The Stovebolt Site Forums The Parking Lot Big Bolts 261 oil line routing

I just acquired a 261 to put in my little truck (3100 series) but can't seem to get a handle on this full flow oiling and remote filter yet. The block casting number is 3769925 and everything I can find show it to be a 58-62 block. Inside the block it is stamped c60 in several places. Any one know what this means? The oil pressure outlet from the block has been reduced down and has just an oil pressure line for the gauge. There is a plug where I thought the oil fitting for the return line should go. There is a plug (I believe) just to the left of this. Have been told this plug has to be driven in (how far) to re-route oil flow. Inside the block where the plug is is a fitting that I assume goes to the discharge side of the oil pump. Can anybody describe how this block should plumb, or better yet, have any pictures? Block is going to be bored early next week and I'd like to do any drilling or tapping early so I can get vatted at one time. Thanks.

If you haven't already done so you may want to post this question in the engine and driveline section

cgresham1212,

If you posted this question elsewhere and received the information you wanted, I apologize for keeping this thread alive.

It looks like you have a 58-62 block ( the inliners site lists it as a '59-'62 261 block number). This block allows for a full-flow oil filter (I thought it was an option but it might have been standard for some/all years). If it was an option, I think there was a procedure to "set up" the block for an oil filter (it looks like you know this - you refer to a "plug being driven in"). I think that once an oil filter has been installed, the holes for the oil filter lines should not be plugged,

I cannot find in the 1958 or 1960 Shop Manuals a description of how the 261 block is "prepared" for the full-flow oil filter. I recall reading about this but I cannot remember where.

Here is a quote from a Technical Article on the 261 engine that is posted on Jim Carter's website:

""Warning" When Installing a 261!

The stock remote filter system has two very visible 3/4" 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 is eliminated) or the engine will fail from lack of lubricant. Many 261 engines have been quickly seized after persons plugged the two oil line holes. They had many years experience on Chevrolet engines without the full flow oil system. Some thought it was an easy fix to just remove the 3/4" lines if one was leaking and cap the holes. This procedure was acceptable on the older 216 and 235 but never on the 1958-62 261 truck engine."

There should be no need to drill or tap the block in order to use a full-flow oil filter. The "3/4" oil lines are, as I recall, connected to 1/2 NPT holes in the block.

The is a picture of the 1960 261 oil system set-up:
[img]http://home.nycap.rr.com/lederman/images/fullflowsetup.JPG[/img]

Tim

I wish upon hope that these old link’s to images where still active᠁

Sigh᠁

I have a 1960 C60 with the full flow filter added to my 261. If you would like, I can take a few pics. I see there are two lines. One from and one to. In and out of the canister filter, in and out of the block. Let me know. Robert

Nice rig robVee, looks like it'd be handy for firewood.

We were working a job one day up in the hills. As the tall weeds were cleared, this truck appeared. Abandoned in 1992. The new land owner wanted it sent to the metal yard to be crushed. I saved it from that fate and trailered it home. The compensator pulley had come loose and it sounded like the crank had broke. Found some 8.25 x 20s and got everything working. Registered and insured last week. I really like the little beauty. Torsion bar front end. Two years only.

robVee Nice save,I know just how that truck feels loaded. If you adjust those torsion bars jack it up to take the load off,adjust,then let it down. Think I still have a bar somewhere.