Project "Blue Venom" (aka "Solent Viper")

[Top banana]

Originally Posted by waverunner

Hightower,

From the photo that engine doesn't look like it is sitting right down onto the top of the transom?

Andy, when you said in earlier post you may have to go for long shaft, is this because of what waverunner is refering to,

obviously the installer of the engine thinks this is ok. but wouldnt this put more stresses on the casting. the reason i ask is that originally i put a deposit
on a 150 verado x long, but in the meantime mike at osprey had alredy cut the transom for a long shaft. when i contacted bill higham and told himwhat had happened, he said it was allright to lift the engine up 3". But after seeing another thread on here about bill higham, im curious to know if his oppinions are correct.

Ps nice seat backs, im having some new ones made shortly with the osprey
emblem stitched on.

[Dirk Diggler]

Originally Posted by Top banana

im curious to know if his oppinions are correct.

He's wrong

[Hightower]

Originally Posted by Top banana

Andy, when you said in earlier post you may have to go for long shaft, is this because of what waverunner is refering to,

obviously the installer of the engine thinks this is ok. but wouldnt this put more stresses on the casting. the reason i ask is that originally i put a deposit
on a 150 verado x long, but in the meantime mike at osprey had alredy cut the transom for a long shaft. when i contacted bill higham and told himwhat had happened, he said it was allright to lift the engine up 3". But after seeing another thread on here about bill higham, im curious to know if his oppinions are correct.

Ps nice seat backs, im having some new ones made shortly with the osprey
emblem stitched on.

Did I say I might have to go for a long shaft? Must have been a very early post as I had the deposit paid on the XL DI since May.

Mike makes his EL transoms 27" high as outboards run best on the Osprey at 2" above the planing wedge. I had him cut mine to 25" as I wanted the option to fit Alloy props and wasn't completely convinced about a prop running so high. The reson for the gap is that the outboard is mounted 1.5" higher based on the information Mike and Roy gave me. The offset is 1.25" to Port.

I can't see how you could run an Extra longshaft outboard on a longshaft transom. The outboard would have to be mounted at least 5" higher just to get the Cav plate on the outboard level with the bottom of the hull. You might then need to increase this gap by at least 1" or 2" higher to get maximum performance. That's 7" above the transom

[Neil Harvey]

Originally Posted by Hightower

Did I say I might have to go for a long shaft?

If I recall correctly, you were talking about the auxiliary

[Hightower]

Originally Posted by Neil Harvey

If I recall correctly, you were talking about the auxiliary

More recently I did, yes!

[Top banana]

the point i was trying to make is, does it matter that the engine is not sitting
supported on the engine bracket, but is soely supported by the bolts and the weekest point of the casting. or should the gap be filled with some kind of
wedge.

[Chris]

Originally Posted by Top banana

the point i was trying to make is, does it matter that the engine is not sitting
supported on the engine bracket, but is soely supported by the bolts and the weekest point of the casting. or should the gap be filled with some kind of
wedge.

No all the strength is where the bracket bolts to the back of the transom, my etec is a normal long shaft and to get the anti cav plate 2" above the wedge I have about 3" between the top of the transom and the underside of the bracket.

Chris

[Hightower]

Yes, all the weight and force of the outboard is taken by the engine mounting bolts, however you cannot raise the outboard by too much as the mounting points for the bolts will become too close and will have an effect on the strength of the installation.

[The Garfish]

Originally Posted by Hightower

you cannot raise the outboard by too much

ifn yorr gonner jakk an enjin upp yewse sikks bowlts insted ov forr.

yewl noe ifn yoove jakt itt upp too farr ifn de botes forls onn itts syde wen yew rev itt upp


sp yorr botom too enjin bowlts arr inn de rong waiy rownd

gaRf

[Jono Garton]

Originally Posted by Top banana

the point i was trying to make is, does it matter that the engine is not sitting
supported on the engine bracket, but is soely supported by the bolts and the weekest point of the casting. or should the gap be filled with some kind of
wedge.

In my experience Longs are much better on 5.8 & 6.2 Vipermax's you can never really get the height with an Extra Long while keeping the centre of gravity low enough.

Suzuki insist that the gap should be filled with hard wood, Merc & Mariner don't mind.

Wouldn't have thought that Evinrude mind, because the DI's generally gone bang before the 20 hour service, not giving the mounting time to crack.

Jono

[Hightower]

Originally Posted by Jono Garton

In my experience Longs are much better on 5.8 & 6.2 Vipermax's you can never really get the height with an Extra Long while keeping the centre of gravity low enough.

Suzuki insist that the gap should be filled with hard wood, Merc & Mariner don't mind.

Wouldn't have thought that Evinrude mind, because the DI's generally gone bang before the 20 hour service, not giving the mounting time to crack.

Jono

Got to disagree with you there.

Can't see that 5" is going to make that bigga difference to center of gravity of any sizable RIB unless it's a massive lump on the back like the Verado and even then I doubt that any normal boater would notice.

If you where that concerned about center of gravity you wouldn't fit an A frame.

Top man Jono! you'd have dissapointed me if you hadn't had a dig at the DI at the end of your post

[Jono Garton]

Originally Posted by Hightower

Got to disagree with you there.

Can't see that 5" is going to make that bigga difference to center of gravity of any sizable RIB unless it's a massive lump on the back like the Verado and even then I doubt that any normal boater would notice.

If you where that concerned about center of gravity you wouldn't fit an A frame.

Top man Jono! you'd have dissapointed me if you hadn't had a dig at the DI at the end of your post

Lets agree to disagree

Sorry I dissapointed you, I just dont like DI's

Jono

[waverunner]

Originally Posted by waverunner

Hightower,

From the photo that engine doesn't look like it is sitting right down onto the top of the transom?

It seems to me that the engine saddle is designed to take the weight of the engine and not the bolts, and the bolts are a means of fixing, otherwise why would manufacturers go to the trouble of designing them to hook over the transom like they do, if this common design in most engines was not its intended purpose in life then why not just bolt a flat engine support plate to your preferred position on the transom?

[Hightower]

Originally Posted by waverunner

It seems to me that the engine saddle is designed to take the weight of the engine and not the bolts, and the bolts are a means of fixing, otherwise why would manufacturers go to the trouble of designing them to hook over the transom like they do, if this common design in most engines was not its intended purpose in life then why not just bolt a flat engine support plate to your preferred position on the transom?

But why would manufacturers bother to put slots and other hole fixings in the saddle if the engine was going to be a fixed hieght? I think the overhang is for mounting the steering gear and athetics.

[Chris]

Originally Posted by waverunner

It seems to me that the engine saddle is designed to take the weight of the engine and not the bolts, and the bolts are a means of fixing, otherwise why would manufacturers go to the trouble of designing them to hook over the transom like they do, if this common design in most engines was not its intended purpose in life then why not just bolt a flat engine support plate to your preferred position on the transom?

I spoke to BRP to get the official line on this as my engine also sits a few inches above the top of the transom and the chap I spoke to said there is no point in choking the gap as all of the force is taken by the bolts.

Think how much force is involved in keep the engine bolted to the boat at full power, of course the vertical part of the saddle is up to the job, and yes why bother having the engine made adjustable if it has to sit on the transom saddle. it makes no difference whether your engine is sat on the saddle or not.

Chris

[truble]

as you are all well aware of engine jacking plates,,they are designed to adjust engine height on the transom,,and the engine height is like tuning suspension on your car,,it can give/lose grip in turns,lose/gain top end speed slip/grip in turns or waves in a sea,and cavitate at the worst times,,and theres no set height for any given engine hull combo as its all trial and error,,and does depend on how much time your prepared to spend on height/prop and even cav plate add ons such as dolefins,,but a general rule of thumb is start at cav level to transom and work up till find a happy mediam for all your needs,,and even that will be a compromise sumwhere,,unless u run variable pitch props and hydralic jacking paltes,i have run 16ft ski boats at 100mph and had engine 6inches up measured from engine cav plate to bottom runner plank,then we can start ton play with engine managment systems on the go,,lol,,endless fun had by all,,,now wheres me beer cheers all

[Nick Hearne]

Originally Posted by truble

as you are all well aware of engine jacking plates,,they are designed to adjust engine height on the transom,,and the engine height is like tuning suspension on your car,,it can give/lose grip in turns,lose/gain top end speed slip/grip in turns or waves in a sea,and cavitate at the worst times,,and theres no set height for any given engine hull combo as its all trial and error,,and does depend on how much time your prepared to spend on height/prop and even cav plate add ons such as dolefins,,but a general rule of thumb is start at cav level to transom and work up till find a happy mediam for all your needs,,and even that will be a compromise sumwhere,,unless u run variable pitch props and hydralic jacking paltes,i have run 16ft ski boats at 100mph and had engine 6inches up measured from engine cav plate to bottom runner plank,then we can start ton play with engine managment systems on the go,,lol,,endless fun had by all,,,now wheres me beer cheers all

Should you name not be "Trouble"?
I suppose you got 100mph out of you last boat because it had Dolphins fitted
Some ones out fishing methinks!

[truble]

no dolefins on race boats,,

[Avocet]

Originally Posted by truble

no dolefins on race boats,,

..... and thick woollen mittens

[Hightower]

Had quite a busy time this morning, fussing around Solent Viper readying her for the first launch. There was the depth finder transducer to fit and pull both the transducer cable and VHF lead though the under deck trunking. On top of this was all the equipement needed for Sea. Flares, lifejackets, tools, rope, Anchor, First Aid kit, not to mention the supplied I would need for a couple of hours of cruising.

Hitched the car up to the trailer and off I went. I was a bit of a nobby no mates today, so had to do everything by myself.

Arrived at Haslar Public slipway at 13:00hrs and had he boat in the water and ready to go by 13:30hrs.

Turned the switch and with a quite roar the Evinrude burst into life. Thought I would warm her up for 5 mins, in this time I reset my GPS trip and fitted my lifejacket.

A gentle cruise up, into Portsmouth Harbour was first order of the day. Selected reverse and slipped my mooring. Engine seemed to be hesitating a little, but put that down to tickover and the fact it's a new engine to me and a 2 stroke. Slipped her into forward and away I went.

Even at 10knotts the engine seemed to be vibrating more than I would have though, espetially as it's a 6 cylinder engine. Though I would give a blip on the throttle and she seemed very eager with no hesitation on pick-up.

I spent around 30mins in the Harbour, just checking gears and steering where OK, the depth finder seemed to work OK and checked the Radio and GPS where operational.

Once out in the Solent I couldn't wait to ease the throttle forward and see what she could do. There was a little chop, but was pleased that conditions where good as I felt very vunrable without a seat back and cushions to lean into.

Opening the throttle was like I'd been released from a very long dream. Made everything feel worth it and was a very gratifying sensation.

Out the hole seemed very quick, with no hint of cavitation or ventilation. The steering felt heavy when turing to Starboard, but a quick play with the trim sorted that. I headed out to Ryde first, with my first target the Hovercraft. The conditions would have been OK with seat backs, but without them , so I set a speed of 25knotts which was just above 3000rpm. Conditions eased slightly and I opened her up to 3500rpm which was showing 29 knotts, this should be a very economical and quickish cruising speed for every day cruising. The boat handled great too and quickly ate all the waves that where comming towards me, was a much smoother ride than lots of other boats I've been in and a big improvment on Kohaku, which some of you remember as my old RIB.

After the target was reached I turned NW and headed out past the pier to towards Fawley Power Station, as I approached the entrance to Southampton water the Sea conditions flattened right off. I thought....Here we go!

Pushing the throttle to Max steadly increase to a speed of 41 knotts at 4500/4700rpm (I was shaking too much to take an accurate reading of RPM) so might be a bit of improvement here as the operating range of the engine is 4750-5250 and there's a bit of weight to be added to the boat yet.

Fuel was lowish and just registering on the fuel gauge, I knew there was quite a bit in there, but with a new set-up there are many factors to think of and I thought I err on the side of caution.

I headed up towards Hill Head past the small cliffs just before, I was amazed at the amount of small fishing boats dragging for shelfish. As I became level with Lee-on-Solent the engine started missing and died down to 1000rpm and really missing (like running on 3 cylinders). Crap I thought, I've run out of fuel!

On throtteling the engine back to tickover, I could hear an alarm, looked down at the mulifuntion Tachometer, it was saying No Oil. I remembered back to last week when the outboard shop had problems bleeding the oil. Still i switched off the ignition and then back on again. With alarm now clear I stared my homeward journey once more at a steady 3000rpm. This problem happened 4 more times in the Solent and once again in the small boat channel of Portsmouth.

Recoverd Solent Viper the the trailer to find several loose bolts on the trailer has caused the trailer to move during lauching and had to be readjusted on recovery mental note....Check every nut and bolt on trailer before next outing.

Got home Ok and gave the guy at the outboard shop a ring to let them know about the problems, it's going down there next Monday.

So to summerise:

Very pleased with everything, can't wait till I get the Stainless and upholstery done.

Terriffic design of RIB which gives plenty of confidence and will be very happy for years to come.

Outboard has teething probs, but hey it didn't blow up Jono!

Might be on the lookout for a new prop, but will check the throttles opening fully first and make sure it's firing on all cylinders .


Anyway, some photo's....Enjoy!
Mend Dry suit, that wasn't very dry

Trailer need looking at.