Classic SeaCraft Community

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- - New Engine (http://www.classicseacraft.com/community/showthread.php?t=29102)

Quote:

Originally Posted by JBASS02 (Post 258076)

I've done close to a thousand miles on the engine already. The islands which we spearfish are 26 miles offshore so a typical day is around 80-100 miles. The engine is great! It gets ~4.5 mpg for the average day could be better but I typically run 48-5000 in the morning. At ~4000rpm(~23mph) it's getting 5mpg at ~5200 it get 4mpg(~35mph). Yesterday was our first day of big seas and the boat did great. We left the harbor at 5:20am to glassy seas and got to around the 20 mile mark before we decided to abort and dive coastal, we couldn't see over the waves which where beginning to break... I'm planning to redoing the deck and possibly building a half height cuddy this winter so I'll wait till then to dial in the prop and go stainless.

Good god and I though i racked up the miles. 1000 in two months, just wow.
checked my odometer 4225 in two years. It sounds like a perfect fit to you and the boat. Best of luck.
Ed & Sue

Finally had a smooth day and was able to get some accurate numbers. I was running solo with spearfishing/freediving gear and 50 gals of fuel so on the light side. The mi/gal numbers are rough... +/- .0001 :D not sure who set that as the default significant figure?

Quote:

Originally Posted by Marshtackie (Post 258094)

The 90 E-tecs do fine. Lot’s of mid range torque with a very flat power curve. I don’t post much on the performance because I sound like another “Lying Fisherman”. I’ve worked mine like a dog since ‘06 on my “freighter”. I did have an EMM go out years ago, but that was covered under warranty. Other than that “touch the key and go”.

Hey T3, I'm not sure exactly what it was, but I think you forgot to load something!! I see some floor space available in the picture for some other stuff! :)

Quote:

Originally Posted by JBASS02 (Post 258891)

. . . The mi/gal numbers are rough... +/- .0001 :D not sure who set that as the default significant figure?

Yea, neither the MPH or GPH number are accurate to more than + 0.1 so any more than 1 decimal place is just looking at noise in the signal! What really counts at the end of the day is the overall average. My experience with the I-Command gage that provides instantaneous mpg is that the optimum speed for the 20’ hull is somewhere in the 22-25 mph range, which seems to be what your data shows and is about where it reaches minimum running angle.

The 1969 Boating Magazine test of the 20’ Seafari in the Literature section showed runnning angle decreased until speed reached 25 mph and then stayed constant until it reached ~ 35 mph. At that point it began to increase. I believe that’s because there is a slight wedge built into the aft 10’ or so of the outer panel, but that panel is completely out of the water at about 35 mph, which would eliminate the “trim tab” effect. If you lay a straight edge on the keel at the transom, it looks like there is a bit of rocker built into the inner panel, which would allow the bow to rise once most of the lift is coming from the center panel. That would allow the bow to rise and reduce wetted surface and increase top speed . . . Just one of many subtle but brilliant details that Moesly built into his designs that allowed his boats to dominate their classes in the Offshore Power Boat races!