Quote:
Originally Posted by jaxx 30
Were the engines dyno'd with the 750 carbs?
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Yes they were dyno'd with 750's. I believe I would have been over 600 with 850's. I also chose to use the Wieand Stealth dual plane intakes rather than a single plane Dart. I was told that going the 850 single plane way I would lose low end torque and push out the usable HP to 6500, but I would be well over 600HP. If you look at the dyno sheet between 4000 and 5750 it flatlined the TQ, Also the torque never drops off.
JimV put this combination together for me. He welded up my intake runners and ported them to match the wedge inserted intake runners on the heads. (this is not port matching, this is a full all out head port job) this changed the runner volume from 320cc to 315cc which increases torque. He knows his s#it.
What I thought was strange was with the Merc 425's my jetting was 77 6.5PV in front 87 no PV in the back. I actually had to jet down to 76 6.5PV front 82 no PV back with this combination.
The other engine will be done first of next week, I plan on being on the water next weekend to start trying props.