Lifter rule in Stock

[Alan Nyhus]

Originally Posted by Mark Yacavone

Yes, but I don't think you need .006. A lot of older motorcycle exhausts were around .003. Somebody try and let us know ....

Mark, this has been done for decades on high perf street engines.

You can be down around .002 (hot) with a solid lifter on a 'hydraulic' cam lobe. Basically, as close to '0' as you can without hanging the valves open. A good rule of thumb.... on a typical iron head/iron block setup, you need around .003 more lash 'cold' than what you want it at 'hot' to allow for expansion. ie: .006 cold will get you .003 hot.

Iron block/alum. heads & alum. block/alum. heads expand differently than iron block/iron head, of course.