commander problems

[boxscore]

Originally posted by SLAPPING_GLASS
Ok fine my mistake then is htm also changing how much blade there is.There is 2 things to consider with props pitch and how ong the blades are. I did nt know if he was talking about pitch or how long the blades were.But I guess after thinking about it a prop 26 across would be pretty damn big...
HEH?

[syke-o]

Originally posted by SLAPPING_GLASS
Ok fine my mistake then is htm also changing how much blade there is.There is 2 things to consider with props pitch and how ong the blades are. I did nt know if he was talking about pitch or how long the blades were.But I guess after thinking about it a prop 26 across would be pretty damn big...

[boxscore]

Of course you need no first figure out why the motor is not running max RPM's.... Mercruiser mechanic is the first stop. Once the motor RUNS... then, evaluate whether you like the hull/customer service from Commander. If you don't, and are able to cut bait and want to enjoy a quality boating existence, look up Ultra (John West), or Laveycraft. They'll help you with your boat and set you up with kick-ass summer after kick-ass summer.

[SLAPPING_GLASS]

Besides prop pitch they also measure the prop form tip to tip across.Now do you follow

[SLAPPING_GLASS]

So not only does prop pitch affect rpm but so does the tip to tip length.I forget which way it works off the top of my head but i believe an increase in tip to tip will decrease rpm by 100 .When you jump up from a lets say 17 pitch to a 19 your rpm jumps up aprox 300 rpm so if you were running a 15x17 prop at 4700 rpm and you wanted to be at 4900 rpm wot. You want an increase of 200 rpm. So you would go to a 16x19 16 tip to tip would decrease your rpm by 100 but a 19 pitch would be 300 more rpm for a total increase of 200 rpm correct.
RPM GOAL 4900 WOT
Strating prop 15x17=4700 RPM
Need RPM increase of 200
so we add 1 inch to tip to tip drops RPM BY 100
Now we change pitch to 19 add 300 rpm
walla 4900 RPM
Or is all of this visa versa
LOL

[Freak]

Thanks for starting my day with some good laughs guys. I love this place.

[Essex502]

Slapping Glass - try this book:
Propellor Handbook (http://www.amazon.com/exec/obidos/tg...glance&s=books)

[Essex502]

BTW....proper term is not tip to tip lenght but "diameter".

[OGShocker]

Originally posted by Essex502
BTW....proper term is not tip to tip lenght but "diameter".
Thank you for backing me up on this! I have been telling the Mrs, "it's all about the diameter" for years!

[Essex502]

Not if you have "2 tips"! I think you're referring to "girth" as the proper term for what you have in mind!