I'm almost done with all the frame mods and starting to work on various things around the frame. So that I can do some of the measuring and fitting I set the old engine and trans from the parts bike into place. The header pipes were all rusted up so I went over them with a wire wheel and it really improved the look. I guess they will rust up again soon though.
I found that when climbing up steep mountain back roads (1st and 2nd gear stuff) in hot weather the engine of my PD would overheat. After a bit of looking around at automotive plumbing catalogs and such I ended up ordering an Earl's
Temp-a-Cure oil cooler, some -6 Perform-O-Flex stainless hose, and a few Swivel-Seal hose ends that would mate the cooler to the threaded holes in GS oil filter cover plate. Other aftermarket parts makers have similar offerings.
I sized the cooler to be a bit bigger than stock and to fit in the space behind the front fender. This photo shows the stock GS cooler compared to the new cooler. It is thicker, and the front has about 30% more finned area.
I wanted to have the front fender so I could properly fit the cooler. I looked around for something with a modern look to it and settled on a Acerbis for the limited edition black CRF450R. I'm hoping the aerodynamics of it will be good at highway speeds.
To mount the cooler I decided to use two aluminum plates that would mount above and below the cooler to stabilize it and offer some crash protection. The lower plate would mount to two brackets that would be welded to the front frame tube. The lower plate would need two big holes to pass the fittings on the bottom of the cooler.
As a first attempt I made these plates from 1/8" flat stock. I machined out the top plate mainly for looks, but also to make it lighter.
The frame brackets needed to be narrow enough to fit between the cooler fittings. I still need to cut off that horn mount, but will need to wait until the engine is out next.
The lower plate then mounts to the frame with four counter sunk screws.
To connect the hoses to the GS filter plate I bought two M12x1.5 'fuel pump' hose ends (Earl's PN 849092). These have the same thread as the stock GS banjo bolts. I also bought some clear 3/4" heat shrink tubing to put over the hose to keep grit out.
The filter cover plate had a recess that the banjo sealing washer fit into that can be seen in this photo.
I filed down the edges of the recess to make a flat sealing surface for the new hose ends.
Here is how the new fittings connect up with the GS filter plate.
Here is my 1/8" lower mounting plate with some temporary hardware. After getting this far I found the lower plate seemed too flimsy, and I felt the plate would eventually crack from fatigue. There is about 67mm between the inner frame mounting screws and the outer cooler mounting screws, with a big hole between them.
As a solution I welded some 90 degree angle stock on the sides of the lower bracket. This photo shows that work in progress. On the bottom I needed to grind away some clearance. With hind sight, I think a better design would be to just make the lower plate from 1/4" stock. The current one should work OK, but I may make up a new one.
I made up this set of spacers from 1/2" round stock to fit between the cooler mount tabs. I machined a flat on two sides to accept a 10mm wrench. I also use two washers between the cooler tabs and the mount plates to space the plates away from the top and bottom of the cooler. The cooler is then sandwiched between the plates to stabilize it.
I was concerned that I would not be able to remove the front engine cover with the oil cooler mounted, but I found that the cooler and hoses are far enough forward that there is plenty of room.
Here's a side view showing the clearance between the cooler and the fender as mounted.
It seems like the front fender will obstruct most of the airflow to the cooler. I'm thinking I'll cut out some of the fender to allow the the air to flow into the cooler, and maybe make some shrouds that attatch to the sides of the cooler to duct some more air through it. I'll wait until later when the bike is ridable and I can do some air flow testing before doing that though. I also need to add the heat shrink cover, and I am thinking I to shorten the hoses by 1/2" or so.