Ceramic coated manifolds

[waterone1@aol.com]

I am wondering what the accepted "run time" is before replacement is recomended for the Mercruiser ceramic coated exhaust manifolds ? The engine is a 1999 Merc 7.4L horizon inboard. It has a heat exchanger, however raw water passes through both the manifold and riser. This boat is used in salt water. Is there any appreciable difference between the older manifolds and the newer ceramic coated ones ?

 

[Don S]

Re: Ceramic coated manifolds

Never heard of ceramic coated manifolds from Mercruiser...........Doesn't mean there wasn't, just I've never heard of them before.

 

[tommays]

Re: Ceramic coated manifolds

is the boat left in the water or trailered and flushed after use.<br /><br />the trailer and flush easly doubbles the life compared to a boat left in the water<br /><br /><br />tommays

 

[waterone1@aol.com]

Re: Ceramic coated manifolds

Merc claims that the water jackets inside of the maifolds are coated with some kind of ceramic material to increase their resistance to salt water. Just trying to figure out if this is marketing hype....or if it has a real world benefit. Tommays, this is a 34 foot cruiser....lives in a slip durring the summer season. Has a flush kit, no idea how often it was used.

 

[waterone1@aol.com]

Re: Ceramic coated manifolds

By the way, the Merc. part number for the manifolds for this engine is 807078A6, even in parts express they are listed as ceramic coated manifolds.

 

[Bondo]

Re: Ceramic coated manifolds

Mercruiser ceramic coated exhaust manifolds

What I've seen is that these are Just Too New....<br />Until they've been on the market for 3/5 years,.....................................<br />Then we'll have a history to compare........<br /><br />Allot of Amazing Things are done with Ceramics..... Time will tell if this is a viable application.....

 

[navigator336]

Re: Ceramic coated manifolds

I've wondered about those too. Given they're six years old, it might be a good idea to pull the risers and inspect the passages. If the ceramic is working, there shouldn't be any cast iron cancer going on. The gaskets ought to be replaced anyway as I don't think they were using the silicone impregnated ones in '99.

 

[rabidfish]

Re: Ceramic coated manifolds

I'd like to see inside also... Take some pics if you don't mind. I haven't come across any that needed replaced. ( I am not in salt water either... )

 

[diablo11]

Re: Ceramic coated manifolds

Waterone1,<br />I have the ceramic-coated manifolds on my engine that are original (1999 Mercruiser 350 Mag). I have taken them off several times to get access to my starter and to change the oil (space is too tight!). I alway inspect them to look for any plugging or heavy scale and they are always in very good shape, even after 5+ years of use in salt water. Wish I could say the same about some of the other Merc parts..............

 

[rabidfish]

Re: Ceramic coated manifolds

Diablo,<br /><br />You need a "remote oil filter" kit.<br />It moves the oil filter to the top, just in front of the port exhaust riser... <br /><br />Mercruiser part # 807459 A6<br /><br />Too bad they can't remote mount the starter...

 

[waterone1@aol.com]

Re: Ceramic coated manifolds

Well, here's the deal. I bought this boat last month for my own use. It is a 1999 with about 230 hours on both engines, and as stated earlier it was used previously in salt water. I will probably keep it for the summer and sell it at the end of the season (I change boats pretty often). Since it is in my shop with the entire engine cover removed (not just the access doors) while I do other maint. I am going to remove the manifolds and risers from one engine and inspect and decide what to do from there. As the merc. service manual doesn't list the recommended replacement time for these, and none of us has much experience with them, I can't think of any other safe way to figure this out. Since I don't know how to post pics on here, and am not sure who really cares.....if you would like to see pics of this...please email me at waterone1@aol.com I should be starting this project in the next day or two. By the way, as far as I can tell, the risers are the usual Merc risers....not ceramic coated....so it would seam that even if the manifolds are in good condition...the risers would be subject to fail as usual.

 

[rabidfish]

Re: Ceramic coated manifolds

They(Mercruiser) wouldn't have put on the ceramic manifolds, and not used ceramic risers also.

 

[waterone1@aol.com]

Re: Ceramic coated manifolds

Rabid, all of the sales literature and the merc website talks about the ceramic coated manifolds but makes no mention of the risers. Also the manifolds seam to cost about $100.00 more than the older ones, yet the risers are the same price.....just seams like the risers aren't coated. I'll know more in the next day or two....I'll keep you posted.

 

[Bondo]

Re: Ceramic coated manifolds

And I Thought they Just Introduced those either This Year, Or Last....................<br /><br />I Didn't Think they were even an Option in 99.............

 

[rabidfish]

Re: Ceramic coated manifolds

I am not certain of the exact date it all happened, but... all the exhaust elbows are ceramic coated.<br /><br />The part # is 807988A2<br />All the center riser manifold now use this elbow.<br />4.3L through 8.2L<br /><br />All the old elbow part numbers superceed to this part.

 

[Northern Eclipse]

Re: Ceramic coated manifolds

Waterone They might be newer than the motor, The first I saw of them was at the Toronto boat show 2003, The Merc rep I was speaking to lead me to believe That this was there New gig, They very well may have been around earlier but since we are fresh water up here we tend to see manifold damage due to freeze not corrosion, but as it is ceramic is very durable just don't chip or crack it.

 

[waterone1@aol.com]

Re: Ceramic coated manifolds

Well, I took a set off today and took a few pics. They look like the same old manifolds and risers to me. Rabidfish you should have mail.

 

[rabidfish]

Re: Ceramic coated manifolds

I agree, they don't look ceramic coated. There is rust in the water jacket area(not bad at all though). My opinion is you should reassemble and run it, knowing you took the time to inspect it.<br /><br />Good work here, now let's go boating!

 

[sue5878]

Re: Ceramic coated manifolds

Hi all,<br /><br />Achris replaced my elbows (1995,4.3LX Gen II) about 2 or 3 years ago, and I haven't had a problem. They do look the same as the original cast iron units, but cost more.<br /><br />Hopefully I'll get more than the usual 5 years from these ones.<br /><br />Neil.

 

[waterone1@aol.com]

Re: Ceramic coated manifolds

Get real, after looking at mine a little more before re-assembling I noticed that there was a little ceramic material left in some areas. At this point the ceramic material is pretty much gone and the metal has some rust and a little scaling (in the water jacket areas). The thickness at the mating surfaces looks good and the manifolds pressure tested good. From what I saw, I would say these manifolds and elbows should be good for at least two more years in salt water and three to five more years in fresh water. Since I believe that these were the original parts (230 salt water hours) I would say that the ceramic coating has extended the life of these units by a few years. Since I am in fresh water, I saw no reason to replace at this time.