Dry exhaust
 

I am looking for advice on the best way to go dry. I am currently running EMI thunders with the long risers. Was having some reversion issues, and I sent the risers back to Eddie Marine. They did some mods to them and that took care of that. Still I would like to go dry. My question is this, would it be better to modify my EMI's or sell them and start over with another exhaust system that is designated dry? I know I will have to do the thru hulls for the dumps. All advice and ideas would be appreciated!

Suggestions?

Are you currently thru -hull?

Dry pipes are much louder. Other than that you still have to water jacket them so the water dump is the big change.

Wannabe

dry pipes with turn downs might be a viable option.

Thanks guys for the responses. Yes I am thru hull exhaust. And I realize it will be much louder. That's actually one reason I want to do it! And I anticipate some more upgrades soon,and want to be totally reversion free.my specs now are .612 .607 lift ,duration at .050 .230 .236 with LSA 112.0 .it is my understanding you can do what you want to as far as cam goes with dry exhaust.

You can run pretty much whatever you want for camshaft with dry exhaust. You don't have to have dumps for the water. They way a lot of them do it is to just dump the water straight down into the lake right at the end of the pipe. They just put a hole at the end of the outer pipe at the bottom of it. That way, it's jacketed all the way and the water dumps out the bottom and never mixes with the exhaust gases.

I would consider a different exhaust if you want to go this route, especially if you are wanting to go larger on the cam. You obviously want to make more power by installing a larger cam, so why restrict the engine with manifolds. Go to a set of headers and dry tails. The Eddie Marine manifolds are certianly not the best out there.
Eddie

which set would you recommend? It's the boat in my signature with a bravo. Thanks for your response also. I have heard many good things about you!

If your handy with a welder, have some SS pipe and have some time you can mod your eddies and make them dry. But selling the entire system and buying a set would ultimately be the easiest route.

John jr

[QUOTE=Young Performance;3937296]You can run pretty much whatever you want for camshaft with dry exhaust. You don't have to have dumps for the water. They way a lot of them do it is to just dump the water straight down into the lake right at the end of the pipe. They just put a hole at the end of the outer pipe at the bottom of it. That way, it's jacketed all the way and the water dumps out the bottom and never mixes with the exhaust gases.

I would consider a different exhaust if you want to go this route, especially if you are wanting to go larger on the cam. You obviously want to make more power by installing a larger cam, so why restrict the engine with manifolds. Go to a set of headers and dry tails. The Eddie Marine manifolds are certianly not the best out there.
Eddie[/QUOTEi totally agree about the EMI"s. have not been happy with them at all. Reversion issues with the cam specs referenced above. Pulled engine twice thinking I had internal issues because of water in oil. Sent the risers back to Eddie marine and they extended inner pipe and changed the way the water dumps into the exhaust. And charged me $300.00 to do the work. In my opinion,they should have took care of that, but refused. They guaranteed up to 750hp, mine is only 500hp. The reversion did stop,but they should have stood behind their product.

Anybody out there got a set of headers with dry tails out there that's reasonable? They will have to work with my set up.let me know what you guys have. 89 Baja with Bravo, BBC.

I am having the same problems with my emi thunders. i have two 500hp motors just redone with three hours and i noticed water in the oil on one. i pulled the motor figuring i had a bad gasket or other internal problem and everything checked out fine. put the exhaust back on and ran motor for about twenty minutes on dyno and pulled exhaust off and it poured out of the manifold. Im getting reversion. I already had them make the risors with a 6 iI contacted EMI and they want me to send the risors back so they can modify them. Can you please let me know what exactly they did when you sent yours back. Im considering just to go dry to make sure i dont have anymore issues. Thank You! Frank

Crap, now you guy's are scaring me. I've been piecing my engine together for 2 year's now and finally getting close to starting it. I too went with EMI thunder also with the long risers, my cam is a little bigger. 234/244 @.050 .629/.612 114 LSA , Does anyone think this cam will be a problem? They are going to have to lock me up if I have anymore issues with this #%$#$%#%$ boat.

Had Cmi and went with a less radical cams to prevent reversion. Didn't work. Switched over to full dry. Might have to put mufflers on but so far no water in cylinders...

I love it when people post negative comments about products thay have not even used....not you guys....call EMI..ask for chris,tell him you guys want to make your risers semi dry pipes which go through the transom..you will have to give him a measurement and most end up being 30 to 40'' long..yes thay are loud but sound way cool..

also make sure your engines are operating at a minimum of 140* or the manifolds will sweat and act like reversion but they are doing the same thing the gil's do but eddie dont make the ss plate that burns odd the moisture..

The angle&drop have a lot to do with reversion. I have under the swim platform tips with CMI e tops. The drop is almost straight down . The drop is about 14".My cam is [email protected] on 112 lobe ctr. Never a sign of reversion.

I agree, call Chris at EMI. He has always been great to work with. Check this thread out.

http://www.offshoreonly.com/forums/d...e-exhaust.html

Ok so I shipped the risers back and looks like Im def. going to have to go dry with running them through the transom. My outlets are about 7 inches higher then normal Bravo exit locations and emi feels I dont have enough pitch on the pipes. anybody have an idea how much space is ok heatwise my pipes will exit under swimdeck with about 4 inches between the pipe and deck. Not sure with the dry exhaust if this will be to hot? Thanks.

You had to pay for it because the reversion wasn't their fault. I don't care if it is on a 112LSA, that cam is risky at best for not having reversion. They can't control what other components are in your build such as intake, carb, head design, intake port velocity, compression ratio, your idle speed, your ignition timing. You tell me which one of those is their fault. I only bring this to your attention because I spent a lot of time on the phone with Bob (RMBuilder) talking about reversion and cam timing isn't the only factor. It is a big factor, but you can build two identical engines, with the exception of say the AFR 305cc heads on one motor and 345cc heads on the other. The 345cc headed motor will be more susceptible to reversion due to the slower port velocity.
Their HP claim is based on what the manifolds can flow.

Got drys need wets if interested - [email protected] thanks

Just my opinion but, tubular headers are something I plan on buying brand new. Last thing you want to introduce into your power I a set of worn and cracked headers.

Just my opinion .Sometimes a deal on good low hour headers comes along , so you buy them.

Yeah, offshore engines don't cost much. :lolhit:

I'm just a 59 year old that's been in boats since a teenager and am clueless .We all have our own opinion

I had some reversion, especially with the mufflers closed, plus my 02`s were dying a quick death.
I was just going to do a single nipple out the back until Mild Blunder mentioned running most of the water overboard and just small nipple to keep the mufflers from getting too hot.
Much better idea and will keep the 02`s dry


The bung is in the bilge

http://33outlaw.zenfolio.com/img/s5/...87314350-3.jpg

http://33outlaw.zenfolio.com/img/s5/...63087132-3.jpg

having the same issues with my lightnings, kills the 02's in mins...went thru 3...question is how little water will can you dump and not have a issue with the headers ?

Stellings would be my only choice. buy therm once and never look back...it is probably the best investment you can make on a performance engine. Remember loud pipes save lives.

buy a set of used stellings or cmi sport tubes and never look back. if your worried about leaks, have them pressure tested. it's hard to justify 7-10k on a new set of exhaust for most people, in fact, it may be worth more than some peoples boats lol. the dumps are at the very end of the pipe and will mix just fine with mufflers if you decide to go with the. i would just leave them off:)