islander 36 2:1 gear reduction;prop size
 

hi everyone, my name is jonathan, I am the owner of a 1977 i36. I have a small problem, I let my zinc on the prop shaft go bad; now I am needing to buy a new prop. there is not a lot of info online about the subject. I have an atomic 4 gas engine with a 2:1 reduction gear.
I talked to the guys at indigo and they suggest a 12" prop with 12 degree pitch. that is on a three blade prop. I found a 2 blade prop online 12/10 but I was told this is not a good match for my boat, and and that I need something more like a 15", but i'm not sure there is enough clearance between my hull and the prop. is there anyone out there with some info that could be of help?

If my memory hasn't failed me, the standard I-36 prop was a 16x10x[shaft dia] RH 2 blade. Standard boat was powered with the Atomic 4 with 2:1 reduction gear.

Having gone thru the re-propping process on a non standard boat here are some links you may find of use.
http://www.moyermarine.com/forums/showthread.php?t=6148

http://www.moyermarine.com/forums/fo...c&daysprune=-1

http://www.moyermarine.com/forums/showthread.php?t=6046
Be aware of the disclaimer in my first post on this thread about faulty tach numbers.

Short version is that a 14 X 9 three blade proved to be a good match for my boat. 12000 # displacement, 25' water line, 2 to 1 reduction gear with proper clearances in the aperture.
Welcome to the forum.
Dan S/V Marian Claire

Edit: You may also need to address the issue that caused the zinc and prop to be degraded.

I have two quotes From different prop companies. One suggests 14/10 another 13/10. I have 8.375" clearance to bottom of hull from center of prop shaft.

My Tartan 30 has a 12" prop, and it only clears the hull by about 1/2". This hasn't been a problem. I wouldn't let tip clearance drive your choice of propeller.

I found a 13/10 prop at a good price. I have room for the 14/10
Will one inch of prop make a huge difference?

Well I guess I answered my own question
Changing prop size one inch or pitch by one degree changes rpm by 200

Finally found an affordable used prop. 14x10 got it a Minnie's for 145.00
Thanks for the help.