SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: 78 PROPDUSTER on August 19, 2007, 09:23:02 PM
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New block
2 mile run, cloudy oil.
Pressure tested system with 15 lbs air for 1hr, no leaks.
capped water to headers.
ran 2 miles, same problem.
any suggestions would be greatly appreciated.
Thanks
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I assume you changed oil and filter between runs, right ?
If you give a little more info ( what engine, is it a jet ) maybe the experts will chime in. Mine had a problem with the intake gaskets leaking water into the lifter valley but only at high RPM / pump preasure. It would run all day and be fine under 3500 rpm, but as soon as I opened it up = instant milkshake >:( !
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condensation, turn water temp up
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Motor is a 454 punched to 468
roller
671
15lbs boost
jet
Yes, fresh oil
I checked the water pressure today, 15 psi at 23000 RPM. pressure came up quick with RPM. I'm sure it went way over 40 at 6000.
Plumbing is odd, pump to a T before the block, most water and pressure exits before the block, then through the block to another exit.
Should I add a valve after the first T ?
should I add the valve in place of the T first exit ?
Was your valley leak a gasket or a crack?
Thanks!
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Propless,
I read your reply again and see that it was the gaskets, what did you do to fix it ?
How much pressure do you run ?
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78PROPDUSTER nice name ;D
I'm curious as to how weird it's plumbed... ???
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Propless, is that the boat off of craigs list?
And is it a v-drive?
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Propless, is that the boat off of craigs list?
And is it a v-drive?
No, I've had my jet boat for almost 8yrs now and my new project for the winter (21ft Eliminator/Daytona) is aaaa,weelll,itsss,kilda,aaaa,sort of an outboard :-[ (propless hangs head in shame) but plans are being made to remove the cancerous growth back there and replace it with a proper motor and drive.
Hmmm V-drive, thats an idea. ;)
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Oops I meant 78 Propduster!
Is yours the one off of craigslist?
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No, not from Craigs list. Jet
Water comes from pump bowl to a T, one line exits boat, ( most water and pressure exits here )other goes into block. Then out of block to another exit. temp. runs 130 in the marina, drops to 100 once on plane.
Tested pressure, 15 psi at 2300 RPM. I'm sure it went over 40 at speed. I was told by a shop and long time boat wrench that it must have a valve to reduce pressure.
Said that blue printed pumps can run as much as 300 psi. My pump has been worked.
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Yes you need a valve to help control the pressure. If that still doesn't work then you can order a "pressure release" from Rex marine I think. Once it gets over 15 or 20 PSI it dumps the extra pressure out of the boat, instead of forcing water into your motor
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If you had a picture of the 1st T after the pump that would help. I am guessing from your description that there is a pressure regulator here, hence the end of the T that exits the boat, if not well... next while an auto runs less than 25psi on the high end I cant imagine that 40 would prove to be a problem if all the gaskets are holding the water as they should. Jet boats were run with no pressure regulation for a long time before people decided to put regulators on them, that said most of us buy insurance for everything we own so my feeling on having one is that it couldn't hurt. If I had to bet I'd guess it's leaking by a gasket somewhere, how long has the engine been together without a rebuild?
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Engine is fresh, has about 1 hr total run time now. I pulled the intake the first time this showed up, nothing obvious. I performed a compression test, all cylinders are equal..
I like the 15 psi releif valve idea,
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That's the same problem I had. I didn't know much about jets, and still don't for that matter :D, but I changed m head gaskets and intake gaskets and realized they were in fine condition. After doing some research I learned about needing a valve between the pump and the engine. I tried that and still had trouble so now I'm using the pressure relief. I've talked to some shops and they said the pump can put out 100+PSI, which an engine can't handle. And is your avatar your boat?
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Any one got a pic of the valve you are talking about? One boat i have has no valve anywhere, the other only has valves for the headers.
2sav
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Here's a pic of it. The water from the pump goes through your valve, then into here... .once the pressure gets passed what you set it at, it dumps it back out the transom.
(https://www.socaljetboats.com/proxy.php?request=http%3A%2F%2Fi16.tinypic.com%2F5yd1f88.jpg&hash=bef53c68c8cd8a40270e0175ff76194ef6aa078a)
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Where did you pick it up at?
2sav
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Rex marine has them, or HTP..... I think even some plumbing stores might have something
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Yo Prop, hows about some pics of the boat? Hows the wing work for ya, that IS your boat right?
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Ya thats my boat, havent ran it enough to mess with the wing. i'm running it without until I get the motor problems fixed. I wonder about the nozzle set up and want to make sure it is right. previous owner was not the original owner who raced it.
The guy I bought it from removed one of the two wedges which aim the nozzle up. I have to run the adjutable nozzle one click up from full down.
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keep me posted on the wing, huh?
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Did you ever have that boat on Craigslist? I KNOW i saw it on there a few months ago. Or at least it was a fake trying to scam money. I even found the thread I seen it on cause everyone was commenting about the wing, but by now that listing was gone
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Bought it in April from a friend, dont know if he had it advertised there at one time.
Ran it tonite, NO WATER IN OIL! Ball valve worked. Temp. came up to 150, good flow out of block.
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Sweeet
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That's good to hear! I knew I saw that thing on there, cause it was the same pic in your Avatar. Leave that wing off.
Are you using hose inbetween the ball valve and the intake? Or is it plumbed?
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Awesome, hope to see you on the water soon!
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Plumbed.
Pipe-T-valve-braided ss-motor. ( bypass from T )
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Piped-T-valve-braided SS to block ( bypass exit at T )
Hey HD, do you know anything about wing set ups? Hear they are only effective after 120 MPH.
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well.........no, thats why i was aksin you. Looks cool as fuc tho, maybe w/ some zoomies. I was wondering about that las night, u want them tp push down or pull up or jus stableize?
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Oh OK, shuold be good then, I had a hose when I installed my ball valve, and then during a river run it blew off and filled my boat with water! :o
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Ran it this morning for an hr. oil was clear, water flow was a little too low, temp climbed too high at idle. Adjusted flow and bumped 20 psi a few times, clouded oil a little. I may have a weak gasket now.
Will install the bypass valve and see how it does before tearing it down again. That will take care of the idle temp. also.
River was nice at 7 am!
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dragboatcity.com for the seats, they have carbonfiber and 'glass, $225-85.
Ebay or racingjunk.com for zoomies.....maybe DBC Dragboatcity.com or hotboat.com
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Thanks for the replies!
Got the water pressure under controll, the bypass valve woked. must have damaged a gasket though, water in oil at 10 psi.
I am installing fel-pro 1071 head gaskets in place of the copper. Talked to two other guys who had the same trouble with copper.