New Guts - Part 7....at last!

Mike Garside · 01 October 2002, 15:56

OK, I must apologise for the delay in starting this new thread. I lorst the dead cheap digi box-camera - it's so small I am always putting it down and losing the pesky thing.

Anyway it's back and the pics down-loaded so here goes.

The new Bravo 2X leg finally turned up after a trip halfway round Britain in the ever elusive E P Barrus delivery truck and we eagerly unpacked it. Frustratingly it was not the 1.81:1 gear ratio version that Barrus had recommended but a 1.65:1 version, instead. But this was no time to quibble....

Mike Garside · 01 October 2002, 15:58

The next thing to do was to fill the leg's gear box reservoir with a dollop of liquid Quicksilver...

Mike Garside · 01 October 2002, 16:01

....before bleeding this right though to the bit that connects the reservoir to the leg...

Mike Garside · 01 October 2002, 16:03

Then, after thoroughly greasing the spined shaft, the leg was manhandled into position and fitted to the stern drive assembly....

Mike Garside · 01 October 2002, 16:09

Then it was time to fit the prop. Interestingly, all props specified for the Bravo 1X and Bravo 3X legs are steel but all those for the Bravo 2X are aluminium. I haven't found out why thi is yet but it's on the to-do list.

Again, another surprise was to find that the 23" prop that the Barrus techie had recommended had been replaced with a 17.75 X 21" version. Again, this was no time to quibble....

Mike Garside · 01 October 2002, 16:12

Then, with a water hose fed into the strainer in the engine box and the leg intakes blocked with a pair of cuffs the engine was fired up and the on-shore tests were carried out...

Mike Garside · 01 October 2002, 16:13

All seemed to be working smoothly and so it was into the briney for the all-important sea trials....

Mike Garside · 01 October 2002, 16:15

And in no time at all we were bombing along faster by far than ever before....

Mike Garside · 01 October 2002, 16:17

Well, I'm afraid from the size of this pic of the GPS screen you'll just have to take my word for it that the Speed Over Ground reads 35.1 knots. Ahhhhh!

Mike Garside · 01 October 2002, 16:27

Well, there you are, folks. We hit 35 knots in both directions on flat water at high tide in the Carrick Roads. Since then we have put about 39 hours on the engine and it does seem that the boat - even with 600 litres of fuel on board continues to run at a speed that satisfies me.

It's been an expensive operation to retro fit a new lump but, with the deal to sell the 4-cylinder Yamaha to Stuart WAVEHUMPER Hopkins, it's been worth it. I now have a RIB that, to me, flies instead of lumbering, and if we can get 1.5 litres to a mile, we have a range of 400 miles.

At the moment I have no idea how much fuel we are using, nor the optimum revs for a balance between speed and economy. That's the next job. The Floscan fuel guage is on the shopping list.

Cheers for now...

Jelly · 01 October 2002, 16:35

Hi Mike
Looks good, congratulations, hope you have fun with her.
These photo stories have been very interesting.
Cheers
Jelly

Alan · 01 October 2002, 16:41

Mike, as I say welcome to the world of high speed ribbing! You will find that being able to sustain a 30kt cruise transforms your long distance cruising.

A few questions......

1) Are you sticking with the gear ratios / prop that you have (as opposed to the ones recommended). I'm guessing gear ratios is not easy to change without replacing the leg?

2) What RPM are you making at WOT both "light" and "heavy"?

3) Have you go her airborne yet?!!

Flocscans are great bits of kit and given the investment you have made so far its worth buying one to round off your kit. Recommend you purchase direct from a retailler in the US rather than from Floscan UK agent (Merlin Power Equip) as they wanted to charge me £150+VAT +Shipping for a sensor I can buy direct from the US for $115!

Thanks for the entertaining series of threads. Make a good magazine article wouldn't it. Now if only we had a decent magazine to put it in..............

Cheers,
Alan

batfalcon · 01 October 2002, 18:54

That's the end of the story (for now) I suppose. Congrtulations for the job. Hope that you have lots of fun with your rib from now on. I don't want to spoil your joy and maybe it's not the right time to say, but 35 knots is not high speed cruising. Ten days ago I saw with my own eyes 60 +, (63 to be exact) on the GPS. Haven't got a photo to prove it though.

Charles · 01 October 2002, 19:09

well done Mike and congratulations.....
One thing you have forgotten and that is updating your profile.

TIPS · 01 October 2002, 19:36

Quote:

Originally posted by batfalcon
That's the end of the story (for now) I suppose. Congrtulations for the job. Hope that you have lots of fun with your rib from now on. I don't want to spoil your joy and maybe it's not the right time to say, but 35 knots is not high speed cruising. Ten days ago I saw with my own eyes 60 +, (63 to be exact) on the GPS. Haven't got a photo to prove it though.

Are you saying you got your RIB to do 63 knots

???? Or have i misread that ?

Mark

Alan · 01 October 2002, 20:09

I think Batfalcon is referring to a RIB he had a ride in recently?
Anyway I know 35kts isn't particularly fast but from where Mike came from (20 if he was lucky) its a quantum leap! The ability to cruise at 30+ as opposed to 20+ makes a hell of a difference.

A high outright top speed is fun for a few minutes but usually involves a petrol engine and frightening fuel consumption. For example I have seen 52kts on Blue Ice but at that point the Floscan was pegged around to the "YOU CANT AFFORD THIS!" mark!

Alan

Mike Garside · 02 October 2002, 07:52

Alan, Michael, Mark, Charles and Jelly, thanks for the feedback and comments. Points noted and profile updated, Charles. In answer to your questions, Alan...

1 Yes, gear ratio, I am sticking with what I've got. The 1.81 ratio was to ensure the tub would get up onto the plane. It does it easily with the 1.65 so there's no no need to change. I will now go shopping for a second prop and will see what works. It will be interesting to see if the originally spec'd 23" does better or worse than the 21". I'll let you know how it goes.

2 What's WOT? The peak revs that are looked for in the book are 3,800 and we can do that but no more before there's nothing left on the stick. It's at that point we hit the 35 figure.

3 Airborne once or twice. But apart from it making Di cross with me for doing so (my sciatica is marginally better, but it aint that good), I'm not that keen on doing the flying thing. I read somewhere on the forum that landing from a flight seemed to be part of the cause of the failure of the Bravo 3 legs. The load that the prop puts on the delicate insides of the leg seem to be too much when it bites again.

Interesting comment about the Floscan and Merlin. I have got prices from both Merlin and West Marine and the gap between them, after taking VAT and shipping etc into account, is about £100 in West's favour. For that sort of money, I am inclined to go to Merlin because of the difficulty of back up from the States. I buggered up a hydraulic line olive on the Bennet trim tabs when I fitted them and getting a spare, when I get around to replacing it ,will, I feel sure, be a pain.

Alan · 02 October 2002, 08:53

Mike,

WOT = Wide Open Throttle or loud stick pushed forward as far as it will go!

If you are achieving the correct revs at WOT then it sounds as though you are fairly right on the prop. Be interesting to try the other one tho'!

Alan

Mike Garside · 02 October 2002, 13:21

Thanks Alan. Seems I still learn something new everyday.