The Stovebolt Site Forums The Shop Area Engine Shop Found a 261 at last

Found a 261 yesterday. It is in a 55 school bus, last driven a couple of years ago. It tirns freely with the starter, but will not fire. This motor has no oil filter, but from what I have rread, the by-pass filter on my 235 should work. I'll try to post pics after I pick it up.

Great find. Hope it's a good one.

You might want to rethink using the bypass filter. If the peg at the filter port on the block is driven in you definitely need to use a full flow filter. Here is a picture of how I did mine. All of the credit, however, goes to Tim Lederman, who showed me how.

http://s578.photobucket.com/albums/...n=view&current=38-OilFilterLines.jpg

If it is a 1955 261, a by-pass filter system should be used with it.

Joe,

That set-up does look familiar. Where did you connect the oil pressure sender?


How do you like the Carter-Weber carburetors?
Did you use the stock jets?

That's a really nice set up. Is there a how-to article on doing that?

Tim:

I've been out of touch so I just read your questions.

I piped the oil pressure gauge line to the outflow side of the oil filter. I handled the choke differently than you did. Instead of a pressure switch, I installed a Cole-Hersey marine push-pull switch on the dash in the same location as the old choke and used the original choke knob and wired the electric choke through the switch to the IGN terminal of the ignition switch.

The Carter-Webers work great. I used whatever jets Tom Langdon supplies. I didn't have to adjust anything on them after installation.

Joe

Joe,

The choke switch sounds good.

What is the push-pull switch part number and from whom did you buy it?

Can you post a photo of the installed switch?

Thanks,

Tim:

Here is a link to the switch:

http://www.westmarine.com/webapp/wc...m=5002&subdeptNum=9&classNum=294

Here is a picture, but it doesn't show much other than normal looking choke and throttle knobs. BTW the throttle knob has the same switch and engages the Gearvendors overdrive.

http://s578.photobucket.com/albums/...es/?action=view&current=DSC01829.jpg

Joe

thats some nive work

OK, I got the numbers off this engine. It came from a 55 school bus and I assumed it was a 55 engine, but the numbers are:
Block: 3769925
Head: 3836850
Paint: Yellow

All the casting number references I have show this to be a 58-62 block and head, so I think it may be a replacement engine. There are also no numbers stamped on the pad by the distributor. There is no oil filter; there is a 1/2 NPT threaded hole in the block and the pressure gage was connected to that. At the lower block, under the carb, is a pin in a hole and it is flush, under that is a 1/2 NPT threaded hole that is plugged and adjacent to that is a 1/8 NPT plug.

Is this a 58-62 block that I can convert to full flow oil by driving that pin in?

Check 6,
Joe D.

Here's a reference picture.

Full flow oiling system.

The forgotten 261.

261 steam hole discussion.

Pin in the proper "IN" position for proper oiling.

Installing a full flow oiling system.

Find your official yellow color here.

Click on Casting Numbers panel on the left.


This is all information I have acquired here on the 'bolt and other places, reproduced w/o permission, but I don't think any will mind as they have placed this out there for us all to benefit. I don't know about anyone else but I sure would like to see a picture of that evasive 261 in YELLOW.

I'm trying to include a link for pics with this. The "Forgotten 261.." lists 261 colors as: green - some later yellow. You can see the yellow paint on the vlve cover and intake in these photos. There is also some on the head, but I can not find any on the block, yet. You can also see the head and block casting numbers as well as the oil exit, return and peg in the block. Note the peg is flush with the block surface. I pulles the starter and the casting date is: D3 3.

http://s858.photobucket.com/albums/ab147/jdaniel171/

Check 6
Joe D.

Cosmo,

You've seen this yellow 261. Not really a good enough photo to try to match the color. I can't recall anyone posting a photo of a 261 that has been re-painted yellow. Elusive, indeed.

Just posted some new pictures to this link:

http://s858.photobucket.com/albums/ab147/jdaniel171/

These show the head casting number and date and the block casting date. If I read the numbers correctly, the head was cast May 22, 1961 and the block was cast April 3, 1963. Does anyone know if any 261 blocks were cast in '63? Again, there is nothing stamped on the pad next to the distributor. I think that might indicate a replacement block. Anyone have any thoughts about the dates or lack of ID number?

Supposedly, 261s were sold (and perhaps made) in 1963, for use in 4x4 Chevrolet trucks.

Thanks for the help. It looks like what I thought was an early 261 has turned out to be a very late 261 replacing the original engine in the 55 school bus we pulled it from. I guess the good guys do win one now and then.

Check 6
Joe D.