seat cutting

While back I wrote about a ko lee grinding set for seats. When I dress a stone it cut it wide band on one side and narrow on the other. I tried a souix brand one, it did the same thing. Is this normal? Do I ignore this? It seemd to cut the seat ok, (I tried a 60 inside the 45) but this was with a home made pilot that was loose in the guide, so I didn't cut but very little just to test it. Anybody know about this situation or are you all dead already? Maybe I'll just bring a souix stone to the machine shop in town and have the guy dress it and watch the pattern. Any info would be good. I'm really not impressed with the looseness of the dresser, I mean the shaft that holds the diamond is loose. The souix dresser is tighter. I talked to the machinest and he said if the stone holder is loose on the dresser pole something's wrong. He said to pay attention to how it cuts the seat, DUHHHHH. Maybe the angle on the stone is right even though it dresses like shite. S help me o knowledgable ones, and don't give me this I don't rember crap. If you can't remember you never knew anything anyway. Nothing frustrates me more than a guy that has a garage full of shite and doesn't know where anything is, yet has balls to yell and say "I said the second drawer" NOT THAT ONE!!, TWO DRWERS DOWN FROM THE TOP"! Yelling is for the grandkids, I can't take that for long. Never had a tolerance for loud abnoxiousness. This older gentlemen would give you the shirt off his back but keeps forgetting I'm an adult. :blink: :ohmy:

nads.com wrote:

While back I wrote about a ko lee grinding set for seats. When I dress a stone it cut it wide band on one side and narrow on the other. I tried a souix brand one, it did the same thing. Is this normal? Do I ignore this? It seemd to cut the seat ok, (I tried a 60 inside the 45) but this was with a home made pilot that was loose in the guide, so I didn't cut but very little just to test i

nads.com wrote:

but this was with a home made pilot that was loose in the guide

Three pieces of advise I was told when I was younger.

A tool is only as good as the person using it.

A job worth doing is worth doing right.

You have to be smarter than what your f###ing with.

Like Larry say's, nothing can be loose. You will find that with either a loose pilot in the valve guide, or if the stone arbor is loose around the top shank of the pilot you will have problems. I found that the stone will climb to 1 side under the torque of the electric motor. For many years I have used carbide seat cutters instead. This is the more popular Neway seat cutters.
www.cylinderheadsupply.com/nebapoeqkit.html#

There are others as well, but be careful about the quality as if the pilots are not the correct grade they will flex slightly. 1 Shop I worked at in the 80's had a carbide set up that did all 3, or even 5, angles in 1 cut, all carbide. If set up correctly this would turn out the most beautiful valve seat I've ever seen. I can't remember the brand name for the life of me. For the cost, the Neway's are the best I've used, and thats what I have to do my head work.

Serdi ? Was that the name of the machine from the '80's that did all the cuts in one operation ?

It's just too much to explain all the aspects of a valve job. I could show you in 15 minutes but it would take me an hour to type it out.

Here's some more tips

Whenever you swap stones on the mandrel, you have dress them. I don't care if you dressed it 5 minutes ago....if you remove it from the mandrel....it probably didn't spin back on exactly square again.....Dress it again.

1st - get a black permanent marker and put several marks on the seat. Mark it down inside and on the top so you can see all 3 angles you're going to cut.

Put the correct solid pilot in the guide. It should not sink all the way to the shoulder.

Put a 60 on the mandrel and spin it with your fingers a couple of times [slowly] to see where the bottom of the 45 is. That will show you how crooked or straight the valve job is.

Repeat that with a 30 cutter.

You'll then see the 45 as it really is.

Don't cut over the old 45.

I start by cutting the top cut. You're looking for it to be cutting all the way around. There can be low spots that the 30 will get rid of.

If you don't really know what you're doing with seat cutters. Get a junk head to practice on before you screw up your valve job on the good head.

A stone is great for the 45 cut. Not so great for the top or bottom cuts.

I recently straightened out a f'ked up valve job done on a fancy valve machine with a blade cutter. Serdi Schmerdi..... A name does not a good valve job make :laugh:

Dont forget a 30 backcut on the valve

TeK9iNe wrote:

Dont forget a 30 backcut on the valve Thanks for the advice guys! I didn't really know wich angle to cut first. The machinest did mention you have to dress every time you take the stone off. The guy who has the tools said to practice on a junk head and even offered one. The valve job that is on the 78 100 Is only two angles, maybe they pounded out? I can clearly see the seat cuts are narrow on one side and wide on the other on maybe every seat. The guides are pretty tight and that's strange. The speedo on the bike says 25,000. I pretty much know the guy that owned it did nothing to the motor and had the bike for many years. He does not know how to do this anyway. I don't know if you mentioned the stone dressing heavy and light (Larry) on your first post because I cannot see the post for some reason. He wanted to order a pilot from goodson for 100$. I told him to wait in case I could find one cheaper. That seems alot of money for one pilot especailly since everyone says the stones don't cut the seats very good anyway. Seems to me that once something better comes along the old stuff is suddenly junk. Kindof like the relationship thing. :dry: I'm not stupid and don't need to be told to folow the rules If I want to fk something up I'll do it. And maybe then I'll learn the answers to the things no one seems to be able to answer. :ohmy: I'm gonna cut those angles and WILL be perfect. It's attitude not hype that gets the job done. All the tech help in the world won't do it. Thats my story and I'm stickin to it. omar if your reading this, you need an emblem on the side cover of your bike.

mjg15 wrote:

Serdi ? Was that the name of the machine from the '80's that did all the cuts in one operation ?

No this was a MIRA set of valve cutting tools.
www.miratool.ch/?id=9
Is the link to their site.
And below is what I used way back when,


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VG-91 Print preview print preview

MIRA VG-91 classic

The VG-91 accurate low cost Valve Seat refacing unit offers the advantage of the MIRA Mulitcut System for smaller workshops. The application range goes from the small motorcycle to the midsized cylinderhead. The MIRA VG-91 gives you high precision and quality and the simplicity of handling.




The VG-91 tooling system with exchangeable DRC-Toolheads.


A large selection of MIRA Multicut Formtools are listed in the illustrated Formtool Catalogue. As well we‘ve a hugh range of original MIRA Pilots in our assortment.

VG-91 Specifications

Seat min/max 23 - 25 mm
Guide min/max 05 - 13 mm
Bores min/max 21 -58 mm Delivery includes:
VG-91 including DRC1 (21-45mm)
Inhex keys 2.0, 2.5 and 3mm
Instruction Manual
Packed in wooden box


ORDER NUMBER: VG-91

Optional Equipment

DRC05 toolhead for 16 - 25 mm seat diameters
DRC2 toolhead for 37 - 55 mm seat diameters





VG - Package

including:
01 VG-91 valve seat ref. unit with DRC1
01 AV-mobile
13 FD-type standard Pilots (free choice)
06 SK-type standard Formtools (free choice)

Manual

Export packing

ORDER NUMBER: VG-Package


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