Twins on a Phantom 25

[ToffenG]

Hi!

I have at last got hold of 2 x Merc 2.5 EFI engines for my Phantom 25. It has been a long long journey.

The engines can be delivered with alien style cowlings or standard race cowlings. The standard cowlings are more narrow, and allow the engines to be mounted closer.

If I am correct, the closest you can get the engines with alien cowlings is 23 inches senterline to senterline. Does anyone know how close you can get engines using old style cowlings? 19 or 20 inches?

Mounting the engines closer will give lower gravity and better bowlift. It will also make it easier to mount the engines using external hydraulic steering such as Mayfair / Latham, etc.

I plan to mount the engines on a 1 inch bracket. However, I have seen some using more setback than this. Any experiences out there?

Thanks for your help.

Cheeers, Toffen G

[FrenchPhil]

Hi Toffen,

I always that it was more efficient to distance the motors as much as possible. Any 4L racers out there ?

[Jon Fuller]

no, you want them as close as poss.

[JamesM]

I have noticed on a few of the twin rig F1 ski boats with alien cowls that they offset the cowls sideways with respect to the rest of the motor thus allowing the motors to be mounted closer together. I guess they have custom made base pans to do this.

Maybe if you really want alien cowls you could have the motors delivered with no cowls and get some custom ones made to your requirements.

Only problem now is finding someone that could make you some alien cowls with offset base pans. Anybody know of anyone who could do that?