2 Answers Please

Fire99

Fire99

Well-Known Member
Joined
11 Oct 2001
Messages
3,983
Location
Bangor NI
Visit site
Hi,
Firstly thanks to everyone who has responded to previous questions. You've been great assistance to this novice "boater"..
Could you great fountains on knowledge please help me with 2 questions?

1. A friend of mine has a Freeman 30 which he has recently replaced the old 3 litre Ford Tractor Diesel engines with 2 Litre Lombardini engines (new).
The lombardini's are rated at 48.5hp at the crank and 45 at the prop and believe it or not the old Ford lumps were rated slightly less.
Anway he was getting around the 14knots mark with the old engines but now is lucky to get 8 knots out of the new ones.
The new ones are easily reaching their 3000 rpm limit but only achieving greater wash with little increase in speed from say 2200 rpm.
The old engines ran out of puff at 2000 rpm.
The boat apparently is around 1 ton lighter with the new engines / boxes. (so i'm told) but the engineer has fitted identical props as on the old engines.
Surely that cannot be right?
Anway waffle over.. any suggestions? and how heavy is a freeman 30 with twin (old ) diesels aprox?
Your help as ever is greatly appreciated.

2. Back to my little Norman 18. Recently it seems to have started slamming the waves more and riding more nose heavy. Ive checked the bilge for water but its clear and i havent suddenly put on lots of weight so any ideas on that? The boat has been in the water now for over a year at a marina. Could the antifouling condition underneath have an effect. The outboard is at the same pitch and engine speed.

Your help is greatly appreciated..

cheers

Nick
 
1 Answer (only)

There is a Freeman Owners Club who will almost certainly be able to help your 'friend' - try a search of the archives on this forum for mentions of it or else do a search using www.google.co.uk

instinct tells me that the props should definitely be different as you're (sorry 'his') engines are revving 50% higher than the old ones.....you could also try Lancing Marine in Sussex as they do petrol to diesel conversions and must be able to calculate the correct prop size for these.

currently boatless
 
Norman 18....yes the antifoul/condition of then bottom of the boat can reduce the speed by 2or3 knots ,ie increasing the drag.Try cleaning ,you didn,t say how old the antifouling was,I have my little boat on a drying mooring witth new antifoul so am able to scrub it often.Check yours is not growing weed etc.Sorry can,t help with other boat.



regards,
T.B.
 
Re: question2

Yes, growth of dreaded weed and so on makes a dramatic difference. have a grope underneath, and unless it's flat, it's slowing you down. You can have the boat lifted and most weed etc washed of with jet blaster for not too much£££££.
 
Re: 1 Answer (only)

Thanks, I let him know.
Funnily enough he's spoken to a prop. distributor and they have confirmed the same. What a nightmare.

Thanks again for the info.
 
Thanks..
Mine is in a drying mooring too and there is a bit of weed starting to accumalate on the outboard power tilt.. its a right mare to remove...
Thanks again for that...
 
Re: question2

Thanks for the info.
Better get the ol girl lifted out and give her a scrub.
some of the antifouling from last year has washed off anyway so it will be a good time to do that aswell.
 
Wrong gearbox ratio ?

If what you say is correct and you are seeing more revs, then the props must be turning slower. If 2000rpm gave 14knts so say 2:1 reduction thats 1000rpm at prop. So now 2200rpm gives 8knots suggests more like 4:1, if the same props fitted. Doesn't sound right to me, too much slippage somewhere.
 
freeman mystery

The Freeman problem is baffling. From what you say, I wonder if the gearbox ratio is different? Did the new engines come with new gearboxes (they often do) in which case has the reduction ratio changed? Unless something's slipping in the drivetrain, that's all I can think of based on those symptoms
 
You must log in or register to reply here.

Share this page

Top