The Stovebolt Site Forums The Shop Area Engine Shop '41 Chevy 1.5 Ton - Replacement Push Rods?

My dad has a 41 chevy 1-1/2 ton truck that's been bobbed for a woods truck. It's been sitting for a couple of years, and some of the valves were stuck. We ended up bending some of the push rods in the engine.

After taking the adjusters out, and moving the arms out of the way, we were able to loosen up the stuck intake valves with a piece of copper pipe, and a 4lb hammer. We tried a piece of wood, but the valve stem was just getting driven into the wood. The copper seemed to work to protect the stem.

Anyway, on to the push rods. The old push rods have a little 1/8" or so hole in the bottom of the cup to hold oil. The new ones from Napa and Rock Auto don't have the little hole. Anyone know were I could find some of the old style rods? It's in a 216 6-cyl

He has some spares, but they go to another engine, and I don't think he really wants to use them if he doesn't have to

Also, I've searched around, but there seems to be some variation on the valve clearances.

Are they always listed hot? I couldn't find any cold clearance specs.

Hot seems to vary between
Intake 0.006-0.008
Exhaust 0.013-0.018 (.020 for 1-1/2 ton)

I found this, but I'm not sure what is actually correct. Maybe it doesn't really matter that much.
http://www.stovebolt.com/techtips/valveadjustment.htm

Thanks. :-)

The Shop Manual shows the same information you have.

In later manuals, they state that clearances can change 0.005" from cold to hot. When the rocker arm assembly has been removed/replaced, I add .003" to the hot settings before the first warmup/adjustment (after re-torquing bolts, as described in this later Shop Manual).

Never seen pushrods with holes, don't you mean lifters? When I replaced the lifters/pushrods in my '38 (for the same reason you are) I found a set of NOS lifters on ebay that had the holes in them. The stock '38 set up used the longer pushrods with the cup type of lifter & I couldn't find the longer replacement pushrods so I was forced to put the later model lifters & shorter pushrods in it. I don't know for sure but my assumption is the purpose for the hole in the lifter is to provide extra oil to the lifter as it drains down the pushrod, into the lifter, through the hole and onto the wall of the lifter cavity. I have no idea why the manufacturers aren't putting the hole in the lifter any longer.

That's odd that others don't have holes in them. It's more of a short hole to just hold a little more oil in the bottom. I'll try to take some pictures.

We didn't take the side cover off to look at the lifters, but they seem to be moving ok.

We ended up bending the old rods back into more or less straight shape, and putting them back in. The valves are more or less free now, but one of them is slow to return. I'll keep putting oil on it, and turning it over with the starter to hopefully free it up. The other two seem to be functioning normally now.
I may have to take that rod out again, and exercise it with the hammer.

This old engine has always been a little bit of a mystery to me, so while it's not the best of timing to have to work on it, I'm learning something about how it works.

Is there a downloadable version of that service manual?

Thanks guys, I'll keep you posted.

I have lots of NOS push rods, so send me the exact length and how many you need. I believe mine are 216 or old 235, but I'll need the length you need. Send me an email [email protected]

Just pulled one off the shelf measures 10 5/8" and has a little hole on bottom end more like a dimple(has dimple on both ends). May have other lengths as well. I think these are military surplus all in original paper wrappers.

Thanks!

I'll measure them when I get a chance.

It's alive!!! :-)

We were able to get the engine started around 8:30 last night. The battery was almost flat from trying, but she finally fired up.

The valves were a little sticky, and causing low compression, but I think they are ok now that it's run a little bit.

We have to clean up the contacts on the generator to get that running, and I think we'll be all set to haul out some wood with it on Sat.