Mercruiser 3.7 elbo to manifold gasket

[Live-liner]

Good morning ,
I have been having issues with coolant leaking into #3, and #4 cylinders. I have replaced pretty much everything from the head gasket up. Before I decided that the head gasket was bad, I replaced manifold and elbow but continued to have the problem. My question has to do with the gasket that is between the manifold and elbow. According to Mercruiser manual #8, the original gasket was three pieces (2 gasket and one metal in between), or the newer style being just one thick gasket. The picture in the manual shows both options with a slot cut out for the passageway toward the front of the motor, and the rear facing passage is blocked off. The new gasket I bought from Mercruiser (BAM) has both the front and rear passages open. Does anyone have any idea if this is correct? I called the distributer, and the said that Mercruiser changed it.

 

[Bondo]

Re: Mercruiser 3.7 elbo to manifold gasket

Good morning ,
I have been having issues with coolant leaking into #3, and #4 cylinders. I have replaced pretty much everything from the head gasket up. Before I decided that the head gasket was bad, I replaced manifold and elbow but continued to have the problem. My question has to do with the gasket that is between the manifold and elbow. According to Mercruiser manual #8, the original gasket was three pieces (2 gasket and one metal in between), or the newer style being just one thick gasket. The picture in the manual shows both options with a slot cut out for the passageway toward the front of the motor, and the rear facing passage is blocked off. The new gasket I bought from Mercruiser (BAM) has both the front and rear passages open. Does anyone have any idea if this is correct? I called the distributer, and the said that Mercruiser changed it.

Ayuh,... Welcome Aboard,... The 470 doesn't use Any holes in the riser gasket, that's the splittin' point, 'tween the closed coolin', 'n the raw water,...

 

[steelespike]

Re: Mercruiser 3.7 elbo to manifold gasket

Welcome,
This is the prop forum,you'll get better help in the I/O forum.
Look for the big red thread starter tab. A moderator may move this there.

 

[Live-liner]

Re: Mercruiser 3.7 elbo to manifold gasket

Thank you,
So the gasket in picture I provided above would cause a problem?

 

[Live-liner]

Re: Mercruiser 3.7 elbo to manifold gasket

Bond-O
Let me re-phrase the question.
Would having both those passages open allow coolant to exit with the raw water?

 

[Live-liner]

Re: Mercruiser 3.7 elbo to manifold gasket

OK, I found and ordered a Sierra gasket that is a replacement for Mercruiser #27-97542. This replacement has only the forward passage open, the Mercruiser gasket had both forward and aft openings on it. When I removed the manifold, antifreeze was in #3 and #4 exhaust ports. Did the wrong gasket cause that? As I stated, I have now replaced head gasket, and am re-assembling.
Any help would be appreciated, I dont want to make the same mistake twice. Thank you!

 

[stonyloam]

Re: Mercruiser 3.7 elbo to manifold gasket

That depends on which 470 you have. As I understand it there are 3 different gaskets depending on the year and style of the engine. The older style, (pre 1983), the newer style with cast iron manifold and the newer style with aluminum manifold. The gasket you show is for the new style with the aluminum gasket. The one you ordered is for the newer style cast iron manifold. Need to year of your engine sn if you have it.

 

[Live-liner]

Re: Mercruiser 3.7 elbo to manifold gasket

Stonyloam,
Thank you. I have a 1986 190 (4bbl) 3.7. Engine #A592844. I have the alumimnum manifold, cast iron elbow. Manual says I need #27-97542 gasket, which is the one with the forward slot open, rear one blocked (which seems to be the one for the cast manifold). All the parts lookup say I need the one with both forward and aft open (which is for aluminum manifold) VERY CONFUSING! I just want to make sure use the correct one.

 

[stonyloam]

Re: Mercruiser 3.7 elbo to manifold gasket

If your manifold is aluminum and the reservoir looks like this: http://www.mercruiserparts.com/showSpecialPicture.asp?pn=98562A6 then you need the 27-18272 gasket. Yeah it is kinda confusing.

 

[Live-liner]

Re: Mercruiser 3.7 elbo to manifold gasket

Thank you for your help with this gasket! My manual and any parts look-up totally contradict each other. Everyone here is very helpful. New gasket coming in today, hopefully have running by the weekend! I will just need to re-torque the head.
I'm missing all the Striper fishing!!