1980 GL1100 blown head gasket Again! Fixed!

[bronko37]

A nice new mill file will take that surface area down quickly and smoothly. No handle on the file and use a draw filing technique, which is 90 degrees to the normal filing stroke that people may use. This way you will have the full length of the file over the surface you wish to level out. Keep checking with your straight edges until you have even contact. Go slow and you long even strokes and make sure you keep the pressure as even as you can on the file. We are looking for the minimum clean up on that surface. It will take you a fraction of the time to do this by hand and you would be done before you would ever even get the motor out of the frame.

 

[zman]

bronko37 » Mon Apr 13, 2015 8:49 am[/url]":2n4lpcvy]
A nice new mill file will take that surface area down quickly and smoothly. No handle on the file and use a draw filing technique, which is 90 degrees to the normal filing stroke that people may use. This way you will have the full length of the file over the surface you wish to level out. Keep checking with your straight edges until you have even contact. Go slow and you long even strokes and make sure you keep the pressure as even as you can on the file. We are looking for the minimum clean up on that surface. It will take you a fraction of the time to do this by hand and you would be done before you would ever even get the motor out of the frame.

Another good method Bronko,The file will keep the cut flat , It seems a shame to take out and disassemble the engine for just a little aluminum material.
This technique was what I was thinking, except it would be on the block while still in the bike.
[video]https://youtu.be/HyKN52HD6RU[/video]

 

[5150jim]

Well I pulled the engine before I came back & read the latest posts. I don't know how I would do with a file. I don't feel that brave. I guess I need to go shopping for a good file. If I do try a big file, should I go back over it with the sandpaper/glass afterwards? It was fun pulling the engine, but putting it back maybe a little more challenging, but after looking at how the cases come apart, I may just put it back & try to mill it myself.

 

[slabghost]

Get the widest longest mill file you can that isn't super aggressive. It needs to take off just a little at a time. Probably easier to judge how much pressure you are using on the file pulling it toward you. Not much pressure is needed let the file do the work for you.Angle the file top toward you and handle end away at as much angle as you can manage and still have one end above the block and the other end below the block. Every few strokes coat the surface fresh with magic marker so you can see exactly where the file is cutting. You want to be sure the entire surface is brought down flat at the same time. Once it's down to where the file is scuffing the lowest point. I suggest a chunk of plate glass and 600 grit wet/dry paper glued to the surface of the plate glass be used to finish the operation. Paper can be attached to the glass with spray adhesive. A spray of penetrating oil can be used on the paper to help wash away the metal you remove. Once your hands learn to do what you are telling them the process will speed up some. Both hands need to push pull at the same rate while applying the same pressure. Apprentice machinist in other countries learn to do by hand before they are taught to use the machines. So you'll be an apprentice for a time.

 

[bronko37]

I still make my students file a rough sawed block square on both ends and down to size within .002". They really hate it, but it you never know when you need such a skill.

I am gonna try to post a small video on the basic draw filing technique for you. Basically you want to push and pull the file perpendicular to what the normal filing stroke would be. This will keep the entire file across the entire surface at the same time and really cut down on any over filing you would do. It will also cut a super smooth surface finish. As soon as I get the video loaded up Ill post it.

 

[bronko37]

[video]https://www.youtube.com/watch?v=w1_f3MJGBfM&feature=youtu.be[/video]

So here is a small video showing the draw filing stroke. Sorry about the poor quality, I was holding my phone with one hand recording and attempting to demonstrate with the other hand. Basically as long as you hold the file this way and keep even pressure you cant go wrong. I would avoid a traditional filing stroke as you may get yourself into trouble. The draw filing technique is pretty fool proof.

 

[dan filipi]

Very good video, thanks!

 

[Ansimp]

dan filipi » Thu Apr 16, 2015 12:33 am[/url]":2mafjvfa]
Very good video, thanks!

+1 :good:

 

[5150jim]

bronko37 » Wed Apr 15, 2015 7:25 am[/url]":35zs6ssj]
So here is a small video showing the draw filing stroke. Sorry about the poor quality, I was holding my phone with one hand recording and attempting to demonstrate with the other hand. Basically as long as you hold the file this way and keep even pressure you cant go wrong. I would avoid a traditional filing stroke as you may get yourself into trouble. The draw filing technique is pretty fool proof.

That helps a lot. After seeing that I think I can do this.
TNX

 

[bronko37]

We KNOW you can do this! Take your time, use light even strokes, let the file to the work. :salute:

 

[5150jim]

slabghost » Wed Apr 15, 2015 4:24 am[/url]":24f0f34u]
Get the widest longest mill file you can that isn't super aggressive. It needs to take off just a little at a time. Probably easier to judge how much pressure you are using on the file pulling it toward you. Not much pressure is needed let the file do the work for you.Angle the file top toward you and handle end away at as much angle as you can manage and still have one end above the block and the other end below the block. Every few strokes coat the surface fresh with magic marker so you can see exactly where the file is cutting. You want to be sure the entire surface is brought down flat at the same time. Once it's down to where the file is scuffing the lowest point. I suggest a chunk of plate glass and 600 grit wet/dry paper glued to the surface of the plate glass be used to finish the operation. Paper can be attached to the glass with spray adhesive. A spray of penetrating oil can be used on the paper to help wash away the metal you remove. Once your hands learn to do what you are telling them the process will speed up some. Both hands need to push pull at the same rate while applying the same pressure. Apprentice machinist in other countries learn to do by hand before they are taught to use the machines. So you'll be an apprentice for a time.

Great info.
So I guess I'll become an apprentice machinist.
You guys are the best. :rocks:
TNX

 

[5150jim]

:help: Okay, one quick question.
What should do to keep the filings out from around the pistons? I was thinking to put paper towels in both cylinders unless you guys have a better idea.
TNX

 

[dan filipi]

Cloth rags in the cylinders with Pistons dropped down 1/2 way.

 

[5150jim]

dan filipi » Thu Apr 16, 2015 9:51 am[/url]":2hc0fg7x]
Cloth rags in the cylinders with Pistons dropped down 1/2 way.

Cool
TNX

 

[Ansimp]

5150jim » Fri Apr 17, 2015 4:36 am[/url]":3e0fqtd3]

dan filipi » Thu Apr 16, 2015 9:51 am[/url]":3e0fqtd3]
Cloth rags in the cylinders with Pistons dropped down 1/2 way.

Cool
TNX

Vaccum all the bits out and then rotate slowly and you will have a ring of fine stuff at the top rings TDC point that you can wipe out with a rag. Fine alloy particles won't hurt the engine but dust and grit will :yes:

 

[5150jim]

Ansimp » Thu Apr 16, 2015 2:08 pm[/url]":2pdku5q0]

5150jim » Fri Apr 17, 2015 4:36 am[/url]":2pdku5q0]

dan filipi » Thu Apr 16, 2015 9:51 am[/url]":2pdku5q0]
Cloth rags in the cylinders with Pistons dropped down 1/2 way.

Cool
TNX

Vaccum all the bits out and then rotate slowly and you will have a ring of fine stuff at the top rings TDC point that you can wipe out with a rag. Fine alloy particles won't hurt the engine but dust and grit will :yes:

I don't have a shop vac, but I did blow stuff out and off with my compressor. Then I used a .002 feeler gauge and a little bit of oil to clean around the pistons before I moved up and down slowly.
I borrowed a bastard mill file from my father-in-law (because none of the tool stores in town had one in stock) and milled my block. Now I need to get a thick piece of glass and some wet/dry 600 or 800 grit sandpaper today to finish it off.
And then to put it back together with the OEM head gasket.

 

[slabghost]

Sounds great! Any pics?

 

[Ansimp]

Excellent progress :good:
opcorn: opcorn: opcorn:

 

[5150jim]

slabghost » Sun Apr 19, 2015 12:39 pm[/url]":1ohv3or4]
Sounds great! Any pics?

As a matter of fact, I do have pix.

 

[brianinpa]

Well, I am impressed!