288's -w- 496HO prop tweakings?...

[Reckless32]

Just Pondering....

With my 496HO stock-box 24P Bravo 4-blade I'm getting 5K RPM on the nose and 69.2 (gps) in great conditions. I've resisted doing anything because as a mostly rough/choppy water runner it wasn't worth the effort to do any tweaking because top-end is rarely encountered. I get no prop blow out whatsoever, either out of the hole or in a hard turn, and I don't want to lose that ability to play the boat...I don't want labbed either because they're too sensitive and in the waters (S. ChesBay/Atlantic) I run in, encountering an occasional sand bar with oyster shells etc. is commonplace...

Has anyone with the same configuration tried any changes either to their original props or with say a Hydromotive, etc and found successful results?? I've got an old spare 24P Bravo that I could experiment with...

Rick

[KN]

I wonder how the New 5 blade Hydromotive would work, But at over $1000 a prop. I wouldn't want to be the one experimenting with it.

Kirk

I'll let you know soon. I had the guys at Sunsation "tweak" my prop over the winter.

[Reckless32]

J-boy, what kind of tweaking of the prop are you having done and how did you come to the conclusion that was the tweak to do?

[Lee]

Reck, It involves trimming a little off the leading edge of the prop which results in a 100-200 RPM increase.

Reckless...

send an email to Dave at Sunsation or actually Wayne. He did the work and either "dished" or "cupped" the prop for higher speed. I forget exactly what he did, but he'll be able to answer. It was his idea for a few more MPH.

- jeff

[Lee]

Jeffreyboy, See above post.

[KN]

Lee is this just blue printing the prop or is it not to that extent. did they do it inhouse or send it out. Do you think it would have the same result on a 32' with 28'' Bravo's. Did you do the same to your 32'? if so what were the reults?

Thanks Kirk

[Lee]

Kirk, No it is not blueprinting, it is a little trick that Wayne does to raise the RPM's , since all Merc factory stock props vary a little in pitch from their marked pitch, this is usually done to either raise the RPM in a single or to Raise the RPM in a twin to match the other engine. It involves applying layout dye (blue) on the leading edge then scribing the leading edge with a pair of calipers I think it is usually around .180" then grind the scribed portion off and touch it up with a file, an instant 100-200 RPM on a BravoI

[KN]

Thanks Lee, now you have raised another question, do you know if there is an engine syncronizer (SP?) to keep the rpm's on both engines the same, installed from the factory. I've never had a twin engine boat before and wondered how to deal with, the engines turning different RPM's.

Thanks Kirk