Dry pipes water dumps
#1
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.
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.
#2
Registered
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.
#4
Registered
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$!king loud. "
"Interesting issue on your exhaust, I had the exact same issues with mine from idle to 2200 rpm. I built fully dry pipes with separate water dumps ( I did have a 1/8" weep hole in the bottom edge at the very tip). That fixed everything from 1200 rpm on up, however below 1200 rpm the exhaust pulses would hit the water behind the boat and it would stir it up and suck it back in getting the O2 wet. So then I also added some drew marine shotgun mufflers onto my dry pipes. The main reason was to disrupt the back wave of the exhaust and keep my O2 sensors dry but also because my KE headers with dry pipes are really f$!king loud. "
#5
Registered
iTrader: (1)
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'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.
#6
Registered
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.
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.
#7
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!
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!
Last edited by vintage chromoly; 08-10-2017 at 04:20 PM.