DPH drive help needed

[Elessar]

Thanks for the replies; I'm not going to attempt to take the props off in the water (I've never removed the props before myself, although I do keep the tools on board to do so, just in case); I'm going to go round to the yard in Port Vauban in the morning and arrange a lift out for next week.

I don't think I'll be able to see if it's just bolt 27 or worse until I've got the props off. Fingers crossed.

The other question is obviously how come it is loose in the first place. Not done up enough at last service? Vibrated loose during road transport? Any other ideas on this? (Should I be taking the props off tye other drive to check the bolt on that side as well?)

it's easy to get the props off in the water - with a standard size bathing platform.........
(sorry, unwelcome intervention I'm sure )

more constructively, when I've done this I've gone stern to a pontoon and laid face down on that. On my S37 this was quite easy, but I did have a stubby platform.

 

[MapisM]

a slipping bush can cause one engine to rev higher than the other causing you to think the problem is with the engine that has lower revs.

Hang on, I can see the logic on your train of thought if we would be talking of higher rev on one side at cruise speed, and with the throttles aligned.
But as I understand, the problem is that at WOT one engine reached its max rated rev and the other didn't.
It would be a weird coincidence indeed if the reason were a slipping bush alone, because it implies that for some reason neither engines can supply enough power to spin the props at their max RPM anymore - on the same boat where both used to.
And just by sheer coincidence, one can reach its max rated rpm courtesy of a slipping bush.
Not saying it's totally impossible, but I for one would be surprised to say the least...

 

[julians]

My dad just had a similar loss of power scenario on his twin d4 engined boat.

One engine wouldnt rev past 2000rpm and the boat wouldnt plane. His instinctive thought was that it was a problem with the engine that wouldnt rev, turned out it was the prop bush on the engine that would rev that was the culprit.

Makes sense when you think about it, the remaining good engine/prop was trying and failing to get the boat on the plane on its own with no help from the emgine with the failed bush ,so couldnt go past 2000rpm,it was effectively overpropped so couldnt reach max rpm. The engine with the failed prop bush would spin the propshaft easily,but provide no forward thrust

 

[jimmy_the_builder]

All this work done and still faults , did you carry out a sea trial in the Solent after launch jimmy ?

I did; 100nm in total, but in suboptimal conditions, so the wot thing didn't present until I was in Soton Water heading for RK for the lift to transport.

 

[jimmy_the_builder]

it's easy to get the props off in the water - with a standard size bathing platform.........
(sorry, unwelcome intervention I'm sure )

more constructively, when I've done this I've gone stern to a pontoon and laid face down on that. On my S37 this was quite easy, but I did have a stubby platform.

Yeah thanks for that

Life is booked for a week tomorrow. I don't fancy dunking myself in the heady cocktail of diesel and black tank that is Port Vauban...

 

[jimmy_the_builder]

My dad just had a similar loss of power scenario on his twin d4 engined boat.

One engine wouldnt rev past 2000rpm and the boat wouldnt plane. His instinctive thought was that it was a problem with the engine that wouldnt rev, turned out it was the prop bush on the engine that would rev that was the culprit.

Makes sense when you think about it, the remaining good engine/prop was trying and failing to get the boat on the plane on its own with no help from the emgine with the failed bush ,so couldnt go past 2000rpm,it was effectively overpropped so couldnt reach max rpm. The engine with the failed prop bush would spin the propshaft easily,but provide no forward thrust

Thanks this - interesting stuff. A first-hand example of what Aquatom was talking about. Either way, with a bit of luck I'll know in a week or so - I'm intending to take a spare prop set down with me.

 

[James L]

Maybe try running on one engine at a time.
If the prop is slipping you won't get up to any speed with that engine. But the one with low revs should show the same symptoms.

 

[jimmy_the_builder]

Maybe try running on one engine at a time.
If the prop is slipping you won't get up to any speed with that engine. But the one with low revs should show the same symptoms.

Ok, but nil points for reading my OP (the gist of which is that the port outdrive is unuseable).

 

[benjenbav]

Usually, in a marine environment, where there's a milky discharge around an aperture, it's a case of having blown a seal.

Probably get away with telling people it's mayonnaise, tho'.

 

[KevB]

A few years ago coming back across the channel, a mate had an issue with one engine starting to struggle to get above 2k rpm. It turned out to be that he'd lost one of the duo props off the other engine. As mentioned above the low rev engine was actually trying to do most of the work for two thus struggling with revs.

 

[James L]

My bad - a bit of a brain fart there.

hopefully replacing the props will sort things out.

If not I guess you must have access to the air filter - I had a similar issue where one of my engines would not rev past about 2500, everything seemed fine except for a bit of unusual noise. Eventually we took the air filter off and could see some damage to the vanes of the turbo, a bit of old filter had fallen off and been sucked in there and bent the vanes out of shape. You might be able to get a camera to look in there if you can't yourself.
The turbo was spinning fine just not providing enough boost to get past that point. Driving the sh*t out of the other engine we could build up enough speed that the revs would pick up and once past that point the engine had full power but with a bit of noise.
We were table to take the vane out and replace while leaving the turbo in place (Volvo AD41). Worth a look if the props don't sort it out.

Of course you'll now point me to a previous post where you have a picture of a perfect turbo vane ;-)

 

[jfm]

Benjenbav, firing on all cylinders tonight methinks

Jimmy, all these good theories about the low rev engine being the good one are much nicer than repairing the starboard turbo, so things are looking up. God plan to bring spare props down. (You shoulda packed them in thr boat. I'm happy to store at my place). Are you lifting at Stefano?

 

[Portofino]

Looking at post #22 and 23 and other thread on power loss ,the engines it understand correctly match rpm to around 2500 ish -where the turbos kick in .Then one ( stb) lags behind ,ends up at 3100 while the other reaches wot .
A bushed prop would deteriorate quickly surley so the rev discrepancy would change -in fact widen as wear progresses .
A bushed prop is not a constant gear ratio ?
Also if the props on the port leg have opened up a 10mm gap or so -how can they move to the stern ,the cone when all is done up tight ,correct washes /spacers fitted when replaced ?
I don't understand how rear prop can slide back if done up tight and the other prop is also done up tight ?

Regretfully I suspect

The two issues are not connected

Low rpm Stb engine 3100 rpm
Clattering noise -loosened bolt
Aire d boom have really good VP guys

 

[jimmy_the_builder]

My bad - a bit of a brain fart there.

hopefully replacing the props will sort things out.

If not I guess you must have access to the air filter - I had a similar issue where one of my engines would not rev past about 2500, everything seemed fine except for a bit of unusual noise. Eventually we took the air filter off and could see some damage to the vanes of the turbo, a bit of old filter had fallen off and been sucked in there and bent the vanes out of shape. You might be able to get a camera to look in there if you can't yourself.
The turbo was spinning fine just not providing enough boost to get past that point. Driving the sh*t out of the other engine we could build up enough speed that the revs would pick up and once past that point the engine had full power but with a bit of noise.
We were table to take the vane out and replace while leaving the turbo in place (Volvo AD41). Worth a look if the props don't sort it out.

Of course you'll now point me to a previous post where you have a picture of a perfect turbo vane ;-)

Nope, no pics of turbo vanes. I do have a cheap endoscope-style camera on board so if it comes to it, I should be able to have a look inside the turbo. I think the order of service is probably (1) tackle the loose bolt (2) replace the props (3) sea trial and then (4) starting pulling things apart around the turbo.

 

[jimmy_the_builder]

Jimmy, all these good theories about the low rev engine being the good one are much nicer than repairing the starboard turbo, so things are looking up. God plan to bring spare props down. (You shoulda packed them in thr boat. I'm happy to store at my place). Are you lifting at Stefano?

Yep, you're right - I even took them to the boat when provisioning it for France, but ended up not loading them because of (lack of) storage space. Ah well. It's a bit of a pita to have to bring them down as hold luggage, but there you are. And yes, lift is at de Stefano on Tuesday; it's essentially just a lift and hold over lunchtime. Will you be around?

 

[jimmy_the_builder]

Looking at post #22 and 23 and other thread on power loss ,the engines it understand correctly match rpm to around 2500 ish -where the turbos kick in .Then one ( stb) lags behind ,ends up at 3100 while the other reaches wot .
A bushed prop would deteriorate quickly surley so the rev discrepancy would change -in fact widen as wear progresses .
A bushed prop is not a constant gear ratio ?
Also if the props on the port leg have opened up a 10mm gap or so -how can they move to the stern ,the cone when all is done up tight ,correct washes /spacers fitted when replaced ?
I don't understand how rear prop can slide back if done up tight and the other prop is also done up tight ?

Regretfully I suspect

The two issues are not connected

Low rpm Stb engine 3100 rpm
Clattering noise -loosened bolt
Aire d boom have really good VP guys

Fair point. However, I think the way forward here is to fix the known faults first, before tackling the unknowns. What I would say though is that while rpms are matched to 2500, boat performance is definitely down (2500 is about where the boat would start planing, previously).

I had this idea that Arie de Boom were not VP agents - am I wrong? Or is it that they are the engineers, and Marine Moteurs are the regional parts dealer?

 

[CHI]

Hi Jimmy

I very briefly met you one Sunday at RK Marine,s yard.

I have had in the past a prop bush failure on the starboard drive, DPH. This has now just happened again on the Port drive leg. The symptom is exactly as described before. The drive leg that has a failed prop bush will allow the engine to reach WOT very quickly , where the drive leg with no problems is struggling to reach 3000RPM as it is trying its hardest to plane the boat.

My props are now 10 years old and are in very good condition generally. I have decided to send mine to Steel Developments for re-bushing which is far cheaper than new replacements.!!!!

Please Pm me if you need ant further info.

Good luck

Keith
CHI

 

[Portofino]

Fair point. However, I think the way forward here is to fix the known faults first, before tackling the unknowns. What I would say though is that while rpms are matched to 2500, boat performance is definitely down (2500 is about where the boat would start planing, previously).

I had this idea that Arie de Boom were not VP agents - am I wrong? Or is it that they are the engineers, and Marine Moteurs are the regional parts dealer?

Yup they are engineers and Marine motors ( off @ J 41 A8 on the main drag to Mandelieu ) are the Cd Z- VP - parts and service centre .
they also have engineers I have seen there vans around in the ship yard + guys in blue fiddling about

A d B service all makes and will fix this all for you in house

 

[jimmy_the_builder]

Hi Jimmy

I very briefly met you one Sunday at RK Marine,s yard.

I have had in the past a prop bush failure on the starboard drive, DPH. This has now just happened again on the Port drive leg. The symptom is exactly as described before. The drive leg that has a failed prop bush will allow the engine to reach WOT very quickly , where the drive leg with no problems is struggling to reach 3000RPM as it is trying its hardest to plane the boat.

My props are now 10 years old and are in very good condition generally. I have decided to send mine to Steel Developments for re-bushing which is far cheaper than new replacements.!!!!

Please Pm me if you need ant further info.

Good luck

Keith
CHI

I remember you

Interesting stuff. I just had a quote yesterday from Steel Developments for rebushing my G6 props - £145 for the bush, £25 for the shimming, £10 fitting charge, £12.50 carriage, all plus vat, and all per prop (ie as opposed to the set). Total £231.00 per prop; yes, this is a lot cheaper than a new prop, but still feels quite expensive. I also emailled Hamble Propellors to get a quote, but no reply.

Which prop has failed in your case - forward or aft?

 

[jimmy_the_builder]

Yup they are engineers and Marine motors ( off @ J 41 A8 on the main drag to Mandelieu ) are the Cd Z- VP - parts and service centre .
they also have engineers I have seen there vans around in the ship yard + guys in blue fiddling about

A d B service all makes and will fix this all for you in house

Thanks L. You've recommended AdB before, and certainly when I've had to contact them for yard work they have been terrifically helpful and easy to deal with. I think my plan is to have a crack at the outdrive issues myself, and if I still have problems at that point, consign the boat to AdB. Unfortunately my other option of bringing down a UK engineer from my local VP dealer is no longer available following the demise of SSL in Brighton.