I dyno tested my 527 C.I 440 block motor last week in Klamath Falls OR on a DTS engine dyno (the dyno is two years old ) I had tested this motor before on a Studka dyno and wanted to run it the same way as before on the DTS dyno to compare the results. The Studka dyno is in Madras OR at around 2300 ft. above sea level, the DTS dyno in Klamath falls is at 4100 ft. above sea level. The weather was similar on both days, not exactly the sasme though The Studka dyno doesn't use a flywheel on the motor and the DTS does require one, I used a 143 tooth aluminum flywheel on the tests done in Klamath, which the dyno owner and operator said made the inertia factor at 1.86, what ever that means The inertia factor on the Studka was 1.31, if I'm remembering correctly The other difference was the fuel, I used a different brand of fuel in June on the Studka dyno than I did last week on the DTS dyno tsts, Both brands are rated at 110 octane The results in June using a 440-2 intake with a tapered adapter to a 4500 carb and a one inch phenolic spacer using a Holley 9375-2 HP carb. with 86 jets squared with 34 degrees of timing was 875 HP at 6100 RPM and 806 ft. lbs torque at 5300 rpm. The motor ended up breaking a pushrod before I was done testing all the things I wanted to test, which was one of the reasons I wanted to retest it again. On the DTS dyno the same combination made a best of 776 Hp at 6100, 6200 and again at 6400 RPM, the torque was 724ft. lbs. from 5100 to 5300 RPM The average torque on that test was 695 and the average HP was 693, we tested it from 4000 rpm to 6500 rpm, the AFR sensors showed it to be lean so we jetted it up to 88 squared for the next tests. the motor lost 1 HP at peak and 1 ft. lb of torque That made me thank that there wide ban sensor was goofy We also added timing from 34 degrees total to 36 which ended up losing another one HP and one ft. lb at peak I put the timing back to 33 and then tested several differnt K&N air filters, the 16x3 with a steel lid lost a little power (3 HP and 4 ft. lbs) and the 14x6 with the extreme lid made the exact same power as no air cleaner I then switch pushrods from a set of Smith Bros. 083 wall to a set of Manton .120 wall with the exact same length, that change ended up making 5 more HP and 4 more ft. lbs torque The dyno operator builds and tests a lot of roundy round motors and he was impressed with those results, just like I was I then switch the intake and carbs to a Indy tunnel ram with the dual 4500 top and a set of 1050 Dominator Holley # 9375 non HP carbs. with the stock jetting, 92 squared. The motor lost power and torque with that jetting, it made a best of 759 hp with 690 ft. lbs torque The AFR showed real rich so we rejetted it down several times 4 sizes each time until it got to 80 squared which made 799 hp and 727 ft. lbs. We then installed a set of K&N air filters, 9x6 with extreme filter lids, which helps the air flow into the carbs. That change made the best pull of the day with 803 HP at 6100 RPM and 732 ft. lbs at 5200 rpm I am pleased with the tests and the results, we made 23 pulls and the motor is still together Just kidding I am going to be able to retest it again on the
Studka dyno using the same fuel as I used in Klamath with no changes to the motor next week so we will know what the actual differences between the two dyno are We will test it with the flywheel and without the flywheel to see what that does to the test results Sorry for so long a posts, IHTH some of you Edit at 11:44 PM PDT 09-23-09 I just remembered one other difference between the Studka and the DTS dyno rooms, the DTS had a very strong exhaust fan, a lot stronger than the one on the Studka dyno room. the one on the DTS would pull a strong enough vacume that I had to struggle to get the door open into the dyno room when the fan was running, it formed a vacume. (shock) The Studka dyno fan has never made that much vacume under any condition. We do leave both doors open into the Studka dyno room and turn the fan up all the way but there is no noticeable vacume in the room under any condition