Repower a Humber Destroyer

BarflyRIB · 30 December 2010, 21:19

I have a humber destroyer 5.8 with an old 150 mariner 2 stroke that's EOL - a friend of mine has a honda 90 4 stroke and thinking of trying it.

I know, I cannot expect the same power, but should a 90 4 stroke be enough to play around?

What about fuel consumption comparing HP to weight?

Mollers · 30 December 2010, 21:28

Imagine taking the engine out of an aging Lamborghini and replacing it with one from a Toyota Yaris. It'll move.

Jono Garton · 30 December 2010, 21:39

Dave Mallet aka wavlength has a 6m Destroyer with a 90hp four stroke, goes very well considering hp / kg , I would expect about 35 knots.

90hp four stroke will use about 1litre per nm

Jono

Dave P · 30 December 2010, 21:50

Curent destroyer (2009 model) with a 90 opti makes 38kts and averages about 0.8l/nm. Ok its a 2 stroke so id expect Jono's estimate to be pretty close to reality.
Hope it helps you.

Mollers · 31 December 2010, 07:11

Quote:

Originally Posted by Jono Garton

Dave Mallet aka wavlength has a 6m Destroyer with a 90hp four stroke,

Funny that, 'coz Andy Scholes aka 'Sticky' has a 90 Honda on a 5.5 Gemini and that's as flat as a fart.

Describing 35knts tops for a 6m boat as 'goes very well', sounds like Jono is trying to flog it.

Chris · 31 December 2010, 07:18

Quote:

Originally Posted by BarflyRIB

I have a humber destroyer 5.8 with an old 150 mariner 2 stroke that's EOL - a friend of mine has a honda 90 4 stroke and thinking of trying it.

I know, I cannot expect the same power, but should a 90 4 stroke be enough to play around?

What about fuel consumption comparing HP to weight?

Wow thats quite a jump and will be equivalent to about half as much power on the rib.

BogMonster · 31 December 2010, 07:53

Quote:

Originally Posted by Chris

Wow thats quite a jump and will be equivalent to about half as much power on the rib.

Half the fuel consumption as well though

Mollers · 31 December 2010, 08:06

Quote:

Originally Posted by BogMonster

Half the fuel consumption as well though

Probably not. The 90 would be getting it's @rse whipped all day to keep it near it's 35knts.

Imagine reselling it. Any prospective buyer is gonna think that the main engine has been pinched.

spartacus · 31 December 2010, 10:26

Quote:

Originally Posted by BarflyRIB

I have a humber destroyer 5.8 with an old 150 mariner 2 stroke that's EOL - a friend of mine has a honda 90 4 stroke and thinking of trying it.

I know, I cannot expect the same power, but should a 90 4 stroke be enough to play around?

What about fuel consumption comparing HP to weight?

There's a Honda 135hp here, but it's an extra-long-shaft? Seems expensive for the hours on it. http://www.findafishingboat.com/hond...-shaft/DS29943

BruceB · 01 January 2011, 15:43

I have a suzi 90 on a 5.8m, admittedly its a bit lardy with a dual console, aux, twin batteries and about 100l of fuel but I can cruise 2 up at around 24 knots and get 30 flat out.
Even without all the extra stuff I don't think 38 knots is realistic with a 4 stroker

bingomike · 01 January 2011, 18:18

I am getting about 30-34 knots on mine (just hitting about 4500 rpm) - 9o hp tohatso on 5.85m. Mike

BTW Happy New Year

chewy · 01 January 2011, 18:30

Quote:

Originally Posted by bingomike

I am getting about 30-34 knots on mine (just hitting about 4500 rpm) - 9o hp tohatso on 5.85m. Mike

BTW Happy New Year

Whats WOT?

Razorbill RIBs · 01 January 2011, 18:43

Quote:

Originally Posted by chewy

Whats WOT?

WOT = Wide Open Throttle (its an acronym mate)

willk · 01 January 2011, 19:02

Quote:

Originally Posted by chewy

Whats WOT?

You know, WOT, one of the two positions on a RNLI throttle:

1. NOT
2. WOT

Jono Garton · 01 January 2011, 20:14

Quote:

Originally Posted by willk

You know, WOT, one of the two positions on a RNLI throttle:

1. NOT
2. WOT

They wouldn't understand, they don't let Chewy or Dan at the Helm

willk · 01 January 2011, 20:25

Quote:

Originally Posted by Jono Garton

They wouldn't understand, they don't let Chewy or Dan at the Helm

I have for you a Spoon, so you can Stir It some more...

chewy · 01 January 2011, 20:32

Quote:

Originally Posted by Dan Worth

WOT = Wide Open Throttle (its an acronym mate)

I know that soft arse, I was asking him as in "whats the rpm at WOT" as he mentioned 4500rpm.

Quote:

Originally Posted by Jono Garton

They wouldn't understand, they don't let Chewy or Dan at the Helm

Times have changed since you were last here....

bingomike · 01 January 2011, 20:42

Quote:

Originally Posted by chewy

Whats WOT?

Hi Chewy,

That is WOT - the prop setup is keeping revs down to just over 4500, book says WOT should max out at 5500. Going to have a play with new props etc in feb. Just finished running in so haven't bothered so far..

Mike

chewy · 01 January 2011, 20:50

Quote:

Originally Posted by bingomike

Hi Chewy,

That is WOT - the prop setup is keeping revs down to just over 4500, book says WOT should max out at 5500. Going to have a play with new props etc in feb. Just finished running in so haven't bothered so far..

Mike

Glad someone knew what I was on about, should get a few more knots with it revving to 5500rpm.

Razorbill RIBs · 02 January 2011, 07:47

Quote:

Originally Posted by chewy

Times have changed since you were last here....

and here too!!