Performance - Page 7

Jonny Fuller · 15 January 2003, 15:34

I couldn't agree more, as I said in my earlier post there are theory's about harmonics and all sorts, I dont think it's as simple as the amount of torque though as mine probably produce more than a yanmar, also, some last for ages and some last five mins, this could back up the harmonics theory, some people may inodvertantly cruise with an rpm/load that just happens to be exactly what billy bravo doesn't like!

Anyway, I didn't say there was anything wrong with that!

crazyhorse · 15 January 2003, 15:35

you make more money out of selling two engined boats in the trade than you do out of one.

When that is realised and people move over to prefer singles diesls then the buisness,s that can survive will go with the market and produce single engines diesl ribs.

In my humbel opinion

crazyhorse · 15 January 2003, 15:37

gota go do a bit of work speake later taraar.

Jonny Fuller · 15 January 2003, 15:44

whilst it's a pain having two sometimes, and bloody expensive, it's nice that your auixillary motor is allready running when you need it, I never much fancied an O/B wiggling about on my transon at high speed day in day out waiting for it's day of glory, then with my luck the b*****d wouldn't start when I did need it!, also if your talking about a high performance boat (60 plus mph) then the neutral torque reaction charicteristics of a twin are difficult to match (the airborne stuff we all enjoy, rib's or otherwise)

Jonny Fuller · 15 January 2003, 15:48

Quote:

Originally posted by Jon Fuller
Cmon, that's not giving much away, how about some history, I've been forced into giving up my identity and history...and pics, how about you reciprocate!

How about it then Crazyhorse! I'm itching to see your rib

Jonny Fuller · 15 January 2003, 15:56

Manos,
your posts say you have two boats, or you have one, and are waiting for the second to arrive, do you currently have one in this country, or do you leave it in greece?... and why did you say you were only going to do a couple of races with the new one? it seems a great expence to have an F2 boat put together just for two races! could you expand please

Julian · 15 January 2003, 15:56

crazyhorse

The whole gearbox was re built . we had strenghtend bearings shafts etc, seems fine now.

Graham has built loads of single engined diesel ribs.

Jonny Fuller · 15 January 2003, 16:01

sorry julian,
I think we're at crossed purposes, I asked how many 9.5 metre rib's he'd made as single's, I know there's been load's of single engined ones, but thought the 9.5 cabin rib was rare as a single!

Julian · 15 January 2003, 16:11

My mistake

Yep the cabin with singles are quite rare. Not sure how many, Brian has one and there's 1 in sweeden at the moment which is our old one which had 2 300 Yanmars in but the guy took one out to sell.

Julian

Jonny Fuller · 15 January 2003, 16:13

So it was your's, how did it handle with all that weight in the back?

Alan · 15 January 2003, 16:17

Akershally I think there was only ever one 9.5m Scorpion cabin RIB with twin diesels and Julian's old man owned it! Twin Yammar 300's went like stink and was fine apart having to remove one engine to change the oil eh Julian?

Also glad to see Brian has posted about driver error, 'cos a reasonable number of the hours on his B3x driver were put on by yours truly at the helm!

If the super dooper US model Bmax drive is $10k then thats about £6.5k for a drive. B3x normal is £5k IIRC so the price is not too bad is it?

T'other interesting thing about the Dave Crawford beefed up drive is that I would expect that Scorpion would be pushing that solution to customers such as Brian who have had a problem. (So severe as to change to B1 drive.)

Fact is that if you have a single engined RIB you want to be able to rely on the drive. Brian rightly has no faith in the b3x after his failures. 10m out of Stornoway en route to Kyle is not the place for a drive failure! Fortunately weather was good and International Rescue in the shape of Hot Lemon 4 was to hand!

Alan

Alan Priddy · 15 January 2003, 16:21

Brian. I have to go back to an earlier posting of mine. After spending 35 years designing and building transmissions, there is "no such thing as indestructable gearbox" they will always let you down when you least expect it.

Here's an interesting theory. We have all been using rib's for a long time and have come to live with the exceptional sea keeping.
When was the last time you went out in a fast hard boat?

Last year I was invited to sea trial a new engine set up in a well known make of powerboat.40 foot, lots of HP and supposingly very quick.
It was not a particularly nice day but not that bad that you would stay at home. As came out of the harbour with the loud sticks open she shot up to 55 knots which was very impressive, but as we headed West along the Solent it got very interesting and the proud owner soon had her back to 20 knots because the boat couldn't take it.
(as a side line, the only time I have broken any bones in a boat was in a Class 1 which landed so hard I put my elbow through two ribs).
Now then on to my theory. Because the type of boat we use is very safe and handles bad weather better than a hard boat we tend to use them more than say, the average Sunseeker owner who would rather stay in the marina than have the crap beat out of them. The Sunseeker owner rarely has drive unit problems and the rib owner lives on a knive edge everytime they go out expecting the outdrive to go bang.
Why is this? because we expect to much from the units that are available and untill someone comes up with a hardening process or design that doesn't break it is something we are going to have to live with.
My recommendation is to keep the outdrive oil clean and the prop in the water. For referenace Still Never Enough had over 1200 hours on her Yamaha out drive, this was after the North Atlantic trip and a full throttle blast from Tower Bridge to Monaco (99hours 12 min 15 sec) Spirit travelled over 20,000 miles on her origanal outdrive before being changed to go around the world. It is the luck of the draw

Alan P

Julian · 15 January 2003, 16:24

Alan

I do believe you are correct. It was the only one with 2 300 yanmars. Hmm changing oil was a tad expensive.

Has brian spoken to dave Crawford about beefing up his leg, mind you I suppose now brian has the Bravo there's not much need.

I must admit doing long trips is a bit worrying with these legs. were often miles out at sea and you start thinking is that leg going to let go. Puts you off a bit.

Julian

Jonny Fuller · 15 January 2003, 16:29

point taken mr p,
but with regard the class 1, if it was a class one worth it's wottsits, you were probably going faster than the speed of light, driving like your life depended on it, that's racing, not a good comparison I think

Manos · 15 January 2003, 16:29

This question does not have anything to do with inboard engines but with trim motors on outboards.
Does any one know which is the best way to keep an outboard engine on a boat full up or full down when say for example you store it for a long time??
I have asked many engineers but so far I never got a clear answer. Some say up some down some say it does not matter.
As a matter of interest when I store my boats I keep the engine full down. Also when I have them in the water the engine is always down. Is the right thing to do or am I wrong

Jonny Fuller · 15 January 2003, 16:32

I would say if your concerened at all, down is correct, as the rams will be retracted into the hydraulic oil behind the seals and protected from the elements!

Manos · 15 January 2003, 16:35

This is what I thought but this is the 1st time I got a STREIGHT answer!!

Thanks

Jonny Fuller · 15 January 2003, 16:36

I've gotta get on with this bloody boat!, see ya later

Dirk Diggler · 15 January 2003, 16:37

Especially if you have a berth in an MDL marina, up would cost you another £50 a month.

Brian · 15 January 2003, 16:41

Julian

Yes, I had long chats with both Graham and Dave about what to do. A rebuild with "heavier" components wasn't mentioned though.

I guess, if you think about it, our ribs do take one hell of a pounding. My natural "mechanical sympathy" does make me wince at the treatment they take sometimes. And I suppose it is no wonder they break. We are just going too far, too fast for the currently available technology, as Alan P. says. They work most of the time and I guess you just have to be philosophical about the breakage.

I have to say though, that you can't beat rib cruising IN COMPANY for all sorts of reasons. Only some of which are touched on above. As Alan W. said, a breakdown 10m outside Stornaway is not the first place you would choose to come to a dead stop at-hence the value of having first-class fellow ribsters around you when you do have a problem.

Is this beginning to sound like a recruiting campaign for BIBOA?