Head Sanding / Flattening

[71_Bronco 1,072]

So I've seen many videos / articles about "flattening" a Kohler head before installing a new head gasket.

 

I assume this process should be done no matter what the engine brand is, correct?

 

I'm working on a S7D Wisconsin (single cylinder, 7HP), and it will be getting a new head gasket (preventative, not due to a blown gasket). This engine has a similar cast-iron block and aluminum head like the Kohlers do.

 

I was planning on doing it anyways, figured it couldn't hurt.

 

Thoughts?

[ebinmaine 70,751]

If nothing else I would take some finer grade paper like 400 or so and at least make a few passes with the head on the paper to see if you have any nasty highs or lows. 

[oliver2-44 10,370]

Yep, flatten every brand

[71_Bronco 1,072]

1 hour ago, ebinmaine said:

If nothing else I would take some finer grade paper like 400 or so and at least make a few passes with the head on the paper to see if you have any nasty highs or lows. 

 

That sounds like a good idea. I may hit it with sharpie first, and do a test cut with something fine. If no high / low spots, I wont have to do a major resurface

[ebinmaine 70,751]

4 minutes ago, 71_Bronco said:

 

That sounds like a good idea. I may hit it with sharpie first, and do a test cut with something fine. If no high / low spots, I wont have to do a major resurface

Excellent idea

[pacer 3,175]

Yeah, its too simple a thing not to take the few mins to give it a check. As mentioned, use wet/dry sandpaper 4-500 grit or more and find the flattest place you can - plate glass is best (if you dont have a granite plate$$)  Wet the paper with some type of oil - kerosine, thinner, WD40, etc and rub her around a bit.........

[bottjernat1 2,190]

I found this hope this helps 

 

[lynnmor 7,566]

I have a vertical bandsaw with a ground table that works well.  Keep in mind that not all glass is perfectly flat and some glass will bend a bit.  If you are doing two or more heads, lay the lapped surfaces together and check for daylight between them or use a feeler gauge, you might be surprised to see that your newly lapped heads are not as flat as you thought.

[stevasaurus 23,069]

Check out this thread...

 

Looking at the video that Nate offered, I don't like that the guy mounted his glass on chip board.  A saw table would be a much better choice.  You need a solid, flat surface for the glass.  

[richmondred01 2,289]

[WHNJ701 4,165]

On 10/14/2020 at 10:03 AM, 71_Bronco said:

 

That sounds like a good idea. I may hit it with sharpie first, and do a test cut with something fine. If no high / low spots, I wont have to do a major resurface

Just use spray paint before you sand them it