New propeller??

[tel1]

But its not just the nearly double the amount of fuel you will use, and the cost, but you have effectively halved your range. And if you think it was difficult to get your engine out, wait until you have to get at the fuel tank! Not that there is any space to fit an extra or larger tank.

If you are using 2500 revs to get 6 knots then you are using a lot of power and fuel for the speed which is not surprising if you are using the smaller prop from the smaller engine. Very inefficient, but if you propped it correctly, revs would fall and the engine would never work in its efficient range and you tickover speed would be even higher![/QUOTE

the 2500rpm with 6kn boat speed, was with tide and 20k wind on the nose. i take it you have never been on a moody 38? i have to remove the fuel tank to get the engine lifted out!

its one thing i dont like about moodys, they built everything into the boat thinking it would never go wrong, but as ive learned with this boat, when things do go wrong they a very awkward to fix!

 

[Tranona]

But its not just the nearly double the amount of fuel you will use, and the cost, but you have effectively halved your range. And if you think it was difficult to get your engine out, wait until you have to get at the fuel tank! Not that there is any space to fit an extra or larger tank.

If you are using 2500 revs to get 6 knots then you are using a lot of power and fuel for the speed which is not surprising if you are using the smaller prop from the smaller engine. Very inefficient, but if you propped it correctly, revs would fall and the engine would never work in its efficient range and you tickover speed would be even higher![/QUOTE

the 2500rpm with 6kn boat speed, was with tide and 20k wind on the nose. i take it you have never been on a moody 38? i have to remove the fuel tank to get the engine lifted out!

its one thing i dont like about moodys, they built everything into the boat thinking it would never go wrong, but as ive learned with this boat, when things do go wrong they a very awkward to fix!

Yes, my experience is with a 37/376 which has a similar engine fuel tank layout. Not the best way of designing a boat for the long term. Without wishing to rub it in, removing the plastic tank in my Bavaria is an easy job, but highly unlikely as it is plastic and not mild steel. Yet another reason why I don't own a Moody - one I looked at had a leaking fuel tank. No thanks! Reinforced by all the finish needing replacing on the bulkheads and the headlining falling down because of water leaks. All this on a boat less than 20 years old at the time and asking price £20k more than my boat was worth at the time!

 

[Heckler]

But you are just about to spend nearly half of that on a new prop! Seriously, don't know how you got to that price difference unless your 78hp was free. A new 50hp Beta or Nanni complete would have been less than that in total and much more appropriate to your boat. I think you will be paying for your "economy" decision for the rest of the life of the engine.

All you can do is prop it so that it runs at sensible revs and accept that you are wasting power and fuel. You may already have discovered the other downside of overpowering and that is high speed at tickover revs which can make maneouvering a pain.

Incidentally, my Bavaria 37 (wash my mouth out) has a Volvo 2030 and has never felt underpowered, cruising at 5.6 ( and less than 2 litres an hour) and top of 7.6 and a dream to handle at low speed.

Stewart
I am sure I came across something in my researches about the TMD22 and the MD22 that all was the same in the engine except that there was a something in the pump that was connected to the turbo to give it extra fuel in the turbo versions. I am sure it was in a Landie forum (they use montego/ldv/perkins prima50/md22s) and it was talked about using a turbo engine but taking the turbo off.
He could take the turbo off, get his old std exhaust etc etc.
Stu

 

[Tranona]

Stu

Would make sense, because the turbo is never going to need to work at the rev range he is going to use. Don't know practicalities of taking it off. My only experience of turbos is when the garage knocked the sensor wire off the turbo when servicing my 2 litre Ford/Peugeot engine. Boy could you tell the difference!

 

[tel1]

Yes, my experience is with a 37/376 which has a similar engine fuel tank layout. Not the best way of designing a boat for the long term. Without wishing to rub it in, removing the plastic tank in my Bavaria is an easy job, but highly unlikely as it is plastic and not mild steel. Yet another reason why I don't own a Moody - one I looked at had a leaking fuel tank. No thanks! Reinforced by all the finish needing replacing on the bulkheads and the headlining falling down because of water leaks. All this on a boat less than 20 years old at the time and asking price £20k more than my boat was worth at the time!

i love the point you made on the tek tank, whilst the engine was out, guess what i done???

yes, a nice new plastic tek tank and fuel gauge, also new insultion!

if your going to do a job properly.......


and regarding the turbo, somebody else said this on here, and apparantly its not that simple. but something i could look in to. one thing i do know is that the fuel pipes on the tmd22 anre bigger than the perkins prima m50