I have twin Crusader 270's with Voyager electronic ignitions (replaced old points distros). Our usual long trips have been around 70-90 miles RT. I have an issue where my port throttle does not scale the same rate as my starboard. They start even, but mid way I have to throttle-up the port to keep sync. Towards the top end (3200-3400) it gets closer, but still does not even out. I can get to about 4100 WOT on each. Last summer, port side blew head gasket (hour meter reads 750, but three have been several owners, and not sure if its original hour meter, or original gasket on engine).
I replaced Head Gasket, and could never seem to get port to run/feel right. Well, this summer, it "seems" to have settled in. I did have the heads re-done when I replaced the head gasket, so I don't know if it had to break-in a bit or what. I also replaced the carb on that side (when I was trying to get it right after the head gasket replacement). So I don't know if the throttle scaling has anything to do with the new carb, or if port is just getting tired. I did a compression test, and all cylinders where all within 5 PSI and if I recall, was 140-150ish PSI (cant recall exactly, but I remember it seemed within spec by the book). To maybe help, I just installed two digital tachometers, so hopefully I will get a more accurate reading. I did not run new wire to the distro though, just used old wiring to new tach.
Aside from that, I was wondering if anyone knows what the cruising speed/rpm (I realize will vary by conditions etc.) of this hull design with my engines. I am trying to determine my GPH for several longer trips. I normally push her at 3200 RPM, but thats primarily because that is the range I grew up with.. seems like most of my boating experience had the crusing RPM at 3200. Realizing that even 100 RPM variance can make a huge GPH change, and (until now) have had no accurate RPM guage, I just want to see what others are running. I dont need to "beat the fleet" but I dont want to run like a snail either. I'm happy at 20 KTS. but more concerned about econemy, and I dont know the sweet spot yet on this vessel.
I'm starting to look into fuel-flow guages, but didnt know those could be installed easily on such an old boat.
Any input, suggestions etc.. would be greatly appreciated.