can i convert a wet joint to a dry joint

[twodawgs]

i have 2000 350 mag mie inboard fresh water cooler
boat is always in salt water can i convert from wet joint manifolds and risers to dry joint
and if so whats involed

 

[Bt Doctur]

Re: can i convert a wet joint to a dry joint

I would think you would have to buy manifolds and risers for dry joint

 

[twodawgs]

Re: can i convert a wet joint to a dry joint

yes i know that but what about the plumbing
i currently have only one pipe going to the manifold now and it looks like the dry joint has 3

 

[Bt Doctur]

Re: can i convert a wet joint to a dry joint

section 7B in here Boatinfo - Mercruiser Service Manual nr. 37 - 2002-Up - Dry Joint Exhaust
looks like just using the correct dry joint gasket you can have warm manifolds(FWC) or raw water cooling

 

[twodawgs]

Re: can i convert a wet joint to a dry joint

right now i have only seawater going threw my manifolds and riser
can i just change to the dry joint and plumb the same way ??

 

[Bt Doctur]

Re: can i convert a wet joint to a dry joint

according to what I read ,yes. just a matter of using the correct gaskets

 

[twodawgs]

Re: can i convert a wet joint to a dry joint

okay great any idea who i can call about it because every one i called told me i couldn't do it
thanks

 

[Bt Doctur]

Re: can i convert a wet joint to a dry joint

Try Andy at Marine Power Service 732-751-1200 add the dot com for the web site. might have a 800 number there
did that link open ok?

 

[Howard Sterndrive]

Re: can i convert a wet joint to a dry joint

heck, I put dry joint merc 4.3 manifolds on my 1982 OMC 3.8L, so I can't see why anyone would say you can't do it unless there's temp sensors in your risers or O2 sensors maybe.?

The standard gaskets that came with my set were properly restricted for open raw water cooling and they have been fine.

 

[Lou C]

Re: can i convert a wet joint to a dry joint

Howard, can you provide details on how you did that? I'd love to use the dry joint system on my OMC 4.3 the next time it needs manifolds, it has the one piece units that you can't get anymore. I was thinking of doing this myself but I thought that the Merc exhaust hose/Ypipe size was different that OMC's....

 

[Howard Sterndrive]

Re: can i convert a wet joint to a dry joint

My engine is hooked to an Alpha Gen 2 Merc drive. But the tstat hsg and hoses etc are still OMC.
In you case, exhaust hose is certainly easy to work with and with a center riser design as the dry joint units are, should be lots of distance to just connect a section of one diameter to a coupler that would change size and then couple to hose of the other dia.

 

[mr300z87]

Re: can i convert a wet joint to a dry joint

I am planning to do this same conversion on my 88 5.7L, bravo, here are a couple things I have learned. 1st you will need longer exhaust tubes to go from elbow/riser to exhaust on tube on the transom. The dry joint elbows are about 2 inches taller than the wet joint so you will also need longer bolts/studs. Also make sure you have the clearance. Merc did make shorter dry joint elbows but I believe they have been nla for a while. The 2nd thing is if you have a cooling hose going to the elbow you need a ristictor gasket between the manifold and the elbow but if it only has cooling hose going to the bottom of the manifold then free flow gaskets are used. The last thing may or may not apply to your setup, on mine the fuel filter is mounted to a boss on the front of the wet joint manifold, this boss is not present on the dry joint manifold. I am thinking I will need to fabricate some kind of bracket to help support the filter assembly. Hope this helps.

Do give marine power service a call I live near their shop and they have always been a great help.

I have done quite a bit of research on this conversion and it should be straight forward. I found the manifolds used locally on clist and the elbows on ebay all oe merc stuff.

Now if I can just find the time and some extra cash to buy the gaskets as they are quite pricey.


good luck

Mike

 

[achris]

Re: can i convert a wet joint to a dry joint

... The dry joint elbows are about 2 inches taller than the wet joint so you will also need longer bolts/studs. Also make sure you have the clearance. Merc did make shorter dry joint elbows but I believe they have been nla for a while....

The elbows that are taller have a 15? drop. The original 'wet-joint' elbows only had a 7? drop. If you want to use the newer 15? elbows, then you need to also change the ali tube between the elbow and the top of the Y-pipe. But you may not have any of that as it's an inboard. But the original 7? dry-joint elbow is still available (and will be for a while). The part number is -864309T02. Depending on the hose configuration of your current cooling system you will need either a full flow gasket, or a restricted flow gasket. Do you have 'warm' manifolds or 'cold' manifolds?

Chris......

Had a look at the manuals. The only diagram that fits your engine shows cold manifolds (only one hose going into the bottom of the manifold. Nothing on the top of the manifold or into the elbow), in which case you should use full flow gaskets, part# 27-864547A02...

 

[kidrocking79]

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