HPBCANADA.COM

I 100% believe the 101mph record, I've spoken to Rolf a lot, he is tuning my 70ces. I thought I had tested lots of different things on this engine but doubt I've even tried 5% of the things he has. There has been a few dyno tests of the 70ces over here, seemingly the max was 115hp, most tuned are around 95-105.

Always knew we weren’t getting the straight goods from yeah Dok...sand bagger!!

This fall on a cool day with Matt at the cottage I did manage a solid 65 mph at 6200 rpm with the Rapidcraft and Merc 60 4 stroke, when I re-borrowed the Jeff Brown SE winning prop [that I got from Jeff Baker and sold to Rick who I believe hasn't tried it yet but who lent it to Matt]. That's a 12" prop that Jeff thought was 25 pitch but I'm not certain the pitch is quite that high. Anyway, takes a while to get up to that speed 'cause the RC/Merc combo is a bit on the heavy side. Still fun, though.

Thanks for the first hand information, With Rolf tuning your motor to 95-105 hp you should see the big improvement in your boats performance.....please keep us informed.

Ron Hill makes a Jeff Brown cleaver if anyone is interested.
I have one and it's my best prop

Is the Hill/Jeff Brown Cleaver a four blade prop? I see one that is 12 1/2" x 22" pitch on their site.

Mine is the 12.5x22 3 blade
Wouldn't surprise me if it was higher in the pitch as advertised
My 56 OMC Stinger with nitro foot does 68 MPH at 6100 RPM

I also have a Ron Hill 3 blade over hub 12.5" 22 pitch that Kawartha re-worked a bit and cut down to 12". With that, 64 mph at 6200 rpm on the Rapidcraft/4 stroke 60 Merc combo. Of course another variable is prop height -- on the RC, centre of shaft is 1.75" below the transom. The motor could possibly go a bit higher [but gets complicated doing that with my setup].

How much set back are you running, Tom?

Little as possible. I first had Bob's Machine reversible jack plates at the min ~ 2" setting, but couldn't get the motor angled in enough to get out of the hole well, based on the transom angle on the RC. So I replaced those with two Bob's wedges, installed to allow the motor to tuck in more, and that worked fine. Could I benefit from more setback? Not sure. Motor is relatively heavy, so I thought maybe it should be a little closer in.