Cleaning Manifolds & Risers

Broaders

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I have removed my manifolds and risers for inspection and they dont look bad at all, I'm planing on cleaning my risers and Manifolds with MURATIC ACID, then flushing them with WATER and BAKING SODA, my question is what part Acid should I use to part water, and same for the baking soda ? And how long should I leave my risers /Manifolds in each mixture.
Thanks to all in advance
 

crazy charlie

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Personally if my manifolds and risers "dont look bad at all"I would simply use
a gun cleaning kit and probe/brush all passageways.Remove any petcocks or inspection ports and probe with wire.Blast with gardenhose water or compressed air and call it a day.Charlie
 

Broaders

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Personally if my manifolds and risers "dont look bad at all"I would simply use
a gun cleaning kit and probe/brush all passageways.Remove any petcocks or inspection ports and probe with wire.Blast with gardenhose water or compressed air and call it a day.Charlie
Thanks I just might use your idea, as I have read that Acid can remove or cut into the metal, picture of riser, manifold and exhaust size of riser, your/anyone's taught's
 

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Scott Danforth

Grumpy old guy who plays with boats
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20:1 mix of water to muriatic acid for removing rust.

or mix up oxalic acid

or wire brush and use as is.
 

Scott06

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Thanks I just might use your idea, as I have read that Acid can remove or cut into the metal, picture of riser, manifold and exhaust size of riser, your/anyone's taught's
before you get too far into it have you scrapped the gaskets off and looked at the mating surfaces? If they are eroded such that you can file flat and get a good seal the corrosion elsewhere is irrelevant
 

Bondo

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Ayuh,..... Ditto what Scott says, ^^^, as it's the gasket surfaces where they fail,......
 

crazy charlie

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Thanks I just might use your idea, as I have read that Acid can remove or cut into the metal, picture of riser, manifold and exhaust size of riser, your/anyone's taught's
Looks like a light cleanup is all you need.Avoid any acids especially since you dont need them.Charlie
 

Broaders

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Up date, cleaned off my Gaskets today and came across this on my part Manifold and riser, taking to a machine in the morning to see if they can take a little off to make it last for this season , opinions very welcome , the cost of risers and Manifolds here in Newfoundland are very,very expensive , so hopefully I can get this season out of them.
Thanks all for your replies.
 

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Scott06

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As long as there is enough meat to mill them down to a good flat sealing surface should be ok. Pic on the right looks like itnhas a chunk out of the sealing surface may require a lot of milling to remove
 

Lou C

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Those would need to be machined flatter than that for them to seal. You want to be flat enough that when you lay a mechanics straightedge across them a .002” feeler gauge won’t fit in. Otherwise you will have water leaking back in the engine via an open exhaust valve. This will lead to engine damage over time, and you’ll have to do a top end overhaul which will cost much more that changing the manifolds. So see what you can do to get them flatter. Here in the USA you can buy a set of Barr aftermarket manifolds & elbows for about $725 or so. That’s what I used on mine last time I did them.
 

Broaders

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Those would need to be machined flatter than that for them to seal. You want to be flat enough that when you lay a mechanics straightedge across them a .002” feeler gauge won’t fit in. Otherwise you will have water leaking back in the engine via an open exhaust valve. This will lead to engine damage over time, and you’ll have to do a top end overhaul which will cost much more that changing the manifolds. So see what you can do to get them flatter. Here in the USA you can buy a set of Barr aftermarket manifolds & elbows for about $725 or so. That’s what I used on mine last time I did them.
Thank you for the infomation, I just took my risers to a machine shop , and now got to remove my manifold and see how it turns out. I also priced new risers and manifolds and the cost here for both sides in , Newfoundland,Canada is $2,285.90. This is out to lunch .
Cheers
 

Lou C

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What brand is that pric for?
Good plan with the machine shop, they will get them back to flat, and the gaskets will seal. That sealing surface and gasket is the thing that can cause trouble with wet-joint exhausts.
Believe it or no, if you had a newer Mercrusier or Volvo I/O with cat converter exhaust, it's far worse. $4500-$6000 per engine USA prices.
The best aftermarket I have come across is Barr made in USA.

you want it to look like this:
 

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Broaders

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What brand is that pric for?
Good plan with the machine shop, they will get them back to flat, and the gaskets will seal. That sealing surface and gasket is the thing that can cause trouble with wet-joint exhausts.
Believe it or no, if you had a newer Mercrusier or Volvo I/O with cat converter exhaust, it's far worse. $4500-$6000 per engine USA prices.
The best aftermarket I have come across is Barr made in USA.

you want it to look like this:
The brand is Volvo, and yes I agree your's look's Soooo sweet, I will be purchasing a new set next year for sure but till then I hope mine will last this summer, and summer here is around 3 months lol, so little use.
Everything here is expensive for boating.
Cheers
 

Lou C

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I got them from Partsman.com they are a local Long Island NY parts supplier, you might see if they can deliver to you, keep in mind that Barr casts the Volvo OE parts, so no need to buy OE at all in this case.
 

Broaders

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I got them from Partsman.com they are a local Long Island NY parts supplier, you might see if they can deliver to you, keep in mind that Barr casts the Volvo OE parts, so no need to buy OE at all in this case.
Thanks I will be looking this parts man up for sure
Cheers
 

Broaders

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Up date, here are my riser and manifold after getting them back from the machine shop, photos of before are in previous trends. The guy told me to use gasket sealent, but I have the orgional gaskets coming from volvo, and I taught those were to be installed dry ??? Any input would be welcome.
Thanks to all in advance
Cheers
Don B
 

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Lou C

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If those are the metal Volvo gaskets I recall reading that they said to use a Permatex copper spray sealer on them. See what the instructions say.
 

crazy charlie

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Up date, here are my riser and manifold after getting them back from the machine shop, photos of before are in previous trends. The guy told me to use gasket sealent, but I have the orgional gaskets coming from volvo, and I taught those were to be installed dry ??? Any input would be welcome.
Thanks to all in advance
Cheers
Don B
Dry gasket method in the industry is derived from installing using too much gasket sealant.Diy"s ,techs,boatyard mechanics etc... Everyone seemed to apply TOO MUCH sealant and when the riser was tightened down,the sealant was squeezed into the passageways and created coolant restrictions in the passageways.This is the main reason manufacturers recommend dry gaskets.This is exactly what I was told from a Mercruiser rep.I use spray " Hi Tack." made by Permatex.It is a gasket sealant that is aerosol so you cant over apply it.There is nothing wrong using a gasket sealant as long as it is not OVERAPPLIED .Years ago when I spoke to a rep from Mercruiser corp,I was told to apply a very thin bead of sealant on both sides of the gasket and install the riser without tightening anything.Wait at least 24 hours before tightening down .this allows the sealant to firm up into a flexible solid that will create a proper gasket seal similar to an o-ring.The rep told me that they dont recommend using sealant ONLY because everyone uses too much sealant.Using sealant is optimal but only if the correct amount is used and tightening down takes place AFTER the sealant has cured.Charlie
 

Lou C

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I used Permatex Aviation as per what the Barr Marine tech told me. Worked out fine 4 seasons later no leaks.
 

Broaders

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Dry gasket method in the industry is derived from installing using too much gasket sealant.Diy"s ,techs,boatyard mechanics etc... Everyone seemed to apply TOO MUCH sealant and when the riser was tightened down,the sealant was squeezed into the passageways and created coolant restrictions in the passageways.This is the main reason manufacturers recommend dry gaskets.This is exactly what I was told from a Mercruiser rep.I use spray " Hi Tack." made by Permatex.It is a gasket sealant that is aerosol so you cant over apply it.There is nothing wrong using a gasket sealant as long as it is not OVERAPPLIED .Years ago when I spoke to a rep from Mercruiser corp,I was told to apply a very thin bead of sealant on both sides of the gasket and install the riser without tightening anything.Wait at least 24 hours before tightening down .this allows the sealant to firm up into a flexible solid that will create a proper gasket seal similar to an o-ring.The rep told me that they dont recommend using sealant ONLY because everyone uses too much sealant.Using sealant is optimal but only if the correct amount is used and tightening down takes place AFTER the sealant has cured.Charlie
Thank you Charlie, what you say sounds reasonable and makes perfect sense, I will be using some kind of sealent, thanks so much for the infomation, find bunch of people on here and so much knowledge
Cheers
Don B
 
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