riser spacer gaskets

[rebars1]

Mutt ChrisCraft Scorpion 230: The guy before me replaced the original engine with an engine from a Volvo A290 350 chevy, and installed into a mercruiser setup with an Alpha 1,GenII outdrive, with closed cooling to the block. I am replacing the original manifolds and risers on this boat with OSCO equivalants. There is a 2" spacer between the manifold and riser (see picture). The gaskets that came with the manifold kit have the side hole open and the ends closed except for a small pin hole. The gaskets that were on it had the side holes and end holes open (they were homemade). My question is should the gaskets between the manifold and spacer have all holes open and with the closed ends ones used between the spacer and riser to allow more water movement around the spacer? None of the diagragms I've found show a condition with closed cooling and spacers.<br /><br /> http://i23.photobucket.com/albums/b365/rebars1/engineside.jpg <br /> http://i23.photobucket.com/albums/b365/rebars1/engineside2.jpg

 

[rebars1]

Re: riser spacer gaskets

bump

 

[Bondo]

Re: riser spacer gaskets

Hey rebar,..... Not ignoring ya,... Just Not Sure.....<br /><br />I would Think that you'll have to incorporate the spacer blocks into the Engine side of the cooling,.... As long as it's getting a Flow of water.....<br /><br />If you incorporate them into the Riser/Elbows,.......<br />There'll be No Way to Drain them, as the riser drains will be Above the spacers.......... <br /><br />The whole draw-back to building a Mongrel is This sort of thing......<br />I Don't see any plugged ports in the spacers,..... But they'll still Drain thru the manifolds.......<br />I just Don't Know if there'll be Enough,.. Or ANY water flow Thru them.........<br />They may become Air-bound,+ Over-heat,.. right from the Git-Go....<br /><br />What it Really Looks like,.. Is you need a Different style of Risers.............<br /><br />Btw,..... Is this the barge with My old junk parts on it,..???....

 

[rebars1]

Re: riser spacer gaskets

Bondo: The barge with your old junk parts is finally ready to launch, but this is a different boat I picked up from a guy who came down with terminal health problems. He was in the process of replacing the engine in the boat when he had to stop. <br /><br />The VP engine/manifold/spacer/riser set up came from a local Harbor Patrol boat that was upgraded. The HP mechanic was helping the guy with the install.<br /><br />There are no drains on either the risers or manifolds-(maybe a California thing?) The water going through the manifolds is pushed by the outdrive impeller, and the closed system is pushed by the water pump on the engine. Water enters the manifolds through a hose into the front of each manifold then exits out the risers.

 

[Bondo]

Re: riser spacer gaskets

So,...... The Manifolds, Spacer,+ the Risers are Raw Water Cooled,.??....<br />And only the Engine Block is Fresh Water,.??......<br /><br />If that's the case,..... I would Think that the Gaskets between the Manifold,+ Spacer would want to have Open Flow Gaskets.........<br />And,......<br />The Gasket between the Spacer,+ the Riser/Elbow would want the Limited Flow Gaskets,..... <br />To Slow the water,+ Take Away More Heat,....?....<br /><br />1 of the other Guys should have a Handle on This.......I know sometimes They don't like Creative Engineering..............<br />I Misunderstood your 1st post,..... Maybe Everybody else did Too........

 

[rebars1]

Re: riser spacer gaskets

Upon closer examination it looks like I need to replace the extension blocks as well. I am having trouble locating them. They are part #841503 2" extension kit. Or if I could just get the blocks, that would be fine too. Any recommendations on where to find them?

 

[cortez]

Re: riser spacer gaskets

maybe this will help???<br /><br /><br />I'm guessing that you are asking about the Mercruiser gaskets. Page 2 should explain their different usages.<br /><br /> http://www.boatfix.com/merc/Bullet/99/99_10.pdf

 

[rebars1]

Re: riser spacer gaskets

cortez: Thank you for the merc bulleton. It helped alot.

 

[rebars1]

Re: riser spacer gaskets

I need to replace the extension blocks as well. I am having trouble locating them. They are part #841503 2" extension kit. Or if I could just get the blocks, that would be fine too. Any recommendations on where to find them

 

[Don S]

Re: riser spacer gaskets

Those extensions are "Obsolete" according to Volvo. The gaskests are the same 857618 gasket as used on the standard Volvo manifolds. No different gaskets like Merc.<br />If you have the room, the 4" extensions are still available. You would have to get a longer hose between the Y pipe and the 90° elbow.<br />You're looking at a hybrid or old Volvo and New Merc that makes parts hook up a real pain.<br />Trust me, Merc and Volvo do not get together and make parts interchangable. You have a "One Off" setup to deal with.<br />Who knows, you may even be able to go to the newer style manifolds and risers and not need extensions at all. But that kind of depends on your waterline.

 

[rebars1]

Re: riser spacer gaskets

Thanks, DonS. Is there any disadvantage to using the 4" extensions as far as water flow?

 

[Don S]

Re: riser spacer gaskets

No, the only reason to use the extensions at all is to keep the water line at a safe distance below the top of the risers.

 

[rebars1]

Re: riser spacer gaskets

I am going to look into the 4" extensions,and/or another riser to use. <br /><br />I am curious, however, in that engine/manifold setup pictured with the 2" extensions in the picture came with the engine from another installation, which I believe was a volvo/volvo setup. What do other volvo people do when their 2" extensions need replacing? Are there shops that stock obsolete parts?