VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc 56 235 tdc and valve settings

am getting old or senile have set valves and timing on 56 - 235 cant seem to get it right this is what am doing think i am at top dead center that i will recheck this week end with friends help now to the lifters (hydraulic) to i get #1 to TDC and the set them both about 1 1/2 turns on both valves like the motor manual says then rotate crank to get distributor pointed at next valve to be set (dont have my manual in front of me at moment) 1 1/2 turns then on to next ones until finished did all this i thought the correct way still running poorly need som helpful advice thanks



think have asked before but cant find my post on here anywhere

The great things about these Chevy's with hydraulic lifters is that you can set them with the engine running. That is the easiest and quickest way I use.

With the engine at operating temperature and at idle just start at one end of the head or the other. Unlock the adjuster nut and slowly back off the adjuster so the piston in the lifter can raise up to take out the slack. You will reach a point that the clicking will not go away. Slowly turn the adjuster down until the clicking just stops. The go another 1 1/2 turns to center the piston in the lifter. Don't turn too fast so the lifter piston has time to bleed down. Lock the adjuster nut and move to the next valve.

I know that the shop manual process is to do it with the engine not running and for each cylinder when that piston is at TDC with both valves closed. Some will argue that you do not need to go the full 1 1/2 turns. What I will say is that if you are within 1/8 turn things will be fine.

That is the method I have always used and 1 1/2 turns.

i would like to adjust the valves with engine running but at moment garage is all weatherproofed to keep heat in when doing them cold which i have done before car. started and ran fine that time but this time something not right could it be that there was no oil in certain lifters and then when i got car started it pumped them up past my settings and of course i think i got it on #1 but i could be wrong , compression stroke would be where finger blows away from plug hole ,but do i have to get compression stroke from each cylinder as i set that valve that could be where mistake has been made i know with hydraulics you dont have to be perfect . the ball lined up on the flywheel should line up with the pointer which is correct but what is the triangle for other then a couple of degrees i guess will have to start over again after listen to more comments and reread manual

To adjust valves without the engine running the cylinder being adjusted needs to be at TDC, which means rotating the crankshaft for each cylinder TDC. The crankshaft only needs to be turned 1/3 of a turn to bring another cylinder to TDC in firing order.
Tony

This is the method I use to make sure #1 is at TDC on the top of the compression stroke.

You are correct that the key is aligning the ball with the pointer. This is 5 degrees before TDC so it is more than close enough for setting valves.

The only question is whether #1 is at the top of the compression stroke or the top of the exhaust stroke.

I determine this by watching the valve action for #1 as I rotate the engine. If the engine is approaching TDC for compression & firing both valves will be closed. Even with hydraulic lifters you should be able to easily rotate the push rods.

If the engine is coming to TDC for the exhaust stroke the exhaust valve will still be open. The tip of that rocker arm will be down and the valve spring will be compressed. The push rod might rotate but it will take more effort due to the load from the valve spring.

Another quick check is that if #1 is at TDC for compression the exhaust valve for #6 will be open because it is at TDC for the exhaust stroke.

Obviously it is easier to rotate the engine with the spark plugs out. That also makes it easier to set the next cylinder in the firing order, #5, at TDC. I drop something like a 1/4' wooden dowel or Phillips screwdriver into the #5 spark plug hole. I make sure it is traveling up as I rotate the engine. Test it on #1 when the ball & pointer line up so you know how much should be sticking out.

Then move on to #3. When you go to #6 the ball & pointer should line up again.