Resurfacing Block

[jhillier449]

As part of my top end rebuild, I have resurfaced the cylinder block on the cnc machine I use at work.

I took a thous ant of an inch or so off the top and bottom sides of the block so as to have a good sealing surface.

I noticed before I started that the steel sleeves seemed to be indented a small bit into the aluminum block.

I machined the whole thing even, so now everything is flush.

Is this a big deal or am I being paranoid?

By the way, the steel sleeves seem really hard by the way it machined.

1980 GS1000G

 

[rapidray]

The steel sleeves ARE hard! How did you machine the BOTTOM of the block? Did you remove the sleeves & then re-install them after milling the bottom? If not, you will have gasket sealing issues. If you DID, you will have ring sealing issues. Ray.

 

[Nessism]

I'm curious how someone could machine the bottom with the sleeves in place, but assuming you found a way, I don't understand why that would cause sealing issues. Please explain further Ray...

 

[rapidray]

Because just maching the outside perimeter would cause the center parts to keep the block higher on the perimeter. Ray.

 

[jhillier449]

I did not remove the sleeves. I just took less than a thou off the outside.

I can go back in and machine the area between the sleeves if I want to.

I can get in there with a small diameter endmill. I have some pics I can post.

Think a half thou will make a difference?

Could I cut away those parts of the gasket?

Cheers

John

 

[jhillier449]

http://s1112.photobucket.com/albums/k481/jhillier449/?action=view&current=Interface011.jpg

Here is a pic of my work, the bottom side of the block.

I did get between the jugs where the cam tunnel is.

You can see the untouched area between the jugs.

Opinions please.

 

[jhillier449]

http://s1112.photobucket.com/albums/k481/jhillier449/?action=view&current=Interface016.jpg

A pic of the top surface finish.

 

[Nessism]

You need to go back in and machine the entire bottom smooth. As Ray said, the step between the cylinders will keep the cylinder from seating down on the engine cases. The material removal is no problem at the amount you state.

 

[jhillier449]

No worries thanks. I did this as a first go yesterday. I did this basically manually.

I think I will write a proper program to face both sides of the block and the cylinder head just a thou on each side, just to remove the old gasket material and pretty it up, it beats scraping the old gaskets off and gives a nice finish.

So I will remove 3 thou in total, shouldn't be too much?

Cheers

John

 

[jhillier449]

Ok.......time for some humble pie.

I'm an idiot when it comes to resurfacing an engine block.

I went to a local motorcycle shop owner who has 25 years experience building engines, a top shelf chap.

He gave me some expert advice on how to do this properly and his coveted resurfacing tool that he made himself.

Going to have another go at this and see what happens. Will post some pics of the process and the end result.

cheers

John