Modified Hydraulic lifters in a 235

[Second Series]

Has anyone modified the Hydraulic lifters and pushrods in a 235? Are there any longterm damages from this? I have a '59 235 with Hydraulic cam and lifters. I took it to a shop and had the valves adjusted awhile ago. Ever since then, it started to pop like a popcorn popper after I drove it for more than 2 or 3 errands - Drive it, stop, start it, drive some more, stop, start it, then it starts popping. I suspected a lifter problem since it never did this before the valve adjustment. It was always noisy, but the valve adjustment helped some. I found this mod for hydraulic lifters: http://chev235guy.blogspot.com/2013/...c-lifters.html
I finally got around to looking into this and tore into the engine the other day. There were 3 kinds of lifters. 2 had a hole on top, 10 had no hole on top, 4 were shorter(the body-the cup was at the same level as the rest). They looked ok other than being different. I took the grinder to the pushrods and the lifters with no hole on top. I reassembled and started it up. It was typically noisy. I let it run for awhile and then it got real quiet. I am happy with this mod. I'll have to take it on the road to see if it had any effect on the popping though. I have never machined any engine internals before. I was just holding these by hand and the groove in the bottom of the pushrod was not pretty. The pushrods spin while the engine runs. Does this groove wear on the cup in the lifter?

[dsraven]

the ends of the push rods and the end of the lifter that contacts the cam are usually hardened. by modifying them in this area the hardening has possibly been wiped off. they may wear prematurely and cause finings in the oil and/or more tappet noise.

[mr48chev]

From looking at the link they didn't grind on the surface of the lifter, it calls for modifying the seat that the pushrod sits in to let air bleed out.

If that engine has mismatched lifters I'd want to think that someone has fought lifter noise in the past and replaced the ones that made noise at the time rather than replacing the set with a matched set. The old just do enough to make it quit rattling but don't spend extra money thing.

[Second Series]

The mod is to port the cup in the lifter and cut a channel in the pushrod. This lets air escape and allows the lifter to fully charge with oil. I had to partially dis-assemble the lifters to remove the cup. I used a C-clamp and small socket to compress each lifter to remove the clip to get the cup out. The shorter lifters had weak springs, I could compress them by hand, but not enough to get the clip off. I’ll probably replace those. I don’t think they are bad, just cheap, something to check for when shopping for replacements.
“The old just do enough to make it quit rattling but don't spend extra money thing.” Yes, I’ll continue the tradition here. This engine has a history of hard luck stories. When I got the truck it had no engine, so I started hitting the junk yards. One day a ’58 DelRey came in. The junkman told me the back story. It had been owned by a mechanic who was dying of cancer. He built it as his dream machine and was living out his last days in it. The back half had been cut away and a camper was attached. I ran that engine for a few years before a valvestem broke. Before that happened, a mechanic chased me down in a parking lot asking me if I wanted to sell. No, he said he had an engine for me in his shop. After the ’58 235 siezed, I looked him up. He said the 235 had been on the shop floor since he took over the business. It had been rebuilt by a fella who was in prison and wouldn’t be out anytime soon. He got to inspecting the replacement engine and found a fracture on the cam sprocket. That’s when he swapped the hydraulic cam and lifters from the blown engine.