At snakehunt a valve broke, didn't hit the piston, just pulled the head off. Heads been in the shop ever since. Got a lot of empty promises as to when it would be done by the original builder, pulled it out and took it elsewhere on July 5. I was told 3-5 weeks it would be done. Just got it back yesterday. Went to assemble it today clayed it up and found I have NO clearance on the exhaust valves. They touched the piston. Thankfully they didn't bend. Now how can I get .080 clearance. Brand new 11.5-1 JE piston, web 109 cams. nothing outrageous. I'm thinking the valves didn't get seated deep enough in the head. I'm really pi$$ed about the whole thing. Now it appears that I have a junk head after putting considerable money into it.

 

Did you send it to a reputable shop who specializes in DS 650 heads?

 

Did you clay it with the cams in place and did you check your valve clearance?

If the cams were not in place and the valves were held completely shut, the only thing I can think of is the valves are too long to seat deep enough to clear the piston. Either the guys that did the head work didn't know what piston you were running or they made some assumptions as to your clearance.

Either way......cams, valves and pistons need to be blueprinted as a workable combination. Just think if you hadn't clayed it.[img]i/expressions/face-icon-small-blush.gif[/img]

One more thing.......what head gasket are you using (how thick) and have you ever head significant material shaved off your head or cylinder?

 

Yes cams were in place. I've had about .040 taken off the head with the last 2 explosions. I'm running a TVI base gasket cause it was thicker than stock. Head gasket is Cometic MLS. If I can find 2, .060 base and .080 head gasket I might be able to make this work.

 

Good info. 40/1000's off the head seems like a lot. I know Cometic has the ability to make a thicker head gasket. I have had one from them before.

Doing as much as you can with the base gasket will help maintain as much integrity of the combustion chamber as possible, IMHO.

Oh yeah, you checked your valve clearance at the cams so you know your valves were all the way shut?

 

Yes valves are shutting all the way. After ipulled the head back off after claying I filled combustion chamber with Thinner after 10 mins still dry in the intake and exhaust tracks.

 

Hopefully the gaskets you need aren't too far out........

 

[img]i/expressions/face-icon-small-sad.gif[/img]

 

.060 base and .080 head did you say? I would cut the piston vr's deeper if possible to save some of the compression, is this your personal build #'s that just happen to come up, or did someone screw up on other parts?

 

YOUR KIDDING ME[img]i/expressions/face-icon-small-sad.gif[/img]...........Man, if you wouldnt have bad luck, you wouldnt have any luck at all. Let me know if there is something I can do.