Proper props for PDQ 34 with 100 HP Yanmars?

Post here if you want to discuss a topic specific to the MV/32, MV/34, and MV/41.
User avatar
AMCarter3
admiral
admiral
Posts: 212
Joined: Thu Apr 21, 2016 8:32 am
Location: Bellingham, WA
Contact:

Proper props for PDQ 34 with 100 HP Yanmars?

Postby AMCarter3 » Fri Aug 11, 2017 2:51 am

Can anyone provide insight on what is the proper size and pitch for the two props on our PDQ 34 with 100 HP Yanmars? I'm not sure what we have now, but I do know we get 3525 max RPM on our Port engine and 3560 RPM on the Starboard. I know these numbers are nearly 300 RPM lower than the 3800 WOT rating listed in the Yanmar manual for these engines.

Our diesel mechanic suggested that we find out what the correct size and pitch should be for this boat. I've seen considerable chatter on this topic in this forum for PDQ's with 75 HP engines. Anyone have prop info for the 100 HP engines?
Mac Carter
2006 34' PDQ PowerCat "All Heart"; MV 98
Bellingham WA

Catrina
1st mate
1st mate
Posts: 31
Joined: Sun May 09, 2004 1:58 pm
Location: Erie Canal

Re: Proper props for PDQ 34 with 100 HP Yanmars?

Postby Catrina » Sat Aug 12, 2017 6:21 am

Do you have 3 blade for 4 blade props.

If 4 blade the prop size is 17 x 14 for the 4JH4-HTE engines.

I have moved up to the 110 HP engines, prop size is now 17 x 17.

Mark C.
Catrina - MV34 Hull # 55 - 110HP - 4 Blade props

duetto
admiral
admiral
Posts: 660
Joined: Wed Jun 15, 2005 11:18 am
Location: ICW (32043)

Re: Proper props for PDQ 34 with 100 HP Yanmars?

Postby duetto » Sat Aug 12, 2017 8:06 am

i think henry clewes did a lot on this.

http://www.snodoglog.com/
john & diane cummings
duetto mv34 #23

User avatar
AMCarter3
admiral
admiral
Posts: 212
Joined: Thu Apr 21, 2016 8:32 am
Location: Bellingham, WA
Contact:

Re: Proper props for PDQ 34 with 100 HP Yanmars?

Postby AMCarter3 » Sat Aug 12, 2017 9:57 am

I have 3-blade props.
Mac Carter
2006 34' PDQ PowerCat "All Heart"; MV 98
Bellingham WA

User avatar
AMCarter3
admiral
admiral
Posts: 212
Joined: Thu Apr 21, 2016 8:32 am
Location: Bellingham, WA
Contact:

Re: Proper props for PDQ 34 with 100 HP Yanmars?

Postby AMCarter3 » Sat Aug 12, 2017 2:11 pm

Thanks, Duetto, for the reminder about Sno Dog's Performance study on PDQ 34's with 100HP Yanmars. I had found that last year and forgot about it. He says the original props are: 17" dia x 14" pitch x 3-bladed.
Mac Carter
2006 34' PDQ PowerCat "All Heart"; MV 98
Bellingham WA

User avatar
AMCarter3
admiral
admiral
Posts: 212
Joined: Thu Apr 21, 2016 8:32 am
Location: Bellingham, WA
Contact:

Re: Proper props for PDQ 34 with 100 HP Yanmars?

Postby AMCarter3 » Wed Aug 23, 2017 4:10 pm

It looks like our boat has 3-blade 17" x 15 props. If the original props were 17 x 14, what might be the impact of these slightly different props on our boat? Could this account for the loss of 300 RPM off the rated max RPM?
Mac Carter
2006 34' PDQ PowerCat "All Heart"; MV 98
Bellingham WA

Catrina
1st mate
1st mate
Posts: 31
Joined: Sun May 09, 2004 1:58 pm
Location: Erie Canal

Re: Proper props for PDQ 34 with 100 HP Yanmars?

Postby Catrina » Wed Aug 23, 2017 4:50 pm

If I recall the conversation with my mechanic correctly, each 1 inch pitch change of prop was around 150-200 rpm difference up or down. In your case the 1 inch additional pitch could account for a good portion of the 300.

Mark
Catrina - MV34 Hull # 55 - 110HP - 4 Blade props

User avatar
AMCarter3
admiral
admiral
Posts: 212
Joined: Thu Apr 21, 2016 8:32 am
Location: Bellingham, WA
Contact:

Re: Proper props for PDQ 34 with 100 HP Yanmars?

Postby AMCarter3 » Thu Aug 24, 2017 12:33 am

Thanks, that's helpful.
Mac Carter
2006 34' PDQ PowerCat "All Heart"; MV 98
Bellingham WA


Return to “PDQ Powercat Forum”

Who is online

Users browsing this forum: No registered users and 7 guests