Running Gear Tweaks

eagle419 · 05-26-2013, 12:53 AM

While the prop is off getting tweaked (as per Benn's suggestion) I decided to go with a PSS seal, rather than continuing with bilge yoga and packing tightening.

eagle419 · 05-26-2013, 01:04 AM

I've also got a new set of heavy duty rope spurs, which apparently will also chew through sizeable wire.
While I've got a hookah diving setup, I don't fancy being under the boat by myself.

Tidahapah · 05-26-2013, 01:29 AM

John,
That's a serious set of cutters, would hate to get my fingers caught there.
By the way, what sort of tweaking did they do to the prop.
Any serious pitch increases etc.

I have previously looked at PSS shaft seals but have never ben convinced that they were a step forward.
We have oil type and lip seals at sea but they both seal inside and out so there is a back up of sorts and usually one can increase the oil head height to negate any water ingress in case of failure.
With the PSS seals there is no back up in case of failure and that does not sit well with me for off shore cruising.

I changed to Goretex packing which has been fantastic , nil drips and no heat. I have grease lubricated fwd and aft bearings on my shaft .

Hope it all goes well with the retuned prop.
Cheers
Benn

eagle419 · 05-26-2013, 02:00 AM

Hello Benn,
We sent the prop along with the specs to Porters, and noted that we were only getting 8.1 @ WOT 1400 revs. They took some pitch out, filled a patch of corrosion and rebalanced. I now get 8.5 @WOT 1445 revs - an extra 45 rpm, but still not near spec - I'll have a peruse of their figures and think some more.
There are three large alternators and two hydraulic pumps running off the 6lxb, plus the stabiliser fin drag, so maybe that changes the scenario. I hear what you're saying re the seal!

BTW we also replaced corroded bearings in the stabilisers

Tidahapah · 05-26-2013, 05:16 AM

John,
have you wacked your figures thru boatdiesel to see what figures they come up with.
If you have not and you are not a member pm me your details, length, water line length , displacement, gear box ratio etc I will throw them thru and see what size prop they come up with.
Also give me the size of existing prop if you want.
Cheers
Benn

eagle419 · 05-26-2013, 07:02 PM

Thanks Benn,
Porters the prop people put the numbers though their system to come up with the adjustment.
I'm waiting for them to send over their calculations and I'll copy them to you.
cheers, John