265 rebuild - oiling question

[Supersonictoys]

Ok, how about this. The bottom of the original distributer has a groove cut half way around it which I assume is for oil to pass around yet all later model gm distributers have this groove "all the way"around. Can a later model distributer be used safely in a 265? also, I just rebuilt my 265 and went all stock on the bottom end and even had the original type slot cut in the cam but noticed that when I step on the throttle hard and the motor revs past maybe 4000rpms there is a loud rattling that sounds like lifters. Is this the oiling problem this thread is all about?

[Farm Boy]

Originally Posted by Supersonictoys

Ok, how about this. The bottom of the original distributer has a groove cut half way around it which I assume is for oil to pass around yet all later model gm distributers have this groove "all the way"around. Can a later model distributer be used safely in a 265? also, I just rebuilt my 265 and went all stock on the bottom end and even had the original type slot cut in the cam but noticed that when I step on the throttle hard and the motor revs past maybe 4000rpms there is a loud rattling that sounds like lifters. Is this the oiling problem this thread is all about?

Yes. A 1957 and later distributor will work fine in a 265 without any modifications.

Originally Posted by Supersonictoys

also, I just rebuilt my 265 and went all stock on the bottom end and even had the original type slot cut in the cam but noticed that when I step on the throttle hard and the motor revs past maybe 4000rpms there is a loud rattling that sounds like lifters. Is this the oiling problem this thread is all about?

Are you getting oil to the rockers? If you are not getting oil to the rockers you may not be getting oil to the lifters and may have a problem with the rear cam bearing. If the rear cam bearing is installed to deep or to shallow the holes in the cam bearing won’t line up with the slot in the cam and the lifters will starve for oil.







I test fit my rear cam bearing on the camshaft before I installed it. After I install the cam bearings into the block I bolted the sprocket to the cam shaft and test fit it to check the position of the rear cam bearing. The thrust surface on the sprocket is held against the front of the block by the rearward pull of the distributor/oil pump gear so with the sprocket installed and the camshaft all the way in the camshaft will be in the correct position to check the rear cam bearing.




The machine shop that rebuilt my 265 installed my cam bearing almost a 1/4 inch too far back. They also used a deep 2 inch freeze plug for the rear cam plug which kept my camshaft from going all the way in. The combination of the incorrectly installed cam bearing and the deep freeze plug would have caused the camshaft to not line up with the holes in the cam bearing.

55-57 Chevy V8's used a thin cam plug that measures 2 1/64 inch. Starting in 1958 Chevrolet went with a slightly larger diameter cam plug. The Dorman part number for the correct 55-57 cam plug is 555-046. The cam plug should be installed flush to 1/32" deep with the boss on the rear of the block.





To get it right I bought a cam bearing tool, the correct rear cam plug, and some new cam bearings and installed them myself. I hate to think what would have happened if I had of installed the engine in my car the way I got it back from the machine shop.

[Supersonictoys]

well , it only rattles when I run it at high rpm. it has about 250-300 miles on it now and the lifters are nice and quiet when driving normally but when you stomp it to the floor and passing gear kicks in and the revs get way up there, it sounds like someone shaking a coffee can full of rocks the instant you are back to normal rpms, its nice and quiet again. seems like if the lifters weren't getting oil it would be rattling at idle and would have locked up by now.

[Farm Boy]

Pull a valve cover and check if you are getting a good flow of oil at the rocker arms. If your rocker arms have a strong oil flow your lifters must be getting oil also, and something else is causing your rattle.

If the oil to the rocker arms looks weak you could have a partial blockage at the rear cam bearing. Hydraulic lifters pump more oil to the rocker arms at high engine speed. Notice how one of the cam bearing holes is partially blocked off in this picture. This would pass just enough oil to the lifters for idle and low speed but would starve the lifters for oil at high speeds. It’s critical that both cam bearing holes are lined up perfectly with the slot in the cam journal on these early engines.



While the valve covers are off it would not hurt to readjust the valves.

[Supersonictoys]

thanks for the help

[Junior]

Originally Posted by Supersonictoys

well , it only rattles when I run it at high rpm. it has about 250-300 miles on it now and the lifters are nice and quiet when driving normally but when you stomp it to the floor and passing gear kicks in and the revs get way up there, it sounds like someone shaking a coffee can full of rocks the instant you are back to normal rpms, its nice and quiet again. seems like if the lifters weren't getting oil it would be rattling at idle and would have locked up by now.

This sounds like severe detonation to me.

PR