How often should I replace my risers?
Even with a closed cooling system, the risers are raw-water cooled. Risers usually fail before manifolds do. Risers and manifolds used in fresh water have an almost indefinite life. Keeping an eye on the gaskets and checking the bolts for proper torque annually still makes good sense. Clean Machine?
Should I replace my risers or manifold manifolds?
If you replace the risers (always replace both at the same time), you need to decide whether to also replace the manifolds, which are both more costly and a bit more difficult to remove. Replacing a riser or manifold typically costs several hundred dollars each, but failure to replace them when needed could cost thousands in engine damage.
How often should I replace the manifold on my cylinder head?
Stainless steel manifolds and risers bolted to aluminium heads means the cylinder head is going to be the material more likely to corrode away. The stainless steel manifolds often come with anodes and a large sticker that states “replace every 3 months”.
How long do boat manifold manifolds last?
With raw-water-cooled engines used in salt water, you might expect their manifolds to have a three- to five-year life. Corrosion may warrant replacement in 10 years if an engine used in salt water has a closed cooling system. Check risers and elbows starting at two years, and annually thereafter, if the boat is used in salt water.
How long do risers and manifolds last?
Check risers and elbows starting at two years, and annually thereafter, if the boat is used in salt water. Even with a closed cooling system, the risers are raw-water cooled. Risers usually fail before manifolds do. Risers and manifolds used in fresh water have an almost indefinite life.
How often do boat manifolds need to be replaced?
six to eight yearsMost experts suggest that a manifold will have a life expectancy of six to eight years.
How long do Mercruiser risers last?
about 4-5 yearsMercruiser, for example, has a wonderful reputation for risers that sometimes don't last a year. On average, in saltwater use, good risers last about 4-5 years. At 4 years, you should start worrying about them.
How do you inspect exhaust risers?
1:036:21Mercruiser 5.7 exhaust riser inspection - YouTubeYouTubeStart of suggested clipEnd of suggested clipItself. So it's very important it's very easy to check - it's mainly four bolts on the top and hoseMoreItself. So it's very important it's very easy to check - it's mainly four bolts on the top and hose clamps that you just remove it and you inspect the water jackets.
When should I replace my manifold?
Signs You Should Replace Your Intake Manifold GasketsPrepare for the Road: Changing a tire. Symptoms of a failing intake manifold gasket.Issues with engine performance. ... Leaking coolant. ... Overheating engine. ... Expect the Unexpected: Handling a dead car battery. ... News Source: Autoblog.
How long do stainless steel risers last?
Stainless steel mixing elbows are the most long-lasting, and provided they've been designed correctly can last in excess of 10 years.
What happens when boat risers fail?
It's the "maybe" part that's a problem because manifolds and risers don't have an expiration date or a warning light to tell you when they're failing. And when they fail, they can destroy the engine. Damage to gas engines is far more common, so that's the focus of this article.
Is 500 hours on a boat motor a lot?
Both inboard and outboard marine motors are dependable for an average of 1500 hours. After that point, they become undependable, and you don't want to be five miles out when they decide to break down.
How much does it cost to replace a manifold?
Replacing an exhaust manifold can be very expensive. For labor and a new manifold, you can expect to pay around $1000.
What does a manifold riser do?
Exhaust manifolds and risers are large metal castings that carry hot exhaust gasses away from the engine block on inboard engines. All V-8 engines, for instance, have a separate exhaust manifold along the side of each cylinder bank.
How do you clean a boat manifold?
Clean them with a scrub brush Scrub the manifold vigorously so that you can remove built-up debris and any type of rust that has started to form. You should be able to use this method to clean the entire marine exhaust manifold and it will come out looking much nicer than before.
How do you clean marine risers?
clean risers I soak them in a tub with CLR. It is not as strong as acid, but it will not be as aggressive either. I use a hacksaw blade to clear the scale between the inner and outer tubes. I clean the gasket surface with a file.
Do outboards have risers and manifolds?
Nearly every inboard and inboard/outboard (I/O) engine has exhaust manifolds and risers.
How do you change risers and manifolds?
12:4623:37How to Remove and Replace Manifolds & Risers/Elbows - YouTubeYouTubeStart of suggested clipEnd of suggested clipThere's two plugs and it's a 9/16 allen key that you're gonna need for this there's one here oneMoreThere's two plugs and it's a 9/16 allen key that you're gonna need for this there's one here one here. And there's another one on the top a little one. But we're gonna get back to that in a second.
How long do manifolds live?
40 Years is the expected lifetime of Manifolds up here on the Sweetwater Seas,.........
Do you have to tap manifolds?
Since the manifolds will be new, you shouldn't have to tap them but it won't hurt if you do. Also I would use new bolts.. This job can be done by the home mechanic. It's very straight forward.
How long do dry joint manifolds and risers last?
But don’t let that fool you into thinking you never have to change them! They can be identified by the external casting of the water fittings where the gaskets join. Dry joint manifolds typically last at least 5 years, and have a much smaller chance of failing and letting water back in the engine. Unless the manifolds are leaking externally, I’ve seen people run these unopened for 5 years and even getting lifespans of 7 years and more. It is still recommend they are pulled off every 3-4 years to monitor their internal condition, and if it all looks good inside they can be refitted and longer lifespans can be achieved. To my knowledge there are no “dry joint” Volvo manifolds.
What to consider when pricing a pair of manifolds and risers?
Whenever you are looking to replace a set of manifolds and risers, it’s important you ask a three important questions:
What about catalytic converter type manifolds?
Because this style hasn’t been around for as long, there is limited information out there. Early reports are that they are holding up well, and when it’s time to be replaced the catalytic converter can be reused. Judging by the design of the manifolds and risers, it appears Volvo are running closer to the exhaust gasket, while Mercruiser has taken a slightly safer approach with some extra space between. Only time will tell how these units hold up, but I would suggest removal and inspection at regular intervals to avoid a damaged engine. It is noted that if the catalytic converter cannot be reused, this style can be the most expensive to replace.
What are the two most common manifolds and risers found in Australia?
The two most common manifolds and risers found in Australia are Mercruiser and Volvo Penta, which we will focus on in this article. The two main styles are defined as “wet joint” and “dry joint” which determines where the water flows. Dry joint refers to where the water flows between the manifolds and risers, implying that it’s gasketed in a separate area to the exhaust gases. Wet joint typically uses one gasket between the exhaust and water, making it more prone to leaking water back into the engine. To identify the correct service intervals, you need to figure out if the manifolds and risers are coolant/freshwater cooled, or raw/saltwater cooled.
What is a manifold in a marine engine?
Manifolds and risers are used to collect the exhaust gases from the engine, cool them down, and also allow the cooling water to exit. On a petrol engine they are subjected to high temperatures and often saltwater, resulting in a very tough life. All water cooled marine engines will likely have some sort of manifold or exhaust elbow (including generators), although some can be coolant cooled as opposed to saltwater cooled.
Do you need to replace manifolds on saltwater cooled exhaust?
Firstly, if you have a freshwater cooled manifolds, and saltwater cooled exhaust elbows, it is unlikely you will need to replace the manifolds, and probably just the exhaust elbows.
Is a Mercruiser wet joint still used?
Mercruiser wet joint manifolds should be superseded/upgraded to the newer dry joint style, when due for replacement. It appears Volvo are still using wet joint style manifolds and risers on most of their petrol engines.
How long do salt water manifolds last?
Manifold. With raw-water-cooled engines used in salt water, you might expect their manifolds to have a three- to five-year life. Corrosion may warrant replacement in 10 years if an engine used in salt water has a closed cooling system. Riser.
Do risers fail before manifolds?
Even with a closed cooling system, the risers are raw-water cooled. Risers usually fail before manifolds do. Risers and manifolds used in fresh water have an almost indefinite life. Keeping an eye on the gaskets and checking the bolts for proper torque annually still makes good sense.
How much does it cost to replace a manifold?
Replacing a riser or manifold typically costs several hundred dollars each, but failure to replace them when needed could cost thousands in engine damage. Any sign of rust in the gas-only chamber indicates a leak, which obviously warrants replacement, but it's more difficult to inspect the interior of a manifold.
What are manifolds and risers?
Manifolds and risers are some of the less-discussed "consumables" on your boat. But when they corrode internally, they often destroy the engine. Illustration: Marcus Floro. Nearly every inboard and inboard/outboard (I/O) engine has exhaust manifolds and risers. But ask most people about the life span of these essential components, ...
Why do risers fail?
Risers tend to fail before manifolds because the water is hotter when it reaches them. This accelerates corrosion and causes the salt to separate and stick to the walls more readily. Also, the top and aft sides of the riser are exposed to both saltwater and air where the two combine — a perfect environment for corrosion.
How to tell if a manifold is leaking?
When the water jacket of a manifold or riser becomes clogged with scale and corrosion, a leak is usually close behind because the internal walls are deteriorating .
Where is the exhaust manifold located?
All V-8 and V-6 engines, for instance, have a separate exhaust manifold along the side of each cylinder bank. The riser, which is often shaped like an inverted U, is located at the aft end or centered on top of the manifold. Sometimes the riser slopes down from the end of the manifold, if the engine sits high enough above the waterline, in which case it's often called an elbow. The exhaust hose is then attached to the aft end of the riser or elbow.
Where is the riser located on a manifold?
The riser, which is often shaped like an inverted U, is located at the aft end or centered on top of the manifold. Sometimes the riser slopes down from the end of the manifold, if the engine sits high enough above the waterline, in which case it's often called an elbow.
Can you remove a riser from a manifold?
The good news is that a riser is usually not that difficult to remove for those inclined to do it themselves. Only a few bolts hold it to the manifold, and the exhaust hose is held on by a few hose clamps. Once off, you'll be able to see if all the water passages are open or clogged.
