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hawaiianstyln

Intake manifold gasket life expectancy

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hawaiianstyln

Do we have an average life expectancy on the intake manifold gasket  for our boats/engines?

i will be changing out a port side riser from a crack but I have the plenum off and it seems easy to just remove 8 bolts and swap out the intake gasket too.  Thoughts?  Its a 10 year old boat ran in a high alkalnity lake.  I feel like it might be worth it. The whole thing of dont fix it if it aint broke is messing with me?

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minnmarker

Mine went out at 11 years and 350 hours. Still ran fine but the whistling was driving me nuts.  Easy replacement but be careful with the gasket compound on the ends.

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hawaiianstyln

Yahi read up about the ends. Silicone on each end or atv gasket?

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minnmarker

I used ATV.

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Woodski

@hawaiianstyln:  Since I have aluminum heads and intake, I used a punch to create a punch pattern to create more gasket grip.  Worked well for my application.

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hawaiianstyln
2 minutes ago, Woodski said:

@hawaiianstyln:  Since I have aluminum heads and intake, I used a punch to create a punch pattern to create more gasket grip.  Worked well for my application.

Shoot man that is an interesting concept!!!!

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Sparky450

At 11 yrs and you are in the engine already. That is a no brainer. Gaskets are cheap and about an hours work. You may even find it actually has a small leak that you don’t know about. 

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hawaiianstyln
10 minutes ago, minnmarker said:

Mine had a leak that made a whistling noise.  Pic in this thread: What is this noise?  http://www.themalibucrew.com/index.php?/forums/topic/61282-what-is-this-noise/&page=2&tab=comments#comment-939356

wow man, you went through a lot of troubleshooting on that issue.  I have not done this intake job yet, but I'm tackling it out in the next week or so.  Is there no concern for placing the intake back on after the new gasket and RTV sealant (front and back) move around at all before bolting back down?  Is the torqueing the same process as the exhaust manifolds?  11lbs on the first pass and 22lbs on the second pass I thought I read somewhere. 

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minnmarker
6 minutes ago, hawaiianstyln said:

wow man, you went through a lot of troubleshooting on that issue.  I have not done this intake job yet, but I'm tackling it out in the next week or so.  Is there no concern for placing the intake back on after the new gasket and RTV sealant (front and back) move around at all before bolting back down?  Is the torqueing the same process as the exhaust manifolds?  11lbs on the first pass and 22lbs on the second pass I thought I read somewhere. 

It was a while ago but I remember following somebody's directions (GM?) to the T.  Torqued the bolts to the right numbers in the order specified.  Also put the RTV beads in the specified places and carefully placed the manifold straight down.  Bakes carries the gaskets (in stock) so it must be a common repair.  Hears a pic of the top of the engine after I cleaned it up a bit.

0826161726ar.thumb.jpg.a5f18d6bfbab9c260e0633ce8c918f83.jpg

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hawaiianstyln
3 minutes ago, minnmarker said:

It was a while ago but I remember following somebody's directions (GM?) to the T.  Torqued the bolts to the right numbers in the order specified.  Also put the RTV beads in the specified places and carefully placed the manifold straight down.  Bakes carries the gaskets (in stock) so it must be a common repair.  Hears a pic of the top of the engine after I cleaned it up a bit.

0826161726ar.thumb.jpg.a5f18d6bfbab9c260e0633ce8c918f83.jpg

how did you clean that up with a razor blade scraper?  Also I'm sure it's not easy cleaning the old crud off as you don't want it to fall into the engine.  I was just about to start finding the gasket and head over to bakes or amazon.

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minnmarker
3 minutes ago, hawaiianstyln said:

how did you clean that up with a razor blade scraper?  Also I'm sure it's not easy cleaning the old crud off as you don't want it to fall into the engine.  I was just about to start finding the gasket and head over to bakes or amazon.

Just a razor blade and wet vac in the other hand.  Don't scratch though.  Don't sweat perfection.  Most of the grunge is on non mating surfaces that have some clearance anyway.  You really don't have to worry about small scraps of soft stuff.  If they get in the cylinder they'll just blow out or burn up.

Make sure you get a mechanics straight edge to check the manifold mounting surfaces for flatness.

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oldjeep

And just stick some paper towels in the valley before you start scraping anything

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Sparky450
3 hours ago, oldjeep said:

And just stick some paper towels in the valley before you start scraping anything

And use a shop vac before pulling the paper towels out 

 

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hawaiianstyln

slightly off my topic:  Previous owner also told me his 90's melted that came off the risers.  I guess they were problematic so people went to brass or installed that replumb kit?  I was looking for these brass 1/2 NPT male to 3/4 barb fittings and was having a hard time.  Some of the cheapies can't handle the PSI.  I just wanted to share that I finally found an ebay racing site where these 90's are $10 each free shipping and can handle the heat and PSI up to 300 (which is a lot)

 

https://www.ebay.com/itm/3-4-Hose-Bead-x-1-2-NPT-Male-90-Elbow-Brass-Barb-Nipple-Fitting-Coyote-Gear-/222094183718

 

Edited by hawaiianstyln

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Sparky450
41 minutes ago, hawaiianstyln said:

slightly off my topic:  Previous owner also told me his 90's melted that came off the risers.  I guess they were problematic so people went to brass or installed that replumb kit?  I was looking for these brass 1/2 NPT male to 3/4 barb fittings and was having a hard time.  Some of the cheapies can't handle the PSI.  I just wanted to share that I finally found an ebay racing site where these 90's are $10 each free shipping and can handle the heat and PSI up to 300 (which is a lot)

 

https://www.ebay.com/itm/3-4-Hose-Bead-x-1-2-NPT-Male-90-Elbow-Brass-Barb-Nipple-Fitting-Coyote-Gear-/222094183718

 

I was told not to use metal because of electrolysis. That is why Indmar uses plastic. Just what I was told. 

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hawaiianstyln

it's a great question really, especially when I had to deal with this and my 04 wakesetter in Hawaii for many years.  I was told that brass is the better between mixing metals in water.  I was trying to stay away from the nylon 90's because I had heard they were problematic with heat.  Skidim was selling these brass 90's for $28 plug shipping in which they are actually an indmar part replacement that indmar suggest for swapping out?  So I decided to find it's replica on the market.  Maybe someone else can chime in here

https://www.skidim.com/prodinfo.asp?number=60-5104

 

Edited by hawaiianstyln

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svnfightsvn

So I wouldn’t replace those nylon fittings with brass. Brass contains high levels of zinc and will corrode. In fact the bakes site even warns against this:

https://www.bakesonline.com/indmar-exhaust-fitting-nylon-elbow-1-2-npt-x-1-barb.html

“DO NOT replace this fitting with nothing other than nylon. Replacing these fittings with brass with cause the area around the fitting to act like a zinc because of the metallurgic difference.”

The nylon ones are made to withstand a high amount of heat (>250 degrees) so they should be fine. If you really want metal, I would try to find the fitting in bronze or even aluminum to match the ext cat manifolds 

Edited by svnfightsvn

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hawaiianstyln

Oh man good stuff thanks!!!  I was able to cancel my order 

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svnfightsvn

Oh and FYI I had the nylon elbows melt on me also when my thermostat went bad. I ended up installing the replumb kit when I fixed everything because it re-routes the water so that the risers always get it even if the thermostat isn’t open. If your boat doesn’t already have it, I suggest that

http://www.themalibucrew.com/index.php?/forums/topic/57658-temp-issue

Edited by svnfightsvn

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Woodski

I use aluminum elbows, work very well and no concerns with melting.

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hawaiianstyln
6 hours ago, Woodski said:

I use aluminum elbows, work very well and no concerns with melting.

Where did you get those?

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hawaiianstyln
9 hours ago, svnfightsvn said:

 I ended up installing the replumb kit 

This sounds stupid but yesterday im looking at the engine and looking at the pic on bakes of the replumb kit and wasnt sure if the previous owner intalled this already or not. Meaning i can’t tell

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svnfightsvn
5 minutes ago, hawaiianstyln said:

This sounds stupid but yesterday im looking at the engine and looking at the pic on bakes of the replumb kit and wasnt sure if the previous owner intalled this already or not. Meaning i can’t tell

Use this diagram. If your cooling hoses already match this, you have the replumb kit already 

http://www.themalibucrew.com/applications/core/interface/file/attachment.php?id=28242

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Woodski

Stainless Marine, they also come with the manifolds they sell.   I would also check McMaster Carr.

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