VCCA Home Forums TECHNICAL - GENERAL Mechanical - Engine, Trans, etc The confusing 261 oil issue...

We just installed a 261 into my 53 bel air and are completely confused on the oil issue for this engine...

There are the two 3/4" ports on the drivers side... One with a pressure gauge in it and the other is bolted... The other night we "unplugged" the one port that is capped or bolted and did the drill with screwdriver on the oil pump trick and it seemed that this had pressure coming out...

There are also two other ports next to these towards the front of the engine, just behind the drivers side motor mount that are also plugged...

We were told that one way to do it was to run a line from one of the 3/4" ports to the smaller port just beneath the valve cover on pass. side which would then oil the rockers... Our fear in doing that is not knowing how the main bearings would get oiled...

Any suggestions, advice??

Your engine was equipped with a full flow oil filter. The filter was tapped into the main oil galery. If no filter with the correct large hoses can be found you could place a large pipe between the openings. Its very important for the oil to flow in large quanaity from port tp port.
The main bearings are fed off that large gallery. The rocker arm oil is taken from the front and rear main bearings. It first passes to the front and rear main bearing and from there to to the front and rear cam bearing. From there to a passage that feeds through the lifter bores -front to center and rear to center. From there it goes up through a passage in the block, than a passage in the head and to the center rocker arm pipe. Important to use the correct lifters with the recess around the center as this allows the oil to pass around each lifter.

Go to http://www.oldchevytrucks.com and click on the "Forgotten 261 Six Cylinder" and you will probably find your answer.You will need to click on technical articles first and then click on 261 engine.

DD

Gene was typing at the same time I was.This old man seems to get slower every day.

DD

So does it make sense that both those 3/4" ports would be under pressure if we turned the oil pump? The one port that has the pressure gauge obviously activates the gauge when the oil pump is turned, the other port next to the just mentioned, we took the plug out of it and I used my finger to plug it while someone else turned the oil pump and I had pressure against my finger...
We're confused if we run a line between these two being they both have pressure nothing would happen...
I was just reading another forum that the other port towards the front of the engine, close to the motor mount would be the in port and we could run a pipe as you suggested...
Any ideas??

I found these pics online about this same issue...

My engine is similar except my engine has another port (seems 3/4") with a pressure gauge from an old tractor screwed into it a little further back from where this engine in the pics is showing an out (with the small hose for a gauge)... And in this pic where the pipe in this pic seems to come out, my engine is also plugged there with a bolt... I do have the port that this one does also that seems to be where the pipe is going in...

http://pic4.picturetrail.com/VOL777/3525700/17499650/327474862.jpg

http://pic4.picturetrail.com/VOL777/3525700/17499650/327474883.jpg

Is there a way I could email you some pics of my engine for further clarification??

Thank you...

On that website there are some pics of engine blocks pointing out the captains bars... In the section of the article it is talking about two 3/4" lines threaded into the block...

We are wanting to run a line from one of those 3/4" lines into another providing oil throughout the engine...

In this pic, http://pic4.picturetrail.com/VOL777/3525700/17499650/327474883.jpg would the one on the right side of the screen (the one above) be the outlet and the other closest to the motor mount be the inlet??

The confusing part on my engine is that further back from the upper line as in the picture, there is another port tapped which has an old tractor pressure gauge in it... We're wondering if we can keep that one plugged and just use these two mentioned...

Some Info. I found on 261 full flow oil filter plumbing.

"Warning when installing a 261"
The stock remote filter systemhas two very visible lines threaded into the block. One is from the pump to the filter and the other from the filter back to the block Oil must leave and return to the engine by these lines. (even if the filter has been eleminated) or the engine will fail from lack of lubricant. Many 261 engines have been quickly siezed after persons plugged the two oil line holes. They had many years of experiance with older 216 and 235 engines without the full flow filter system. some thought it was an easy fix just to remove the 3/4" lines and cap the holes."

I knew I had the info. some place and just found it.
This goes back to what I said, if no filter is used the two holes must be connected with larger 3/4" line. If you find the filter system later it can always be installed.

Thank you...
I have read that info too...
The only thing we now need to know is which two 3/4" holes... I have one directly behind the drivers side motor mount and another about 2" behind that one AND another one about 2" behind that one... Total of 3 3/4" holes... The 2 rear ones have pressure...
From pictures I have seen, a line has been run FROM the 2nd hole to the 1st hole which leaves me to assume that the 2nd one which has pressure is an outlet and the one directly behind the motor mount is an inlet...??? Any ideas??
Thanks again!!

cmrutledge , If you will email me the pictures of your engine I will process them thru my website for posting pictures and post them here on this thread, tomorrow night since I will be at the Comanche Powwow car show tomorrow. please take one or two pics that show the entire side of the engine from slightly off center of the sides, then take a closeup with the two sets of 3/4 inch holes and the one with the tractor pressure gage with enough other background area to be able to have good references as to where on the block the holes (ie the throttle mounting stud hole and the soft plug holes).
I don't mind doing this, I have done it before for chatter members here.

....Try chevytalk.org....go to the 1949-54 forum and the discussion "does a 261 need an oil filter?"....good info and pictures :)

I have a 1957 261 block.

I have read the 261 did not have full remote oiling untill 1958.

My block has the two THREADED bosses for the in and out remote oil filter LINES (original to motor).

BUT Just above the in Boss there is another boss with a plug that is flush with out side boss. Looks like this plug is not threaded but maybe a compresion fit type.

I notice in this picture that the boss above the in line boss is not showing the plug in question. Does this plug need to be moved in to direct full flow out to the oil filter?

I have tried to move the plug in but to no avail. Might just be stuck (not sure)?

Confused as to whether this is a full flow oiling system motor.

Block has a cast date of september 1957.

From the info that I have (parts book and 1958 truck engineering features) the 1958 261 did not have a full flow oil filter. Your Sept 1957 block could very well have been for a 1958 truck or was a replacement sold through parts. Either way its designed for a by-pas type filter. Thats what I would use unless the vehicle is used for hauling dirt or gravel under dusty conditions.
Under normal conditions and changing oil every 1500 miles or so the engine will go 100,000 miles with todays oil and NO oil filter.

Chevygene;

The text below was taken from an article written by Jim Carter and found on the Internet.

Title of the article is "The Forgotten 261 Six Cylinder"

In 1958-62 (the 261 now had a full flow remote oil filter) it became standard in the 2 ton chassis up to 19,000 pounds gross weight. Above that Chevrolet substituted a V-8.

This article does not jive with what you have stated about the 58 261 being a by pass filter set up and not a full flow system.

I still do not know what the compression type plug is all about above the forward in line port. Can you exxplain it possibly?

Still confused, please give more advice if possible.

Thanks for all your help,

Riff

Hello...
I have run a stainless line to and from each port...
However I still do not have oil coming up to my rockers...
I have ran the engine for only 20/30 seconds at a time but still nothing... Why would this be?? I'm afraid to let the engine run too long but I don't know how long it could take for oil to show up in the rockers...
HELP!!!

As to the above question MR.cmrutledge:
Maybe the oil pump needs to be primed before it can pump in that amount of time. Just a thought??

I have now found out the plunger above the in boss has to be moved completly in before it shuts of oil flow to main oil galley and makes all the oil go through the full folow oil filter and back to main galley. My 1957 261 that was forged in September 1957 has the capability to be full flow but never had te plug moved in to force the oil to the full flow filer.

My problem is still getting the plug to move forward. It is stuck in the out position and needs to move to the in position. I still need an answer as to how to get it to move short of whacking it and cracking my block.

So as early as september 1957 the 261 did have the option of having remote full flow filtering or by pass filtering.

Case closed I would think, except on how to move the dow rod forward.
Riff

It can take up to two minutes to get oil to the rocker arms when the system is dry. Will depend on the temperatue and weight of oil being used. Thats why 5W-30 is best for break-in, it flows much faster.

I would try the old trick of spinning the oil pump by using a distributor shaft from an old distributor and spinning it with an electric or battery powered drill. Put the distributor shaft in the drill chuck and set it in the distributor opening down to the oil pump. Spin it with the drill until the oil flows out at the top of the engine.
Another idea is to remove all of the plugs and turn the engine over with the starter until the oil flows out at the top of the engine. With virtually no compression because of the plugs are removed, the battery can spin the engine easily for a few minutes until it begins to flow. Be sure the battery is fully charged before using this method.
I've used the drill/distributor method and it worked for me.
Someone else may have a better idea.
Good luck!
Joe

If you have doubts about the rockers getting oil, use a squirt can to squirt a good amount of oil on the rockers and rocker shafts then start the engine, notice that there is not any part of the rocker system that makes a complete revolution , just back and forth motion, you aren't liable to damage anything there for a good while. If you run the engine for 30 or 40 minutes and there is no oil being pumped to the rockers, and dripping off a few drops all along the rocker shaft, pull the small pipe plug in the center of the head on the right side and use a stiff wire to see if the passage in the head is stopped up. (get ready for a hot oil bath!)
the next step is to pull the tappet panel cover off and check if oil is passing by the lifters. I have seen a oil line in the tappet area that had a hole worn it where a push rod rubbed on it
This stuff isn't rocket science just be sure the oil is flowing. And don't expect to see oil squirting up every where like on a SBC V/8 or a 230, 250 or a 292 six with the SBC tappets.