grooves on head

[xlr8tn]

Been cleaning up my head this weekend and found these grooves on both sides. Can I just smooth this out with my dremel? This engine is at os1 (0.25). Also how do get the parts clean near valve guides?

thanks
Brent

 

[I am Carbon]

Hey Man pix will help to answer your question.
Also I clean loose parts with soda blaster then wash em up
here I was cleaning a part

 

[xlr8tn]

attached

 

[I am Carbon]

I have not seen head damaged like that and on both side too.
There are other guys here that can give you an answer on that.

 

[TwoManyXS1Bs]

That sure looks like a history of intake valve float. Possibly from over-reving, followed by piston smack into valve, then bent valve stem, then piston beating the bent valve head against the outer edge of the combustion chamber.

Careful smoothing of that area(s) will be fine. Just keep away from the seat(s).

You may want to double check the quality of previous repairs to the valves, guides and seats.

 

[zmaxmotorsports]

I wonder if it was some home brewed way of unshrouding the valves with a dremel?

 

[jay760]

Should be able to take out that area here's a picture of my head

 

[Lasper01]

Im also having this problem with ('77650D 447) my head.. on the intake at both sides

 

[zmaxmotorsports]

Looks like dremel marks to me anyway,Im still leaning towards somebody trying to unshroud the intake valves.

 

[TwoManyXS1Bs]

There's a couple of threads in here, somewhere (I can't find them), with good pics of mysterious cleanup/notching/clearancing work done in that same area. So, this isn't exactly a rare phenomenon. But, if you guys can find those threads, it would sure help with this, and possibly bring closure to those other threads...

 

[NONclow]

The combustion chambers are cast iron or steel, I'm not sure, but they are magnetic. Therefore, in the casting process the chambers are cast with an 'ear', or tang for use in locating the chamber in the mold when casting the aluminum around it. Those grinding marks present next to the intake seat are left from the removal of the ear.

They were in my '71, and the '80. Not a problem (for stock, but quite a few of us can't leave well enough alone).

...........I believe............

 

[5twins]

Those are "tooling" marks from the factory. This was a mass produced bike. The head work was one step above terrible, lol. I would just grind it smooth. I would be more concerned with the terrible finish on the ports (I fix that with my Dremel).

 

[Lasper01]

Ok, good info! What tools do you use on your dremel to fix the ports? Wirebrush or sandpaper?

 

[TwoManyXS1Bs]

Here's a pic of a Lillie head with that area smoothed out.

 

[jkr277]

I would avoid removing any material with such tools like a dremel. As long as its smooth for the gasket to lay on.. And I'd go ahead and find new valves along with keepers and such.

 

[5twins]

For cleaning the ports up, I use the #191 and #192 Dremel ball cutters for smoothing out the tool marks and casting bumps .....



I use the 1/4" and 1/2" sanding rolls for smoothing most of the port walls and Cratex wheels for a better polish on the exhausts. The Cratex wheels are rubber impregnated with grit.

You don't want the intake ports highly polished. After smoothing the lumps and bumps out of them, I "texture" them back up with a sanding roll .....

 

[Lasper01]

Thanks! Very good info! Merry Christmas

 

[xlr8tn]

excellent info ... thanks all