Diesel for Llittle Boats

[cormorant]

Ahhh Woo I think we were posting at the same time I wasn't replying to your reply. We are both on the same page re - oil changes but we do the tests as a extra and in the past it has served us well to upgrade or rebuild early rather than have a complete failure. The new electronics on the diesels can hide declining performance and with the lighter weight fast spinning ones they can die pretty fast.

[Smithy]

Forgot to add to my post yesterday that Clayton Galants are no more. Saw it on my Facebook yesterday. Clayton Peake has just built his last one for his step-son or son-law or something. Bit of a bugga. Another Aussie boat building icon hanging up his hat. Back to those Witch Crafts, Theodores etc. now!

[PB]

yeah he was trying to sell it for ages, i think he still had heaps of work if he wanted it but he just wanted to retire i was told.

[The Woo]

That is a shame. A long bloodline of building some pretty fantastic boats. Many of the skipperCrafts I'm sure are still in active service.

[Midnight]

PB,
Absolutely nothing wrong with the cockpit layout and dimensions you are quoting. It looks good.

Please do me, and the future owner a favour and factor in a custom exhaust riser, that uses all of the available height under the engine box to get the spill over point as high above the loaded water line as possible. A lot of diesel sterndrives suffer early turbo failure on the exhaust side, as the loaded water line can be within inches of the turbo at rest in some installations. Not a good scenario for longevity.

I hope you get to build what you have drawn and that it works out well. There is a market for it for sure.

Cheers,
Myles

[PB]

Thanks Midnight, i think it will work very well as the main aim was to keep the transom clutter free. We have designed this boat for a client but i would like to build the first one for my self as iv been wanting to do something like this for some tome now.

Cheers PB

[Horse]

I think there is a great future in these 7-9m diesel powered craft. They are just made for visiting the reef and short term live aboard trips. What are the issues with moving the motor further foreward and incorporating a raised helm/bridge rather than an engine box in the cockpit? It would provide plenty of engine access and storage

[PB]

We first looked at placing the motor under the bride but found it played with the boats trim to much and the hull shape would end up being more of a displacement hull rather than a planing hull. Displacement is fine if that's what you want but there not ideal for trailering. Even mounting the motor in the middle of the cockpit had its chalangers, if you look closely at the keel line in the drawing you will see what talking about. Some of the 233 fans might notice it.

[ScottB]

Hi All,

I've been looking for a pic for a few days now, but haven't been able to find, so I figured I would have a go at describing it anyway. Spacecraft Boats in Lake Macquarie have done diesel models in the past with a forward mounted engine in the center of the cockpit, but rather than use a jackshaft, they also mount the leg forward of the transom (on a "false transom" if you like) in a tunnel so that the leg is actually under the cockpit. If you looked at it side on, it would look like the leg was coming out of the bottom of the boat, IPS style.

This would have to offer the best option in terms of fishability, with nothing extending past the transom, and reviews that I can remember reading claim that the handling was excellent. I always wondered why the idea didn't take off, the fishability of a shaft drive and the maneverability of a stern drive.... seems like a pretty good idea to me?

Anyone else have any thoughts on this concept?

Scott

[PB]

Sounds interesting. What size boat was it? The sole height off the water line would have to be very high for it to work.

[ScottB]

Hi PB,

I have seen examples in 6.4m and 8m boats. The engine box is raised as in your design. I have a couple of PDF tests but they are too large to post on here and the pictures aren't that great anyway.

I could email them too you if you want, just PM me your email address.

Scott

[myusernam]

black watch/ deep v 26 used to have slightly raised floor but now have under floor install at transom

[The Woo]

Sounds interesting. What size boat was it? The sole height off the water line would have to be very high for it to work.

I too would imigine a high floor height. Unles the ungine/drive are positioned further aft in the cockpit.

I can also imagine the absolute disaster for service access to the strendrive leg.

[Smithy]

Ben,

just read your thread on THT. Have you been out on any 30' or 34' Black Watches? I wouldn't call a 33' Obrien dry. They are one of the wettest things I have been in. The motion in a sea is the same as a Black Watch running or trolling but the BWs are amazingly dry. I've done a bit of time on Nauti Suzanne which was Parksey's from Townsville. Originally it had sterndrives and then they put a couple of shaft drive SRM33 Fiat/Ivecos in it with a couple of big trim tabs. I like them as boats, they are just bloody wet.

[The Woo]

G'day Smithy, yeah mate, been on 30&34 BW's mate. They are a pretty dry boat, but their motion I feel is very different to an O'B, after all, even the 34's are half the weight of a 33'O'brien, so feel like a trailerboat in comparison
So sure, a 34 BW will ride up and over most waves, bounce off it, and onto the next one, whereby a 33 OB is more likely to shoulder charge through it and give it a fat lip. Gives a MUCH better ride in my opinion, and does shift some water, but they throw it well clear. I've found most spray in really snotty conditions is wind blown, but would never call one "wet".
Bobbie Jones, without doubt one of Oz's most respected skippers, rates the O'Brien miles ahead of a Blackwatch, and he's done time on both.
I've spent time on a few different 33 O'briens too, and given they're all quite differently set up, some are better boats than others, given they are quite fussy on weight placement and trim. They like to be trimmed properly by an attentive skipper (we're instally auto tabs from Bennet this refit, should be great!)
Each one I've been on has had different fual tank placement, different engine packages, even different cabin layouts. I don't think I've ever claimed it was the driest of dry boats, so, how about I say, it's drier than an original 40' O'Brien? And in my very humble opinion, a better boat than a 30/34 Black Watch (which feel like overgrown 25/28 Betrams with their step-down-into saloons and engine boxes - meh)