exhaust on a pre alphe mr1

[big ken]

had my inline six in a cut in half 55gal drum testing motor and noticed exhaust and warm water running out of two holes on bottom of bellhousing or gimmell housing [not sure what is is called.] one on each side right at the lower anode bolts, is this normal? i thought all exhaust came out of prop. thanks ken

 

[Fishermark]

Re: exhaust on a pre alphe mr1

It's normal.

 

[acupajoe]

Re: exhaust on a pre alphe mr1

Wow timing couldn't be better for this question. Also noticed the same thing and got worried because all I hear is that the exhaust comes the prop...So much to learn.

 

[achris]

Re: exhaust on a pre alphe mr1

When you are running at idle or very low speed the back pressure on the 'through prop exhaust' is too high for the exhaust system to overcome, hence the exhaust reliefs at the side of the gimbal housing. Once you start moving a bit quicker the area behind the prop hub creates a region of lower pressure for the exhaust gases to exit into. The diffuser ring on the out edge of the prop hub stops these same gases vortexing back into the low pressure area at the back to the prop blades.

Chris.......