Valve Shim Troubles

79MKII wrote:

The shop owner's reaction meant a lot, to tell you the truth. Mistakes happen to everyone, and the way they are handled makes all the differenct to me.

Thanks for all of the help everyone.

Exactly....

When you ship something like that out to any shop, it's a good idea to try to speak to the person in charge of that work. Ask questions. Be specific about what you expect and let them respond. Try to establish some "real" communications right from the start. ....If they treat you like you're a pain in the ass.....well, let your gut feeling be the judge of that....

Post edited by: larrycavan, at: 2007/08/15 05:29

Post edited by: larrycavan, at: 2007/08/15 05:32

Your cylinder head guy is correct. When installing oversize valves, it is necessary to sink them to get adaquate valve to valve clearance.

When we do these, we get the valve to valve correct, then grind the stems down to put them in the shim range. Then we assemble a retainer on the valve and make sure that the distance fron the top of the retainer to the valve stem in no more that .100". If it is more, we machine the top of the retainer. This will allow a 200 shim to be used without tappet to retainer interference. Anything more that .100" risk contact if thin shims are used.

We have had heads in here that the stems were so short, that the tops of the keepers had to be ground.

As for big valve installations, the best way id using blank valves. You get the valve job done with corect valve to valve ( we like to see .185" between them when sitting on the seat )

Then cut the stems off at the right length, then put the keeper groove in at the correct location. The everything fits just like stock without machining or grinding on any of the valve train parts.

Jay

Jay u say u like .185" v to v at the seat.Is that the same with a kz and j head?or does the angle of the j allow for less?of coause the j will take a bigger valve so ??? Thanks for your input.

WE use that figure for both.

Jay

Good discussion. Keep it going....I'm taking notes.




Later, Doug

Thanks Jay.
1 other option is to order new cams (more lift and duration for more power.he.he,he,evil: :woohoo:) with SMALLER base circles.They can be ground to your specs

Just an update on my valve issues:
I received the head back from the shop with a 1 week turn around and everything looks fine now. The head was disassembled and the valve stems "topped" so a normal shim range could be used to set valve clearance.

One more question (for now anyway ):

Web suggests setting valve lash at .006". Do you think a range of maybe .005-.007 would be OK? It's not always easy to get them right on, so is it better to be a little loose or a little tight? If I remember correctly, I think normal wear will close the gap, right?

Post edited by: 79MKII, at: 2007/09/01 11:19