Propellor size for 27 foot boat / 1GM10

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tyce

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Hi what size propellor do you reckon would suit my Parker 27 powered by a 1gm10.
The current prop is damaged where the sizing info is printed on it so not sure which size replacement would suit.
Any ideas anyone
 
You can get an approximation by feeding your data into the Propcalc programme from Castlemarine - free on their website. One piece of crucial information is the gearbox ratio as there are 3 different ratios available and there is a big difference between them.

Alternatively as you need to buy a new one, go to a specialist like Sillette or T Norris and they will supply the correct prop from the information you give them..
 
Old Troll

For your information I have a 1GM10 with the 2KM2P 2.62 reduction gearbox instaled in my 27ft yacht displacement about 5070 lbs. The prop size is Dia 14" (360mm) and pitch of 9" (230mm). The prop is the Two Bladed fixed version.
I have come to the conclusion that the prop size is as big as the engine can take but would be interested if anyone has a different experience. Regards.
 
Old Troll said:
For your information I have a 1GM10 with the 2KM2P 2.62 reduction gearbox instaled in my 27ft yacht displacement about 5070 lbs. The prop size is Dia 14" (360mm) and pitch of 9" (230mm). The prop is the Two Bladed fixed version.
I have come to the conclusion that the prop size is as big as the engine can take but would be interested if anyone has a different experience. Regards.
Click to expand...

By comparison, I have a 1GM10 on my 6000lb 26 footer. 13 x 9 three blade fixed - the original was apparently 12 x 9, but everyone upgrades. It seems a bit marginal, though - the slightest barnacleage seems to overprop her.
 
Old Troll

I would agree that any load on the engine at max revs would appear to be overproped with black smoke appearing. However if I use Approx 3200 revs (cut back a little) as max all seems to OK.
 
Hunter 27, Yanmar 1GM10, prop fixed 2 blade size PROP 14"X8.5", not sure of the gear ratio.
Pete
 
5 years too late I know but it may help someone else. Firstly the last time that I tried Castle Marine's Propcalc it didn't work! I got a message in red type stating that the calculator was in sixteen-bit code and that I needed a (retro) computer that could handle 16 bit programs. Now even if one had a Windows 95 machine available it would be a VERY BAD IDEA to connect it to the Internet as one might get Ransomware on it within minutes as AFAIK anti-virus for 95 is not supported anymore.

All is not lost however as Victoria Propellers have their "Vicprop" calculator. This will run OK on modern computers that run Windows. Vicprop asks for a lot of data that may not be to hand unless one has the boat plans available and ready. Good luck!
 
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