Bored by Petter Diesel Engine

[BamBam]

Hello Folks

I read that some of you changed for a Yanmar 1GM10.
Does one of you see the possibility to fit in any engine with about 12 ~ 15 bhp ? The more the b(p)etter
Thing is: I got a little bit mad about my Petter. With front waves and wind its a kind of slomo leaving the harbour.
Don't wanna race going by diesel, but I see more power in a kind of secure thing.
What do you think ? Any suggestions or hints ?

Thanks mates,
Tristan

[JBaldo]

Hi Tristan,

I fitted a 1GM10 in place of the Petter when it wore out. There is plenty of room for other engines, if there is one you would prefer. We have a 2 bladed folding prop 12 x 8 which is about the largest diameter that can be fitted given the clearance between blades and hull, with a conventional shaft and p-bracket. If you fitted a larger diameter its tips would be too close to the hull. You could fit a 3 bladed prop or one with a larger pitch, to give more speed with a more powerful engine and with a higher ratio gearbox you could use higher shaft revs.

I got about 5.5 kts with the 6 H.P. Petter on flat water and about the same with the 9 H.P. 1GM10 which has a lower gearbox ratio than the Petter. I think the Petter was 2:1 and the 1GM10 is 2.62:1. The cruising revs (80% of maximum) for the Petter and for the 1GM10 was 80/100 x 3600 = 2880rpm. and this gives a shaft speed of 1440rpm. for the Petter and 1100 for the 1GM10. She would go a little quicker if you ran up to 100% of engine speed, but of course, fuel consumption (normally 1 litre/hour) increased considerably.

Against wind and waves the speed was lower with this prop. I haven't tried another prop. The 1GM10 costs over £3000 and quite a bit more for fitting unless you can DIY. A new prop starts at about £500 for a folder or somewhat less for a fixed. I needed a new longer propshaft (£400) as I also fitted a new sterntube of larger diameter, to give more clearance for the shaft with the increased engine movements associated with the softer mounts on the 1GM10.

John

[Rich]

As a side note, all of these things can be done cheaply DIY.

Example of the propshaft, on Chicane I got 2m of 25mm stainless bar from local fabrication company, for around £60, I then took the prop and and shaft to a local engineering shop and they machined the shaft, including keyway and key for £75, I then cut the shaft to the correct length myself.

The sterntube was got from chopping up a windsurfer mast

[BamBam]

Hello Folks

I have the opportunity to buy a mint and almost never used Ruggerinni Diesel with 27 horses
What do you think. Too much Power ? Problem concerning the right diameter of the obligatory new propeller ?

If it fits in the Eygthene ...

Regards.
T.

[Rich]

FAR to much power!
I imagine it will weigh a fair amount as well, IMHO I believe that 10hp is a little on the overpowered side. Just my thoughts..

[BamBam]

yes rich, I totally agree (and the engine won't fit).
but about 12 hp wouldn't be far overpowered. just power at maximum