Thread subject: Whaler Central - Boston Whaler Boat Information and Photos :: Choosing propeller for Classic (1973) 13' Whaler Standard e-Tec 30
Posted by martindupre on 06/04/21 - 8:53 AM
#1
I have a 1973 13' Standard that I recently purchased a lightly used e-tec 30 HP for. The motor is rope-start 15" transom tiller steering (electric starter added).
I have just completed restoration of the boat and have not even had it in the water as of this writing. (Plan to launch it in a couple of days).
The motor came with a BRP stainless 10x13 3-blade. This will suffice for the majority of use which will be me alone or me and my wife.
I wish to purchase a 4-blade SS prop with less pitch to use on the occasions when I will have 4 adults in the boat, or alternately 2 adults and pulling a skier.
Now before anyone starts in I know it is not an ideal ski boat, and I know a 40 HP would pull a skier better. But the 13 with the 30 e-tec is what I have. Skiing, if it happens at all, would be occasional and no fancy stuff, just an adult on top of the water with a ski on each foot having a little fun.
I intend to buy a Solas Titan HR 4. If you were choosing for the applications just described, would you choose 10x11 or 10x10 ?
And by the way the boat is verified original weight; no water-logging. Oh, and for those with a sharp eye, yes, I know BW switched to 20" transom in 1972, but nevertheless mine is 15" and the capacity plate says "Standard" and max HP 40. The Whaler is somewhat of an anomaly.
Thank you.
Posted by Phil T on 06/04/21 - 9:11 AM
#2
Typically the recommendation when going from 3 to 4 blades is to drop 2" of pitch without changing diameter.
Posted by martindupre on 06/15/21 - 10:00 AM
#3
I chose the 4-blade 10x10. In an initial test, it delivered 25 mph at 6000 rpm with 3 adults aboard. 24 mph at 5700 rpm with 4 adults. Have yet to try skiing.
Posted by Phil T on 06/15/21 - 10:31 AM
#4
Martin, don't think that is a good cholce based on your speed.
With a 4 bladed stainless prop your WOT should be 28-30 running solo, a reduction from the 32 mph member's reported using the BPR 10"x13" stainless.
What is the brand and model of the 4 bladed 10x10?
Edited by Phil T on 06/15/21 - 10:31 AM
Posted by martindupre on 06/15/21 - 10:46 AM
#5
32 mph is what the 10x13 SS calculates to at WOT at 6000 rpm and 7% slip.
I have that prop also, and got 29 mph at 5700 with 2-200 lb adults aboard. That calcs at 11% slip. But I have not yet adjusted motor height. It is running with AV plate in the water, so I expect an increase after I raise it. I have not clocked it running solo as of yet.
The 10x10 4-blade is a Solas Titan HR 4. With only 10" pitch, I thought it was doing well at 25 mph.