My 1956 Corvette had it's original engine re-done by Fain's Machine Shop back in 1965. It's a .030" over job that was built "loose" for drag racing. It has solid lifter and a non-stock cam but I'm not sure what the specs are. I don't want to tear into it right now to see what cam it might have. It's not so crazy of a cam that I can't daily drive the car so I'm not worried too much about replacing it with a known original cam. I just want to get it set close. The only spec suggested to me thus far is .018 ex.-.012 int. I don't race the car but wouldn't mind the max power available if possible. I'm removing the 2x4 setup to reinstall the original 1x4 setup and I figured I would adjust my lash while I have the valve covers off. They have seemed a little louder than they should anyway. I just want to car to run well and be reliable. Anyone care to spitball what I should set the cold lash to that would be a safe bet? Also, how often should I go back and re-spec the lash? Thanks!<!-- google_ad_section_end -->
You really need to know what camshaft is in the engine to adjust the valves corectly. Invest in a set of locking type adjuster nuts so they stay adjusted.
Well in the old days of my youth, most cams ran about what has been suggested. Some of GM fuel camshafts ran something on the order .030 for both seems like. I'd suggest doing one side with what ever you choose to start, drive it and recheck the lash. When it is good and hot, you want just a little clearance left over so as to not stick a valve or break a rocker. The exhaust run a little hotter so that is why they usually run a little more lash. A solid lifter has no give, so even hot there has to be a little clearance. Old school thinking was to tighten lash for more top end and loosen for more low end, as the lash changed the cam timing. I never saw much difference.
Tight lash cams are a new thing,,,,almost all old hot rod cams had about .030 lash. got the ISKY web site and check the specs for OLD cam grinds,,most are .020 to .030. Duntov's GM cams in the 60's had .030 lash. isky link http://www.iskycams.com/pdf/2010Catalog-Lobe-Master-Chart.pdf also look here http://www.compe***ionproducts.com/Elgin-Chev-SB-Mechanical-Cams/products/295/ arnold from East Detoroit.
also, check your current lash on all the valves and write them down for each valve,,,,check them both HOT and COLD. Use the fireing order method,,start with #1 tdc compression, then roll the engine 90 degrees and check the next cyl in the firing order,,then another 90 degrees,, and so on. that will help you pick some lash specs
The solid lifter cam that Chevy used from '57-'63 was .012/.018. The solid lifter cam that replaced it and was used from '64-'69 was .030/.030. Anything else, it's anybody's guess until you I.D. it.
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