Valve Shims
#1
What size valve shims are people running after mods such as cams, valve springs, etc? For some reason I am at the smallest Bombardier shim size and still need more clearance. BMW sells slightly smaller shims, has anyone else had to go with non-Bombardier shims smaller than 2.10mm?
http://faq.f650.com/FAQs/Valve_Shim_Change_FAQ.htm
http://faq.f650.com/FAQs/Valve_Shim_Change_FAQ.htm
#4
Three possible causes-
1- valve job that sunk the valves deeper into the head without ginding the ends the appropriate amount to compensate. This is caused by someone doing head work that didn't know how to do it right. The head should be checked to ensure that too much valve or seat material hasn't been removed. If too much valve material is taken, you could end up with-
2- "Tuliping" valves, the valve face is actually cupping, allowing the stem to travel too far into the head. The only proper way to fix it is to replace the valves. Once they start to "tulip" they continue untill they break.
3- The last option would be a cam ground on too large of a base circle. If the base is too large, there would be no room. The valve stems could be ground to compersate, but care must be taken to ensure proper clearance remains after the grind.
I've done ALOT of shimming, and never had to go that thin befor.
1- valve job that sunk the valves deeper into the head without ginding the ends the appropriate amount to compensate. This is caused by someone doing head work that didn't know how to do it right. The head should be checked to ensure that too much valve or seat material hasn't been removed. If too much valve material is taken, you could end up with-
2- "Tuliping" valves, the valve face is actually cupping, allowing the stem to travel too far into the head. The only proper way to fix it is to replace the valves. Once they start to "tulip" they continue untill they break.
3- The last option would be a cam ground on too large of a base circle. If the base is too large, there would be no room. The valve stems could be ground to compersate, but care must be taken to ensure proper clearance remains after the grind.
I've done ALOT of shimming, and never had to go that thin befor.
#5
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Glamis, I was thinking about having plenty of the shims available, or getting everything installed and taking some measurements and then ordering the shims I need. Thanks for the info.
I guess I need a compression washer. I will see if knutz has them and can send me one. Thanks for the heads up.
I ordered a service manual, but I don't have it yet, so I may wait to do the install until it comes in.
Thanks
Bat
I guess I need a compression washer. I will see if knutz has them and can send me one. Thanks for the heads up.
I ordered a service manual, but I don't have it yet, so I may wait to do the install until it comes in.
Thanks
Bat