- Joined
- Mar 24, 2005
- Messages
- 1,231
I just received this letter from Jim Wilson:
Testing the CMB Beta .21 Engine.
I received a Beta .21 in December 2013 and began testing it in February, 2014. Instead of installing it on a rigger with rear sponsons, it was installed in a seven pound Sport .21 to determine if it had the torque needed to be competitive in boats that weigh more than four pounds. I realized immediately that it produced much more torque than the VAC.21, exceeded 33K RPM's and was radared at 71 MPH.
In it's first oval competititon, it lapped the field by pulling a 642 with 5 inches of cup compared to the competition's 440's, 640's and 225's. In early June, it established NAMBA Heat Racing Records in Sport .21 and .21 Mono. Yes, it was using unmodified original parts except for a Zoom Carburetor that was installed for comparative testing.
I used eight gallons of fuel to verify the Beta's consistency before releasing these test results. My pit person remarked: "CMB is finally making a good .21 engine again!"
The engine I received had exhaust timing of 186 degrees with transfers at 127 and boost at 129. It was easy on plugs (OD9 and 289) and it performed the best on 50%, 60% and 65% Odonnell Punch fuel.
So, if you are looking for a durable engine to power a 4+ pound boat with big propellers and great RPM, the Beta is an excellent choice.
Respectfully,
Jim Wilson
Testing the CMB Beta .21 Engine.
I received a Beta .21 in December 2013 and began testing it in February, 2014. Instead of installing it on a rigger with rear sponsons, it was installed in a seven pound Sport .21 to determine if it had the torque needed to be competitive in boats that weigh more than four pounds. I realized immediately that it produced much more torque than the VAC.21, exceeded 33K RPM's and was radared at 71 MPH.
In it's first oval competititon, it lapped the field by pulling a 642 with 5 inches of cup compared to the competition's 440's, 640's and 225's. In early June, it established NAMBA Heat Racing Records in Sport .21 and .21 Mono. Yes, it was using unmodified original parts except for a Zoom Carburetor that was installed for comparative testing.
I used eight gallons of fuel to verify the Beta's consistency before releasing these test results. My pit person remarked: "CMB is finally making a good .21 engine again!"
The engine I received had exhaust timing of 186 degrees with transfers at 127 and boost at 129. It was easy on plugs (OD9 and 289) and it performed the best on 50%, 60% and 65% Odonnell Punch fuel.
So, if you are looking for a durable engine to power a 4+ pound boat with big propellers and great RPM, the Beta is an excellent choice.
Respectfully,
Jim Wilson
