Petrol to BMW Diesel

[wmcruiser]

Yes you are correct on fuel.
North south runners ???? Are you refuring winds or something else.


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[g-c-m]

Hi wmcruiser,

WInds, no I wasn't thinking adiabatic/katabatic (Mistral etc), I was thinking more of the very fast craft "burning rubber" at night that carry various "cargoes" in a south/north direction, that you would not want to get in the way of, or any where near for that matter. More of a problem around Gib Straits, probably not so much of an issue elsewhere.

Back to the engines, did you on trials when re-propped get the engines up to any where near the quoted maximum rpm (4800rpm), or have you over propped slightly knowing that you are going to impose a much lower maximum rpm whilst in use. I think you said you are an engineer, as such, have you fitted exhaust gas temperature sensors?

Regards

[wmcruiser]

Hi,got limited internet so may be week inbetween posts.
Original 2:1,gear on outdrives with 15x15 overred to 4400.
Wanted with 75% so proped to 16x17 max rev full loaded 3550 and she gets up on plane quick with the lower torque.
Exhaust just loop out through transom.
Yes each exhaust got temp probe fitted to monitor abd alarm over 75 degrees
Run about 30 at full power with clean scrubber basket filters.
Will reply nxt week or when i can get free wifi.

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[Ian_D]

Thanks for the updates!

Blimey, I was expecting you to say 'Been out for a couple of hours' not 'On the way to the Med!!'

Fantastic news! I had just about decided that i'm going to leave my old VP 75hp engines in mine, and sell the 2x bmw engines which are in the garage... but after reading this, i'm back to square one again, thinking about swapping them! Arrrgh! What to do? There's nothing really wrong with the engines that's in mine, but a bit more power (double with the M51's) would be nice! Not to mention smoother running / less smoke / cheap bits etc.

Any pics? or better still, videos?

[wmcruiser]

M51 engine

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[wmcruiser]

Pics at beginning of post of engines

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[Claude_Marie]

Hi Ian, Edwin,


Depending upon use of your boat, like waterskiing at high speed, you might consider an oil pan baffle or sump baffle.


You definetely do not want your oil pump to suck air.
(should it occur, on some engines you can hear the pump going clik, clik, clik when going up hill at high revs on a low oil level, in the automotive world).


People converting "street engines" into race engines overcome this problem either with a sump baffle or pourring oil in excess, or both.


Exceeding the manufacturer recommanded quantity may create a problem of over building pressure in your sump/crankshaft assembly.
Should it happen, you are at risk of blowing one of the two "O ring (?)" at each end of your crankshaft ( this ring with a tiny spring inside.


For some reason, it is nearly always the one on the fly wheel side which starts dripping first.


If you go down that route, you must make sure that your sump can breeze properly.
Discard the original BMW "breezer" and run a lenght of pipe from it to a drip can to collect condensation from oil dropplets/vapour.


Out of interest, I would be interested to know if any difference of design between the BMW "breezer" sometimes called "Flame trap" (Volvo engines) and the Land Rover one.

[wmcruiser]

As far as i can see its direct back into air intake

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[Claude_Marie]

Originally Posted by wmcruiser

As far as i can see its direct back into air intake

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correct, due to automotive emissions/pollution standards.

Re-routing into a catch can is just less "green"...and safer.

It prevents oil from being sucks into the air intake and ending up with an engine going out of control.
(self fuelling with its own oil = engine destruction)


https://torquepost.wordpress.com/201...-choose-build/

[wmcruiser]

Just an update. 120km at sea 462km inland 99hrs and bmw engines running sweet and very economical.south of paris at present.

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[wmcruiser]

Update ,south of france 867km all running well.


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[wmcruiser]

Canal de briare


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[Ian_D]

Long time I know... But thanks for the updates!

Ended up leaving my Princess with her original engines in. And sold the BMWs.

Since then I've also sold the Princess!

However, a friend (who bought the BMWs off me), is fitting one of them in his Princess 32 (small world I know!) - So would be interesting to see how his goes on a single engine. Should be good on fuel from what I've read on here!

[wmcruiser]

Hi all.
Well done year round med 420hrs 2500 +miles and only had leak on rocker cover.
Engines worked very well and economical .
Have returned back to UK now .
Any further info please contact me.