Re-power project.

burgundyben said:
Rebuilt BW Velvetdrive 72C with new fwd and reverse clutches, seals and gaskets.

BWpainted_zps7a60d8db.jpg



Man at R and D says I need a 50 AE 101 but that won't fit, too deep and can't be turned round as the AE element only runs one way. I think I might need a 4 P 5. I'll give them a call.
Click to expand...


Hope that's not snow on the windows. I'll have to get the boat heating on sharpish...
 
burgundyben said:
The M265Ti is in fact 240hp.

Umm...it won't be sudden instant death....I'm rebuilding them with new clutch plates and seals etc.

I have the 72C's to consider and that I only have 1.25" shafts (albeit in Duplex), I'm fairly certain that my props won't be able to be pitched and cupped to absorb the full 240hp, so we'll see.
Click to expand...

You will note from my question that I am lacking mechanical expertise, but looking at the Vetus catalogue it seems to me that their duplex 30 mm is good for 170 hp @ 3000 rpm [suspect that is prop speed] & their 35 mm for 260 hp. Dropping the revs to 2000 gives about 110 hp & 185 hp respectively. In the unlikely event that my interpretation is correct, might the shaft be too small?

If anyone has the time to explain, I should be much obliged.

John G
 
Jegs said:
You will note from my question that I am lacking mechanical expertise, but looking at the Vetus catalogue it seems to me that their duplex 30 mm is good for 170 hp @ 3000 rpm [suspect that is prop speed] & their 35 mm for 260 hp. Dropping the revs to 2000 gives about 110 hp & 185 hp respectively. In the unlikely event that my interpretation is correct, might the shaft be too small?

If anyone has the time to explain, I should be much obliged.



John G
Click to expand...

I am going through the same process at this time (Replacing HT6.354s with D4 180s).

There is a relatively simple formula for calculating shaft diameter:

Diameter = 3√ 321,000 x SHP x SF / ST X RPM


Where:

Diameter is in inches.
SHP = shaft horse power
SF = safety factor - probably 3 or 4 for your (pleasure) use
St = yield strenght (torsional shear) in PSI
RPM = shaft RPM

Your shaft is probably stainless so a yield strenght of 20,000 should be OK.

Easier to put the formula into excell as you can play with the numbers.

With thanks to Dave Gerr and the excellent prop handbook.
 
Long overdue for an update.

All sorts of things have been conspiring against me, not being in the tent makes a huge difference.

Turns out that my engines could have had one of two injection pumps, I have the bosch ones which can be would up to the M300Ti spec...

This series of pics is a what happened next.

20131220_085755_zps0175f7d4.jpg


20131220_093729_zpsafe010c9.jpg



20131220_093738_zpsc6e815d2.jpg



What happened next is that they didn't fit....so we put it all away again.

Bit complicated to explain here, but no big deal, could of things to sort out, hopefully I'll get them in over Christmas. She's parked near and A frame and chain block.

I'm working abroad for a fortnight in January and would like them in place before I go.
 
burgundyben said:
What happened next is that they didn't fit....so we put it all away again.
Click to expand...

:(

even if or rather when they fit, isn't it going to be a bit tight? Will you be able to remove exchangers et al with both engines in place?

and off-topic, so your approach is to paint the bilges. Treated ply with something beforehand, or straight grey bilge paint Ben?

cheers

V.
 
They will fit, install manual says minimum shaft separation of 27 inches and I have 28! The marinisation of the Phaser block by sabre had replacement of ageing 6.354's as part of the breif.

Its just moving a few bolt holes and modifying the rubber feet, spoke to R and D, I know what I need to do and have a plan. Need to borrow a chain block and have a go over the Chrimbo break.
 
I had an email from the yard, there's 480hp sat in my Huntsman. Do you think she'll go ok?

Not able to crack on until 16th Feb, so I think the tent will need to make a brief appearance.
 
Ben to save digging tent out, I have a couple spare covers you can borrow for a month or so if you wish, but you will need to ring me as it will have to be tomorrow afternoon or Friday morning, maybe meet my my yard?
 
Floating Preferably said:
OK Ben, I arrive back on Sat 1st, so drop me a line for the sunday if you wish. Hope boat is not completely open at present as plenty rain here. If so I will dig Hoops out and go and cover it tomorrow for you.
Click to expand...

Its ok, the tonneau is on.

Forgot your off on the piste, i have a dangerous weekend ahead, partying with Mr and Mrs Seward...
 
You must log in or register to reply here.

Share this page

Top