Installation of a "through hull" to cool engine

Lazy Daze I am always willing to learn that why I always do research before I do anything.
I just want to make sure I understand this before I do it.
If I add two 1 1/4" thru hull with scoop strainers ( I boat Great south bay ) that protrude down about 2" from the bottom of the boat I am not going to lose any performance or speed.
This was one of my concerns before doing it.
Maybe I am looking in to this to much.
 
Lazy Daze I am always willing to learn that why I always do research before I do anything.
I just want to make sure I understand this before I do it.
If I add two 1 1/4" thru hull with scoop strainers ( I boat Great south bay ) that protrude down about 2" from the bottom of the boat I am not going to lose any performance or speed.
This was one of my concerns before doing it.
Maybe I am looking in to this to much.
You’re not going to loose speed. There’s a reason they are also known as South Bay strainers.

Do yourself a favor and get the rectangular type that screw on and have an access door. Makes it much easier to clean out any growth an apply antifouljbg paint to the intake.
 
Lazy Daze I am always willing to learn that why I always do research before I do anything.
I just want to make sure I understand this before I do it.
If I add two 1 1/4" thru hull with scoop strainers ( I boat Great south bay ) that protrude down about 2" from the bottom of the boat I am not going to lose any performance or speed.
This was one of my concerns before doing it.
Maybe I am looking in to this to much.
Question... if I provided the same answer again, does it make it MORE true? ;)

I'm more curious as to where you read information stating that those two, tiny little scoops would have such a big impact on the speed of the boat?

Yes. You are over thinking it :)
 
So if I remove my B3 outdrive, I can expect to gain 22 mph on my top speed? It hangs down pretty low and causes a lot of drag.

I know I read that somewhere, once, so it’s gotta be true!
 
I did this on my 87 230 when I installed the new EFI motor. Solved a lot of cooling problems, if you trailer you need to plunger flush the through-hull.
 
My 270 AJ 350 Mag Horizon and BIII came from the factory with a thru hull raw water intake and a grocco strainer. It doesn’t and never did take any water through the outdrive. My mechanic loves the setup and wishes all boats were so equipped. I’d say go for the change.

By the way, my father in-law has a 98 270 DA. His transom assembly is leaking and is being replaced.
I would recommend going with an 1-1/4" thru hull assembly vs replacing transom assy. The 5/8" intake on the 5.7 is not adequate. Bad engineering
 
I would recommend going with an 1-1/4" thru hull assembly vs replacing transom assy. The 5/8" intake on the 5.7 is not adequate. Bad engineering

The transom assembly is being replaced because it’s leaking and was falling apart. Replacement was not optionalto keep the boat operational. We’re addressing that this year, and perhaps in the future will install a through hull intake. The transom and other engine repairs are about all we’re prepared to deal with on his boat this year. You can check out the repairs in this thread.
 
Lazy Daze I am always willing to learn that why I always do research before I do anything.
I just want to make sure I understand this before I do it.
If I add two 1 1/4" thru hull with scoop strainers ( I boat Great south bay ) that protrude down about 2" from the bottom of the boat I am not going to lose any performance or speed.
This was one of my concerns before doing it.
Maybe I am looking in to this to much.

Did you wind up doing through hull? I have a 2003 240da that looks like it might need help.
 

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Take the plastic gooseneck off and evaluate the corrosion on the transom assembly. Even if you use a thru-hull your going to have to seal that spot with a block-off plate. If the surface is good you can just replace the water hose with the new and approved version which is mostly plastic
 
Damn it…. 2 yr old thread. Read first page even “liked” posts. So if you’re still getting likes 2 years later it’s because I can’t read dates :(
 
Did you wind up doing through hull? I have a 2003 240da that looks like it might need help.
I recently just did this. It was about $500 of parts plus about 5 hrs of my mechanics labor to install. We also installed a perko flush kit so I can easily flush on the trailer (260 sundancer). I installed a drive shower and probably will just leave the seacock closed to the hose coming from the drive as that is still hook d up along with the through hull
 
I recently just did this. It was about $500 of parts plus about 5 hrs of my mechanics labor to install. We also installed a perko flush kit so I can easily flush on the trailer (260 sundancer). I installed a drive shower and probably will just leave the seacock closed to the hose coming from the drive as that is still hook d up along with the through hull
Suggestion... rethink the Perko "breaks easy" kit. It's known to fail. It's better to make your own out of some real bronze stuff - a T and some shut-offs. The bilge in the 260DA is EXTREMELY DIY friendly so getting to the valves is only a 1 minute thing. Also, the drive really needs water FLOWING through it for cooling. Using the shutoff stops that. Either leave it open or cut the hose on the outside of the boat and let it just dump back into the water.
 
Suggestion... rethink the Perko "breaks easy" kit. It's known to fail. It's better to make your own out of some real bronze stuff - a T and some shut-offs. The bilge in the 260DA is EXTREMELY DIY friendly so getting to the valves is only a 1 minute thing. Also, the drive really needs water FLOWING through it for cooling. Using the shutoff stops that. Either leave it open or cut the hose on the outside of the boat and let it just dump back into the water.
What exactly breaks on it? It's already installed so we will go with it for now. We ran a remote Joseline to the transom to make an easy hookup for flushing so I shouldn't have to touch that assembly at all. Also decided to fix the corroded intake at the transom so I'll have cooling both ways. Engine ended up having to come out for other reasons so I won't say I wasted 1200 on thru hull cooling as it's clearly an upgrade in water volume.
 
I don't think we can talk about "Bravoitis" enough. this pic was sent to me just now by my mechanic. he had already installed a thru hull for me because we suspected Bravoitis but on my 260 da it's near impossible to get at it with the engine in the boat well my motor blew up for other reasons so I told him since we have it out to be rebuilt let's check on the bravoitis situation and repair it through the transom as well since that is supposed to also help cool the drive. This boat only had 410 hours of use and at least half of that use was freshwater so it doesn't take much to corrode that .
IMG_20211210_134515.jpg
 

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