VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 Setting valves when engine is hot

The information below comes from a previous post for setting lifters cold. Is this the same method use for setting lifters when hot. And, is this the most foolproof method of setting valve lifters when hot. I can find firing on #1 easily but how do you find firing on #6. There is no marking on the flywheel for #6 just for #1.


"setting the valves cold is ok to get an initial start up but solid lifters should be adjusted with the engine at normal operating temperature.

If you do set them cold, here is a procedure you can use.

Bring the timing ball to the pointer for number 1 cylinder TDC. The ball comes to the pointer at TDC for number 1 and number 6 cylinders.

At number 1, you can adjust;

1) Intake & Exhaust
2) I
3) E
4) I
5) E

At number 6;

2) E
3) I
4) E
5) I
6) I & E

adding .002-.003 would be okay but should be checked at temperature"

when the timing mark aligns with the pointer it will indicate number 1 cylinder at top dead center OR number 6 is at top dead center.

let's say it is determined number 1 is at TDC, mark aligned, both valves closed. by rotating the crank 360 degees, align the marks, you are now at TDC on number 6.

it's best to make the final hot adjustment while running at a slow idle with the motor at correct operating temp

Ok I will try but must the engine be running to adjust?

to be done correctly, yes. it's one of the joys of maintaining a solid lifter motor

these make it easier

The valves should be adjusted with the flywheel at the U/C mark, which is the top dead centre mark on the flywheel. The timing mark is 12 degrees advanced ( before top dead centre)

yep, U/C = TDC (Top Dead Center)

Paul

After setting all the clearance on the valves listed with #1 at TDC rotate the crank 360 degrees and you will have #6 at TDC so you can set the other valves.

please remember that the instructions for setting the valves without the engine running is to get a BallPark setting. To do the job right the engine needs to be Running at a slow idle at operating temperature. This does not mean the engine coolant is mearly warm, the engine needs to be AT OPERATING TEMPERATURE!

Ok, guys, I have always adjusted the valves with the engine hot and running. But, now that I think about it, if the engine is fully warmed up and the valves are fully closed why wouldn't it work with the engine stopped? It is always a pain to adjust them with the engine running and the hot air from the fan and the oil splattering all over, not to mention the rocker arms pulsating and trying to keep your wrench on the lock nuts and a screw driver in the adjuster slots etc. Ofcourse, I have never had the neat tools Dads shows in the above pics. lol
It just seems like you could be more precise with everything not moving. Is it because all the cam lobes are not at full release?

It is probably due to the changing temperature of the engine ,and the running engine is the most stable to ensure burnt valves don't occur from have too close an adjustment.

Page 15 in the 1931 repair manual tells us "slow down the motor and set tappets to a clearence of .006" for intake, and .008" for exhaust........, The feeler gauge should have a light drag through clearance.

After all the tappets have been adjusted, run motor fairly fast for three minutes to settle tappets then recheck .006" for intake and .008 for exhaust. This part of the adjustment is important,as it invariably brings out tappets that have changed their adjustment. lock nuts on adjusting screw must be tight."

I bet not many carry out the second part of the instructions.!!

The Chevrolet Repair Manual states "Heat motor by running until heat indicator shows red." That means the gauge would be showing 200 - 210 + degrees.

With these old cylinder heads prone to cracking, I sure wouldn't get the engine that hot. I would go with normal operating temperature.

I always set them a few thousands looser than what is recommended. Yes , it does make for more tappet noise but I would rather hear that than the woof woof woof of a burned valve.

Me too!