Old prop rendered scrap, room for improvement on new one on Volvo 280?

[RogersJetboat454]

Hello all,

I am in need of a new prop for a Volvo 280 short hub, with an AQ170b engine. All this is attached to a '76 Glastron 18' V-184.

Last year the old prop got bent up while leaving a sand bar. It is a 3 blade 14X19P.
Not sure of the manufacturer, but I am pretty sure its not VP. The prop had pretty satisfactory performance, other than having some difficulty with coming getting on plane with a fully loaded boat.

Here are some figures off the top of my head;

With just me in the boat, 1/2- 3/4 of a tank of gas my average speed is 45-47 mph at 4700-5000 RPM. The WOT RPM range for this engine is 4600-5000.
The drives gear ratio is 1.89:1. It is currently set up for a counter rotation prop (not sure why, previous owner maybe?).

I have been looking at the Iboats props, and it would seem that Solas has some props that are in my price range.

My questions are;
#1 Am I correct that a 270 short hub prop will fit my 280 short hub?
Iboats does not have a listing for a 280 short hub.

#2 From everything I have read, switching to a 4 blade over a 3 will decrease my time to get on plane W/ a loaded boat. If I elect to go the 4 blade route, Should I stick with a 14X19 or change it to something else? Keep in mind I have no illusions that this old run-about is really a cigarette boat in disguise. If I loose a couple MPH top end for better take off, and lower acceptable WOT RPM's, so be it.

#3 If I stick with a 3 blade prop, would I notice any difference if the prop diameter is changed? What would change between using a 14 and 15" 19P prop, if anything?


Thanks in advance for any help you could provide.

 

[usskydvr]

Re: Old prop rendered scrap, room for improvement on new one on Volvo 280?

1. Yes
2. Stick with the 19 pitch, don't worry about the dia as the prop Mfg design parameters will determine the correct dia. for their pitch.
3. There may be 'minor' improvement in hole shot with the 15" dia vs the 14"
(both with the same pitch)

 

[RogersJetboat454]

Re: Old prop rendered scrap, room for improvement on new one on Volvo 280?

Thanks for the response.

I just ordered the Solas 4 blade 19P 14" prop. The extra blade cost $.38 more than what the comparable 3 blade was. Lets see how it works out in August....

 

[RogersJetboat454]

Re: Old prop rendered scrap, room for improvement on new one on Volvo 280?

Just wanted to post a follow up...

Installed the 19P 14" Solas 4 blade. Hole shot seems good. Midrange nice and smooth as to be expected with a 4 blade prop. Top end was 40MPH @ 4200 RPM WOT. The WOT RPM is about 400 RPM lower than the 4600-5000 RPM range Volvo states, but it doesn't bother me much. I expect the RPM to come up a little when some fresh fuel is added (still has old fuel from last year). I am also toying with the thought of picking up the 17P 4 blade... but we shall see.