Solid Lifter Adjustment Procedure

[Ron Witt]

Does anyone have the correct procedure for adjusting the lash on Solid Lifters for 63, 340HP engine?

Thanks

 

[Tom Bryant]

Welcome to the CAC, Ron. Do a search in this forum using valve lash or adjustment. You should get a few very long threads on the subject. I know it has been discussed at length before.

Tom

 

[Ron Witt]

Valve Lash Adjustment Solid Lifters

I continue to read different methods on how to adjust the valve lash on solid lifters. Adjust cold with feeler gauge, adjust hot with feeler gauge, adjust with no feeler gauge?? The most recent was to adjust while running... Backoff adjusting nut until clatters starts, tigthen until clatter stops, 1/4 turn on nut - wait 10 seconds, repeat until one full turn is made. I know this would be a messy method, but does anyone know if this is the correct process? Does anyone have the offical GM procedure for adjusting?
I would prefer the hot method to adjust with feeler gauge when engine is not running. If this is correct, what is the correct lash for a 63, 327cu, 340hp for exh & intake?

Thanks for the help.

 

[Tom Bryant]

Ron,

The method of adjusting running and turning down 1/4 turn after the clatter stops is for hydraulic lifters. DO NOT use this method with solid lifters. You will be holding the valve open and it will result in pistons contacting valve heads, bent valves, bent push rods or pulled rocker studs if you have the press in kind.

The clearance specification is with the engine hot. You can adjust it cold but add a couple thousands to the gap to make up for expansion when it warms up.

The 1963s still used the 097 Duntov cam. The clearance is .012 intake and .018 exhaust. Racers and many of us would be racers used to set the intakes at .008 to pick up a little performance. I don't know if it really worked but we always though it did. It doesn't hurt anything and it will be a little quieter.

I warm the engine up to operating temp then shut it off. Use the feeler guage and back off the nut til the guage easily slips in. Then tighten the nut until you have a very slight drag; just to the point that the clearance is gone. Make sure that the lifter is on the base circle of the cam, valve fully closed and you will be fine. After you run all 16 go back through them again to double check.This way if you weren't clear on base circle on any lobe it will show up as loose. A deep socket on the balancer nut and a long handle rachet is an easy way to turn the engine. Pull off the coil wire just for safety's sake, especially if you decide to use the starter to bump the engine over. If you are doing a complete tune up adjust the valves when the spark plugs are out. The engine will turn easier.

I like to use neoprene rubber valve cover gaskets on solid lifter cars. They don't stick or pull apart and you can use them over many times. Also the adjusting nuts seem to loose their grip after many years so if it seems like they are turning too easy or they don't stay in adjustment put on a new set of nuts.

I'm going to consolidate your 2 Threads since they are on the same subject.



Tom

 

[rponfick]

Tom, you bring up a question that still bothers me. What happens to clearance between hot and cold. Hot Rod Mag. article on page 75 of Jan. 1999 issue states that iron head and block will gain .002 inch when hot (meaning to set clearance slightly tighter when cold). My ISKy cam timing sheet says to adjust my cam at .02 hot and .022 cold. This to me is just the opposite recommendations. Any comments.

 

[JohnZ]

Generally speaking, with iron block and heads, add .002" to the recommended "hot" setting when setting them cold and you'll be pretty close. The "097" Duntov cam in the '63 340hp has minimal overlap, so you can set them with only one crank rotation. Set it at #1 TDC (both valves closed on #1), and adjust:

Intakes: 1-2-5-7
Exhaust: 1-3-4-8

Turn it 360 degrees (both valves closed on #6) and adjust:

Intakes: 3-4-6-8
Exhaust: 2-5-6-7

Note: This will NOT work for the '64-'65 "30-30" cam (365hp and Fuelie), as both the intake and exhaust valves are still on the ramps at TDC with that cam.

 

[Tom Bryant]

rponfick,

Sometimes magazine articles aren't that clear. The gap will always be tighter when hot due to the parts expanding with heat. Your Isky cam card is correct. Maybe by gain they meant that the valve length will increase when hot; a gain in the materials of the head and valve would be a decrease in the clearance between the two.

I have always used the method John outlined on my Duntov cams but a cam with longer duration will require more precise positioning.

Tom