... can i use any 3 or 4 port filter housing? I could make my own bracket to mount it under the header to the block.
You can use any three port adapter that has two in and one out.
From my point of view, this two into one oil cooler set-up is not a benefit and if the oil system is plumbed just like the factory designed it and the oil temps are maintain at acceptable levels then the engine will run just fine and last for many years of service.
I do not use, install or believe in the combining of the two systems and I have personally won 3 INEX national events, too many INEX National & State points titles to count since 1994 and have been providing my customers with the same system which has resulted in the same results.
Frankie Marks won the 2011 Pro World Finals, 2011 Pro National Championship as well as the state and club titles too. While my two sons finished 1 & 2 in the 2011 Thunder Roadster World Finals as we as the National, State and club titles as well this year.
I had a local guy buy one of my customers car with my oil cooler set-up. This guy is a HSR customer running the complete engine/cooler package on his sons car. After running both cars at the same track, in the same race and seeing the sons car bury the gauge and run hot, while the car he got from me was running 230*. He decided to change over the sons car to the factory designed plumbing and my oil cooler package and that car now runs at the same temps as the car he bought.
I also do not believe Setrab coolers are a very good product, not for INEX racing anyway. I am mandated to run them in my Thunder Roadsters and I have to run two of the three pass coolers to get my cars to run cool.
Prior to being told I was mandated to run the Setrab, I used the Tru-Cool cooler and only ran one 11" x 11" to maintain the same temps.
On the Legends car I run a large Tru-Cool cooler on the main oil system, with -8 hose out of the back on the motor, through the filter adapter, to the cooler then the cooled oil is returned to the engine. The oil filter adapter is mounted to the firewall just to the left of the driveshaft, down low to keep it out from under the header and the associated heat found under there.
The small cooler is run with -6 hose right off of the two oil pan fittings. I do agree with Jim about blocking the air flow to the engine, thus the large cooler is mount as far right of the frame rails to allow unobstructed air flow to the engine. The small cooler is mounted under the large cooler and centered on the bracket.
While I disagree with Jim, that this is solely an "AIR" cooled engine; really it is air & oil cooled. Since we put the motorcycle air cooled engine in the car sideways out of proper airflow, the oil cooling becomes paramount into engine longevity and performance. If Yamaha did not see a need to have oil cooling, they surely never would have spent the money to design and install an oil cooler system on the unknown number of FJ, XJ, XJR bikes produced from 1984 until today.
Don't get me wrong, I am not knocking the HSR system or any other system for that matter. Hank is a friend of mine and hundreds of people use his oil system and are satisfied, but there are a lot of people who run my cooler package are happy with their results. On the same note Jim and I buy & sell from each other and have a good relationship.
But what I am saying is there are plenty of ways to cool oil, you just have to select the one that you are satisfied with.
That is the great thing about racing, there are so many different ways to accomplish the same outcome.
Randy - RPM