Ehaust tip flappers
 

Help me out here.......I have a completely "gutted" set of corsa tips that came on my Baja. They still have the external flappers. Do I need to install internal flappers as well? I am worried about water inversion but really don't want to fool with internal flappers if not necessary...All opinions are welcome.

You definitely need to worry about reversion as you don't want to lock your motor and start compressing water....bad things happen at that point! I'm not sure what the rule is when looking at the waterline versus the exhaust and the riser height. My exhaust is under the water when I'm off plane and I don't have a very high riser so I have external flappers AND internals and I still worry!!!

Do a search in the forums for REVERSION and see what comes up. I'm sure others have opinions/advice!!!!:cool: :cool: :cool:

Be careful of all of our advice....sometimes you get what you pay for! :D :D

Dave,
Thanks for your reply...seems you are the only one out of 68 viewers that have an opinion....maybe the only one who even knows what "Flappers" are. I will go with your opinion...inside flappers it is. I get the feeling if it isn't a 1000hp race boat people just don't care..

srpbaer, sorry you feel that way about the amount of views compared to posts. I have no idea on your flapper problem, so I didn't post any info. My exhaust is thru hull and about 6" off the water, don't think I'll have a reversion problem

I got inside and outside flappers might be overkill but I have seen bent rods and broken pistons caused by water. Rag's

srpbaer,
Yeah...sometimes people don't post much but spend lots of time "viewing". When I have the opportunity (and the knowledge which is usually limited) I will post a reply. I have been thinking about reversion lately as well and my transom looks similar to ragtops so I make sure I take extra precaution. There are a few of us on the board that don't have 38+ foot boats and we don't run 1000hp either. There is a huge knowledge base on the board, just be patient and you'll get the information you are looking for!!!;) ;) :cool:

I have just the outside flappers and I have a big cam and headers with 0 problems.

Lets get something straight here. Those flappers whether salisbury internal type or rubber externals will not help to eliminate reversion. They may actually contribute to it. Their sole purpose is to help prevent water from backwashing into the engine from either a following sea or waves.
I only have the external rubber flappers on mine. I have Teague switchable tips, but I kept on blowing out the internal salisbury flappers. The last time they blew out, I refused to replace them again. I hope nobody was behind me the times they blew out of my pipes!!:eek:

I replaced my mufflered Corsa cans with Corsa gutted with the internal, and we have external Salsbury's. I just want the added protection.
And yes, with the hatch up you here the internals clack a bit, but normal running you do not know their there.
The Corsa warranty is good too.
Bryan

Another view.

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

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

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.

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

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:D

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!!!!

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.

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

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

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.

srpbaer ... I have noted on a few occasions that when talking to these customer service people at teagues and others, they often lack substance to their advice. Start to ask technical questions outside the norm and you will see. The advise you are getting here is right on the money. Good things come to those who wait.

Good luck,

Oh yeah, I have the internal flappers with the counter weight and have not had a single problem with inversion. That is what you called it in your original post and I thought that meant backwashing, not reversion. Made sense to me... that is scarey.

BT :cool:

14 years later........if any of you guys are still out there! I have CMI E-top headers on my boat. The water exits thru a pipe fitting on the top of the exhaust roughly 8 inches or so before the tail. If you look in my tail pipe tho there are 3 little holes drilled in...the water jacket I guess you may call it. Little water does exit there. My question is can I use external rubber flappers to prevent water from coming in during launch, coming off plane, and sitting still when there are waves? I'm always nervous water will get in the pipes and I'll turn the key and boom! Just dumped more money then I have in this motor so I want to keep it going. Also if I can use the rubber external flappers is there any problems they can cause like forcing the exhaust water back in? Thanks guys

I continue to run the external rubber flappers only and have zero issues with backwash. And I have taken big wakes on the transom while floating enjoying life. I don't believe they have any effect on reversion whatsoever.

BT

I ran wet lightening headers for years with just ext flappers also. No issues what so ever and that was with cams even on 110 lsa. Been at this for over 30 yrs now and the most I had was a milkshake with a cam on a 108 but that was back in the day when reversion wasn't discused much and 75 mph was fast.

So the rubber external flappers shouldn't melt even with dry exhaust?

Btw I still think 75 is fast!! I start getting scared in the mid 80s

75 IS fast in the wrong boat.
My Daytona at 75 is like riding in a CADDY on the highway.

Neither Internal or external won't fair well with dry exhaust. Shotguns simple solution. The only rubber I like to smell burning is whatever I can get the tires to burn on a good brake stand and the smoke passes the front of the vehicle - you know your on a good one. Lol.

If you don't like the rubber ones go stainless that's what I did and looKS way better [IMG]http://i1149.photobucket.com/albums/...psvbj77ds7.jpg[/IMG]