We're in a quandary

BlueMoon1

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We\'re in a quandary

My brother and I share a Seamaster 25. It has an ancient (1963) Perkins 4.99 engine, which we've nursed back into reasonable performance but it still only manages to push us along at 6mph. Good enough for the mid-Thames, where we're based, but we'd like to go down to the estuary and the Medway.

We went to the boat show yesterday. I don't know why (yes I do) but we looked at alternative engines: Nanni and Sole particularly. The Sole man, Adrian Taylor made us a very resonable offer on the purchase price of a Sole 44 diesel -- almost a thousand pounds less than the list price.

We were both attracted to the idea but... It's an old boat (mid to late sixties) and, although we've done a lot of improvements already, I wonder if we're not over-investing in her.

In favour of the new engine: peace of mind. We have no auxilliary and it'd be no fun to break down downstream of Richmond or in the estuary. Against: the old Perkins chuffed us all the way up from the Medway when we bought her in the wet summer of '07 (albeit it took 13.5 hours with tidal assistance!)

Would the performance be significantly improved by fitting a new engine? We've checked with Norris & Co and the prop we've got is right for a 40hp engine and a 1:1 gearbox. I'm not savvy enough to work out what the maximum speed you can expect from a boat of this type. Maybe it's design speed is 6mph!

We've got a few days to decide. We'd appreciate comments from all you boaty folk on whether to go ahead with the purchase or not.

Alan
 
Re: We\'re in a quandary

I would say leave the old engine in and buy an outboard . Seamasters hold thier price and if you sell on the mid thames i dont think a new inboard will help the price . Unless of course you intend to do the trip lots of times .
 
Re: We\'re in a quandary

My father did the same on an Elysian 27 thirty odd years ago on a Morris 1000 petrol engine.
He fitted an outboard bracket with a 20Hp Mariner for emergencies which lasted couple of years and got us down the Medway.

Later on he replaced the engine with a 2Litre Ford Petrol which gave 9knots and took us to Ostende!

A 4.108 will only give you 7knots despite what No Regrets is saying as its 48Hp, my Dads 2Litre Ford was 98Hp and gave 9Knots. Seamaster 25 and Elysian 27 very similar boats.

One thing that you would gain with new Diesel is reliability and peace of mind.

You wont get all the money back when you sell it again but it will increase in value a bit.

Only really worth doing if you plan on keeping it a few years. If you think you may sell it in next 5years dont bother, sell the boat and buy one with a bigger engine.

Lots of old Freeman 30s around with twin Diesels perfect fot that Trip and prices keen at the moment.

And if you havent considered it, where you are on Thames consider joining a club as much more fun in company.
 
Re: We\'re in a quandary

Hi,Bluemoon 1
Unless your boat is finest example of the marque,you intend keeping her until the beginning of the next millenium and do 1000 hours per annum,it would be very difficult to justify spending about 3/4 + ? thousand on a new power unit on a boat worth ????.Will engine bed need altering/replacing/beefing up will shaft/gearbox handle new power output,what about prop pitch?
As others had mentioned your old engine could probably be completely rebuilt back to almost new standards and later cylinder heads etc would help to bring back missing performance.
However as always.its your boat and just dropping in a new lump and turning the key may appeal,remember to clean fuel tanks and replace old fuel pipes while you are at it,but suspect who ever does job will recommend that.
 
Re: We\'re in a quandary

4.108's are 60-70bhp according to some sources! /forums/images/graemlins/shocked.gif

Is it really only 48? /forums/images/graemlins/confused.gif

Even the Broom 30 will achieve 8-9 knots with a 4.108....although 7 for cruising.
 
Re: We\'re in a quandary

[ QUOTE ]


Even the Broom 30 will achieve 8-9 knots with a 4.108....although 7 for cruising.

[/ QUOTE ]

Smoke: Smoke On... Go!

(Red Arrows or red diesel?)

/forums/images/graemlins/laugh.gif
 
Re: We\'re in a quandary

The best boat to buy is one someone has just fitted a new engine to, usualy the best price for the type but no more. The worse boat to sell is one you have just fitted a new engine to, all the money you just spent is lost.
If it was me i'd get it partialy rebuilt, probably only cost £1-1.5K and will be as good as new. Usualy old engines are not worn out, so it probably only needs injectors, waterpump, new injector pump, heat exchanger etc... and a nice new clean fuel tank.
 
Re: We\'re in a quandary

Alan, your Seamaster, is it a cadet/ admiral? These are the only Seamasters listed as 25', 24' 8". Fitted with several engine options, 40 HP BMC diesel, top speed 8/9 knots. Fit two engines of same power speed only 10/12 knots. Suggests hull speed is only 8/9 knots. In your position, I would look for used 4108 and fit or rebuild existing engine.
Your trips to Medway will always be an expedition with that hull. Just plan tides carefully,hit the estuary at low water then use the tide to take you up the Medway.
At those speeds, you would need to be at Putney or lower down river at high water to get to the estuary for low water. Aux outboard even very small essential for steerage if you are traveling alone. Club membership a good idea, find one with similar boats or at least similar age.
 
Re: We\'re in a quandary

Don't forget you can always flog the old engine as a working unit for a fair old whack if you do decide to change it, thus minimising expense!

Ramage might need a new one soon judging by the lethargic performance /forums/images/graemlins/laugh.gif
 
Re: We\'re in a quandary

To be polite "no regrets"....bollox!! /forums/images/graemlins/grin.gif(Sounds like your Brooms spec sheet has been exaggerated a bit!)

My dad ALSO had a Senior/Project 31 (long and narrower than Broom) with TWIN 4.108 and would cruise at 7.5-8 knots, it could just about do 10knots when dropped off a cliff and would overheat rapidly at this speed.

A Broom 30 with a SINGLE 4.108 MAY do about 7Knots on a good day and I very much doubt that. Remember with GPS to do speed test up and down river to negate the effect of the stream.

As to engine specs they are so old and hence difficult these days but found this site that refurbishes those engines.
HERE

As you can see 4.107 - 36Hp and 4.108 is 48Hp although they say 50.

Worth a rebuild on the engine, best grand you will ever spend!

If you are a bit handy taking the engine out and refitting again is fairly straight forward job you can do yourself with a few strong mates or slip the marina crane driver a few quid to lift with crane.

You should be able to get an exchange unit out of one of the suppliers in Exchange & Mart Car section as these engines were fitted to Vans and hence quite a few about.

Mike
 
Re: We\'re in a quandary

According to Birchwood the Sea Tiger was good for 10 knots at full revs. That is from a claimed 78hp.

The Sea Panther is 30hp.

I have had Carli doing 14 KPH (approx 8 knots).

Remember these boats are running in displacement mode.

Stephenson Marine http://www.stephensonmarine.i12.com/

now own the Sea Panther rights. They sell new & reconditioned full and short engines and also can now supply reconditioned and/or repair BMC 1.5 & 1.8 also Ford Dover & Dorset engines.

/forums/images/graemlins/smirk.gif
 
Re: We\'re in a quandary

I would love to see you do 8Knots with a 30HP engine, look forward to a demo at TVR.
That is a REAL 8Knots, and I will show you what that looks like if you like!! /forums/images/graemlins/laugh.gif /forums/images/graemlins/wink.gif
 
Re: We\'re in a quandary

Thats SOG. Downstream. (With a following wind!!) /forums/images/graemlins/laugh.gif

The fact is, as No Regrets seems not to be grasping, a displacement hull speed for 25 feet is around 6 to 7 knots.

Even for 30ft it is not much more....

see here http://www.solarnavigator.net/hull_speed.htm

and here http://www.sailingusa.info/cal__hull_speed.htm


At Thames non-tidal speed all those lovely juicy engines are wasting their talents. Even No Regrets old Sea Tiger petrol was too powerful for the job.

I happily agree that for tidal, estuary and sea use more grunt is good, as is a semi displacement hull and twin engines.

Having been down to Greenwich in a 15 ft dinghy and having had to remove plastic bags and other garbage from the prop several times I would not take a single engined vessel down there without an outboard as spare!

/forums/images/graemlins/smirk.gif
 
Re: We\'re in a quandary

From Perkins 4108 Manual (I am sad I still have it)

3188952194_fb7328585b.jpg


PM me your email address and I will email it to you.
 
Re: We\'re in a quandary

Source: Motor Boats Monthly report on the Broom 30.

They quote 8.5 knots tops, 7 knots cruise /forums/images/graemlins/grin.gif

I'll send them your comments however, and ask them to retrospectively apologise..... /forums/images/graemlins/laugh.gif
 
Re: We\'re in a quandary

[ QUOTE ]
The formula was provided in the text by Juan Baader, published by Norton & Co. in 1965. The theory is based on repeated observations of the behavior of sailing yachts and the study of wave motion.

[/ QUOTE ]

Smart.

A bit like the Highway Code's stopping distances then. A Ford Anglia on Crossplys..... /forums/images/graemlins/blush.gif
 
Re: We\'re in a quandary

[ QUOTE ]
Source: Motor Boats Monthly report on the Broom 30.

They quote 8.5 knots tops, 7 knots cruise

[/ QUOTE ]

And I said:[ QUOTE ]
a displacement hull speed for 25 feet is around 6 to 7 knots.
Even for 30ft it is not much more....

[/ QUOTE ]

And 1.5 knots is... not much more! /forums/images/graemlins/smile.gif



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