Update on Engine Swap

[Nasher]

Some of you know that I spent a good part of the beginning of this year converting my Ocean 6.25 to take the Suzuki 200HP EFI I’d picked up cheap to replace my old Johnson 150VRO.

Now I’ve used it a few times I thought I’d pass on some findings.

The Ocean is a heavily built boat in my opinion, and has a good sea-going hull rather than an out and out sports hull, just what I wanted when I picked it up in a sorry state 2 years ago. The Johnson 150VRO fitted was always going to be changed.

The VRO used loads of fuel, @2 to 2.5l per NM and gave me around 35Knots max.
I never actually managed to find a prop that suited the boat/engine combination.
I was constantly running around at WOT to keep it on the boil and could only back off WOT very slightly to cruise at around 25Knots.
Harbours, or any sort of speed restriction, were a nightmare as it would oil up after 5 mins. of slow running

The Suzi is averaging @1.2l per NM, and I’ve seen 52Knots on the GPS.
It obviously gets the boat up on the plane a lot easier and is loads quieter.
I’m now cruising at 25knots and around 1/2 - 3/4 throttle at 3500 – 4000RPM
The engine came with a 22inch pitch stainless prop that appears to be spot on.
I’m slightly disappointed with the slow speed control, partly as its doing 6Knots the moment it goes into gear, but as Mr Halliday pointed out, that’s probably more about me than a fault with the engine.

There is still some work for me to do to get it exactly how I want it, but at the moment it’s like having a new boat again.

Nasher.

[Mollers]

Originally Posted by Nasher

Some of you know that I spent a good part of the beginning of this year converting my Ocean 6.25 to take the Suzuki 200HP EFI I’d picked up cheap to replace my old Johnson 150VRO.

Now I’ve used it a few times I thought I’d pass on some findings.

The Ocean is a heavily built boat in my opinion, and has a good sea-going hull rather than an out and out sports hull, just what I wanted when I picked it up in a sorry state 2 years ago. The Johnson 150VRO fitted was always going to be changed.

The VRO used loads of fuel, @2 to 2.5l per NM and gave me around 35Knots max.
I never actually managed to find a prop that suited the boat/engine combination.
I was constantly running around at WOT to keep it on the boil and could only back off WOT very slightly to cruise at around 25Knots.
Harbours, or any sort of speed restriction, were a nightmare as it would oil up after 5 mins. of slow running

The Suzi is averaging @1.2l per NM, and I’ve seen 52Knots on the GPS.
It obviously gets the boat up on the plane a lot easier and is loads quieter.
I’m now cruising at 25knots and around 1/2 - 3/4 throttle at 3500 – 4000RPM
The engine came with a 22inch pitch stainless prop that appears to be spot on.
I’m slightly disappointed with the slow speed control, partly as its doing 6Knots the moment it goes into gear, but as Mr Halliday pointed out, that’s probably more about me than a fault with the engine.

There is still some work for me to do to get it exactly how I want it, but at the moment it’s like having a new boat again.

Nasher.

Nasher, I'd say that she's tickin over a little too high, which wont do the gearbox a lot of good when engaging gear. Not sure what you're saying about the prop. If it's a 22P then thats quite a high pitch prop, also adding to the high boatspeed at tickover. I tried a 23P on a 21ft hardboat that I had with a 260hp V8 inboard and the thing couldn't get on the plane, it would of flown if it had. 21P was the optimum. However your Rib would be much lighter. I'm running a 19P on my rib and she "Trols" at just under 3knts at tickover, just right for mackerel :-)

[roycruse]

Originally Posted by Nasher

I’ve seen 52Knots on the GPS.

Originally Posted by Nasher

I’m now cruising at 25knots and around 1/2 - 3/4 throttle at 3500 – 4000RPM

Without even taking aditional slip into account if you are doing 25 knots at 3500 - 4000 rpm then when you were doing 52 knots your engine would have to have been at least at 7280 - 8320.

Is that even possible on a suzuki 200 i thought its max WOT rpm was around 5600 or 6000.

I cant imagine it would be doing it much good at 8000 rpm.

[Nasher]

Guys

They are all approx figures taken as an average in a wide range of sea conditions. Perhaps my Farina revcounter isn't very accurate mid range.

She ticks over between 500 and 750 and maxes out at around 6500.

I don't know the make of the stainless prop so can only comment on how it appears to work well on the boat.

Most important she sounds 'happy' and I'm happy.

Nasher

[roycruse]

Originally Posted by Nasher

Most important she sounds 'happy' and I'm happy.

That is after all - what its all about

[codprawn]

Thanks for the feedback - will be interesting to see how my 225efi compares!!!