The Stovebolt Site Forums The Shop Area Engine Shop hydraulic lifters adjustment

Hi Everyone,

I'm tuning the engine of my '58 Apache 1/2 ton s/s 235 column change and would like to ask that when the pushrod is resting on the lifter, how many turns do I give it to push the rod into the lifter? Is it a quarter turn or as much as a whole turn? It's had a lot of work done such as inlet manifold, twin carbs,stage 4 head etc. Thanks.

Stock engine would have had mechanicla lifters, if it has a hydraulic lifter cam it would be good to know the specs for that specific cam, i.e. manufacturer.

Tighten enough to take the play out of the rocker/pushrod to begin with. Then tighten when hot and running by giving it an additional 3/4 turn. If it still has a noise then tighten enough to remove it.
Get yourself a Repair Manual or Motors Manual, available online at many of the normal vendors, public library or Amazon.

Do you know for certain that this block is one with oiling galleries for the lifters? If not then it won't work with hydraulic lifters.

All 1958 and later blocks are drilled to supply oil for hydraulic lifters whether they came with solids or hydraulics.
Hydraulic lifters are set a 1 1/2 turns. See Shop Manual link, paragraph #2.

Yes Dave 58' and later do have but as is so often the case he does not say that the engine is original. Also it may be a Powerglide block which were drilled for lifter oiling like my 55 engine. Hardly any of them have the original engine in them after 60 yesrs.
And starting with 3/4 of a turn is proper.

Adjustment procedure for 1955 hydraulic lifters. If the procedure/initial-turns are different for 58-63, maybe someone with a car Shop Manual will scan it and post it.

Post the block casting code and casting date and maybe someone will check the Shop Manual for the procedure for that year and model.

If you have a 1958-63 block, you should check the lifters to confirm which style you have.

Thanks to everyone who replied with advice on the lifters. I've got a retired mechanic coming round tomorrow so I'll be able to let him see the link to the manual which Pre '68 Dave sent me, and starting with 3/4 turns first. The truck came from Arizona with the original engine which seems to have been uprated there before coming to Britain. It can cruise along at 65, but the fuel consumption is only 11 mpg, hence why the mechanic thought he could get it to run better by adjusting the lifters. Tomorrow I'll find out.

When I here poor gas mileage I always suspect the carb base gasket.

If you still have a Rochester carb the base gasket needs one of the four slots in it to line up with the power valve port hole on the bottom flange.

Most rebuild kits come with the wrong gasket which blocks the port.

Incorrect timing or a bad vacuum advance can also be the problem.

A old trick that still applies was to set the lifters the minimal amount to keep them from ticking. The old engines would "float" at high rpm when set to factory lifter spec's. There wasn't enough clearance/oil in the lifter when set deep to keep the lifter from floating off the cam and holding the valves open at high rpm. So by backing the adjustment off, you could gain clearance and more oil for slightly high rpm before it would start "floating" again.

3/4 turn after zero lash is a good starting point. If the lifters are quite at that setting, going deeper is not going to change anything. To deep and you can hold a valve open causing some running issues, to little and you get the ticks which shouldn't hurt fuel milage, but still should be taken care of.

Check the carb gaskets as suggested, and vacuum leaks. With all the work done to the engine, fuel milage sounds like it wasn't an issue. Dual carbs are fuel eaters if not sized right for the engine. No amount of tuning will cure that. Cam choice is another factor. Head work doesn't seem to effect fuel milage unless it was opened up way more then needed.

Keep us posted on you out come, Joe

So does it matter if the adjustment is done cold or up to operating temp?

Either way is fine with hydraulic's

Hi Guys,

Sorry for the delay - I've been away for Christmas. The mechanic came round and adjusted the lifters as suggested. It seems to start and run all right, but I haven't taken it for a spin yet. He tried to turn the mixture and idling right down, maybe too much as it takes a bit of revving to start it now. I suspect because of the engine tuning that I'll have to put up with high fuel consumption. I don't know what a stock engine's like, but this truck is like a car to drive in terms of speed and acceleration. Thanks for all your help and I'll let you know how she behaves once on the road.