Re Engine

[gorde]

I have a Bayliner 2455 with a 4.3l EFI Mercruiser engine.
At the beginning of the season the bottom is obviously clean and the performance is good. I can get up to 30mph with 4 on board.
As the season goes on and the bottom silts up I lose performance badly which means that I have to take the boat out of the water for a scrub. Depending on the circumstances this could be quite frequent and is expensive.
I have considered a re engine (perhaps with a diesel) but I have been told that this is probably too costly, especially if the leg has to be changed also.
Has anyone else come across this issue? the boat is really too big for the engine.
Could the engine be modified to get more HP out of it?
Any advice or cost information would be appreciated.

Gorde

 

[Spi D]

You are absolutely right. Unless somebody gives you an engine for free, it will get too costly.

Extra power from the EFI is not possible (at least not compared to cost).

Many who have done the maths end up with "sell it and buy one that is what you want".

BTW: Any boat will foul the bottom and suffer severely in performance. And any boat will not if used frequently (enough).

The right antifouling for your waters will help a lot and may even make growth wash off when moving through water, but still sitting for extended periods will make things grow

 

[Sandyman]

30 mph !!! whats that at sea ?

 

[Spi D]

30 mph !!! whats that at sea ?

Approx. 26.07 knots

 

[sigmasailor]

Slow down, relax, take up sailing.

 

[mm1]

Slow down, relax, take up sailing.

Very helpfull!,do you have the option of dry stacking somewhere,just a little weed/growth on the leg can have a very big effect,regards mm1

 

[burgundyben]

Swap the 4.3 for a big block V8, wont cost alot but the running cost will be higher.

Or get a wetsuit and jump in and wash her off in summer.

 

[Spi D]

Depending on your sterndrive it will or will not cope with a larger engine (HP).

If you aim for 30 knots, the typical US topspeed, calculate your ready-to-go weight with fuel, all gear and persons and divide by ten. You now know the approx hp needed.

Surely around 300-330 hp which takes a big block V8 petrol.

Fuel consumption relates to the work done, so if you want to produce 300 hp prepare to supply plenty of petrol. Close to 1.5 x your current consumption.

 

[neale]

A mid season scrub every year for the next 10 years will cost nothing compared to an engine swap. If the boat is good for 30mph at the start of the season I would either find an antifouling that works in your waters or accept that a mid season lift is a requirement. Not sure where you are but sea lift in the Solent are perfect, and more cost effective than a normal lift, for a quick scrub.

 

[davidej]

I don't know where you keep your boat but this might be an alternative to dry stacking:

http://www.boatfloatboatlifts.com/index.html

 

[ontheplane]

Get a good wetsuit, a bit of basic scuba training and then go over with a non-stick type scourer and just scrub it off yourself. about half-way thru season give it a lift and jet wash.

I also concurr that a good antifoul will help - we used Cruiser Uno which seemed ok for Weymouth.

I also agree that a dry-stack will help if this is a very real problem.

The other thing - go through EVERY item of kit and work out if it's totally necessary....

If you can, get rid of a couple of hundred kilos of stuff - works wonders.

 

[BartW]

I have considered a re engine (perhaps with a diesel) but I have been told that this is probably too costly, especially if the leg has to be changed also.
Has anyone else come across this issue?

I had the same plan with a 25ft boat some years back,
but I learned here from this forum that it absolutely didn't makle sense,
too costly and too much hassle for the result,

just start looking for another boat, and sooner or later you might be able to do the upgrade or trade-in ...

 

[oldgit]

Lift that leg me hearty !

Or.........pick a nice calm sunny day and beach her on a sandy beach/shoreline or slip way and scrub the old girl off with a stiff broom,but definately have a good clear out of "stuff" that WILL sneak onto boat over time.

 

[carlton]

...As the season goes on and the bottom silts up I lose performance badly which means that I have to take the boat out of the water for a scrub...

This may be a dumb question, but you do apply antifoul to the hull, don't you?

 

[carlton]

This may be a dumb question, but you do apply antifoul to the hull, don't you?

I think we can take that as a 'No'...

 

[gorde]

Poor assumption! I antifoul every year and lift and scrub mid season.

 

[carlton]

Poor assumption! I antifoul every year and lift and scrub mid season.

I was hoping for a response.

I don't think you need to re-engine. There's gotta be something else wrong if, as you say, the boat goes well with a clean bottom.

It could be that you're using the wrong antifoul for your cruising ground. What do you use at the moment?

Do you apply anything to the drive and prop?

 

[longjohnsilver]

Wetsuit, forget scuba gear, scrubbing in water is easier than on land or a grid. Used to be able to do my old 32' in about 30 minutes just holding my breath, can't be arsed with a snorkel. Just get some gloves and a scotch barite type scrubbing pad. I use those that stick to a plastic handle , Velcro type affect, most chandlers sell them.

 

[gorde]

I usually use Blakes. I have used "hard racing" and I think the other one I have used is Xtra (rated for fast motor boats).
I usually spray the leg and prop with Blakes paint, can't remember the name but it is designed for the leg.
What would you recommend?

Gorde

 

[carlton]

Best to check with other boat owners in your marina/location.

I've used just about everything on the market over the years, but I've had the best results with Interspeed Ultra on the hull and EU45 (white - no copper content) on the drives, with lanolin on the props. Although I'm currently using EU45 on both the hull and the drives.

The drives get a bit of growth on them if I haven't taken the boat out for a coupla weeks but it just falls off as if by magic.

Bear in mind that you will get growth on the hull and drives regardless if you don't take the boat out regularly. Not having a pop here - it's just a fact of (marine ) life, that's all.

If you find you're having to scrub the hull mid-season you could be in a heavy fouling area and your antifoul may not be man enough for the job.

It's your call, but I'd be tempted to try another brand for next season. As I say, prob'ly best to ask other boat owners at your marina and see what they recommend. Good luck with it.