valve lash

P

prpmmp

Senior Member
Started a thread on the HAMB about this video. According to the video setting lash cold the setting should be less then the hot setting then when hot it will be correct. example .016" hot set at .012, When the engine heats up the lash gets looser not tighter. So my question to the flathead guys I have cam card that states .016 for both intake and exhaust so I should set at .012?? Please watch the video it explains it. the opposite of what I thought. Thanks Pete https://www.youtube.com/watch?v=V8liNwa-NEI&list=RDCMUCQxdMMwjFXLcPQ65M-8MByg&index=1
 
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Your problem seems to be is that you are trying to apply OHV engine technology to the flathead engine that does not have valves in the cylinder heads.
So the expansion or contraction of aluminum cylinder heads has no effect on valve lash.
For the most part valve lash in a flathead is set cold with no compensation applied.
 
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prpmmp said:
Started a thread on the HAMB about this video. According to the video setting lash cold the setting should be less then the hot setting then when hot it will be correct. example .016" hot set at .012, When the engine heats up the lash gets looser not tighter. So my question to the flathead guys I have cam card that states .016 for both intake and exhaust so I should set at .012?? Please watch the video it explains it. the opposite of what I thought. Thanks Pete https://www.youtube.com/watch?v=V8liNwa-NEI&list=RDCMUCQxdMMwjFXLcPQ65M-8MByg&index=1
Click to expand...



That's not correct when things heat up they expand not shrink.

If the cam card specification for a flathead cam is for .016 clearance that's what you set it at. This then takes into account the actual slight expansion of the components when hot so that there's still clearance between the lifter and valve tip.
In other words they get tighter not looser.
Ronnieroadster
 
Ronnieroadster said:
That's not correct when things heat up they expand not shrink.

If the cam card specification for a flathead cam is for .016 clearance that's what you set it at. This then takes into account the actual slight expansion of the components when hot so that there's still clearance between the lifter and valve tip.
In other words they get tighter not looser.
Ronnieroadster
Click to expand...
Yes that is what I always thought until I came across this video and they(seem to prove the opposite), Yes it is on a OHV engine.I did set them at .016 but seem to be a little noisy. I'll stick with your information for sure! Just thought I post the question to get a discussion going. Thanks Pete
 
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