Bravo 1 oil loss
 

I have a Magnum27 Sport with twin new build 450 hp Small block motors which rev to 5800 rpm.

I fitted aftermarket oil reservoirs from CP performance which I keep at about half full with Mercury gear oil. Both drives are fitted with drive showers but the left hand rotation drive blows it`s oil out of the reservoir breather at high rpm.
I am at present modifying the shower caps to flow more water down the sides of the upper gear case to provide more cooling.The oil does not look or smell burnt or off colour and there are no metal particles to be seen on either the upper or lower magnets or in the oil.

Has anyone else had this problem, are my reservoirs to small, I am I using the wrong lower unit oil ? The oil does not look or smell burnt, it just expands beyond what I ever expected. Any help on the subject please, would be appreciated.
Many thanks
Kalaazar

On the stock reservoirs there is a check valve in the cap that allows air in but not out. This causes the drive to pressurize when it gets heated up from normal use. Do your new reservoirs hold pressure??

Yes they do to the point that it blew the "o" rings out of the bottom of the reservoir, so we had to fit a small vent pipe in to the system

What is your fill procedure??
From the bottom till it flows out of the top plug, then install the plug and continue to fill from the bottom until it reaches the reservoir. Then let it equalize and put the bottom plug in, then add to the bottle as needed..
Is this how you are doing it??

Yes it is exactly that and the problem is only on the left hand rotation.

I have now been told that I have to improve the cooling to the sides of the Port drive upper gears and increase the capacity of the drive reservoir which is considered as being way to small for the power we are putting into the drive and thus the heat.
Thanks for your interest, appreciated.
Kalaazar

Your welcome! A larger reservoir will be a big help. And the cooler the better! Let us know how it goes..

Dick

Thanks Dick, will do,

Kalaazar