Page Last Updated 05 June 2005
Special thanks to Bruce "Phat" Childs and The StoveBolt Page for a lot of the technical content in this article. Please visit their website often. Lots of great stuff over there!
This is all about how to install Full-Flow oiling on your 235 or 261 engine. In case you didn't know, the old canister filter assemblies mounted on the manifold only filter about 20% of the oil in your engine. They are inefficient, hard to keep clean, and filters are becoming harder to find. This How-To will change all of that!
On the later model 261s with the large 1/2" oil lines coming out of the block, you can skip down to the section on how to install the spin-on filter adapter assembly.
This is how I have done the full-pressure oil filter on the 235/261. I don't suggest you do this unless the motor is completely apart for a rebuild. With the drilling and tapping, there will be too many metal chips to do this on a motor that is already built.
All of the drilling and tapping will be done on the oil pump side of the block.
Step One: Get a 1/8 NPT Tap. Now, go about 1.375 in the hole (being careful not to damage the threads for the pump fittings.) Tap and install 1/8 Pipe Plug. This will plug the passage to the mains.
Step Two: Put the block on its oil pan flange. The next hole you will drill from scratch, and it may be a little scary for the first-timer. Just take your time and look at the pictures. I tend to drill this hole a little on the high side so you don't get into the fitting for the oil pump.
Start with a 1/8 drill bit on a slight angle (see angle of tap below.) Go to a 3/16 then to a 9/16 drill.
Be careful and try to keep it lined up straight with the oil pump passage. Now tap the hole with a 3/8 NPT tap being careful to keep the same angle that you drilled on.
Step Four: The next hole is drilled about halfway between the last one you drilled and the flywheel end of the block. Get the hole centered on the passage.
Drill it with a 21/64 drill, then tap with a 1/8 NPT tap.
Step Five: You may choose not to drill this one if your filter has a place for a 1/8 NPT to plumb your gauge. I have done them both ways.
We use the Trans-Dapt remote filter in our shop, but others will work. There are other ways to do this, but I have found this one to look and work the best.
Total time to do the job is about 1 hour (it took me longer to do this article!) Have fun and be safe! - Bruce Childs (aka Phat)
Well, now for my first part of this exercise, I will give you an idea of how to install an Oil Filter Relocation Kit on a 261. This was because my engine didn't have an oil filter at all, and this was a real neat solution to the problem. I used this adapter available from Perma-Cool. I paid about $50 for the kit. Here are all the parts you will need. The only thing provided in the kit is the aluminum adapter in the foreground. Everything else was rustled up separately.
The black adapter you see here I made myself. I found a real nice place on the engine block to secure the filter and needed to make a plate with the proper bolt pattern to accomodate the place I wanted to put it.
Some scrap metal, a few spacers and some nuts and bolts later, I had the perfect solution.
I included these shots so you can see how this was constructed. On the 261, there are engine mounts that are not used when installing in the Advance Design Trucks, so this made the perfect place to mount the filter. If you need this area, the lower part of the bell housing is another nice place.
Here it is directly installed on the block. It looks like it belongs there! Installing it directly on the block will eliminate any friction (thus wear & tear) on the oil lines due to engine vibration.
This is after the copper tubing. I chose copper because I can bend it, it's solid, and it isn't prone to wearing out like flexible solutions. It should last a while.
