I've read here sometime ago that you couldn't use the "simple" two revolution method with the LT1 cam. Something about there being too much overlap or that the ramps were too long. The theory was that when one valve was completely open the opposite valve was already starting to move. Bob

 

You are correct! GCD1962 has an error and it should be corrected.
When #2 Exh is at full lift, adjust #3 Exh.

Plasticman

 

Got it corrected. Thanks for pointing it out. I almost made it to the end with no mistakes !

 

Did this come from Century Performance Center?

 

Crower Cams uses this method.

Plasticman

 

Thank you John, I'll start with .023 on both exhaust and intake using the, "look at exhaust-adjust intake" method.

 

Remember that clearance is the spec, but can be varied a few thou either way (depending on cam, probably up to .010" either way of spec), depending on where you want to power to come in & what else has been done to the engine.

More clearance will shorten up the duration (and the valve will open a hair less on lift), giving you more low end (and probably more valve clatter).

Tighter clearance offers more top end power (at the expense of the lower end power) with more duration, and decreases valve to piston clearance by a very small amount with it's increased lift (.010" decreased clearance will result in ~.015" increased valve lift if running stock type 1.5 ratio rockers).

Very common (back in the day) of running looser clearance on the street, and tighten it up at the track.

Bottom line (since you don't know what cam you have) is trial and error and probably more adjustment!

Good luck,
Plasticman

 

Thanks Plasticman, I adjusted to 0.023 for both valves and got the engine running. It would not idle below 1000 rpm with some occassional back fire in the exhaust pipe and an very occassional "puff" sound out of the carb.
Before I started messing with the timeing I thought I'd see if anyone had suggestions.
Again Thanks for the Help!

 

My father was a mechanic and he taught me to set the lifters on my first car (1948 Chev, 216 ci.) with the car running, warm, and use a feeler gauge. Other than the cosmetic opportunity to throw oil around the engine bay, with the valve cover off, is there a mechanical reason not to adjust the lifters while running?

 

This is the EXACT reason I like doing it my way. One cylinder at a time.

I don't recall ever wearing out a starter or flywheel with this method.

 

The only other good reason I can think of not to do it hot is if your rocker arms are worn on the valve stem ends, they'll eat up a feeler guage before you get done. Of course, if the rockers are worn, you can't set the valves correctly whether the engine is hot/cold, running/not running.

It's not necessary to be exactly in the middle of the base circle to set the valves anyway. Just "somewhere" in the base circle and that leaves a lot of leeway.

 

I think you are missing the point, and think most guys should continue to adjust the valves when running. This is indeed the "most" accurate method to adjust solid lifters (if done properly). Hydraulics are not that fussy, and no reason to adjust them running, other than if you are just comfortable with that method (even if adjusting them to minimal 1/8th turn running clearance to minimize valve float aftereffects) .

The reason for the cold ("engine stopped") method is when the cam has been just been replaced (or if the valve adjustment was loosened for any reason) and you need to make an initial "accurate" adjustment. With this method, no need to start the engine and worry about the valve adjustment.

And no one should be using the starter for turning over the engine. Trying to get that kind of accuracy in stopping at the exact valve event point necessary is very difficult! The plugs should be pulled, and the engine turned over by hand (wrench).

And if you do not have a crank torsional damper bolt, it is about time you think about having one installed (loosing the damper as you drive down the road does not make for a "good" day, and even if not lost, a loose damper will ruin the crank - and the threaded hole makes installation of the damper soooo much easier). Also, as pointed out in a previous post, there are other alternatives for turning the crank (other than the damper bolt) for the valve adjustment.

Plasticman

 

DO NOT USE THIS METHOD WITH SOLID LIFTERS-You'll bend push rods.

 

I'm in the same boat as you are. I have a CE (replacement) 350 1973 block with the LT1 heads, large valves, solid lifters but no clue what cam. I have checked my lash cold and it appears to be .016 on the intake and .018 on the exhaust. I am assuming the motor is basically a LT1 350/370 hp motor as it runs very strong. I verified it has the dome pistons also. You have an earlier motor so not sure my lash settings are good for your motor or even if the cam is similar to mine but maybe try to see if minor tightening might help? Just a thought, not something I would do without a little expert advise.

 

Get a crank bolt (and do not risk using the damper pulley bolts, if one breaks ).

If you have a manual transmission it get's even easier to rotate the engine, just put the car in-gear and roll it. Pull the coil wire (something you should always do when rotating the engine), and bump the car forward until the #1 cylinder is at TDC of the compression stroke and adjust the valves (guaranteed to have #1 cylinder I/E lifters off the cam lobe and ramps - works for any cam).

Bump the car forward until the damper rotates 90 degrees and adjust #8 E/I (the engine is now at TDC of the #8 cylinder compression stroke). Bumping the car is usually much easier than fighting a strong arm on the crank bolt (with the fan and accessories ready to bite your knuckles).

Do the same bump and adjust (or pull on a crank bolt) following the firing order at 90 degree increment marks on the damper (1,8,4,3,6,5,7,2). Adjust the valves at TDC of the compression stroke for the respective cylinder in the firing order. The crank only turns two turns (8 * 90-degrees for 720 degrees, two turns).

If you bump the car in 1:1 (4th) gear, the car only moves about four feet for the two engine revolutions. If you are standing at the front fender, adjusting the valves, it's easy to grab the front tire and roll/rock it forward and backward to place the damper exactly at TDC on the compression stroke for the respective cylinder (again, better than skinned knuckles). With a little practice you can adjust the valve lash in less than 10-minutes with the bump and adjust method (easily between late rounds in the hot pits at the track, and no need to remove the spark plugs unless you need to read them).

You do not need to remember any chart or wild combination of intake or exhaust timing, only the firing order and how to recognize cylinder #1 is at TDC of the compression stroke to start the sequence (both valves should be loose and the distributor rotor should be pointing at the #1 post).

This valve adjustment method works for any 4-stroke engine, of any cylinder combination, as long as you know the firing order and the degrees of firing separation (it even works on odd-fire V6's and radial engines).

Now, I know all you guys with automatic transmissions will forget this manual trans bump & adjust method, but skinned knuckles and remembering the firing order is a cheap method to assure correct valve lash (rather than risk bent push rods, and... those cute mechanics gloves and arm sleeves are worth it - a good Christmas list item).

 

.
A no method

As the intake closes adjust the exhaust. as the exhaust starts to open adjust the intake...

heres a hint, but you might have to remove the plugs.

With the engine in the car place a long handle 1/2 drive or breaker bar with a 15/16 socket and turn the engine over using the alternator. Much simpler than hunting for a non existing crank bolt or crawling under the car trying to move the flywheel with a screwdriver. Or if there is a bolt in the crank, trying to rotate a engine with everything in the way cutting knuckles and fingers all up on the fan or some thing else. ....

 

Wally is right on. And it is about time some one stated it. As all of us racers know, This is the only way to do it. And it works with radical cams also. Time to adjust all 16 valves on a hot engine....10-15 minuets. Done. But what do we know, we only want max. hp to win races. If the starter is not up to the task, get a better one. For the life of me, I do not understand why this forum makes such a big deal of adjusting solid lifters.

This helps, with plugs still in, home made push button starter cable. In the old days we permanently wired it to the starter and put a push button on the fire wall.

 

All methods work, but some are better than others. Of course everything is relative to how your engine runs after adjusting, but my original post is the only one that guarantees the lifter is on the base of the lobe when adjusting without the engine running.

 

Always have done it this way. Knuckles are banged up enough.