Manifold ?

For the past couple of years I have seen alot of carbon on the outside of the engine below the manifold. I bought a manifold gasket set. I have attached 3 pictures. I dont have any cracks in the manifold but there is some rust. I guess what I'm asking is where do I go from here? Do I take the manifold in some place to get it cleaned and repainted or is that something I can do myself? Also when I do put the new gaskets back on, do I use RTV on the Gaskets?

Thanks

Re: Manifold ?

I am in a salt water area. That looks great!!!! I would just wire brush it off paint it with high temp paint where it burned off , chase the threads and reinstall.

Re: Manifold ?

Thanks,

That sounds good to me. What does Chase the threads mean?

Re: Manifold ?

Oh I forgot . Do I use RTV on the gaskets?

Re: Manifold ?

Rinker85 said:

Thanks,

That sounds good to me. What does Chase the threads mean?

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run a nut or bolt down the threads to clean them up so you can get the manifold tight and even all the way across it. no sealer.

Re: Manifold ?

Lyle29464 said:

I am in a salt water area. That looks great!!!! I would just wire brush it off paint it with high temp paint where it burned off , chase the threads and reinstall.

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That Looks Great ??? CRINGE

Re: Manifold ?

paultjohnson said:

That Looks Great ??? CRINGE

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LOL In this area that manifold would be solid rust. It and the engine ports would be half gone and pitted. The question would be can I take off enough metal so it will seal or buy a new one. But I always look at the bright side. It would be very light.

Re: Manifold ?

Thanks for your help everyone. One more question. I have read a ton of stuff about soaking the manifold in mariatic acid for no more than 2 hours at a time to get the carbon and rust out. Any thoughts on this?

Re: Manifold ?

The acid is nasty, Dangerous, hard to work with and dispose correctly. Normaly you can clean out the passages with some small hand tools. once they are so bad that you need acid it is about time to replace them. Often the acid will eat through.

Re: Manifold ?

Lyle29464 said:

LOL In this area that manifold would be solid rust. It and the engine ports would be half gone and pitted. The question would be can I take off enough metal so it will seal or buy a new one. But I always look at the bright side. It would be very light.

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Soory ! Im in Mn where we use our boats 4-5 months a year. Never see salt water. That looks scary 2 me!! LOL back at ya!

Re: Manifold ?

The only thing I might add is take it to a machine shop and have it surfaced. It's kinda hard to tell from looking at the pictures, but it looks to me like the riser surface needs some attention.

Wayne

Re: Manifold ?

Seriously? Time for a new one -your gonna have a hard time sealing the elbow like the last time with all that gasket goo. You might be able to get away with it by why bother its off it looks like crap and needs to be replaced. If and when it fails it will run u more than the cost of the exhaust manifold because your engiune will be shot as well from the water that entered from. All that carbon is from small exhaust mani leaks from a failing gasket.IMHO you need to pony up the dough and get yourself a new exhust mani. Im going to guess that this is the second riser for this engine being it was obviously pulled off once before seeing all that blue goo by a diy. The reason for all that carbon is the bad sealing job of the second install of the exhaust. engine head intake an exhaust need to be cleaned well. New gasket that should go on dry with new exhaust mani would mean no more carbony build up and leaks. Maybe you can clean this manifold up for short money but in the long run your toast and when i say long run i think you would last 2 seasons with a clean up job aslong as u keep bandaiding her up with rtv . Sorry to be so blunt i just ahd to make the same decision. Sorry

Re: Manifold ?

No problem being blunt. I'm here for answers and opinions on my situation. Tell like it is. LOL.

I didn't use the muritic acid like I had asked about in an early post. I did clean all the old gasket material off the manifold and have attached some pics of that. See what you think. Two areas concern me. The first is in the center of the manifold. The ports have some pitting. Now I don't know if that is some repair jop that someone did or what because it is solid there. the other area of concern is near the front of the manifold there is more pitting there. This is where the leak was when it was attached to the engine.

Its a 1985 Rinker. I bought it in 1991. It sat from 2005 to 2009 because I did not have a place to store it or a vehical that would pull it. Now I have a truck and a house and my boat is once again back with me. I have spent a ton of money this summer on new seats, Carpet, apholstry, teak wood..........you know the story. Had it out last weekand and the engine did run a little rough at low idle. So with all the work I have done so far and all the money I have put into a 25 yr old boat, I dont want to ruin the engine by doing a patch job on the manifold. I asked earlier about the RTV because I saw all of that on there. I can't remember if I did that 19 yrs ago or not. I use to keep a log of everything I have done but can not find it. I'm not sure if it is the original Manifold. My boat is a 1985 and the date stamp on the manifold is 1983. And while cleaning it I saw blue paint. I think the older OMC's were blue.

So the question is do I stop cleaning this manifold and buy a new one or what?

Thanks

Re: Manifold ?

I hate to say it after trashing the mani from the first pic but it looks pretty good. Its really hard to say with the manifolds . The rtv is just a leak waiting to happen and in my circle of knowledge is a nono for the exhaust mani even though many do it. I know its a nice chunk of change so its a tough desicion. The manifold cleaned up nice, Im thinking your cleaning with a wire wheel and pulling of some metal so the decking will not be flat. I think youll have lesss headache with a new one and at least not have to worry about that . There are so many other potential problems why keep that problem around? This a maintenance item that needs to be replaced every 6-15 years"YMMV" depending where you boat.

thats a 27 year old mani get a new one and a new riser. INMHO

Re: Manifold ?

You can probably put it on and get a couple years out of it. I would check with a machine shop to price out resurfacing the manifold to head surface. Weigh out your options of resurface this one, replace with new, or just put it back. Whatever makes the most $$$ sense to you. I can see a potential exhaust leak down the road at the head surface that will lead to the carbon build up that you originaly took it apart for. In other words you will be doing a short term fix for the issue you took it apart for if you just put it back on. Could be tuff to hold a good seal at the exhaust ports. With both ports next to each other the heat is pretty extreem there.

Re: Manifold ?

I agree with adirondack

Re: Manifold ?

+1 on the resurfacing.
If you get it redecked, bead blast the rust and repaint as the rust was the reason they are in poor shape.
remember to use a good quality gasket's and retorque after you run it up to temp, just to be sure.

Re: Manifold ?

I see your new pictures of the cleaned up manifold. The pitting in the center part makes me wonder what the cylinder head looks like. If there is pitting on the manifold, there is probably matching pitting on the head. If there is, then you need to pull it and either have it surfaced too (may as well have the whole head rebuilt in that case), or replace it. That kind of pitting is leak that just hasn't happened yet.

Wayne

Re: Manifold ?

Just givn you a ---Double : At A Boy !!! on your clean up job!!! Nice work... I have sealed some pretty rough gasket surfaces on TRUCKS with a gasket and some good gasket goo. But never on a boat If it fails on a vehicle, it just leaks, but doesnt destroy other stuff. I suppose for you it depends on how many nickles you still have in your piggy bank. Kinda damned if you do- damned if you dont.. Best of luck!!