I normally adjust the valves to the Engle recommended .018" & .020". I am going to adjust the valves this week before we head out to the track on Friday...

Question:

Should I stick with .018-.020 or tighten it up OR loosen it up a bit? It's a PITA to get my passenger side VC off (until the tax man brings me the Vintage Air lol)...so whatever I do I'll be sticking with it for a couple of months. Any recommendations?

Steve

 

Adjusting valve clearances slightly alters valve lift and cam duration. tighter clearances means the valve opens earlier and has more lift, looser clearances have the opposite effect, admittedly only slight in both cases.
It may be altering your clearances will improve your engines performance, or make it worse, you would have to do a lot of trial and error experiments to find what is ideal for your engine,
Remember the cam is part of the whole package, you may well need to alter ignition timing and carb settings as well to get the best results.
You need to factor in parts that can't be adjusted as well such as manifolds, heads etc. A wild cam is useless with restricting heads for example.

Roger.

 

I'd use stock specs--and they are probably hot not cold engine. I find with an all iron engine that about .001 tighter works cold to get what I want. Find out from the cam mfg. what range of lash is acceptable with their ramps. If different lash makes any noticeable difference, you should have a different cam anyway.