1923 Big Six push rod adjustment

Ladies and Gents

for the first time in my life I tried to adjust the push rods on a big six. I have never worked on a flat head always on overhead valve. It seem to me the lifter must be female threaded with the male threaded push rod screwing into the lifter and locks after adjustment via the nut on the pushrod. On one of the loose one's the feeler gauge will not pass between the hexhead of the pushrod and the end of the valve. Can the head of the valve be worn into the pushrod hexhead? Someone got a pic of the pushrod lifter assembly out of the engine. Are these hard to get (lifter pushrod assembly). Where to go?

my first hour working on a big six

Ken

here are some worn pushrods I am thinking the are supposed to be flat on top. how many miles to wear this amount? where can I find these? can a modern hardened bolt be used in its place?

On my Pontiac (sorry for using a bad word here) the tappet had an adjusting screw like yours with a lock nut. To adjust them you needed three wrenches along with your feeler gauge. Flat head Dodge (sorry again) uses the exact adjuster but theirs have distorted threads so there is no lock nut. Perfect fit and much easier to work with. Perhaps they would work on your engine as well.

Year of Pontiac and Dodge Please.

thanks

ken

My Pontiac is a 1930 but tappets and adjusters were the same style from 26 to 54. Flat head Chrysler product 6 cylinder 1934 to 1961, and same engine used in lots of industrial equipment in to the 1990's.

They are 3/8 SAE thread 1" long. It was my machinist that wondered why I was using these when the Chrysler ones were the same except for needing a lock nut.

None of my adjusters were worn like yours but I changed them so they were easier to adjust.

Reid

would that be 3/8 sae be 3/8 24tpi

Hi 27 chevy

on my dodge the lifters had worn like yours , my solution was to have the tops ground level to enable correct adjustment

has worked for 15000 miles ,this was a cheap operation ,you can actually do this yourself on a grinding wheel ,taking measurements to ensure accuracy

best of luck

Queensland

thanks from Chicago!

Ken

Ladies and Gents

made a new push rod adjusting bolt by taking a 7/16 20 grade 8 flywheel bolt from modern era car took my grinder ground down the hex head to 1/2 cap hex head, no precision machine shop result but a 1/2 open end fit it and I was ready to put it back together! So off I went adjusting the clearance on all of them the old fashion way, move it up and down until it seemed to be .008 or so. Started it up and it sounds great! runs great! a good thing!

Ken

Ladies and Gents

after reassembly and cool down I restarted engine and noted valve train noise that went away after warm up. I then recalled installing the rear lifter assembly and having a hard time sliding unit back into hole in block onto cam. Had a hard time removing it also. The others in and out. Upon cooling off and restart noise comes back so I removed cover and lifter assembly with pry bar and wood block in place, upon removal I quickly noted that the valve keeper had fallen out and there laid the spring and cap with no keeper. The keeper had fallen into the hole and disappeared. After looking at the diagrams of the engine it appeared to me that it could only fall into the oil pan below, IS THAT A GOOD GUESS??? Where can I get a keeper??? Time to remove pan.

Comments please

Ken

Pan coming off in morning, going with pin made from 5/32 hardened steel drill bit shank end. 7/8 long.

maybe I will find the other pin in the pan.