BryanTuvell

7 inch Corsa cans made custom to replace my mufflered ones.

BryanTuvell

Here is where I am at Idle.

Hope the pictures help, my view is you can never have to much protection, even if the externals are not all that awesome to look at! Never had one fall off yet, but have read of some who have!

Best of luck,
Bryan

Unchained

checkmate454mag is right about the purpose of external or internal flappers: to keep water from washing up through the exhaust while launching your boat at the ramp or anchored and a wave hitting the stern. Reversion is caused by high lift cams and valve overlap, causing water to be sucked back into the engine during the intake stroke, which is why boats with radical cams usually run dry exhaust. External flappers should suffice.

Tinkerer

I knew what he was talking about from his post--So I answered it

1Boatnut

unchained and checkmate454mag have nailed it. Reversion has absolutely nothing to do with internal or external flappers.Reversion is usually caused with big lift cams. With dry pipes,water is not injested at the riser like the normal wet exhaust. The real purpose of the internal flapper is to shut ff the exhaust and divert the exhaust through the prop. If your Silent Choice is open,so are the valves,so your pipe then acts as a straight through pipe anyway. The idea behind the Salsbury flapper is to keep water frome coming back up the pipe when coming off plane or as stated before,following seas,or when your boat is anchored in wavy conditions.
Believe me,without a high lift cam,the external valves will do you plenty.
Hope this helps! Sorry about a late reply,but this was only my 1st view

srpbaer

1Boatnut and all others,
Thanks for the replys....I too had always thought that a big cam was the main cause of water reversion. BUT...I was talking to Dino at Bob Teague's and in this conversation I had mentioned the gutted tips...He stressed not to run them without the internal butterfly style flappers. He stated no question I would have problems very soon with just the external Salibury Flappers. My boat really doesn't have high risers or elbows and that is what made me feel like I may have a problem if I didnt runt internal flappers. Now I am really confused!!!!

1Boatnut

srpbaer, maybe you should get a explanation. I for one would certainly like to hear it. I have dry exhaust with nothing more than the salsbury flappers and have had no problem.
Sorry this seems to be confusing you more,but I guess there are different opinions. Again,I would get Dino's explanation,cause to me it makes no sense.

srpbaer

Thanks, I will get a reason behind the opinion...

traviss

we have had no luck with internal flappers. I put new IMCO tips on dad's boat with internal rubber flappers. When we first ran it on the hose I found flapper half way down the driveway, it had blown it out. So we replaced it and a few weeks after, looked in and no more rubber flappers. So he has external flappers now.

On my boat I bought the eddie marine tips with the metal flapper, after the rubber tips blew off the flappers it was a clattering noise. I just looked at them in the boat and they are junk, the rod that goes through the flapper is broke of the side of the pipe ( after 98 hrs) I did'n't like the cattering noise anyways and don't want to fix them so it gets external flappers this year.

just my story and .02 cents

srpbaer

Traviss,
Thanks for the experience.....I know exactly what you are saying...By the way Eddie Marine now offer what they call a new and improved and I think they have a "lifetime warranty". Isn't that scary???? Rubber flappers have always burned out and lasted about a week with me....I still have the Salsbury flappers on the corsas but thought need both internal and external flappers. My tips are never under the waterline at any time.
Thanks for your reply.