Fuel Numbers for my "Speed Demon" (not)

[Miles Offshore]

Have been playing with my new navman and gotten some interesting results for you inboard guys if you like. 350 magnum 270 hp PCM inboard and I am currently turning an old ,tired 17"/15 pitch wheel-with the following results- 3000 rpm's 20 knots at 9.5 to 10 gallons an hour. 3200 rpm's 22 knots at 12-12.5 gallons an hour. 3800 rpms 25 to 27 knots at 20 gallons an hour. Funny how my new tach only reads WOT at 3800. The old tach read 4200 rpms. Boat tachs have always IMO been P.O.S.
The 17/15 is not real efficient but is a great trolling wheel because I can troll real slow during rockfish season. I believe a 16"/17 pitch is what originally came on the boat. I am going to reprop it soon and am still debateing on the 16"/17 pitch 3 blade or a 16/16 4 blade both cupped.I think both my economy and speed will increase preety much although that slow trolling speed will be gone. Most of my rockfishing anyways is from November into february so I can change the wheel if need be.

I support the "BIG FISH CATCH AND RELEASE THEORY"

craig

[John R]

Miles - drag a bucket or a board of the stern, will slow you down from the fast troll...

[ocuyler]

I support the "BIG FISH CATCH AND RELEASE THEORY"

<font size="2" face="Verdana, Helvetica, sans-serif">Amen, brother.

[PipeDreamsMarine]

Miles... I'd get a good Tach before I'd start playing with wheels. I have a good number of years messing with inboard boats. But it's your choice if you beleive me or not.. But your not turning up to max RPM's (if the new tach is right)with the 17/15 wheel. 1 inch of Diam is 1000 RPMS and 1" of pitch is 500 rpm's. Your at 3800 with the 17/15, knock 1" of Diam. off and your up to 4800 that's about 200 over max for your motor, so add a little cup and it should be just right. The 16/17 is allmost the same wheel, just at lower rpms(idle speed)your gonna move faster. I'd look at a 16/15 with a cup, A case of beer says I hit it right on the money [img]images/icons/shocked.gif[/img]

[Miles Offshore]

Thanx Don,I appreciate the advice. Im going to put one of those timing gun tachs on it and see where its at. I really think the old tach was right and the new one isnt. She seems to be turning up real well, and btw I drink Bud or Corona's. [img]images/icons/cool.gif[/img]

[PipeDreamsMarine]

Miles.. Sounds like a good plan..but if the new tach is wrong all bets are off.. [img]images/icons/tongue.gif[/img] .. Your close with the old tach, I'd just have the wheel worked and it just may turn up.. But Corona's it will be.. cuz themz Budz give me a killer head ache.. But on another note..hows the tuna fishing been off shore, any size yet?.. I see that the VA.Beach bouy has some nice water temps. I'm planing to start running to the Dog soon..