Propellor Replacement

[markmulligan]

I note a number of you are using larger propellers--up to 15inch. My question is how do you get these on? The design section of the pearson35 website shows my set up exactly--only 1.25 inches from the end of the shaft to the rudder--so you have to thingy the propeller (with a 2.5 inch hub lenght) to wiggle it on. This works with teh 12-7 three blade prop the boat had when for the Atomic 4, and it works for hte 13-14 3 blade used with the Universal Diesel. How are some of you getting 15 inches wheels on here?

[markmulligan]

nice censorship! I used an english verb meaning to place something at an angle and the website thinks it refers to something male--hence the "thingy" edit on my post

Computers is dumb

[Jack Olsen]

I use a 16" prop. To remove it, I had to pull the transmission off and then slide the shaft forward.
I have since taken a saws-all to the rudder and increased the aperture size.

[Mark Mulligan]

An interesting indea, increasing apperature in the rudder. It would not take much--just a notch to help get the hub in. I thought the rudder post ran down the whole leading edge of the rudder--you seem to imply it does not, and we just have fiberglass around the aperature.

[patrickc]

What would be the benefit have replacing a 12-7 prop with a 15" or even a 16"?

[johnmercier]

Hello, I have a Westerbeke 30 in my 35, and I'm going to switch from a 2 blade to a 3. Does anyone know the dimension of the bore?

Many thanks,

John

[Jack Olsen]

My Westerbeke 30 had a one inch shaft if that's what you are asking. I have a 16 x 10 3 blade prop.

[hirover]

You'd better measure the shaft. My 1969 boat, originally equipped with an Atomic 4 has a 7/8" shaft. A-4 was replaced with a Yanmar 3gm spinning a 13//12 prop. The transmission ratio is the lower numbered (fater spinning) ratio that was offered with the 3 gm.

Going with a larger diameter prop has it's benefits but be careful that the transmission gear ratio isn't a problem. If the prop spins too fast, it loses efficiency right quick. The smaller the diameter, the slower the tip speed of the prop for a given engine rpm.

[roland]

Slow Dance was repowered by her previous owner. After consulting with Yanmar's engineers he fitted her with a 17" 10 pitch 3 blade prop. The rudder aperture has been enlarged to make room for it.

With a clean bottom this easily pushes her to hull speed at 2800 RPM (max engine torque) and in calm conditions 2000 RPM gives 5 - 5.5 kts while burning about a liter of fuel an hour. The other advantage is that when I put it in reverse I can effectively stop her.

There is a considerable hit in light air sailing speed but Frank justified it by stating that while sailing he wasn't in a big hurry to get anywhere but if he needed the motor he wanted all the performance he could get.

[FJC]

hello P35 community.
I recently purchased a repowered P35 1976 with the current prop at 14 x 8 Left handed, 1"inch. The engine I have its a 28HP Volvo 3cylinder, the transmission is model KGMS 23 (not sure of the gear ratio). My question is, can I upgrade to a 16 X 12?

[harmony]

Jun 5, 2012 10:59:48 GMT -5 roland said:

Slow Dance was repowered by her previous owner. After consulting with Yanmar's engineers he fitted her with a 17" 10 pitch 3 blade prop. The rudder aperture has been enlarged to make room for it.

With a clean bottom this easily pushes her to hull speed at 2800 RPM (max engine torque) and in calm conditions 2000 RPM gives 5 - 5.5 kts while burning about a liter of fuel an hour. The other advantage is that when I put it in reverse I can effectively stop her.

There is a considerable hit in light air sailing speed but Frank justified it by stating that while sailing he wasn't in a big hurry to get anywhere but if he needed the motor he wanted all the performance he could get.

[harmony]

Roland,
I would like to know the transmission ratio on the Yanmar you have in Slow Dance.
Thank you very much,
Mike