VCCA Home Forums TECHNICAL - GENERAL Trucks and Vans VALVE LASH / ROCKER NOISE

I have 1954 235cu motor that I recently completely rebuilt. The motor is running good, but it has an irritating clicking noise which is more pronounced at higher RPM. I adjusted the valve lash and the noise went away for a while, but now its back. Its the second time that I have adjusted the valve lash. I thought I cranked the adjusting nuts pretty good to prevent anything from loosening up. Any ideas on what I may have done wrong. Also, how much damage can I do to the rockers, lifters, push rods, valves , etc. if I run with this "clicking".

The rocker arms getting loose with use would indiacte that something is wearing. I would suspect the camshaft lobes. If it were mine I would remove the side cover and pull out the lifters. Look for wear on base of lifters and inspect cam lobes through the lifter openings. If there is wear in this area the metal pieces could destroy your bearings.

gENE:
I put a new cam and lifters in it. Have less than 500 miles on the motor. Could wear be a problem already?
Scott

Yes, if its a poor quality cam (from China) ,The incorrect lifter material or ???.....There was a cam material change in 1954.The previous cams were forged and the late 1954 235 truck engines (and all other engines) changed to cast iron. The early 235 truck engies had the old small journal cam bearings, late had the larger cam bearings that the rest of the engines had. The lifters were made of a different material to match the cam, same for the distributor gear....but they shouldn't were out in 500 miles. Did you use a camshaft break-in oil with the new cam?

I just went through this last year on the way to Grand Junction. A new rebuild that every 500 miles or so I had to adjust the valves . We were on the road for 30 days so this went on about every other day. When I return home I pulled it apart and found 3 lifters I could use as a shot glass. Call were I purchased the cam and as soon as I said it wiped a cam they sent another one at half price. The second one did the same thing. I pull the motor and found it need all new rings and bearings from all the junk in the oil. The 3rd cam came from clifford and seems good. If it were me I would put the lifters and look at them and if there is wear put the cam before it does any damage to the bearings.

This is the problem that is being blamed on the new SM oils that have less vinc additive. The problem is with the materials used to make the camshafts. We never had this problem with new cams years ago when there was no zink in oil....and every problem that I have heard of has been with new aftermarket cams.

Unfortunately I did what you guys recommended and looked at the lifters in my 235 and they are shot after less than 500 miles. I talked to an engine builder that I know and he says he has been having a lot of trouble with aftermarket cams. He lost two in a row on his dyno last month. He says the lifter people are blaming the cam people and vice versa. Does anyone have a recommendation on where I go now to get another cam and lifters?

At least they are not blaming the new SM grade oil as most of the cam makers are.
Do you know what brand/sorce the cam and lifters came from. Was it a forged or cast cam? Were the lifters designed for that cam material?
The 1954 235 engines were the first to use cast cams. Prior to that they were forged. The early 1954 truck engines had the small journal forged cam. The late 1954 truck engines had the large journal cast cam...They used different material for the lifters and distributor gear also...to add more confusion.

To know where it came from would help us greatly. We would not purchase one from that vender...Thanks...Oscar

:cry: Iam sorry you got a bad cam an lifters one thing that i have done is also pull the pan and clean it out good. Then place a small magnet about 1 inch x 2 inch x 1/4 in the bottom of the pan that will hold on to any loose metal that didnt get flushed out from past or future wear. you dont need to glue it in as the magnet will hold itself in place hope your running again soon.

There are many webpages that discuss the issue of wear on flat tappets. Many consider the issue to be the lack of ZDDP to modern oils. This article discusses some of the preventive measures:
http://www.oldgmctrucks.com/photos/FlatTappetCamTech.htm

Coach

On a 235 it is necessary to remove the pan to remove the camshaft.

Please remember that the old cams amd lifters didn't wear out like the junk stuff does, with any oil. a special oil is just a feel good excuse to make the buyer get off the backs of those to blame : the junk cam and lifter vendors.

And so, where does this conversation leave us? Just exactly who is making/marketing a properly ground and heat-treated stock camshaft for a 216 or 235 now days?
I haven’t seen any NOS GM 6cyl camshafts and lifters for sale anywhere, not to say there aren't any out there.
It seems by having a forum like this and the Stovebolt that it would be a simple matter to eliminate the vendors that are selling junk and list those that offer a quality product.
Denny Graham
Sandwich, IL