Probably as many opinions on cruise speed as on best anchors, etc. Plus like
many simple questions, the answer: ‘It’s Complicated’ (also a local power boat
name!).
I faced this issue years ago when I decided to go to a 2 blade folding Gori
racing prop from my former 3 blade feathering prop. IIRC, it started with the
space I had for the prop to spin with minimal interference/maximum clearance
from the hull. This set the prop diameter and my waterline length along with
engine/transmission optimal rpm set the prop pitch to reach hull speed in flat
water.
In my case, it required a different transmission than the original that came
with my Beta 28 and which worked fine with my Max-Prop.
Anyhow my Beta has ~ maximum power at 3200 rpm with 3600 as redline and most
diesels like to be run and are designed to run near max rpm for various reasons.
Thus with guidance from Geoff at AB Marine and these parameters, I got the new
prop and transmission and now cruise in flat water at ~7.2-7.4 knots with 3200
rpm.
This was also my cruising speed before I made the changes but again the prop,
transmission and engine were ‘matched’ (mostly by Max-Prop blade diameter and
it’s adjustable pitch) to have the engine do 3000-3200 rpm and the boat get to
hull speed (+\-) at that rpm in flat water.
YMMV but this is my story and I’m sticking to it!
Charlie Nelson1995 C&C 36 XL/kcbWater Phantom
Sent from AOL Mobile Mail
Get the new AOL app: mail.mobile.aol.com
On Tuesday, June 23, 2020, Matt Wolford via CnC-List <cnc-list@cnc-list.com>
wrote:
#yiv1292176394 #yiv1292176394 -- _filtered {} _filtered {}#yiv1292176394
#yiv1292176394 p.yiv1292176394MsoNormal, #yiv1292176394
li.yiv1292176394MsoNormal, #yiv1292176394 div.yiv1292176394MsoNormal
{margin:0in;margin-bottom:.0001pt;font-size:11.0pt;font-family:sans-serif;}#yiv1292176394
a:link, #yiv1292176394 span.yiv1292176394MsoHyperlink
{color:blue;text-decoration:underline;}#yiv1292176394
span.yiv1292176394EmailStyle18
{font-family:sans-serif;color:windowtext;}#yiv1292176394
.yiv1292176394MsoChpDefault {font-family:sans-serif;} _filtered
{}#yiv1292176394 div.yiv1292176394WordSection1 {}#yiv1292176394
My decades-old Westerbeke 40 is happy at 2000 RPM, maybe slightly more, which
produces a solid 6.5 knots in good weather.
On Tue, Jun 23, 2020 at 9:53 AM Rob Hamlin via CnC-List <cnc-list@cnc-list.com>
wrote:
Hi
What is everyone’s motor/ rpm optimal motoring speed?
Thanks
Rob
Sent from my iPhone
_______________________________________________
Thanks everyone for supporting this list with your contributions. Each and
every one is greatly appreciated. If you want to support the list - use PayPal
to send contribution -- https://www.paypal.me/stumurray
_______________________________________________
Thanks everyone for supporting this list with your contributions. Each and
every one is greatly appreciated. If you want to support the list - use PayPal
to send contribution -- https://www.paypal.me/stumurray
_______________________________________________
Thanks everyone for supporting this list with your contributions. Each and
every one is greatly appreciated. If you want to support the list - use PayPal
to send contribution -- https://www.paypal.me/stumurray
