Grinding valve seats - a question or two

If you go this way with a traditional seat grinder rather than finding someone who knows how to apply a modern seat machine to a flathead, get a supplier catalog FIRST. Goodson is the one I have...they have everything needed to keep an elderly B&D/Snap-on or older Sioux running, AND they make brand new flathead pilots for them. They can supply all kinds of stones, including the B&D ruby ones. You don't want an older machine that is a complete orphan, so check the catalogs!
You need multiple angles to control seat width, but the multiple stones needed are not expensive. Be sure that grinder set has the diamond tool to shape stones.
 
I ran a machine shop (within and auto parts store) for 5 years and when the boss decided to retire and close the store i ended up buying a bunch of the shop equipment.

I ended up with the valve grinder and seat grinding tools also, we always got all of our suplies at goodson, good place to deal with and pretty quick shipping, they had rebuild kits for the head of the seat grinder which i had to do every year or so, the bearings now a days just aint worth a **** and i could tell when they were going bad, the seat grinder just didnt work as good.

ive done a ton of valve jobs and lots of flathead and 4 bangers etc etc, and they are easy to do.

i would usually cut the 45 (46 dagree) cut in the seats first, then cut a 30 dagree cut te set the contact on the valve face in the correct area and your gold, dont lap the valves, that an outdated thing, if you cut the seat the valve and set the intersecting angle and the valve seats your done.

JEFF
 
I received my kit from Neway today, which includes a 1 1/32" pilot, and 30, 45 & 60 degree cutters. My block is at the shop getting bored to .125 over (Egge pistons & Hastings cast iron rings) and some minor crackage fixed as well. In the meantime I will clean up the connecting rods and get them to the same weight.

This project is slowly coming together, but I would rather take my time and be comfortable about what is going on. Looks like getting the crank balanced will be next, to the tune of about $300. I still need to study the cam, I don't think it's stock, but I have no idea what it might otherwise be. I guess I will be drilling 4 holes in my degree wheel tomorrow.

Thanks for all the input, I will update my progress, as it happens.
 
Connecting rods are not to be done at home. There is not a lot of room to remove weight and they will most likely nedd to be resized as they get egg shaped on the big end over time. You will want to have new bushings professionally installed also.
 
Ronnie said:
11/32 pilot won't work you need a pilot for a Flathead. It is 1" 1/32 and a tapered fit...

The guides fit too loose to use a 11/32 pilot and get a reliable nice seat unless you loctite the guide and don't plan on taking it out until next rebuild, then you could glue 16 guides in and go with a expanding pilot 11/32" pilot.
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If you use the 1 1/32" pilot to grind the seats, then install a "too loose" guide, that would seem to leave you with valve/seat alignment problems.
 
Goodson sells new flathead pilots in a couple of pilot sizes.
Flathead pilots like that, as normally used with valve grinders, and regular pilots set into guides share potential seat problems if fit is loose, and the fit is always going to be looser than normal types of guides.
Racers use guides much tighter than original, either entirely special ones or stockers that have been copper plated, externally knurled, or whatever to make them press fits.
 
I agree flatheads will have a "looser than normal" fit (absent heroic efforts like copper plating). Then, does it make a big difference to pilot on the guide bore in the block vs. the guide itself? I've seen some guides modified with pressed-in bronze inserts, but that seems to be to be only a partial solution for the fit problem.
 
You should put the degree wheel on the crank a much more common reliable way to dial in a camshaft. But feel free to try it on the cam I haven't seen it done on cam alone so I will reserve comment at this time perhaps the 2 guru's JWL & Old Ron can enlighten us with degree wheel on cam.

http://www.lunatipower.com/Tech/Cams/HowToDegreeACam.aspx

http://www.carcraft.com/howto/116_0701_how_to_degree_a_camshaft/index.html

http://www.iskycams.com/degreeing.php

The discussion will go on forever on the pilot story. As soon as you take the large Flathead pilot out you are not guaranteed it will go back where it was. Bin there done that. But the large pilot will work, but still has an error factor depending on your tolerance level of acceptance. You want a way that has the least amount of error is use a serviceable guide install with loctite get your valve job done never take guide out and move on. This changes your assembly procedure but can be done.It all depends on the level of tolerance "YOU" want,and can accept not what "WE" suggest here. We can only report on what we have seen and done.This being your first valve job it will have a certain amount of error anyway guaranteed . You should practice first to get your feet wet.
Ask as many questions as you need answered there is a wealth of knowledge here on this forum just start picking the engine guys brains here. Hope this helps before you begin. Have fun.
 
There are several disadvantages to trying to "degree" directly from the cam. There will be some gear tooth "slak"(clearance), between the crankshaft and camshaft, which might not be accounted for with the degree wheel on the cam. There will also be a problem with precise readings. If the degree wheel is 10 inches in diameter, it will have to be 20 inches in diameter at the cam to equal the reading accuracy of a 10" wheel on the crankshaft. Too, some math skills will be needed to double all the readings. So, if the starting point is in question due to gear cleances and if the readings are less accurate, why do it?

Yes, Ronnie, this discussion has already gone way beyond a reasonable length.
 
Alot of good stuff here, I'll add just alittle. The 15/45/60 for the intake and 15/75/60 for the exhaust is a good long lasting seat. The major diameter should be near the top of the valve and a small radius should be placed on the valve. his eliminates the sharp edge and prevents burning. Although sometimes refered to as a 3 angle jalve job, It is infact just a stock valve job.
 
My grand son did that. I told him I was looking for a young lady in her mid 60's with good eyes and a pickup. Pays to advertise.
 
I have an old Sioux pilot, the top is a peg fit. There is a hex on the top that expands the bottom to the fit of the guide hole... I have faith that it's as accurate as can be. When I do seats, I start by using the cutter-or grinding stone-60 degree-that defines the inside of the seat, not a lot of grind, just enough to mark around all of the inside of the seat. A thin line. Then I use the 30 degree cut to narrow the seat so that it's under the valve... and the I use the 45 to cut the actual portion that will contact the valve... Using the cutters in this way will "walk" the seat in, lessening the material that pushes the cutter off center on the 45 degree cut... During this proccess, I remove the pilot and use a valve and guide against the seat to find out where the seat is in relation to the valve, twisting the valve on the seat with hand pressure will make a faint mark on the valve to tell where the seat is... I used to use a fine film grafite spray for the 45 degree cut on the seat, could use on the valve... This realy helped when I used a grinder, to see seat width... Enough??? Karl ps, rods HAVE to be rebuilt before balance work...
 
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JWL;48753 Yes said:
No, this dioscussion should keep it course...sure, you
ve
"been there done that" and it's academic to you, but those who need to learn and want to learn, will keep tuning in.

Don't try try to kill a thread, just because it's old hat to you.
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