Crazy thought- thru hull exhaust.
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Category: General Correct Craft Discussion
Forum Name: General Discussion
Forum Discription: Anything Correct Craft
URL: http://www.CorrectCraftFan.com/forum/forum_posts.asp?TID=39979
Printed Date: April-27-2024 at 6:09pm
Topic: Crazy thought- thru hull exhaust.
Posted By: velde99
Subject: Crazy thought- thru hull exhaust.
Date Posted: September-26-2016 at 3:52pm
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So I have a 1991 barefoot Nautique I am putting back together. I have uploaded a video of it running on YouTube. The engine bay would allow me to run straight pipe exhaust through the back no problem. I have seen some ski boats with exhaust on the sides. Want to hear the roar of the 454. I had a boat with straight/ thru hull exhaust and loved it!! Figured I'd ask for some opinions. https://www.youtube.com/watch?v=YHMMLIUyGGQ&feature=youtu.be |
Replies:
Posted By: DayTony
Date Posted: September-26-2016 at 4:02pm
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first of all when i watched your video the first thing that youtube put up as related video was "how its made, chicken nuggets" Whats up wit that? haha when you say straight/thru hull exhaust are you talking like your going to punch holes above the platform like a cigarette boat exhaust? or are you just thinking of straight piping it into two exits similar to the earlier BFNs? (below the platform between the stringers) personally i like the sound of the 454 but i wont be making mine any louder on purpose anytime soon, i like people to know its there but not when i'm pulling into a crowded lock or making maneuvers early AM at a private lake. To change to dual exit similar to the earlier model BFNs i dont think would be a mistake but to straight pipe it above the water line your looking at a substantial increase in Db. so thats something to consider. ------------- 1988 Barefoot nautique-454 |
Posted By: Air206
Date Posted: September-26-2016 at 4:05pm
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Brian (Hotboat) put them straight thru the transom on his 91 BFN - above the waterline and the swim platform..... It was loud...... There was exhaust on the swim platform and I don't think your neighbors would care for it...... but it was loud. Mark has a dual exhaust on his 91 BFN below the platform / waterline. ------------- https://tinyurl.com/y6t5e3bu" rel="nofollow - 04 Air206 http://tinyurl.com/9urzgls" rel="nofollow - 91 Barefoot 78 SkiTiq |
Posted By: DayTony
Date Posted: September-26-2016 at 4:14pm
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on that note.....some down-swept (below water line) side exits would probably sound pretty cool. similar styling to a 40' post or most big sportfish boats. I cant say i have seen it on a lake boat before. ------------- 1988 Barefoot nautique-454 |
Posted By: velde99
Date Posted: September-26-2016 at 4:18pm
| The muffler is broken on both sides in this boat. I thought if I ran the exhaust through the hull (above the waterline) like a cigarette boat it would be cool. The muffler is trash- and I wasn't sure if anyone has ever piped a vdrive. Easy on a traditional boat to remove the muffler. Not even sure what materials are used for it. |
Posted By: JPASS
Date Posted: September-26-2016 at 4:44pm
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There's a guy on the lake we frequent who has Chris Craft cuddy cabin with the exhaust exiting above the rear platform. It sounds sweet and can be heard from clear across the lake. ------------- '92 Correctcraft Ski Nautique |
Posted By: 63 Skier
Date Posted: September-26-2016 at 5:12pm
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There's no harm in doing it, I doubt it will have any performance gains, the muffler isn't very restrictive. I'd say the only caution is to make sure you aren't routing the pipes "uphill" at all as they head to the transom. I wouldn't want it, prefer the water muffling at non-planing speeds. My jet boat with 454 and no mufflers, just wet logs, is not at all loud at idle around the dock, but sounds very nice when you step on it. I like that better than drawing attention around the dock. I'd suggest you delete the muffler but stay with the below platform exhaust, but just my opinion. ------------- '63 American Skier - '98 Sport Nautique |
Posted By: velde99
Date Posted: September-26-2016 at 5:21pm
| Has anyone ever done an excel or BFN below the waterline? Not sure what materials to use. Do the make a PVC style pipe that is heat rated for exhaust.? |
Posted By: Orlando76
Date Posted: September-26-2016 at 7:52pm
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Do it. ------------- Please support The Cystic Fibrosis Foundation 1976 Ski Nautique 351 Escort 1993 Ski Nautique purple and black 351 HO PCM |
Posted By: SNobsessed
Date Posted: September-27-2016 at 12:16am
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Fresh Air Exhaust makes underwater adaptors. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: velde99
Date Posted: September-27-2016 at 12:17am
| I'll take a look- thanks |
Posted By: DayTony
Date Posted: September-27-2016 at 8:31am
if you want to glass and fair in a set similar to this  In that case I would use FRP tubing rather than PVC. Epoxies and resins will not make a strong bond to pvc and I wouldnt want it below the water line. other style thru hulls will get installed with 5200 or similar sealant. ------------- 1988 Barefoot nautique-454 |
Posted By: 8122pbrainard
Date Posted: September-27-2016 at 9:00am
This is my opinion as well. It's not that far from being original!  ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
63 Skier wrote:Posted By: velde99
Date Posted: September-27-2016 at 9:03am
| Yes I have decided to delete muffler- and stick with original exhaust port. In the near future I will post the progress. Someone sent me a photo of their resto- which I was not a fan of- but it gave me ideas! Gonna stick below waterline. |
Posted By: quinner
Date Posted: September-27-2016 at 9:45am
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Something to consider if the exhaust is above the platform is the station wagon effect and the possibility of exhaust fumes lingering back into the boat. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1143" rel="nofollow - Mi Bowt |
Posted By: Hollywood
Date Posted: September-27-2016 at 11:39am
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Posted By: velde99
Date Posted: September-27-2016 at 11:43am
| That's awesome! |
Posted By: DayTony
Date Posted: September-27-2016 at 12:47pm
  ------------- 1988 Barefoot nautique-454 |
Posted By: 63 Skier
Date Posted: September-27-2016 at 12:53pm
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How does it work with an inboard's wet exhaust heading down under the floor, then uphill to those very high pipes on the transom? I'd have thought either the water has to be scavenged elsewhere or it would create a trap that impeded exhaust flow. ------------- '63 American Skier - '98 Sport Nautique |
Posted By: Air206
Date Posted: September-27-2016 at 1:27pm
Hmmm,..... Orange,...... motor tweaked.........Shrimp Tique version 1.0? ------------- https://tinyurl.com/y6t5e3bu" rel="nofollow - 04 Air206 http://tinyurl.com/9urzgls" rel="nofollow - 91 Barefoot 78 SkiTiq |
Posted By: Hollywood
Date Posted: September-27-2016 at 2:31pm
| The trapped water has to climb about 12", that's not enough head pressure to choke up a V8 exhaust. |
Posted By: MSST30
Date Posted: September-27-2016 at 4:45pm
| Standard schedule PVC (white) is rated for 140 degrees. CPVC has a higher heat rating. |
Posted By: velde99
Date Posted: September-27-2016 at 4:59pm
| So cpvc pipe can be used???? |
Posted By: MSST30
Date Posted: September-27-2016 at 5:08pm
| I do know about using it as an exhaust piping. In the plumbing industry schedule 40 is only rated for piping carrying water at temperatures of 140 and less. it will soften ad begin to sag at higher temperatures. I definitely would not use it if water was not running with the exhaust. I am not sure what temperatures ratings are for CPVC. Google Charolette pipe and you should be able to find the temperature ratings for CPVC |
Posted By: MSST30
Date Posted: September-27-2016 at 5:19pm
| Spears CPVC has a maximum temperature rating of 200 F. probably not enough for a dry exhaust |
Posted By: 63 Skier
Date Posted: September-27-2016 at 5:40pm
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I have experience with schedule 80 PVC, and while more robust than schedule 40 it still drooped quite a bit with hot water in a factory environment. Doubt you'd have good results with CPVC. Not sure I'm picturing correctly what you are trying to do. Wouldn't you use exhaust hose onto standard exhaust tips? ------------- '63 American Skier - '98 Sport Nautique |
Posted By: velde99
Date Posted: September-27-2016 at 5:50pm
| Headed to work- I will post some pictures later. Thanks for the comments 63skier |
Posted By: 8122pbrainard
Date Posted: September-27-2016 at 6:50pm
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Rod, I'd stay away from PVC all together. Yes, it may work and has for some but keep in mind that the section you want to replace is below the water line. I don't feel it's worth taking a chance. FRP tubing, rubber hose all the way, aluminum, SS or even copper are better choices. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: MSST30
Date Posted: September-27-2016 at 7:03pm
| My 75 Nautique has copper tubing and no muffler. Yes, it is louder than the other boats on the river but it has a nice rumble. Everyone knows who it is when my boat is running. |
Posted By: SNobsessed
Date Posted: September-27-2016 at 9:04pm
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The PVC temp problem is not normal operating conditions, rather the overheat condition when the RWP fails. Failures happen, best not to let them cause a secondary failure, like sinking the boat. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: WheelsUpATX
Date Posted: September-28-2016 at 1:29pm
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I have a 1978 Correct Craft. Any ideas on reducing exhaust odor? Will new exhaust flappers help reduce does it really matter? Mine are a bit tore up... back seat passengers sometimes complain of exhaust odor, which is normal for an older engine duh. It has gotten better b/c my mechanic explained to me that people often put too much oil in my particular engine so since we dialed it down it's been much better. I was wondering if I swapped to a solid platform with no gaps and just solid wood and potentially extend it out a few inches it might give the exhaust a little more of a barrier to transmit odors and wash out with less backdraft ...That yellow correct craft gives me a lump in my pants. ------------- 1978 Correct Craft Twitter: WheelsupATX |
Posted By: 63 Skier
Date Posted: September-28-2016 at 1:45pm
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There are a few threads on this site that show putting a barrier under the platform to keep fumes from coming up through the slats, I think maybe plexiglass was used but not sure. Too much oil - can't understand that one. Even if you overfilled the crankcase it would not cause exhaust fumes unless you had excessive engine wear and blow-by. Exhaust smell - it's possible your engine is running rich and the fumes are laden with gas. In general, in the older boats with people in the back seat there is more chance of fumes being pulled into the back of the boat, especially at just below planing speeds with the huge wakes and bow up attitude. ------------- '63 American Skier - '98 Sport Nautique |
Posted By: 63 Skier
Date Posted: September-28-2016 at 1:47pm
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Oh, and flappers have no impact at all, they are just there to avoid taking a wave up the tailpipes with the engine off. Most older boats don't have them anyway. ------------- '63 American Skier - '98 Sport Nautique |
Posted By: 8122pbrainard
Date Posted: September-28-2016 at 1:48pm
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Dan, The flappers are not intended to redirect the exhaust. They are used to prevent water from being forced into the exhaust when abruptly reversing the boat. "Too much oil"? I think you may have misunderstood your mechanic. I think what he was referring to was a fuel rich odor caused by the carb. Maybe a carb rebuild is due? What did he do to "dial it down"? Keep the platform original and address the carb. Also, keep in mind the primary use of the boat is skiing so minimize passengers in the aft seat. ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: 63 Skier
Date Posted: September-28-2016 at 2:20pm
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Pete, sometimes I just have to push back a bit. Avoid having passengers in the back seat of his boat? The guy has a very cool classic boat, if I was him I'd have passengers back there and cruise around the lake every chance I got. That's not the answer. ------------- '63 American Skier - '98 Sport Nautique |
Posted By: 8122pbrainard
Date Posted: September-28-2016 at 2:43pm
------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: 63 Skier
Date Posted: September-28-2016 at 3:24pm
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Ok, you said minimize, I said avoid. Pretty similar, but I agree not exact. With a following breeze, my '63 gets fumes in the back seat at speeds in maybe the 8-18 mph range. I have no platform. But I've had so much fun in that boat cruising around with friends/kids in any and all seats that the last thing I'm going to do is minimize back seat usage. I usually just add some throttle and get on plane, with the smaller wakes and speed generated breeze the fumes are gone. ------------- '63 American Skier - '98 Sport Nautique |
Posted By: TRBenj
Date Posted: September-28-2016 at 3:48pm
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Ignore Pete, nothing wrong with having people in the back seat. Excessive fumes are not normal. Do you also get soot on your transom? An improperly adjusted carb will cause both. |
Posted By: quinner
Date Posted: September-28-2016 at 4:09pm
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Thinking Pete has been sniffing too many exhaust and glue fumes, lmao!! Get carb worked out, if you feel problem still exists then by all means add barrier as mentioned above. The factory did it at some point, early 90's IIRC for the open platform, today they are all closed platforms for this exact reason. ------------- http://www.correctcraftfan.com/diaries/details.asp?ID=1143" rel="nofollow - Mi Bowt |
Posted By: SNobsessed
Date Posted: September-29-2016 at 12:37am
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Did i mention Fresh Air Exhaust adapter? It works & is non-permanent. ------------- “Beer is proof that God loves us and wants us to be happy.” Ben Franklin |
Posted By: WheelsUpATX
Date Posted: September-29-2016 at 2:48pm
I'd rather poison the fish than my passengers, so this looks intriguing..... the marine fresh air exhaust adaptor I always wondered if you could do and I had to google it to see. Wow that's brilliant. No soot on my transom. I need a new platform anyway I might go solid and see how that does. I am not having gas or buring oil types of smells, it's just exhaust and obviously that's part of having a 78 boat but I'll have to investigate some more since I'm always the selfish bastard driving :)  ------------- 1978 Correct Craft Twitter: WheelsupATX |
Posted By: 8122pbrainard
Date Posted: September-29-2016 at 3:06pm
As mentioned, I feel you need some work on the carb. What did your "mechanic" do to "dial it down"? ------------- /diaries/details.asp?ID=1622" rel="nofollow - 54 Atom /diaries/details.asp?ID=2179" rel="nofollow - 77 Tique 64 X55 Dunphy Keep it original, Pete < |
Posted By: tullfooter
Date Posted: September-30-2016 at 10:10am
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My buddy Shawn bought Brian's (Hotboat) '91 with the through hull exhaust. I have to say it sounds sweet. I thought it would be obnoxious to foot behind, but I was wrong. At 100' and at water level, it sounds like my boat. From the shore, it sounds a little like a drag boat. The other nice thing is that it's not too load inside the boat. ------------- Play hard, life's not a trial run. '85 BFN '90 BFN White Lake, Michigan |
Posted By: velde99
Date Posted: October-04-2016 at 1:56pm
 1991 Barefoot  1991 Barefoot with extra exhaust port  Was thinking of using something like this to split the exhaust at the bottom instead of cutting a second exhaust port in the hull. I think this would be a pretty good option. |