What grit for sanding head?

[71_Bronco 1,072]

So I've been working on my K321 a little bit each night, and have it just about tore down. Gonna be cleaning it and then prepping for re-assembly.

 

One thing I want to do, is sand the bottom of the head as most people do / recommend.

 

What grit paper do you guys use / stop at? 2000? Or is it not required to go that high?

 

Thanks

[JAinVA 4,619]

You really don't need to go that fine.The idea is to make sure the surface is flat.If you don't have a machinist surface plate or similar, a piece of glass supported works.240 to 400 grit is fine.A lot of people will coat the gasket with copper coat.Once dry it will help with gasket creep.

Edited October 11, 2018 by JAinVA

[WHNJ701 4,164]

as JaInVa said I have a thick piece of glass plate I use on heads and carburetors (makes a huge difference on those old 2 piece updraft briggs)

[JAinVA 4,619]

What you are proposing to do is lap the head.Lay the paper grit surface up on the glass plate.If you are using wet or dry paper use a lubricant and move the head around the paper in a figure 8 pattern.Not in a straight line.Once you see full contact with the paper suface,clean the head and you are good to go.

Edited October 11, 2018 by JAinVA

[WHNJ701 4,164]

I scuff it first then hit with flat black spray paint and scuff again that will show the high and low areas

[ebinmaine 63,133]

I do as above and have a piece of tempered glass from an old screen door setting on a table with a piece of cloth between them below the glass.

I taped a full sheet of either 180 or 220 to it.

Along with figure 8s be sure to turn the head in your hand so as to keep the wear and pressure points turning on the head.

Many people with habitually push harder on one side than the other.

Turn it maybe every minute or so.

 

If the head is in decent shape you'll be sanding for 15 - 20 minutes.

I had one we sanded for closer to an hour and it came out nice.

 

[stevasaurus 22,230]

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