[frers-list]Propeller Sizing
Rod Stright
frers-list@lists.frers33.com
Thu, 26 Mar 2020 17:19:56 -0300
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Thanks Art that was for a Max Prop but the pitch is likely close. I would c=
ontact Fred as he is a wealth of knowledge but you need to have the transmis=
sion ratio and the info on your engine.
Stay safe
Rod=20
Sent from my iPhone
>> On Mar 26, 2020, at 4:49 PM, Art Kelley <akelley@optonline.net> wrote:
> =EF=BB=BFI found the old posting regarding an oversized prop. Not saying i=
t=E2=80=99s the right answer, just additional input.=20
>=20
> Hi Bill,
> =20
> =20
> I have a 17" Max prop on Equinox. I started out with 18 degrees and
> increased it to 20 degrees as I could only get 4.5 kts at 2800 rpm. It
> depends on your engine and the gear ratio of your transmission (marked on a=
> plate on the transmission). I would contact Fred as he is a wealth of
> information and knows a lot about the maxprop. You will need the model
> number of your engine as well as well as the transmission ratio. If your
> gear ratio is the same as mine you likely need 2 degrees more pitch than I=
> do since your prop is smaller. The problem I encountered was that I had t=
o
> turn 3200 rpm to get close to 6 knots and the engine would overheat
> quickly. With the 20 degree settings I get an easy 6 knots at 2700 rpms a=
nd
> she backs up like a dream and doesn't overheat. The twenty degree angle
> equals about 11.5 inches of pitch.
> =20
> Fred Hutchison
> 12532 Beverly Park Rd.
> Lynnwood, WA 98087
> Tel: 425-355-3669
> Fax: 425-355-3661
> E-mail: hutch@pyiinc.com
> Web: www.pyiinc.com
> Regards
> Rod
> =20
>=20
> Art
>=20
>>> On Mar 26, 2020, at 2:57 PM, Art Kelley <akelley@optonline.net> wrote:
>> =EF=BB=BF16x10 was the original prop. Somewhere in our archives there was=
a description of someone going to a longer blade, says there is room for th=
at.=20
>>=20
>> I fixed the problem I had last year when I couldn=E2=80=99t get full spee=
d from my engine. The throttle cable finally snapped and when I put the new o=
ne on, I found the revs I had lost over the years. I am back to getting 360=
0-3800 ROM. Much cheaper than a new prop.=20
>>=20
>> Art
>>=20
>>>> On Mar 26, 2020, at 1:02 PM, Jerry Black <jcblack099@aol.com> wrote:
>>> =EF=BB=BF
>>> I have a 2 bladed max-prop feathering. 6 kts at 2,000rpm. Best thing is=
that when backing down you get the same thrust since the bldes rotate 180 d=
eg. Also I don't have to align the shaft to insure folding. My preferred opt=
ion if I have to replace.
>>>=20
>>> Jerry Black
>>> Pelirrojas
>>>=20
>>>=20
>>> -----Original Message-----
>>> From: Brian Higgins <brian@sailingit.com>
>>> To: frers-list@lists.frers33.com <frers-list@lists.frers33.com>
>>> Sent: Thu, Mar 26, 2020 11:42 am
>>> Subject: [frers-list]Propeller Sizing
>>>=20
>>> When running at 2900RPM (race clean & prepped bottom) in pretty flat (<1=
ft seas) water and light wind, I'm usually doing about 5.2-5.4kts, where it s=
eems like I should be doing at least 6kts at that RPM. Further I=E2=80=99ve=
never found where the throttle actually stops because it reaches max RPM be=
fore it runs out of power (also suggesting not enough propeller).
>>> =20
>>> My prop is the same Martec 16x10 two blade folding prop that at least a c=
ouple other boats have (I definitely spied on a few of your props in the boa=
tyard recently =F0=9F=98=88). Does anyone have experience going to a higher=
pitch, something like a 12=E2=80=9D opposed to the 10=E2=80=9D? Some gener=
ic calculations I looked up suggested a 13=E2=80=9D, and Gary from Martec s=
aid he too thought 10 was underpitched for the boat but suggested 12 as prob=
ably the right pitch. Before I send the prop off (it=E2=80=99s already remo=
ved for the cutlass bearing replacement), I wanted to check and see if anyon=
e has done testing and played with repitching the prop.
>>> =20
>>> Sent from Mail for Windows 10
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<html><head><meta http-equiv=3D"content-type" content=3D"text/html; charset=3D=
utf-8"></head><body dir=3D"auto"><div dir=3D"ltr"><meta http-equiv=3D"conten=
t-type" content=3D"text/html; charset=3Dutf-8">Thanks Art that was for a Max=
Prop but the pitch is likely close. I would contact Fred as he is a w=
ealth of knowledge but you need to have the transmission ratio and the info o=
n your engine.</div><div dir=3D"ltr"><br></div><div dir=3D"ltr">Stay safe</d=
iv><div dir=3D"ltr"><br></div><div dir=3D"ltr">Rod <br><br><div dir=3D"=
ltr">Sent from my iPhone</div><div dir=3D"ltr"><br><blockquote type=3D"cite"=
>On Mar 26, 2020, at 4:49 PM, Art Kelley <akelley@optonline.net> wrote=
:<br><br></blockquote></div><blockquote type=3D"cite"><div dir=3D"ltr">=EF=BB=
=BF<meta http-equiv=3D"content-type" content=3D"text/html; charset=3Dutf-8">=
I found the old posting regarding an oversized prop. Not saying it=E2=80=99s=
the right answer, just additional input. <div><br></div><div><p class=3D=
"MsoNormal" style=3D"-webkit-text-size-adjust: auto; margin: 0in 0in 0.0001p=
t; font-size: 11pt; font-family: Calibri, sans-serif;"><span style=3D"font-s=
ize: 10pt; font-family: Arial, sans-serif;">Hi Bill,<o:p></o:p></span></p><p=
class=3D"MsoNormal" style=3D"-webkit-text-size-adjust: auto; margin: 0in 0i=
n 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;"><span style=3D=
"font-size: 10pt; font-family: Arial, sans-serif;"> </span></p><p class=
=3D"MsoNormal" style=3D"-webkit-text-size-adjust: auto; margin: 0in 0in 0.00=
01pt; font-size: 11pt; font-family: Calibri, sans-serif;"><span style=3D"fon=
t-size: 10pt; font-family: Arial, sans-serif;"><o:p></o:p></span></p><p clas=
s=3D"MsoNormal" style=3D"-webkit-text-size-adjust: auto; margin: 0in 0in 0.0=
001pt; font-size: 11pt; font-family: Calibri, sans-serif;"><span style=3D"fo=
nt-size: 10pt; font-family: Arial, sans-serif;"> </span></p><p class=3D=
"MsoNormal" style=3D"-webkit-text-size-adjust: auto; margin: 0in 0in 0.0001p=
t; font-size: 11pt; font-family: Calibri, sans-serif;"><span style=3D"font-s=
ize: 10pt; font-family: Arial, sans-serif;">I have a 17" Max prop on Equinox=
. I started out with 18 degrees and<o:p></o:p></span></p><p class=3D"M=
soNormal" style=3D"-webkit-text-size-adjust: auto; margin: 0in 0in 0.0001pt;=
font-size: 11pt; font-family: Calibri, sans-serif;"><span style=3D"font-siz=
e: 10pt; font-family: Arial, sans-serif;">increased it to 20 degrees as I co=
uld only get 4.5 kts at 2800 rpm. It<o:p></o:p></span></p><p class=3D"=
MsoNormal" style=3D"-webkit-text-size-adjust: auto; margin: 0in 0in 0.0001pt=
; font-size: 11pt; font-family: Calibri, sans-serif;"><span style=3D"font-si=
ze: 10pt; font-family: Arial, sans-serif;">depends on your engine and the ge=
ar ratio of your transmission (marked on a<o:p></o:p></span></p><p class=3D"=
MsoNormal" style=3D"-webkit-text-size-adjust: auto; margin: 0in 0in 0.0001pt=
; font-size: 11pt; font-family: Calibri, sans-serif;"><span style=3D"font-si=
ze: 10pt; font-family: Arial, sans-serif;">plate on the transmission). =
I would contact Fred as he is a wealth of<o:p></o:p></span></p><p class=3D"=
MsoNormal" style=3D"-webkit-text-size-adjust: auto; margin: 0in 0in 0.0001pt=
; font-size: 11pt; font-family: Calibri, sans-serif;"><span style=3D"font-si=
ze: 10pt; font-family: Arial, sans-serif;">information and knows a lot about=
the maxprop. You will need the model<o:p></o:p></span></p><p class=3D=
"MsoNormal" style=3D"-webkit-text-size-adjust: auto; margin: 0in 0in 0.0001p=
t; font-size: 11pt; font-family: Calibri, sans-serif;"><span style=3D"font-s=
ize: 10pt; font-family: Arial, sans-serif;">number of your engine as well as=
well as the transmission ratio. If your<o:p></o:p></span></p><p class=3D"Ms=
oNormal" style=3D"-webkit-text-size-adjust: auto; margin: 0in 0in 0.0001pt; f=
ont-size: 11pt; font-family: Calibri, sans-serif;"><span style=3D"font-size:=
10pt; font-family: Arial, sans-serif;">gear ratio is the same as mine you l=
ikely need 2 degrees more pitch than I<o:p></o:p></span></p><p class=3D"MsoN=
ormal" style=3D"-webkit-text-size-adjust: auto; margin: 0in 0in 0.0001pt; fo=
nt-size: 11pt; font-family: Calibri, sans-serif;"><span style=3D"font-size: 1=
0pt; font-family: Arial, sans-serif;">do since your prop is smaller. T=
he problem I encountered was that I had to<o:p></o:p></span></p><p class=3D"=
MsoNormal" style=3D"-webkit-text-size-adjust: auto; margin: 0in 0in 0.0001pt=
; font-size: 11pt; font-family: Calibri, sans-serif;"><span style=3D"font-si=
ze: 10pt; font-family: Arial, sans-serif;">turn 3200 rpm to get close to 6 k=
nots and the engine would overheat<o:p></o:p></span></p><p class=3D"Ms=
oNormal" style=3D"-webkit-text-size-adjust: auto; margin: 0in 0in 0.0001pt; f=
ont-size: 11pt; font-family: Calibri, sans-serif;"><span style=3D"font-size:=
10pt; font-family: Arial, sans-serif;">quickly. With the 20 degree se=
ttings I get an easy 6 knots at 2700 rpms and<o:p></o:p></span></p><p class=3D=
"MsoNormal" style=3D"-webkit-text-size-adjust: auto; margin: 0in 0in 0.0001p=
t; font-size: 11pt; font-family: Calibri, sans-serif;"><span style=3D"font-s=
ize: 10pt; font-family: Arial, sans-serif;">she backs up like a dream and do=
esn't overheat. The twenty degree angle<o:p></o:p></span></p><p class=3D=
"MsoNormal" style=3D"-webkit-text-size-adjust: auto; margin: 0in 0in 0.0001p=
t; font-size: 11pt; font-family: Calibri, sans-serif;"><span style=3D"font-s=
ize: 10pt; font-family: Arial, sans-serif;">equals about 11.5 inches of pitc=
h.<o:p></o:p></span></p><p class=3D"MsoNormal" style=3D"-webkit-text-size-ad=
just: auto; margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri,=
sans-serif;"><span style=3D"font-size: 10pt; font-family: Arial, sans-serif=
;"> </span></p><p class=3D"MsoNormal" style=3D"-webkit-text-size-adjust=
: auto; margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, san=
s-serif;"><span style=3D"font-size: 10pt; font-family: Arial, sans-serif;">Fre=
d Hutchison</span></p><p class=3D"MsoNormal" style=3D"-webkit-text-size-adju=
st: auto; margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, s=
ans-serif;"><span style=3D"font-size: 10pt; font-family: Arial, sans-serif;"=
><a href=3D"x-apple-data-detectors://1" dir=3D"ltr" x-apple-data-detectors=3D=
"true" x-apple-data-detectors-type=3D"address" x-apple-data-detectors-result=
=3D"1" style=3D"color: currentcolor; text-decoration-color: rgba(127, 127, 1=
27, 0.380392);">12532 Beverly Park Rd.</a></span></p><p class=3D"MsoNormal" s=
tyle=3D"-webkit-text-size-adjust: auto; margin: 0in 0in 0.0001pt; font-size:=
11pt; font-family: Calibri, sans-serif;"><span style=3D"font-size: 10pt; fo=
nt-family: Arial, sans-serif;"><a href=3D"x-apple-data-detectors://2" dir=3D=
"ltr" x-apple-data-detectors=3D"true" x-apple-data-detectors-type=3D"address=
" x-apple-data-detectors-result=3D"2" style=3D"color: currentcolor; text-dec=
oration-color: rgba(127, 127, 127, 0.380392);">Lynnwood, WA 98087</a></span>=
</p><p class=3D"MsoNormal" style=3D"-webkit-text-size-adjust: auto; margin: 0=
in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-serif;"><span s=
tyle=3D"font-size: 10pt; font-family: Arial, sans-serif;">Tel: <a href=3D=
"tel:425-355-3669" dir=3D"ltr" x-apple-data-detectors=3D"true" x-apple-data-=
detectors-type=3D"telephone" x-apple-data-detectors-result=3D"3" style=3D"co=
lor: currentcolor;">425-355-3669</a></span></p><p class=3D"MsoNormal" style=3D=
"-webkit-text-size-adjust: auto; margin: 0in 0in 0.0001pt; font-size: 11pt; f=
ont-family: Calibri, sans-serif;"><span style=3D"font-size: 10pt; font-famil=
y: Arial, sans-serif;">Fax: <a href=3D"tel:425-355-3661" dir=3D"ltr" x-=
apple-data-detectors=3D"true" x-apple-data-detectors-type=3D"telephone" x-ap=
ple-data-detectors-result=3D"4" style=3D"color: currentcolor;">425-355-3661<=
/a></span></p><p class=3D"MsoNormal" style=3D"-webkit-text-size-adjust: auto=
; margin: 0in 0in 0.0001pt; font-size: 11pt; font-family: Calibri, sans-seri=
f;"><span style=3D"font-size: 10pt; font-family: Arial, sans-serif;">E-mail:=
<a href=3D"mailto:hutch@pyiinc.com" dir=3D"ltr" x-apple-data-detectors=
=3D"true" x-apple-data-detectors-type=3D"link" x-apple-data-detectors-result=
=3D"5" style=3D"color: currentcolor;">hutch@pyiinc.com</a></span></p><p clas=
s=3D"MsoNormal" style=3D"-webkit-text-size-adjust: auto; margin: 0in 0in 0.0=
001pt; font-size: 11pt; font-family: Calibri, sans-serif;"><span style=3D"fo=
nt-size: 10pt; font-family: Arial, sans-serif;">Web: <a href=3D"http://=
www.pyiinc.com/" dir=3D"ltr" x-apple-data-detectors=3D"true" x-apple-data-de=
tectors-type=3D"link" x-apple-data-detectors-result=3D"6" style=3D"color: cu=
rrentcolor;">www.pyiinc.co</a>m</span></p><p class=3D"MsoNormal" style=3D"-w=
ebkit-text-size-adjust: auto; margin: 0in 0in 0.0001pt; font-size: 11pt; fon=
t-family: Calibri, sans-serif;"><span style=3D"font-size: 10pt; font-family:=
Arial, sans-serif;">Regards</span></p><p class=3D"MsoNormal" style=3D"-webk=
it-text-size-adjust: auto; margin: 0in 0in 0.0001pt; font-size: 11pt; font-f=
amily: Calibri, sans-serif;"><span style=3D"font-size: 10pt; font-family: Ar=
ial, sans-serif;">Rod<o:p></o:p></span></p><p class=3D"MsoNormal" style=3D"-=
webkit-text-size-adjust: auto; margin: 0in 0in 0.0001pt; font-size: 11pt; fo=
nt-family: Calibri, sans-serif;"><span style=3D"font-size: 10pt; font-family=
: Arial, sans-serif;"> </span></p><br><div dir=3D"ltr">Art</div><div di=
r=3D"ltr"><br><blockquote type=3D"cite">On Mar 26, 2020, at 2:57 PM, Art Kel=
ley <akelley@optonline.net> wrote:<br><br></blockquote></div><blockquo=
te type=3D"cite"><div dir=3D"ltr">=EF=BB=BF<meta http-equiv=3D"content-type"=
content=3D"text/html; charset=3Dutf-8">16x10 was the original prop. Somewhe=
re in our archives there was a description of someone going to a longer blad=
e, says there is room for that. <div><br></div><div>I fixed the problem=
I had last year when I couldn=E2=80=99t get full speed from my engine. The t=
hrottle cable finally snapped and when I put the new one on, I found the rev=
s I had lost over the years. I am back to getting 3600-3800 ROM.  =
;Much cheaper than a new prop. <br><br><div dir=3D"ltr">Art</div><div d=
ir=3D"ltr"><br><blockquote type=3D"cite">On Mar 26, 2020, at 1:02 PM, Jerry B=
lack <jcblack099@aol.com> wrote:<br><br></blockquote></div><blockquote=
type=3D"cite"><div dir=3D"ltr">=EF=BB=BF
<div style=3D"color:black;font: 10pt arial;">I have a 2 bladed max-prop feat=
hering. 6 kts at 2,000rpm. Best thing is that when backing down you ge=
t the same thrust since the bldes rotate 180 deg. Also I don't have to align=
the shaft to insure folding. My preferred option if I have to replace.
<div><br>
</div>
<div>Jerry Black</div>
<div>Pelirrojas<br>
<br>
<br>
<div style=3D"font-family:helvetica,arial;font-size:10pt;color:black">-----O=
riginal Message-----<br>
From: Brian Higgins <brian@sailingit.com><br>
To: frers-list@lists.frers33.com <frers-list@lists.frers33.com><br>
Sent: Thu, Mar 26, 2020 11:42 am<br>
Subject: [frers-list]Propeller Sizing<br>
<br>
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=20
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om:.0001pt; font-size:11.0pt; font-family:"Calibri", sans-serif;} #yiv233770=
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<div>
<div class=3D"yiv2337709264WordSection1">
<div class=3D"yiv2337709264MsoNormal">When running at 2900RPM (race clean &a=
mp; prepped bottom) in pretty flat (<1ft seas) water and light wind, I'm u=
sually doing about 5.2-5.4kts, where it seems like I should be doing at leas=
t 6kts at that RPM. Further I=E2=80=99ve never found where
the throttle actually stops because it reaches max RPM before it runs out o=
f power (also suggesting not enough propeller).</div>
=20
<div class=3D"yiv2337709264MsoNormal"> </div>
=20
<div class=3D"yiv2337709264MsoNormal">My prop is the same Martec 16x10 two b=
lade folding prop that at least a couple other boats have (I definitely spie=
d on a few of your props in the boatyard recently
<span style=3D"font-family:UI sans-serif;">=F0=9F=98=88</span>). Does a=
nyone have experience going to a higher pitch, something like a 12=E2=80=9D o=
pposed to the 10=E2=80=9D? Some generic calculations I looked up sugge=
sted a 13=E2=80=9D, and Gary from Martec said he too thought
10 was underpitched for the boat but suggested 12 as probably the right pit=
ch. Before I send the prop off (it=E2=80=99s already removed for the c=
utlass bearing replacement), I wanted to check and see if anyone has done te=
sting and played with repitching the prop.</div>
<div class=3D"yiv2337709264MsoNormal"> </div>
=20
<div class=3D"yiv2337709264MsoNormal">Sent from <a rel=3D"noopener noreferre=
r" target=3D"_blank" href=3D"https://go.microsoft.com/fwlink/?LinkId=3D55098=
6">
Mail</a> for Windows 10</div>
<div class=3D"yiv2337709264MsoNormal"> </div>
=20
</div>
</div>
</div>
</div>
</div>
</div>
</div></blockquote></div></div></blockquote></div></div></blockquote></div><=
/body></html>=
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