DynoDon
Moderator
I just thought I would share this with you guys
I wanted to share some information with you guys about H.P. numbers. I have three guys near me that have three different dyno's. Oil, water and inertia. they all will give different numbers. I use mine as a comparator more than a true H.P. number machine. Although mine was calibrated to a well known engine builders dyno about 8 years ago, I still do a basic check with a harbor freight 6.5 at 3600 rpm to see how close it is. It checks positive each time. In the above post I said My purple plates were close to 9 horse. I decided to pull the paper on the last purple one I did. I have the H.P. numbers before the new 2015 head rules and the new numbers after I did the head work.
Before head work: Correction factor 1.0155972 ( H.P. formula: torque X .525=_______ X rpm=_______ divide 5252= ________ X c.f.= H.P._______
18 torque @ 3940 rpm 7.19
17 torque @ 4300 rpm 7.42
16 torque @ 4770 rpm 7.74
15 torque @ 5150 rpm 7.84
14 torque @ 5620 rpm 7.98
13 torque @ 6000 rpm 7.91
12 torque @ 6390 rpm 7.78
After head work: correction factor: 1.0379777
18 torque @ 4580 rpm 8.55
17 torque @ 4910 rpm 8.66
16 torque @ 5060 rpm 8.40 engine flutter!!
15 torque @ 5570 rpm 8.66
14 torque @ 5890 rpm 8.55
13 torque @ 6070 rpm 8.18
12 torque @ 6240 rpm 7.76
This engine was a full rebuild with the standard piston. Dynoed with the 2014 rules and then the head was disassembled and done to the 2015 rules and redynoed on the next day. My H.P. numbers may be higher than some one elses but based on the knowledge I have about "MY" dyno, I am able to see the difference in the change I made.
I wanted to share some information with you guys about H.P. numbers. I have three guys near me that have three different dyno's. Oil, water and inertia. they all will give different numbers. I use mine as a comparator more than a true H.P. number machine. Although mine was calibrated to a well known engine builders dyno about 8 years ago, I still do a basic check with a harbor freight 6.5 at 3600 rpm to see how close it is. It checks positive each time. In the above post I said My purple plates were close to 9 horse. I decided to pull the paper on the last purple one I did. I have the H.P. numbers before the new 2015 head rules and the new numbers after I did the head work.
Before head work: Correction factor 1.0155972 ( H.P. formula: torque X .525=_______ X rpm=_______ divide 5252= ________ X c.f.= H.P._______
18 torque @ 3940 rpm 7.19
17 torque @ 4300 rpm 7.42
16 torque @ 4770 rpm 7.74
15 torque @ 5150 rpm 7.84
14 torque @ 5620 rpm 7.98
13 torque @ 6000 rpm 7.91
12 torque @ 6390 rpm 7.78
After head work: correction factor: 1.0379777
18 torque @ 4580 rpm 8.55
17 torque @ 4910 rpm 8.66
16 torque @ 5060 rpm 8.40 engine flutter!!
15 torque @ 5570 rpm 8.66
14 torque @ 5890 rpm 8.55
13 torque @ 6070 rpm 8.18
12 torque @ 6240 rpm 7.76
This engine was a full rebuild with the standard piston. Dynoed with the 2014 rules and then the head was disassembled and done to the 2015 rules and redynoed on the next day. My H.P. numbers may be higher than some one elses but based on the knowledge I have about "MY" dyno, I am able to see the difference in the change I made.