I have a .590 for my small block and the lash is recommended to be set at .28/.30 cold. How much can I tighten or loosen this up and be safe? Could someone explain why these are set up to have that much lash in them? Thank you.

I havent run that cam but I do have a roller that calls
for 28/30 lash... right now I have it set at 18/18 with
alum heads... hot

I have run it at .016 &.018 with iron heads. Jim

I would try it stock at the track and then tighten it up .003 to .006 at a time to find out which way you want to run it

I have the .590 cam too and I think the valve lash setting atleast on ours 28/32 was to loose. Will be experimenting with tighter valve lashes and see where it ends up!

I had good results with both lobes lashed at .018" on both big and small blocks. Made a little more power on the dyno,and faster e.t. at the track.
Keith

I run that cam in my 408 and I set it 28/32 and the car is very consistant with that setting and has been problem free.I've heard of racers running them tighter but I just don't want the failure problems.

Hello everyone, hope all is well! I wanted to bump and revisit this. Was wondering if anyone else was running lash different than the .28/.30 Mopar recommendation? I still have my same combo of Aries domed pistons/ open chamber W2's and the .590 Purple Shaft. I did set it to .25/.25 cold and didn't notice any difference. I would like to go a lot tighter (.18/.20?) to see if there would be gains. Do you see any possible issues? Thanks again for your help!

I have the 557 solid on a 360 with eddy heads and runs best at .026 cold across and adds 5 more cranking comp.From 140 to 145. Never had a problem that loose even on turnpike.
Rick

I've seen alot of guys tighten the lash up on the 590 cam with good results but it never helped mine, it liked 28/32 in my 451 with Eddy heads and it was a 9 second bracket car. Maybe it just didn't like the extra lift since it was a mild combo with low compression.