VP DPH-A New H series props

[kennyh]

Hi all

I need to get a new prop set for my VP D4 with a DPH-A drive.

I plan on replacing the old Nibral, G series props with the new Stainless Steel H series props.

I understand the props have a slightly different fitment and the rear cone needs to be changed.

Q. Has anyone else moved from G series to H series props on a DPH-A drive? Anything I need to look out for?

Thanks in advance for any help!

 

[SC35]

Yes, I have.
It‘s a straightforward enough change, and they come with instructions.
Also look at the thread about antifouling stainless props.

 

[QBhoy]

Maybe just need to think about the possibility of losing some rpms, should you go to the same pitch. It’s been known for some to drop in pitch when doing this on VP DP drives. Some may also think that the enormous price of the stainless props may not be worth it on most boats that may not be able to take advantage of them in terms of performance. Not sure if this is relevant to you or not.

 

[marcochi76]

Why the drop in rpm?
As they are more rigid?
So this means that we should expect faster boat as same rpms?

 

[QBhoy]

Why the drop in rpm?
As they are more rigid?
So this means that we should expect faster boat as same rpms?

They don’t lose their form the way ally do under load, so hold their true pitch and have less slip as a result. Also able to run more trim and hold their grip on the water. Ally lose their grip close to the surface with trim. More trim can mean that the hull can lift from the water more. More lift…better efficiency and pace. All depends on the boat too really. Sometimes you won’t lose rpm. Just with the hull lifting and gaining speed…you can actually end up gaining rpm occasionally. Again…depends on the boats ability. If your boat has moderate performance, you may not notice a huge difference. But you’ll certainly usually be more efficient through the water. Enough to notice or see any gains…to offset the enormous cost of them…depends on the boat and it’s ability perhaps. I’d say that most boats that have Dp’s and are able to take advantage of them…usually have them fitted from new. As far as I’ve seen anyway.

 

[SC35]

I’m getting pretty much the same performance from H4 vs G4.
Maybe a fractional increase in speed at the same rpm due to the thinner blades, but the pitch is very close indeed.
Nibral Props don't flex much, but they are very heavy.

Costs are the same as the previous Nibral Props, about £3800 for four props.

A block of wood between prop blade and outdrive helps stop the prop turning when doing up / undoing.
Plenty of marine grease on the shafts is also a good idea to prevent "Help I need a puller to get them off at the end of the season" type events.

 

[SC35]

Before …


After …

 

[Meagain]

Before …
View attachment 146875

After …

View attachment 146876

View attachment 146877

Your original props looked pretty good in the photo, what prompted you to change, if you don’t mind me asking?

 

[QBhoy]

Before …
View attachment 146875

After …

View attachment 146876

View attachment 146877

Sure look pretty!

 

[SC35]

Your original props looked pretty good in the photo, what prompted you to change, if you don’t mind me asking?

Bit of a sob story.

Previous season, one G-Series prop spun on its hub, so I had it re-hubbed.
Then earlier this season, another prop also spun on its hub.
So ... I sent the other props to be re-hubbed.
Result: Four G-Series props, all in reasonable condition with new hubs.

Then one of those re-hubbed props spun the hub again.
I won't use the exact words that Mrs SC35 used, it wasn't very ladylike.
The general theme was "You really need to fix this propellor issue or sell the boat and extend the house".

Hence four brand-new H4 Propellors ?

 

[SC35]

For Sale, three re-hubbed G4 props that actually work.
And one G4, for use as table ornament or drinks coaster?

 

[kennyh]

And just double checking…..there’s no aftermarket replacement props available is there? (ie a cheaper option)

 

[kennyh]

Two more related questions on this topic…..

1. The reason I need to change my props is that it looked like my rear prop hub “moved” and the rear prop was grinding against the front prop (leaving no gap on the shaft). Q. Does that sound like a feasible explanation rather than some other reason for the props grinding together?

2. I understand the new H series cone comes with a lock bolt for the rear nut. My DPH-A shaft does not have bolt hole to take the lock bolt (I believe this was a later revision to the shaft design). Does that mean the lock bolt is simply left off a DPH-A, or is there another fixing that has to be applied in its place?

 

[oldgit]

noticable increase in blade area on stainless props ?

 

[SC35]

And just double checking…..there’s no aftermarket replacement props available is there? (ie a cheaper option)

Not aware of any aftermarket options, but then again, I didn't really look.

1. The reason I need to change my props is that it looked like my rear prop hub “moved” and the rear prop was grinding against the front prop (leaving no gap on the shaft). Q. Does that sound like a feasible explanation rather than some other reason for the props grinding together?

It's the most likely explanation, other than some sort of internal outdrive disaster.
When my prop spun, it made contact with the other prop.
That's not a good condition to run in for any length of time.

2. I understand the new H series cone comes with a lock bolt for the rear nut. My DPH-A shaft does not have bolt hole to take the lock bolt (I believe this was a later revision to the shaft design). Does that mean the lock bolt is simply left off a DPH-A, or is there another fixing that has to be applied in its place?

The lock bolt gets left off.
Instead it's 100Nm of Torques on the cone, "locking agent" part no 23284156 on the cone thread.

 

[kennyh]

Not aware of any aftermarket options, but then again, I didn't really look.



It's the most likely explanation, other than some sort of internal outdrive disaster.
When my prop spun, it made contact with the other prop.
That's not a good condition to run in for any length of time.



The lock bolt gets left off.
Instead it's 100Nm of Torques on the cone, "locking agent" part no 23284156 on the cone thread.

Brilliant! Thanks for the info and taking the time to share the doc.

 

[ICTM]

As said above I have DPH ‘A’ and these went on last summer without using the locking bolt and so far no issues.

 

[SC35]

"Nobody asks what antifoul you used when it comes out of the water looking like this ..."
?

 

[GrahamHR]

What on earth do those cones on VP Sweden drives do ? An overcomplication surely ?

I had boats with 5.7 V8s and DPS drives from 2001 to 2014. No cones on them, they did 42 to 48 knots. Easy prop changes, a hexagonal nut and a special nut needing the same tool as the DPH ( home made, but it lasted 17 years !)

I suspect the "not invented here" rivalry between VP Sweden and VP USA. The VP USA stuff was a lot more reliable in my experience than the VP Sweden stuff I had in the latter years !

 

[SC35]

What on earth do those cones on VP Sweden drives do ? An overcomplication surely ?

I had boats with 5.7 V8s and DPS drives from 2001 to 2014. No cones on them, they did 42 to 48 knots. Easy prop changes, a hexagonal nut and a special nut needing the same tool as the DPH ( home made, but it lasted 17 years !)

I suspect the "not invented here" rivalry between VP Sweden and VP USA. The VP USA stuff was a lot more reliable in my experience than the VP Sweden stuff I had in the latter years !

I suspect the answer is to do with trying to improve efficiency at moderate speeds.
The cones are easy enough to remove and replace ... think of them as a nicely shaped prop nut that is harder to drop
You don't need any special tools to remove a cone, just a large socket and a smaller one for the additional lock screw on DP-D and later.