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-   -   Dry Sumping Volvo DPR'S (https://www.offshoreonly.com/forums/drives-lower-units/267620-dry-sumping-volvo-dprs.html)

peterunwin 09-20-2013 12:58 PM

10 Attachment(s)
Hi rickg1984,
At long last the 12 volt stainless steel actuators and synchronization module have arrived so i have been able to finalise the geometry of the mounting brackets, they have much more stroke than i actually need but it will enable me to test beyond the wings efficient range which will result in more drag.

Peter

rickg1984 09-20-2013 04:25 PM

I had some Volvo penta big wigs in at work the other day and showed them your project on it but cant put what they said on here lol

peterunwin 09-21-2013 01:26 PM

10 Attachment(s)
Hi All,
Diesel filler and vent pipes are now installed, visual flow meters for the dry sump system are fitted and all the hoses have been swaged and installed permanently, also completed the wiring for the battery master switches.

Peter

pstorti 09-21-2013 01:57 PM

Hi Peter nice work as usual, any reason you went with a 90 degree fitting in the fuel fill line as opposed to a smooth bend? The dry sump system is for the drives?

peterunwin 09-23-2013 07:30 AM


Originally Posted by pstorti (Post 3999789)
Hi Peter nice work as usual, any reason you went with a 90 degree fitting in the fuel fill line as opposed to a smooth bend? The dry sump system is for the drives?

Hi Noli,
There is about 2ft 6 of vertical pipe before the 90 so i think gravity should drive it ok as i need the room for fender storage and i can just about crawl into the space for maintenance. Are you coming down to Keywest for the races it would be great to catch up we leave on the 20th October can't wait, we are also doing fantasy fest!!! i am going to have Carolyn painted...:cool-smiley-011:

All The Best
Peter

21smuggler 10-02-2013 09:28 AM

2 Attachment(s)
Just to let you know, your tread has inspired me to do something about my propellers.... Currently run a 29 feet boat with single stepped hull that weigh in at 2800kg with a VP D4 300 diesel and DPH drive. It tops out at 42 kts with 3470 rpm but feels like it's much more there as hull is running very wet and I get zero bow lift when trimming out. Have just bought a set of G9 props and will send to Steel developments which you mentioned in your tread. The G propellers are really huge with 4 blades at the front prop as you probably know. Looking to do the following based on what you and other have discussed in the tread, however your input would be much appreciated!!

1. Remove 35% of the blade area of the front prop, leaving the diameter the same removing most of the area from the bulbous front section if deemed appropriate.
2. Remove unnecessary blade are on rear prop, leaving the diameter the same removing most of the area from the bulbous front section if deemed appropriate.
3. Thin and sharpen all blade edges.
4. Equalize pitch between blades.
5. Press a lot more cup into all blades to help with bow lift.

Do you think I'm on the right track in terms of mods and going up one step in pitch?
Regards
Gustav
[ATTACH=CONFIG]509061[/ATTACH][ATTACH=CONFIG]509062[/ATTACH]

denpol 10-02-2013 01:26 PM

Hello Gustav,


Before starting these drastical ideas; have you already tried to move the LCG back?

I run 3 ( non stepped ) mono hulls with 350 hp D6, with DPH's , weight of the boats is about the same or even heavier.
These boats all run 44+ kts and are perfectly trimmable, although one feels nicer than the other because of weight distribution. Trimmed nose down, they reach max 36 kts! And when trimming the bow up they keep on gaining speed up until the ideal setting.
With bow down as you mention the step may not ventilate right and even ruin full waterflow to the props.

regards

Paul

peterunwin 10-03-2013 12:23 PM

Hi Gustav,
Removing 35% of the blade area on the front prop is a little drastic i would go for cupping front and rear props first without changing pitch, as your engines are only running 3470rpm the cupping will load the engines even more until you trim out. As Paul said it is worth checking your longitudinal centre of gravity and if it is too far forward move heavy items towards the rear. It may be possible to gradually reduce the blade area on the front prop but i would do this in stages no more than 10% at a time, ideally you need to strip the lower unit to check the load wear patterns on the gear teeth.
Please keep us informed of your progress

Best Regards
Peter

peterunwin 10-03-2013 12:46 PM

6 Attachment(s)
Hi All,
Lots more progress on the wiring have also modified the strainer caps so that i can install a hydraulic quick release coupling which is normally connected to a two bar relief valve to protect the system from being over pressured, i can also use the same coupling for flushing the engines, all the parts are made from 316 stainless which i have machined internally and externally to reduce their weight and given them a quick polish.

Peter

denpol 10-03-2013 03:12 PM

Peter

Great idea and again serious boat porn!!


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