Thornycroft Engines

[mikeyboy1966]

A question for the more knowledgeable than I.

nya have a nice Freeman 32,

they list the engines as 2700, 108hp

quick tinternet search shows up nothing.

Can any of you boaty types shed any more light?
I believe 6 cylinders.

if you’ve experience of the engines what would be the likely fuel consumption at river speeds.

also availability of spares.

one more,just out of interest,would these engines get the boat planing?

my old mk1 30 should ,originally had these fitted ,but when I bought it ,it had a pair of 4108’s fitted.more throttle just made a huge wave,lots of noise and probably used a load of fuel

[Smoggy]

Possibly Ford Dorset engine, thorneycroft are just the mariniser, they did lots of different makes if engine.

They will shove it along well but probably not quite on the plane.

[floydraser]

I looked at a few Freeman 33s and they were all Ford 6 cylinder powered. I think Freeman favoured Ford power as there were a lot of them in the smaller boats too.

[Vaughan]

8 hours ago, mikeyboy1966 said:

just made a huge wave,lots of noise and probably used a load of fuel

That is because a Freeman is a semi-displacement hull, not a planing hull. This means no matter how much power, it will not get up "over the step" and plane across the surface.

I have seen Freemans with Ford 4D engines, known as the Parsons Pike.  Big, solid, indestructible lumps. Built, I believe, for the Thames Trader lorry.

[ChrisB]

Theoretical Hull speed (Nautical/ Imperial, I don't know the metric calculation)

Speed in Knots = 1.37 X The Square Root  of the Waterline Length measured in Feet.

 Over this speed the boat will effectively try to climb it's own bow wave.

The above calculation works for normal mono hulls it is not true for twin/multi-hulls or the super fine racing hulls on say a Rowing 8.

[ChrisB]

Most Nautical Engineering  Formulae are now available via calculators available on the Internet it seems.

[BroadAmbition]

Your boat speed calculator seems about right to me, it’s puts ‘B.A’s hull speed at 8:6 knots or around 10mph

Griff

[floydraser]

A good bet for spares: https://www.sheridanmarine.com/freemancruisers