The Stovebolt Site Forums The Shop Area Engine Shop 261, Fenton Headers, and the oil lines....

I am fairly new to this site. I have a '51 1/2 ton Chevy that I am installing a 261 with an Offy intake and Fenton exhaust.

After my struggles with getting the two manifold to fit, I am now dawned with the task of figuring out the oil lines. I am installing a screw-on oil filter (NAPA 1515). I can not see how to install the lines so that I do not touch the hot exhaust pipes, and still have use for oil pressure gauge and the oil line the goes to the head (is this needed??)

Anybody that can give me some guidance and/or pics would help...

Thanks in advance.

I can't help you with the spin-on filter install but very definately you need that head lubrication line. Thats where the rocker arm gets it's oil.

Come to think of it, aren't the spin-on on the distributor side? If so then run the lines around the back of the engine.

51Greenmachine,

Do you know what year 261 you have?
The 1958-1962 had large 1/2" NPT oil line fittings on the intake/exhaust side of the block. The 1954-1957 261 had the smaller oil filter lines (as on the 235) on the intake/exhaust side of the block.

I have a 1960 with a spin-on filter adapter (on the intake/exhaust side of the block, where the original oil filter had been installed).

The line that I think 53moneypit refers to is on the distributor side of the engine, and, as he posted, it feeds the rocker arm (and is not normally not used to feed either an oil filter or oil pressure gauge, but some people have done this).

Did you engine have a canister-style oil filter or did the engine originally have no filter?

Post here the size of your oil lines and I will post a few pictures of small oil lines or big oil lines.

The oil pressure gauge line is usually attached to a "T" fitting on the inlet side of the oil filter. Where was it originally attached to the head/block on your engine?

Tim

My 261 is a 1959.. It has the 1/2 NPT ports on the manifold side. I do have the canister, but it will not bolt onto the Offy manifold, or will it?????

I doubt if it will attach to the Offy intake without an adapter. That is one reason why I changed from the original canister to a spin-on (my 261 also has the Offy/Fenton combination).

[img]http://ares.cs.siena.edu/~lederman/truck/Photos/Pickup/OilFilter3.jpg[/img]

[img]http://ares.cs.siena.edu/~lederman/truck/Photos/Pickup/OilFilter2.jpg[/img]

[img]http://ares.cs.siena.edu/~lederman/truck/Photos/Pickup/OilFilter1.jpg[/img]

tclederman:

Did you tap the hole in the 90 fitting going out of the housing for the pressure gauge?

51Greenmachine,

No, that hole was already there and I think it might have come that way from the factory. But, I do not know that for sure - I bought the engine at a salvage yard in 1972. The engine came out of a school bus and the oil filter was the GM full-flow large canister (quite an impressive unit).

If you have the brass fitting and it has no hole, it should be fairly easy to tap a hole (you might be able to see that the hole in mine needed a reducer for the line to my '54 gauge).

In the photo below, it is not possible to see the oil pressure line but the diagram shows the direction of flow of oil. I my first post above, I said the oil pressure line was on the inlet side - I was wrong, it is on the outlet side of the filter (inlet side of the engine).

Also, note the stand-off tube/pipes on the oil lines - the one on the left is easy to see.

[img]http://ares.cs.siena.edu/~lederman/truck/Documents/fullflowsetup.JPG[/img]

Tim

As soon as my truck gets back from the exhaust shop, I'm going to fabricate my oil filter lines out of brake lines. I want to ust 3/8" if I can find them. I will get the neccessary fitting and put it together like I did my intake cooling lines. I found it pretty easy to make nice bends in these lines with an $8 bender from LMC. The male parts of the fittings come with the lines and all you need is the bender, a cutter. and a swaging tool with dyes(I think that's what they are called) so you can make double flare ends on the ends that you cut off. Then get you fitting adapters with inverted flare that fits the size of lines/fittings you are using and your off to the races.

Sweet, I'm watching you and your progress. When I get ready to redo my 261, I'll be calling. Be sure you get everything right and document it all with photos and a long narrative. I might even give up a Corona or two with you and Phillip to coerce you out of your expertise.

Hey, no problem, works for me!!!!!!!!!!!!!!

In fact the great switcheroo is setup for next weekend!!

:confused:
tclederman: I have question concerning the pictures you have posted.

As I look at the pictures, I wonder why the oil return line is shown to return the oil into the engine at the spot where the oil pressure guage line comes off the engine to the oil guage for it's readings? It seems backwards.

I have always been told the guage takes the pressure at the oil galley toward the back of the engine. That oil galley runs down the full left side of the engine from front to back. It's the same galley that is plugged on both the front of the block to the left of the timing cover and on the back in the bellhousing area. The lower spot to the front of the engine is just ablove the pan rail and is the discharge spot for the oil to return to the engine.

Something doesn't seem right.

6cylindersovertexas,

I agree with you (I had been told the same as you about the oil return). That is why I added a correction with the photo of a 261 from the 1960 Shop Manual that shows direction of the flow.

Maybe the photo is labelled incorrectly (for direction of flow), or the 261 is different from the 235 (I doubt that).

I can't be sure that the oil pressure sender on my 261 had not been changed before I bought it in 1972, but the oil pressure sender was on the fitting on the right side of the filter canister and that line went to hole on the lower rear side of the engine.

Maybe someone else will clarify this.

Tim

In my 1960 manual, the 261 is described a a full pressure filter and the manual says to not plug the block where the oil filter lines normally go or you will get no oil circulation. My 235 in contrast is a "by-pass" filter and those holes can be plugged, the filter is basically an accessory. Maybe this is my ignorance speaking, but that tells me that the circulation of oil in the block differs between the two motors. Hopefully, someone more knowledgeable will chime in and explain the difference.

Well, it's been a long time since I worked on a 261 but as I recall, the oil is routed directly from the oil pump to the filter, without entering the oil gallery. From the filter it is routed to the gallery. Any gauge location on the gallery or oil line should provide the same reading.

I believe if you look at the oil fitting coming from the block (pump) you are basicly going to be looking directly at pump output.

As a matter of fact, I bought 2 brand new short blocks from an Chevy dealer (who shall remain nameless) back in the late 60s. Their shop had installed both of these in a truck which came with a 235 with no filter. So, they simply plugged the holes. While setting the valves with the engine idling, 'it just died'. Locked up for lack of oil. I replaced the bearings after having the cranks turned and had an essentially new engine.

I failed to state what I started out to do:

The filter doesn't 'return' to the engine on a 261 full flow system in the same sense that a bypass filter return works. The return from a 261 full flow filter is the pressure supply to the oil gallery.

The circulation difference is that in a 235 the oil is routed from the pump to the gallery.

Gentlemen Stovebolters -

Again (and I have lost count on how many times this has happened), I have learned something I needed to know from the Stovebolters on the Stovebolt web site!!!

Thank you everybody!!

Joe

So does that meen that the direction of flow on the 235 is the same as the 261? I have a 235 with a remote filter setup and i am not getting oil to the rocker arm assembly and i think the lack of oil to the top of the motor is directly attributed to having the filter plumbed backwards. The motor was set up with the bhive filter from the factory.

Thanks in advance for any and all help.
Jackson

There is something ya'll should note that Tom Langon pointed out to me.

The 235 and 261 were both set up to run without a filter. The 261 block has a diverter plug pin set in the block just above the front 1/2 NPT hole. When the pin is fully pushed it, it diverts the oil flow from the pump directly to the filter. If that pin is pushed in, you must either install a filter or at least route the oil from the front hole on the intake/exhaust side of the block to the rear hole, otherwise there will be no oil circulation and you'll get bearing failure pretty quick.

My 1962 261 just had 1/2" soft copper line from the front hole to the back hole with the oil pressure line run to the rear fitting.

I don't imagine it matters much where you put the oil pressure sensor line in this circuit, unless you think that as the filter gets obstructed the actual pressure in the engine will reduce because the pressure coming out of the filter to the block is lower that what comes from the pump to the filter. In that case, the oil pressure line should come off the filter 'output' line.

If your 261 does not have the diverter plug pushed all the way in, no matter how many filters you put on that line you won't be filtering the oil.

I'm putting a remote filter on it from NAPA during the rebuild and am planning on mounting it using the threaded engine mount holes just behind the generator, 1/2" soft copper and compression fittings. I'll put the oil pressure sensor line on the outlet side of the filter. Once I get it done, I'll post some pictures if anyone is interested.

Clarification.... If the pin is pushed in you won't be FULL PRESSURE/FULLY RECIRULATION filtering the oil, it'll probably still 'bypass filter' a little. Whether the pin is IN or OUT you've got to have a line from one hole to the other.

The pin closes the oil galley from the front oil port (pump output) to the rear port (the remaining lube system). With the pin out the oil galley is open from the front to the back port.

When the pin is driven in the oil galley is now closed and oil MUST be routed from the front port to the back port in order for oil to get from the pump to the rest of the engine. Putting the filter in the line connecting these ports will filter all the oil pumped.

Racecarl- Thanks for clearing up the pin thing, I thought that you'd still have some flow if the pin was not depressed/flush with the block surface.

Here's a picture of how I mounted and set up my oil filter using the following pieces:

On the block outlet (to inlet on filter) brass nipple, brass 45, compression fittings, 1/2" copper.

On the block inlet (return from filter at rear of block) brass street 90 (one side male, one female), original compression seat tapped for oil pressure line, 1/2 copper.

On the filter mount inlet-compression seat fitting.

On filter mount outles - brass nipple, brass 45 and compression seat fitting.

To mount the filter mount I made a j shaped bracket from a piece of plate steel that mounts to the top and lower front tapped holes in the block for side engine mounts. Then I used washers between that bracket and the filter mount to get the filter to clear the side of the block.

Here's a link to pictures of the installation.

http://www.kodakgallery.com/BrowsePhotos.jsp?&collid=870158533106&page=1&sort_order=0