 |
This is the cooler unit I started with, an Earl's cooler purchased from Summit Racing. Probably considerably larger than required but I wanted more than an oil cooler....I wanted to approach the point where I had an oil cooled engine. |
 |
This shows the location of the
holes drilled and tapped into the engine side cover prior to the installation of the
fittings. The position of the holes if of course very critical, they must intersect the oil passage that runs along the front of this cover and not "break out" into any other part of the inside of the cover or you'll have no oil pressure to the engine. |
 |
First thing was to find suitable points to tap
the oil system. This shot shows the supply gallery where the oil enters the right side
engine cover from the oil supply outlet in the upper engine crankcase. I tapped and plugged the center of this passage to force the oil to flow out of the fitting shown here. |
 |
The tap points shown from the outside. The passage plug will force the oil to flow out of the lower fitting....through the hose to the cooler and it will return through the upper fitting....this fitting connects to the passage show above but on the other side of the brass plug. Basically I've just created a "detour" by putting the plug in the middle of the passage and providing a detour route to the cooler...after the oil returns through the upper fitting it continues on as it would normally. |
 |
The two passage seen here in the oil filter access cover have been enlarged by 1/32"...doesn't sound like much but it represents about a 15% increase in the area for oil flow. The matching passage connections in the engine side cover were also enlarged. This has to be done very very carefully. The passages are drilled at a specific angle that must be maintained when they are enlarged. I set the parts up carefully on a milling machine with an angle vise for the job. |
 |
Here I'll explain the passage of oil from the
pump, through the crankcase, to the engine cover. Here we see where the oil pump outlet connects to the crankcase....it shares this passage with once of the main crankcase bolts...the passage is larger than the bolt to provide room for the oil to flow...also the bolt itself is turned down in diameter to allow for more flow....still...this setup is not the best. I'll show what I've done to help it out. |
 |
In the upper portion of this photo you see the
unmodified crankcase bolt that passes through the passage shown in the photo above.
I've done two things...on the lower bolt you can see that I've turned down it's
diameter just below the threads farther than the stock bolt...the reason for this will
become evident in the next photo. I've also polished the length of the bolt...since oil must flow around this bolt and up the passage it needs to be as smooth as possible to prevent any turbulence or resistance to flow. |
 |
Here we see where the oil exits the crankcase
and enters the engine side cover a couple of inches above the oil pump outlet. You can see
the top of the crankcase bolt and the area that is turned down. This photo shows the
modified bolt in place. I you picture the stock bolt in this location you can see that it
would block quite a bit more of the outlet passage because it's larger in diameter for a
greater length. The step where the bolt decreases in diameter on the stock bolt is almost
all the way to the bottom of the passage, making the oil try to squeeze around the bolt to
exit the passage. This modification provides much more room for the oil to flow. The cavity seen to the right of the round oil passage is just an empty cavity...although it matches a cavity on the engine side cover it serves no real purpose. |
 |
Here is the installation completed. All fittings are Earl's "AN" type from Summit Racing. The fittings and hose came to just over $100. Expensive, but the best fittings and hose money can buy, and you don't want to take chances on your oil supply or having a leak that contaminates the race track. |
 |
Cooler mounts on rubber vibration isolators using the OEM mounting holes for the horn. I fabricated the red mounting plate from 16ga steel. I had though to use aluminum but once again...I don't want to take any chances with the oil system. Fittings just clear the lower fork clamp at full lock. |
 |
View from the front. Cooler is mounted with the
ports UP to prevent the oil in the cooler from draining out when the engine is shut down
and to prevent air from becoming trapped in the cooler. It's located so that it gets air flow from over the fender without blocking too much air flow to the cylinderhead. Air does pass through the cooler...but it will reduce the flow to anything behind it. |
 |
Left side view. Care must be taken to keep the
light weight nylon braided lines from getting too close the exhaust system. The long bolts going down from the mount to the bottom of the cooler might not seem necessary...but they are. If you were to use short bolts and just connect to the top of the cooler unit...it would eventually pull off the top of the cooler and cause a huge leak. The long bolts pull the whole cooler unit up against the mount both holding it against the mount, and strengthening the whole unit. One long bolt on each side should be plenty...if the unit was hard mounted I'd use four bolts. |