Exhaust tube flapper

[starsnstripers]

1970 MC-1 165hp L-6 The only thing holding me up from installing my engine is that the exhaust flapper is missing in the tube, I dont dare install it without it where i'm going to be in salt water and maybe some snotty wheather. The ears are there and the cross bar. Wondering if i can fabricate one, but not sure of the operation? It must be weighted to stay open unless there's back water pressure? Or off centered? Is the lower of the flapper longer to keep it open utntil there's backpressure or? I couldn't find the right one/part# for my application. So any feedback would be appreciated. thanks

 

[Don S]

Re: Exhaust tube flapper

May sound like a silly question, but an OEM shutter is less than 25 bucks. Why reinvent the wheel ??????? Mercruiser PN 45586

 

[starsnstripers]

Re: Exhaust tube flapper

I didn't thik they cost very much but all the parts listings had every flapper except for my application. Guess i got aggrivated because i couldn't find the right part#. Thanks Don I'll get the right one, you have a point. thanks

 

[ziggy]

Re: Exhaust tube flapper

It must be weighted to stay open unless there's back water pressure? Or off centered? Is the lower of the flapper longer to keep it open utntil there's backpressure or?

if ya lay a flapper flat, it's an oval. when installed the flapper is below the brackets and rivots that hold it there. the flapper can't pass these by + as their washed backwards twards the engine, the try to slightly wedge into the exhust tube as it's an oval in a circular exust pipe. with the flappers folded, looking down on them they apear to be a circle. with water and exhust flowing, they just flap straigt down and out of the way.....
that's the way i see it.......