SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: BIG JOHNSON on July 08, 2012, 11:21:09 PM
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Since I'm losing the battle with leaky exhaust risers, I took manifolds off to have the surfaces machined flat. Couldn't find a shop open on Saturday, so I cut some pieces of aluminum to press into water jacket ports on manifolds and risers with the thoughts of welding, epoxying or jb welding to seal the water and serving as a block off, since I will never want the water passing from manifolds to risers. If I can jb it and be done without spending cash and sand surfaces flat, that'd be great since I'm saving for the wedding. I rotary filed the insides of the jackets and roughed up the aluminum since pic was taken.
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Buy headers stop fuckIng around
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Buy headers stop ******* around
that looks a lil nutz to me too :screwy:
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Ok then buy heads and headers
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well ive seen some strange stuff in my time...
perhaps take whole exhaust setup to machine shop, have it milled flat, and then just use some plain ol RTV to fill in the tinnnny cracks and be done with it?
i dont get the point of filling in the passages just to keep the riser and manifold cooling separate.
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They're separated by a blockoff plate with two gaskets each side. Water goes through manifold for pre heat, then through block and out into the exhaust through the risers.
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dont qoute me, but i believe if you block off those ports the exaust hoses will get super hot and most likely burn thru
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How sure are you that this is where the water is coming from in the first place?
If your going to weld those ports up you will have to mill them anyways.....
Your doing something wrong......Is there a small hole or holes (like 1/8") somewhere in the block off plate? there should be.
How certain are you that there is not a crack somewhere?
This is almost silly. :-\ If both surfaces are flat and you have new gaskets, the only way this could leak is if they are broken or you are using silicone sealant on the gaskets and over torquing the hell out of the mounting bolts.
The only issue I see with welding them closed is that it wont solve your problem and would be a waste of time/money.... :screwy:
GT
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JB weld will not hold up to exhaust heat. You must have water thru rubber exhaust hose....it will melt and your f....d ask Marc.
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Had the jacket ports welded up and surfaced. Water isn't configured to run into risers from manifolds otherwise water that's supposed to exit would be trying to re-circulate back into cooling system, and a certain amount of cool water entering the manifolds would be bypassing the block and heading out through the riser and gone with exhaust.
Water is plumbed in from jet to pre heat in the manifolds, from there water exits the front of manifolds and goes into front of block. Water that exits top of block is hosed into the front of each riser and out with exhaust down the tubes and keeping flappers happy.
I'm sure that's where the water comes from, its always leaked on the outside so I always imagine its leaking inside. The two cyl's below riser that was leaking when I bought it have lower compression than the rest.. maybe crusty valves or rings due to moisture. As tip top as it is running now, not gonna pull it apart anytime soon, just wanna keep the water out.
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Post pics of your manifolds and the risers, and/or a casting number on them if you could. Something seems seriously amiss here. That riser LOOKS like a Berk unit that is a little weird compared to other center risers. Not uncommon to see them plumbed wrong either, I have 2 sets here that were. And you'll probably ruin them, or the engine trying that!
That hose barb on the riser looks added on, but the riser looks like a Berk unit is why I ask. Berk center rise exhausts are designed to run with a thermostat and a 4 outlet T-stat housing. Plumbed VERY different from what we normally see.
Ray
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Is that plumbed from factory that way? I mean, the water outlets going to the snails, is there a boss there that looks like it was suposed to have a hose fitting there?
They're not Berkeley, BTW, BUT could be a cousin!
Ray
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first off... what psi is getting to the exhaust? is there a pressure reguator or are you trying to hold 50+psi at your manifold/risers with a gasket?
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first off... what psi is getting to the exhaust? is there a pressure reguator or are you trying to hold 50+psi at your manifold/risers with a gasket?
The only thing controlling waterflow is the gate valve I added after I bought it. PO said when driving the boat in needles/laughlin the water temp will not move off its 100* starting point. I've adjusted the valve to let it run at 150* in needles/laughlin.
I've had these apart and together using the paper gaskets, paper gaskets with gaskacinch and made lead gaskets.
I've laid out and duct taped ascending grits of sandpaper on scrap granite to slide parts around on to flatten both surfaces as well as I can.. these water ports have had a block off plate since day 1, so I take it they're completely vestigial.
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Is that plumbed from factory that way? I mean, the water outlets going to the snails, is there a boss there that looks like it was suposed to have a hose fitting there?
They're not Berkeley, BTW, BUT could be a cousin!
Ray
http://i270.photobucket.com/albums/jj114/ro69rag/motor.jpg
Here's a better pic of how the leaky risers look on someone else's boat.
Lookin like Marine Power plumbed all their big blocks that a way.
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no doubt you're plumbed correctly but id guess that trying to hold back full psi from your pump its going to be difficult. if set on plugging things id think the manifolds should have been plugged since they are the first thing to see the full psi from the pump if you're going the pre-heating route. once it goes thru all the hoses, fittings, water passages, etc it probably cuts down on the pressure quite a bit and then it has a nice big exit hole out of the back where it meets the exhaust.
let us know how your plugging works out. worst case get a pressure regulator on it to cut down the psi to a more manageable level where its not blowin gaskets. i know its a loooooong debated topic but i bet your motor would thank you too on cutting down the psi if its high enough to blow riser gaskets. hey, it couldnt hurt and its fairly cheap.
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Nah, worst case is header time, but is rather have those built when the motor is on a stand... I'd really like to get another big block and start building one little by little in its own corner of the garage.
But anyways, I'll see how this works.. might ought to fix the symptom of too much pressure, I know that the gate valve had to help with pressure and obviously operating temp.
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