Head machining ?

[Anonymous]

In the process of rebuilding the head on my gs 1000. How much material can be machined off safely? I'm going to take it to work and have one of the machinist do it for me. Will this raise the compression much? Will I have valve interference problems? Once this is done I plan on installing a set of cams off a 78 gs 750. Hopefully these mods will net some performance gains.

[SqDancerLynn1]

I would say you could take .020 .030 off without any problem BUT you will have to degree the cams as it will change the relationship to the crank With the quality of todays gas I would just clean up the surface

[Anonymous]

curious, how does shaving that minute amount change your cams that much

[SqDancerLynn1]

Techcally it makes the front side of the cam chain longer by moving the head closer to the crank. It will still run, it could be up to 8-10 degrees off depending on how much is taken off the head or how much it was off to begin with from the factory

[Anonymous]

I could see that problem showing up if your cam chain was stretched but I've never seen 8-10 degrees using a new chain on any bike. most I've seen with 20 thousandths was 4 degrees. thats the reason I'm asking.

[SqDancerLynn1]

That could be I was just trying to show that it is important to do it. Even 4 degrees could make a big difference in the way the bike runs

[KGB]

I agree about the cam chain change.

BUT another piece to remember or look at is the deck of the cylinder head.
You may cut the head, but mounting it to a cylinder deck that is not perfectly flat will cause leakage, loss of compression.

Have the machinist also check the cylinder deck. Only takes a couple of minutes and could save you lots of frustration.

[Anonymous]

That could be I was just trying to show that it is important to do it. Even 4 degrees could make a big difference in the way the bike runs

yes I agree if you were going for max performance then definately get the cams degreed if staying stock you should be fine leaving them straight up to factory specs. if your a casual cruiser like me then you probably wont feel the change