saltwater manifolds

I have a 100 hrs of my boat in saltwater use and everything is perfect except that the manifolfds are starting to rust. I flush my boat after every use with salt away. I know the rusting manifolds is inevitable but are their any manifolds made for salt water. I found these GLM Manifolds http://www.glmmarine.com/manifolds/features.html
It says they are given a galvanized coating and then black paint. Does the galvanized coating make them good for salt, i also found some stainless steal ones but they are almost 2,000$ and for that i'll just stick to replacing them. Anyone know of any other ones?

go to a closed cooling system. Your fighting an uphill battle w/o it IMO. If your constantly in saltwater it's your best route. Should help resale when you go to sell.

i have a closed system but the manifolds still get salt water

Manny it would be difficult to trade out manifolds to a aftermarket brand and keep warranties in place. It probably would mess with the performace as well because Indmars manifolds are specific to the factory settings. I would just keep doing what your doing and not worry about it until they have to be replaced. I would also keep a light coat of WD40 on the rest of the engine ie motor mounts,intake etc.

You might have better luck running aluminum manifolds like mine. They have a dry joint between the manifold and elbow.

http://www.wakeworld.com/MB/Discus/messages/65921/335581.html

how long should these manifolds last me. How do I know when to change them out. I dont want them to rust and leak saltwater all over my engine

They are a lot thicker than you think. They will start to leak slowly, its not like they will just blow out. Just keep and eye on them, I have seen manifolds last years before needing replaced. If you flush it out like you say the they should last a good while.

One of the biggest problems is the wet joint between the manifold/elbow. Get new gaskets from skidim and coat them with copper coat and torque them down. Replace these gaskets anually (or bi-annually), they should last at least 10 years.

Even with fresh water cooling you should be rinsing the motor/bildge after every ride, and flushing the motor/manifolds every time it will be longer than a week before the boat gets back into the water.

just my $0.02

My last two boats never saw salt, every one before that ran in salt over 50% of the time.

Don't worry about that even when the boat is going to be in the water the next day i flush it with salt away but they're still rusting. Mikeski, your boat with aluminum manifolds, is that used in salt?

Isn't saltwater fun ?

Probably a dumb question, but what is the best way to flush the bilge...just put the hose in the hull?

As mikeski said you should replace the gaskets between the risers and manifolds annually. If you see rust forming then you have a bit of salt seepage. When you take them apart scrape off the old gasket and take a flat file to the 2 surfaces. This will clean off any corrosion that may be starting. Another thing you can do is have your closed cooling plumbed where there are plates between your risers and manifolds allowing the raw water to pass through the risers only.....much cheaper to replace just the risers than the risers and manifolds.
I have also seen a one piece riser/manifold made by Indmar for salt water applications.

I am not running my current boat/manifolds in salt, although every time I go to a Giants game I get the urge to go get the boat and head to McCovey cove. We ran aluminum manifolds in salt on the Keaton back in the 60's at Aquatic Park in Berkeley. Aluminum tends to hold up better than cast iron in salt environments. If you were to get some of the rev marine manifolds like mine it would be easy for you to plumb them as deepcove describes.

I run in salt exclusively, have closed cooling and flush mine after every use.

I got 8years and about 1000hours from my MC manifolds in saltwater before I sold it. Think its still on the same ones now.

I just flush with fresh water for 10 mins or so after use and spray all the engine down with wd40.

Friends who leave their boats moored in salt and never flush get years of use too.

Fresh water cooling shouldn't realy be fitted to boats after 50hrs / 1 years use as existing scale inside the block will be forever blocking the heat exchanger.