Manifold and Riser Wet or Dry Joint

[shanz_2008]

Hi again I need an advise this is the seventh year since the engines were fitted on the boat and i think its time to change the manifold and risers. The manifolds that I have on the engines or dry joint with a 4.7"extension.

When i went to buy new once the dealer told me to change for the old version the wet joint because they are cheaper and it is much easier to buy wet joint extension.

Does any one knows what is the difference between the Dry Joint Manifolds and the Wet Joint.

 

[shanz_2008]

Is the Dry Joint better than the wet Joint?

 

[Scott Danforth]

the wet joint is easier to leak into the engine, therefore taking out your motor

the dry joint can not leak into the engine.

you can get risers for both wet joint and dry joint

we can help further if you indicate what motor you have.

 

[shanz_2008]

Yes forgot the engines are Mercruiser 4.3 mpi and were bought from Mercruiser dealer
In December 09

 

[scoflaw]

Dry joint is much better than old style, but the elbow can fail in the same old way, sending water into the cylinders. Best to remove and inspect at the age you have

 

[achris]

Ignore that dealer, stay with the dry-joints. They last longer and are less likely to dump water into the cylinders. As for risers, just as available as the 'wet-joint'. If you're having trouble buying locally, just ask us what you need, we'll find the right paart number for you and you can buy on-line.

Chris.......

 

[HT32BSX115]

Does any one knows what is the difference between the Dry Joint Manifolds and the Wet Joint.

Yes, "wet" joint risers and extensions can destroy your engine. Dryjoints will not. (unless they crack)

There is NO WAY I would switch back to the older style manifolds and risers.

If a shop or mechanic told me it's ok to switch, I would switch mechanics!

 

[johnkom]

Wet versus Dry joints??????????? What are you guys talking about. My engine's risers/manifolds are wet on the inside and hopefully dry on the outside. What am I missing??

JK

 

[Scott Danforth]

Wet versus Dry joints??????????? What are you guys talking about. My engine's risers/manifolds are wet on the inside and hopefully dry on the outside. What am I missing??

JK

You really need to google it.

The dry joint has separate exhaust and water connections. The dry joint manifolds came out long ago, and there is near zero chance of them leaking into a motor where the traditional wet joint has both exhaust and water being sealed with one gasket and has a high potential for taking out the motor when it leaks

 

[achris]

Few years ago I did a drawing explaining the differences. I haven't searched for it, but I'll check and see if I still have it on the computer (using a phone atm) and will post it here if I have.

Chris.....

 

[achris]

Found them...

Here's the old style 'wet' joint. Ran from the very early days (60's) to the mid 2000's...



And the latest and by far better method....



I hope this clears up any misunderstandings....

Chris......

 

[achris]

Wet versus Dry joints??????????? What are you guys talking about. My engine's risers/manifolds are wet on the inside and hopefully dry on the outside. What am I missing??

JK

"What am I missing??" - The word "joint".....

Chris......

 

[shanz_2008]

I found to buy locally both manifold and risers dry joint and to be honest I don't want to go for the wet joint but what I didn't found to buy is the 4.7" extensions.

Last year we inspected the manifold and extensions and were good the risers were change last year too but what I am afraid of is that till now I didn't found 4.7" extensions I only found them as a kit which include the risers too.

Clive

 

[johnkom]

"You really need to google it."

I did. And it took me to two forums with very good explanations. Maybe I should be hanging there instead of here.

Thanks Achris. Very good info.

JK

 

[achris]

I found to buy locally both manifold and risers dry joint and to be honest I don't want to go for the wet joint but what I didn't found to buy is the 4.7" extensions.

Clive

Clive. If you have closed cooling, the part number for 4.7" riser extension is -866208A03. If you have standard cooling (not closed) the kit number is -866208A02.
These kits include both gaskets (top and bottom of the extension), pipe fittings and the screws (LOOOOOONG screws)... But not the exhaust elbow. The bare riser on its own is not sold seperately.. Never has been. But if you need to replace the risers, then you need the gaskets and pipe fittings anyway.... And the price does include 2 risers in each kit (a full engines' worth).... See picture below (the elbow is 'greyed out')...

Hope this helps.

Chris.......

 

[scoflaw]

There's a pair of risers 4.7 on ebay now. If there's AF in the manifolds there's probably nothing wrong with them

 

[shanz_2008]

The risers were changed in February. The dealer said that if i will need to change the 4.7" extentions i am not going to find to buy the extensions alone and i have to buy the whole lit which include the risers.

 

[scoflaw]

I believe what you are referring to with the word riser is more commonly called the elbow. Like I said in post 16 there is a pair of what your looking for on ebay.

 

[shanz_2008]

Yes that's what i am looking for and are available after market too.
Now I can keep the dry joint manifolds
Thanks very much for your help!

 

[shanz_2008]

Hi chris what is the difference between the 866208A03 And 866208A02?