Marathon

[Scand]

Well a single engine boat won the E-class in the around Britain race in 2008.
The outboard engine must be “sufficiently retained” so can presumably it be bolted down/stored inside the boat?
I recon your Bananashark Sterling would be really nice with a single 500-600hp petrol engine, and it would cut cost a lot?

[Cookee]

Originally Posted by Scand

Well a single engine boat won the E-class in the around Britain race in 2008.
The outboard engine must be “sufficiently retained” so can presumably it be bolted down/stored inside the boat?
I recon your Bananashark Sterling would be really nice with a single 500-600hp petrol engine, and it would cut cost a lot?

The rules say:

Single engined craft and single shaft driven boats may compete. All such
boats MUST carry an auxiliary engine for use in emergency breakdowns
capable of propelling the craft at 5mph for a minimum of 35 miles. This
engine can be stowed in the boat but must be shown to be sufficiently
retained so that it will not work lose or cause damage.

Yes it would cut the cost considerably and make the boat more simple with reduced weight in terms of engine, drive and of course fuel - the only downside is you lose the redundancy of a twin setup. I'm sure one of the 525's for sale on here would propel a Stirling at a reasonable pace and take you into D class, not sure it would have the outright speed in very flat conditions but it would certainly be competitive when it is a bit choppier! Of course a big Ilmor would be a better bet!

[lain]

Originally Posted by Adam

If an engine is legal then there is not really any dispute. Only to consider looking at rule changes - but as whenever this has been mentioned before it has been like blaspheming...

Affordable is all relative...but I don't think there has been too much effort to make a really competitive and affordable class anyway. I mean a class where you can put together a relativley cheap and lowish powered boat and be competitive.

Looking at the entry classes (admittedly I'm just thinking inboard), why are they divided by litre of engine and not hp. Surely a hp division in class would allow old to race with new and have greater chance of preventing check book racing?

At the moment over 600hp of diesel can race in a lower class than an off the shelf 496ho and next year if developed and you have enough money that could be 700hp. The disparity's just too great and doesn't allow budget racing.

If entry classes were divided by hp older engines can stay in play. They may have more torque but they've got the weight to make up4 it and need more fuel.

And i don't see why modifications would matter too much. If you had classes set at say 450, 650, 850 and you're dyno'd you're stuck in a class with related hp vessels. If you've modified the engine output then you end up, up a class. This leaves most contenders concentrating on strength and reliability mods which i can only see as a good thing as then whatever you have you can make it work, if you have more dosh you are just gonna buy better new anyway. This way Peters engines will race like hp boats and you wouldn't need the hottest new hp per litre engine every year. Wouldn't this encourage a more open; 'bring wat ya got' attitude and increase numbers by stopping older from being as uncompetitive?

This way you could race a single home built 425hp 7.4 and build a few spares cheaply and not feel completely outclassed.

I know I'm looking at this from one side of the coin, I'd like to understand the other side?

[Scand]

Without using data loggers it’s very difficult to monitor/verify what horsepower the engines are producing, so classes based on engine volume are easier.
I think Peter Unwin was looking into a low cost petrol engine option for the E class, I guess he is working on other projects at the moment
The highest commercially available diesel engine that can be run in the E class is 480hp.
I think the highest rated commercially available petrol engine that fit the E class is the 6.2l V8 from ilmore at 430hp.

[Cookee]

Iain - The problem with changing class structures is that inevitably some engine packages will become more or less competitive, and I for one would resist change on that basis alone - stability of regulations is absolutely paramount if the Marathon class is expected to grow.

Petter - Which E Class Diesel engine does 480hp? Would that be for single engine use?

[Scand]

Both the 5.8l from Yanmar and the 5.9l from CMD makes 480hp and fits the E class.
There is also an option from FTP @ 480 hp and 5.9 litre.

[Cookee]

Originally Posted by Scand

Both the 5.8l from Yanmar and the 5.9l from CMD makes 480hp and fits the E class.
There is also an option from FTP @ 480 hp and 5.9 litre.

I believe the issues with single big diesels outweigh the advantages - finding drives that would take that HP and torque reliably would be tricky, you would need an auxiliary motor, one drive would be less stable than two and there's more "Get you home" power with a twin rig.

[Jon Fuller]

I think a single would be great. A 500-ish HP Yanmar, in a boat like the 30 foot buzz at Drivers would make a bulletproof bit of kit. Trimax, big inboard gearbox. great fuel economy, and don't see why you couldn't get one running 70, or 70+.

And Iain, if you were running a 500hp diesel, you'd want/need a few horses advantage over a pissy (read small & light) little small block to even start having a fair cop given the weight penalty, and drive penalty you'd be fighting, not to mention the massive price difference in the engine & drivetrain. You're talking as if no one had the foresight or understanding to consider all these details when planning the classes.

[lain]

Originally Posted by Jon Fuller

You're talking as if no one had the foresight or understanding to consider all these details when planning the classes.

I never thought or meant to imply that. I just wondered why they are set as they are and you don't find out if you dont ask.