VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 261 ci oiling concern

I recently acquired a 1951 5 window 3100 that has a new, never run, 55-57 261 ci motor installed. I have been trying to check the motor prior to starting and I've run into an area concerning the oiling system that I need info on. The previous owner was installing a remote oil filter that involved enlarging the original block fittings, one for oil pressure gauge and the other as a return to the sump, and running them through the remote spin-on filter. The rebuilder is not available and the previous owner is not particularly knowledgeable, so I'm having to analyze the result of this modification from scratch.

I don't understand why this is desirable to start with but you play the hand you're dealt.

My concern is that oil is being directed where it should be and that the oil pressure is not negatively affected. If I'm getting oil to the rockers when I spin the oil pump, can I assume that the circulation is as it should be? What else can I verify?

I'm not sure this is the right forum; perhaps I should have noted the '55 forum.

Thanks for any suggestions,

What they were attempting to do is install a full-flow oil filter.
If it were my engine I would plug the holes and if a filter is desired install conventional by-pass filter such as what was offered in 1955-1957. Reducing bushings/pipe plugs could be used if necessary.
The by-pass filters did an adquate job of filtering the oil.
I have an article some place that covers installation of a full-flow filter. Will try to find it.

Just looked at the "Stove-bolt" forum. Losts of info. there.

I found a lot of info. with Bing - 261 full flow filter

I understood that the later 261 required a full flow filter.

I was thinking that 261 had a full flow to and through the filter orifices. Thus offering far better filtering opportunity than the almost usless trickle offered on the 216 or 235.

I have a 261 engine with the filter still on it. It is a relatively deep filter and appears to be original.

There were posts here some time ago about the danger of blocking the orifices for the filter (if filter is eliminated) but bypassing with a tube so the oil flowed back into the engine for essential lubrication of other parts.

Charlie

I had done the "Bing" search as well as found some articles on step-by-step conversions. In most cases they talk about installing a "plug" in the oil galley to the mains for some reason. The previous owner said there were no modifications internally to the engine, but I don't believe he was involved enough to be sure about that. No way I can confirm that without pulling the pan and oil pump for inspection. I have spun the oil pump with a drill and have good oil flow from the rockers so I think the flow is OK, just not totally comfortable. I did see that the oil overflow/relief line in the center of the rockers had been "pinched" off. Not sure what they were trying to accomplish.

Oil to the rockers.
Depends on what year parts were used. The center oil connector was pinched off as a part of the redesigned oil flow system in 1959. This forced more oil to the rocker shafts. The oil grove in the arm was then off set to one side (not inline with the hole on top of the rocker arm) to restrict the increased flow of oil.
For 1958 and prior there was overflow loop. When rocker arm oiling problems arose the practice was to rather than fix the problem pinch off the oil supply to get more oil up to the rocker arms. Oil is supplied from the from the rear main bearing , from there the oil flowed to the rear cam bearing and from there to the oil line.
The later engines with no line fed the rocker arms from the front and rear main bearing, again passing through the cam bearings.
The 1955-1957 261 engine had a pipe behind the push rod cover. It ran from the lower rear corner to the center top. The real late 1967 and up had no pipe.
The fact that the rocker arms are geetting oil means there is oil going to the main bearings. If it is getting to both the front and rear is another question.
The full flow filter came with the 1958 or 1959 261 engine.

Can you send me a picture of the lower left side of the block?

Will do on the picture. Right now the filter is not installed. There is just a line running between the two added fittings for oil flow.