Dry pipes water dumps
 

hello all.
got the boat running and I'm going through the final test a checkout process.

boat has lightning, dry to the tip, headers (water mixes at the tip through five 3/8" holes around the perimeter of the exhaust opening)

-plenty of fall (probably close to 30 degrees)
-cam has a 114 LSA
-idle at 1000 RPM

i killed an o2 sensor and it made consider reversion (didn't think I'd have this issue with the LSA, the fall and dry to the tip pipes). I shined a flashlight up the tailpipes and I have water all the way to the primary merge at the collector. Plugs are dry.

At at this point, it looks like the "fix" is to weld up the discharge holes at the tips and install discharge bungs in the tail pipes inside the boat and route it out via through hull water dumps in the transom.

Couple questions:

1) should I leave a small weep hole in the outside bottom of the tailpipes to drain out the water past the discharge ports inside the boat?
2) I'm thinking I need to put the discharge bungs in the top of the tailpipes as close to the inner transom as possible. Is this correct?
3) should I use 1" discharge fittings and hose as I have 1" hose feeding the headers? I'm assuming I have to evacuate water at the same rate as I'm introducing water into the headers.

Thanks guys!

Also, pics of how anyone else has rigged their dumps is always appreciated.

I had a very similar problem with dry CMI headers which also had the water opening on the perimeter. I played back a video of the tail pipe and you could see the water getting sucked back into the exhaust pipe! Consequently my exhaust pipe was also wet inside and especially at the collector merge. I purchased some GGB silencer inserts (second shortest model) and reversion problem solved. The water flowing out of the tail pipe significantly increased compared to without an insert. GGB said that this was a common use case for the product. This was a quick and dirty fix that didn't interrupt my boating season! I was happy with this reversion solution so didn't pursue changing the water dump locations as you mentioned.

I will pull out my Gil Hi tork exhausts when I get home. they were set up by Gil, so however they are plumbed is probably correct.

I had posted this some time back in a reply to a similar issue, I just cut and pasted it below. Maybe it will help you out...

"Interesting issue on your exhaust, I had the exact same issues with mine from idle to 2200 rpm. I built fully dry pipes with separate water dumps ( I did have a 1/8" weep hole in the bottom edge at the very tip). That fixed everything from 1200 rpm on up, however below 1200 rpm the exhaust pulses would hit the water behind the boat and it would stir it up and suck it back in getting the O2 wet. So then I also added some drew marine shotgun mufflers onto my dry pipes. The main reason was to disrupt the back wave of the exhaust and keep my O2 sensors dry but also because my KE headers with dry pipes are really f$!king loud. "

I'm a big fan of the GGB inserts but if they actually help prevent reversion is a big bonus.

VC, Photobucket' phuchup on you restoration thread is one of the larger shames on this site.

I would not do a weep hole
use 3/4 or 1" is fine
id mount them at 11 and 1 clocked towards the outside top of each pipe and run them out the side of the boat.
If you want to make both side even you will have to run ball valves at the bung going out the boat. Don't do the transom dump and put the hot water on the drive.
To make it simple have you tried slasburg flaps.

Thanks for the replies fellas.
I can see the water being pulled back up on a video I shot.

what's a slasburg flap class? Is that the rubber flapper?

Without a weep hole at the bottom of the tip, won't water get kinda locked / trapped in the end of the pipes and stay there? Could that create a hot spot?

Again, thanks to all!

Also, are you guys using a high temp silicon at the tailpipe / collector slip joint?
i did as I figured it wouldn't hurt.

Weep hole it outside. Yours go all the way out. Or are you using tips

no tips class.tailpipes pass right through the rubber ring to the outside.

So, a small weep hole on the bottom tip to drain the water is a good idea?

If you do it. Put it outside. It all drain the pipe for when it sits in between using it. And it won't freeze up if you get a unexpected freeze

I have the same headers. Your problem is probably the joint between the header and the inner extension pipe.
I use high temperature silicone ( red ) AFTER I make sure both pipes mating surfaces are clean and no old sealant.
Mine don't leak and O2 sensor is doing fine.
BUT I do have water dumps that spray onto the top and sides of the upper drive. ( no chalking there also )

I can see the water spray getting turned 180 degrees and sucked back up the pipe.
I have high temp silicon at the slip joint.

Can you post a pic of how you did your dumps tinkerer?

I just installed dry headers on a fresh HP500 had the same issue with water reverting , thank god we caught it right away , we closed the end of pipe with silicone and also piped the discharge bungs with a 45 degree stainless pipe pointed up to my swim platform this way we wash it down and avoid any melting fiberglass

Ok fellas, I've bought some bungs, fittings and discharge dumps.
We're going to TIG them in this week.
Question / assumption:

im assuming I want the discharge bung as close as possible to the silicon rubber ring at the transom.
It would fit and plumb easier in this first picture, but I could get it back another 2 inches of I grind a little notch on the inside of the boat at the top
of the transom and hold the bung right up against the inner transom.

Check out these pics. Again, first pic=easier install
Second pic=closer to the end of the tailpipe by 2 inches

thanks guys

I lost an AF bung too. Matter of fact, I lost 2. My cam is very similar to the 525 cam with a little bit more lift. On some headers there is a little ramp looking thing that acts like a dam. I think most of that moisture burns off before it reaches the actual exhaust port.


At what point is moisture considered reversion?

i just dropped and broke my camera, so no pics.
i'll try to explain where the holes are best i can.
so these are gil dry trs pipes.
the tail is 31 7/8 inch to the weld on the riser
the center of 3/4 i.d water dump is 13 3/8 from tip.
inside the pipe on top are two 1/8 holes 1 inch in from the tip
outside the pipe on the bottom is one 3/16 hole 1 1/2 inches from tip. (drain hole)
the trs is 10 3/8 longer than bravo so if you subtracted 5 3/16 from each end (tip and weld) the water dump would be in same place
from the scuff marks where the tail goes thru the transom to center of the 3/4 i.d. dump is 7 1/2 inches.

been 5 days, so your probably welded hoses rigged and in the water already.
by the way that was a nice write up that mag did on your boat, well deserved

Thanks OOS.

We are welding them them as i type this.
Those measurements are just about what I'm going to end up with as well.

PS. The seat bottoms are 22" from the floor surface in the pantera.

Won`t let me post more than one picture per post.. this site really blows now..

Don't see much difference, your post is clear and well done.
ben

To answer your original questions, all three are YES.

You want a drain hole on the bottom of the tip to drain the water out of the falling part of the header/tip. I think mine is 1/4".

And its a yes again about the RTV in the slip joint between the header and tail pipe.

Thanks for all the replies and pics fellas! Much appreciated!
We got the pipes modified over the last couple days. I'm a beginner TIG welder, so I asked a friend to come by and lend a hand.
j used a carbide 7/8" hole saw to cut a hole in the outer pipes as close to the inner transom as possible.
I cut some patches to cover the original "at the tip" water outlets while my friend welded in the bungs.

Here re are some pics:

Looks good.

If you want, itll probably be fine to have one hole to dump water in the exhaust if you want. May be a little late now as you welded them all up, but if it needs to appear like you have wet exhaust an 1/8 or 1/4" hole will let just enough in. Thats how mine is setup, I have lightning headers as well.

I took the wife for a boat ride last night and, much to my dismay, I still have wet pipes and collectors.
Looks like the tailpipes are blowing water up at idle and the exhaust is sucking the aerated water right up the pipes.

Im going to pull the plugs after work and make sure no water is getting that far up
the exhaust. The boat runs fine, and I think the water droplets are burning off before they get to the cylinders. (When I pulled the headers for the mods, the exhaust ports showed no signs of water)

also, im going to fire the boat on the hose to confirm it's a low exhaust / water being thrown about issue. I've pressure tested the headers twice and they are fine.

At this point, im leaning toward trying those rubber Salisbury flaps (hate those damn things)

Any other suggestions would be welcome. Maybe the Gibson inserts are the fix?

I have 20 degrees of advance at idle and I idle at 800 rpm.

thanks guys!

Try putting a yardstick up the exhaust before you start it let it idle then shut it down and see if you can see any water on the yardstick,maybe then you can see how far the water is getting sucked back up the exhaust.

I just measured from the waterline to the bottom of the tips.
My tips are only 4" off the surface of the water.

I don't think it will be a problem, the inside of the pipes are hot it will burn it right up

Don't run the rubber flappers with dry exhaust, they will make a funny smell!

Ok, so I ran the boat on the hose last night and I have leaks at the slip joint between the tails and the header collectors.
I used what I thought was a lot of permatex high temp orange silicon on the slip joint, but apparently not enough.

What are are you guys using to seal the slip joint?