isnt a chance that they may not be concentric.
If you turn it within .001"-.002" of finished size then polish it to the finished size it will work fine. What I normally do if I need to is to turn it to within .005" then heat it until it becomes non magnetic and quench it in hone oil (or olive oil). Then I grind it in my crank grinder to size.
You dont need to grind it unless it does bend when hardening it, so I would try turning and polishing, then hardening. If you lower it into the oil straight down holding it by one end it usually stays straight.
Then again, if its only for one specific job, I probably wouldnt bother hardening it.
If youre using one size a lot its well worth buying a carbide pilot, the difference in the seat finish you get is well worth it! They dont flex and I have some over 5 years old with no wear at all. (just dont drop them! they are brittle)

[bruce]

On the subject of seat grinding anyne want to share some tips on what works for them or should I say how they do it?

My equipment consists of a B&D vibro-centric seat grinder and a Sioux valve grinder with coolant.

Should the pilots have any lube on them? My B&D seat grinder makes some horrible noise sometimes from the pilot. I spray it with silicone and it goes away, should I be using something else?

What type of coolant do you use in your valve grinder? I've swapped over to using tranny fluid and it works quite well.

There really isn't alot of "insider" info on the proper technique on grinding seats and valves.

[Greg]

Bruce,
The synchro stone/vibrocentric stuff is great, I use it to touch up seats after I cut them in my seat and guide machine. I dip the end of the pilot into a little tub of engine oil to lubricate the pilot in the guide. Ive seen pilots seize in the guide running dry, they wear pretty quick too.
I use a Repco RVR seat and guide machine, its an oldie but a top machine, kind of like a Sunnen but heaps cheaper. I put a reverse switch on it so I can use it to tap for screw in studs etc. Its air float to move the head of the machine back and forward and adjustable in 2 axis on the head and the table. Its accurate down to about a .274" guide size but under that the floating head is too heavy to centre properly. These machines are fantastic for their age and you can pick them up for 2-3000 needing a little fixing up. I dont know if Repco ever exported them to the US?
For the smaller stuff I use a Serdi Pro, this thing will cut from a 14mm seat and 4mm stem size up to big diesels. It has an amazing centering setup that works spot on every time. I use the same tooling in both machines with Serdi carbide profile tips so you end up with exactly the same profie on every seat. I use carbide pilots for the common sizes because they reduce chatter heaps, dont deflect and never seem to wear. This was pretty dear new but they are getting cheaper now. I use it on multivalve stuff every day and I'd be lost without it.
Before I had these I used to use Newen and Mira ball drive tooling in my turret mill. You need to be careful setting up but its a really cheap way to cut perfect seats, throat heads, cut for valve seat inserts etc..
I use Sunnen hone oil in my valve facer, it stinks but compared to soluble oil it lasts longer, doesnt get stuff growing in it, leaves a better finish and I reckon I would dress the wheel about 1/3 as much as I used to. Its also not supposed to be carcinogenic (spelt right?) as some oils are, its worth thinking about when its splashing all over your hands and vaporised in the air around the machine. The valve facer is a Repco 242000, theyre Aus. made too, its a top machine, air chucking etc.. also handy for facing rockers and machining valve shims.

[Nick]

I'm looking at picking up a used valve seat grinder, any recommendations? Also, what is the correct way to re size a guide. I see there are thin wall liners, carbide balls, honing tools, and knurling tools. What is the procedure? Are there any good books covering these subjects?




Nick

[gofaster]

For most Harley seat work, I use the Serdi. All pilots are carbide. I have specific fixtures I made for it for H-D work, which index the heads to the same position every time to speed set-up. After the fixtures were finished I sent them out for hard anodizing to prevent wear and make them easy to keep clean. I especially like the Serdi for H-D and V-8 high performance and blueprint work because of the precise control it has over repeatability of seat depths, widths and concentricity. I use Sili-Kroil to lube the pilots and WD-40 or Goodson SCF-10 to keep the cutters from loading up.

For automotive and other general rebuilding, I have a Sunnen bench with diamond cutters and diamond guide sizing. Very fast! Only Sunnen oil here.

For odd shapes, flatheads, work-in-chassis, etc. I have a Hall-Toledo grinder that travels in an orbit around the pilot and is great for light touch-up work as well as full valve jobs. It has a nice thumbscrew depth adjuster that makes it easy to control the depth and rate of cut. In my opinion, it is the "Cadillac" of portable stone valve seat grinders. Sili-Kroil on the pilot and dry stones.

I also have portable carbide seat systems, Neway and Serdi Micro, but I rarely use them anymore. With the Neway it takes care and patience to achieve a good concentric seat. The micro is good for small valve heads. Again Sili-Kroil to lube the pilots and WD-40 or Goodson SCF-10 to keep the cutters from loading up.

For valve grinding, I use a Kwik-Way grinder. When concentricity starts to go, the chucks are rebuildable. I use the Goodson valve grinding fluid. Would like to upgrade to a Serdi centerless grinder, but they are too much $$$ for me at this time.

For guide sizing, I like to use a piloted reamer in new guides provided that there is enough material there to make a good cut. If only a few thousandths need to be removed, I'll hone them with a Sunnen hone or run a Sunnen diamond tool through them. I like to finish with a pass with a flex hone to put some crosshatch in the guide for oil retention. Sunnen oil for honing, Goodson BW303 for reaming bronze guides, and ream cast iron guides dry or with soluble oil. My soluble oil is a Castrol product for cast iron, but I no longer have the original container.


[quote]

Nick, in my opinion knurling and sizing balls are only for general rebuild work, and are not good enough for serious performance work.

[gofaster]

[Nick]

Thanks for the reply Jim. A serdi is not in the budget for what I'm doing right now. Looks like I'll be stoning. (not getting stoned) I found an interesting thread on speed talk today about valve seat concentric. From the other articles I have read, it looks like you can get good results from stones. The guy who I used to have valve jobs done used a bridge port to cut seats. His stuff never ran that great. The last guy I had do work for me used stones, and his stuff seams to run better.

Here's the the thread:



Any comments?


Nick

[bruce]

I use stones in my application. I think its all in the care you take when cutting. My engines are single cylinder so I only have 2 seats to cut and I don't have to match other seats to them. I think this is where a Serdi style setup shines ahead. Stones allow me flexiability to cut what ever angles widths I want to cut at a moments notice without having to buy a cutter.

I have been looking at making my own Serdi style holders to hold cutters but thats just another project and not near the top of the list. For now stones is the way I do my seats.

I also have a Sioux valve grinder for which I need to make a protractor setup so I can get a more accurate valve grind on faces other than standard 30, 45 those are the only markings on the machine besides 90. I'd like to figureout a way to grind the valve underside to various shapes back to the stem using this machine. I am working with alot of Ti valves cutting them down for my tractor engines, most of the work I can do in my lathe but the grinder would do a nicer job on them. I have thought of using a toolpost grinder on the lathe but I don't want the mess that can make.

[Scott]

Bruce, I made a set up like the serdis use it was a nitemare, I was never happy with the results. The geometry on those inserts are terrible. I have made a form cutter blank with three different cutting surfaces, and an 1-1/4" shank. Its at the toolgrinders right now, he'll solder the carbide in it and grind it for me. The body took me a day to machine with a rotary on a sine plate. 30-45-60 spaced 120 degrees apart. Tool grinder guy says it should cut like gangbusters. When I get ambitous I'll make one that uses indexable inserts like the ones on a boring tool. IMO after being a jobshop machinist/mfg.engineer the better part of my life, every seat "cutting" setup I've seen has not impressed me.......

[gofaster]

99% of my work is on Harleys. I do most of them on the Serdi. I have 1" thick fixturing plates that carry 2 heads at a time. The plates help by making the set-up rigid, and reduce the chances of chatter. New seats cut like butter on my machine, but the old seats that are work-hardened can be a source of trouble. One way to skin those cats is to chase the profile with light single angle cuts to bring the seat close to the desired widths and depth, and then just kiss it with the finishing multi-angle cutter. If I get one that has hard spots and just wants to chatter, I'll rough it in with the Serdi, and finish it with the Hall-Toledo. The easy way out would be to pop new seats in the heads, and just do the gravy work on all new parts, but that's not fair to my customer. If I feel the old seats will clean up and be within valve stem protusion limits, then I'll do my best to save him the expense of installing new seats. For the largest part of my work the Serdi gets me where I want to go.

Before I got the Serdi, I was using the Hall-toledo for years. I learned that if I took my time, and got the seat nice and level using a bubble level that I made to fit over the pilot, that things sort of took care of themselves after that. If you are going to use a stone system, I feel that the Hall-Toledo is the way to go. It's easy to dress stones to any angle you want to use in your seat design, and the grinder has a nice feed system so you can keep your cuts light and watch where you're going.

Back in the late '70s or early '80s Harley was promoting the use of Neway cutters in their service manuals. Naturally, I had to go out and get a set. They take a lot of patience. I don't recommend them. I don't know why Harley was so thrilled with them. If you take your time, and work very carefully, you can get good results, but the problem is that you're hand turning the cutters and hand regulating the downforce. If you unconsciously favor or push more to one side, you end up with an out of round seat, and seat width that goes from wide on one side to narrow on the other. If it's all you have or all you can afford, you'll learn how to do a good job with them, but in my opinion, they are a royal pain.

I'm not sure if I'm answering your question or not but I hope I'm shedding some light on the subject for you.

I looked back at the old Speedtalk topic you posted about. All of the valve seat finishing methods they spoke of can get good results provided the guy doing the work has the necessary skill and talent to do it right, and is puttig out his best efforts. After years of using the Hall-Toledo grinder, I initially didn't like the Serdi, I thought I made a big $$$ mistake by even buying it. They sent a rep out to see me, and we worked together for a few days. When we were done, I knew what I could and couldn't do with my Serdi, and I loved it!

[B][I]

[Nick]

So for the guy who wants to do his own work, and is not trying to make a living at this, a stone setup would do just fine.

Here's a question, does the serdi table ever "lock down" ones you get the head into position, or is it always floating.

What if someone wants to put in hardened seats in or bigger valves, do I need a mill or bridge port to do that or can it be done another way.

Is there a fixture to use when you want to ream the guides to put in bronze guides? I have seen reamers that center off a cone that sits in the valve seat, do you use a drill with the reamer?


Mostly what I want to do is touch up seats after porting, and in the off season.


Any help is much appreciated.


Nick

[gofaster]

Nick,

The Serdi only floats until you get everything lined up then you lock it down one step at a time to make sure it's right. When you're cutting, everything is tight.

If you want to install valve seats, most stone cutting systems have a provision for driving a seat counterbore. You can buy fixed and adjustable counterbore cutters from Goodson.

You can also do it with a Bridgeport, (and I know one guy here locally who uses his drill press), but the set-up is a little tedious as you need to hold the head rigidly and you need to have the guide bore dead nuts in line with the spindle centerline. Or else you need to use one of the ball drive set-ups like Goodson sells to allow some misalignment on a Bridgeport. I've done it on a mill before, but I've never used one of those adapters, so I can't recommend it one way or another.

The centering cone is what you would use to help line up the reamer to bore the head out for new guides. You can do it on the bench with hand held power tools, it's just much easier with a guide and seat machine.

I mention Goodson because I buy supplies from them, and that's who I think of first. There are other sources that have the same things, comparable pricing and service.

You can get along just fine with a good stone system, especially if you just want to touch up seats. When you reach the point where the seat has gotten too deep, the stem protrusion is too great, the rocker geometry is getting affected, then it's time for new seats.

[Greg]

A few years back, I used to cut all my seats, fit inserts etc in a bridgeport. I made up some stands similar to what the old IDL machines use. All it needs to be is a 2 flat plates that you can clamp down to the bed for the mill with a 1.25" or so tube welded vertically to each one. There is a 5'16" threaded rod that runs up through the centre of each tube. The top of the tubes are milled off to the same height.

I sat the heads on the stands, if I was cutting intakes I would sit the head on the exhaust seats. You just drop the head down with the threaded rod up through the guides and the spring seatssit down on top of the tube. I sat a tapered edge washer over the threaded rod and clamped it down with a nut.

This sets the seats up at the same height (or very close to) with the valve guides perpindicular to the mill bed. This works really well on inline valve heads, chev &ford sb and the like. For canted valve heads like clevelands or BBC I made spacers to sit under the spring seat to tilt the head until the guides were perpindicular to the bed.

The whole setup cost about $20 and i used it for about 3 years, I still do every now and then when I need to mill chambers.

[larrycavan]