warm boat awfully loud noises . . . AND THAT ALTERNATOR

[peacekeeper6]

hey all i have a new/old 1973 wellcraft with a inline 4 vovlo aq115 B20 block. I just did the rewiring and have mostly everything correct, i just need to know what goes to what for the alternator to the regulator. its a motorola 3 wire. ALso i took the boat out on the water for the first time after doing the rewire and it ran fine for about 10-15 minutes then it got this loud knockin, it was not so loud at first but as i listend it worstened from a 2 to a 10 on a 10 scale in about 30 seconds. i just rebuild the carbs and adjusted the rockers and i dont know what to do next and to go about trouble shooting. i dont under stand why it would run fine for a few minutes then when i am cruising for about 10 minutes it knocks, i also scored the old prop on a rock and a chip flew off. Any help would be appreciated and thats all i can think of right now that i have done to it thus far, i am going to get a tach and temp meter tomm cause when i rewired i tore all that stuff out.

 

[waterone1@aol.com]

Re: warm boat awfully loud noises . . . AND THAT ALTERNATOR

Just wondering if you left the oil pressure gauge connected, or was that torn out also ?

 

[olbuddyjack]

Re: warm boat awfully loud noises . . . AND THAT ALTERNATOR

"Ayuh"(to quote a wise old well read philosopher)<br /><br />The first thing to check is the oil psi.

 

[Nos4r2]

Re: warm boat awfully loud noises . . . AND THAT ALTERNATOR

Yup...knocking when warm suggests worn bearings-as the oil warms up it gets thinner and takes up less clearance and the pressure will drop dramatically.

 

[trog100]

Re: warm boat awfully loud noises . . . AND THAT ALTERNATOR

yes sounds like a big-end knock.. run it at WOT for too long like that and it will throw the rod.. the worse case scenario is a big hole in the side of the block.. <br /><br />trog100

 

[peacekeeper6]

Re: warm boat awfully loud noises . . . AND THAT ALTERNATOR

hum so i have to do the lower end rebuild eh? that sux this engine doesnt look taht hard to work on its just getting the parts. where can i get the parts? evertime i goto autozone they are like . . . a boat?

 

[RubberFrog]

Re: warm boat awfully loud noises . . . AND THAT ALTERNATOR

try napa

 

[peacekeeper6]

Re: warm boat awfully loud noises . . . AND THAT ALTERNATOR

ok, what do i tell them?

 

[RubberFrog]

Re: warm boat awfully loud noises . . . AND THAT ALTERNATOR

Buy a service manual, first. Figure out what parts you need. More than likely you're going to need some machining on the block. Between the service manual and the machinist, you should be able to figure out what you need.

 

[peacekeeper6]

Re: warm boat awfully loud noises . . . AND THAT ALTERNATOR

i have a shop manual.were sure that i need a rebuild, this isnt due to detonation or anything like that?

 

[RubberFrog]

Re: warm boat awfully loud noises . . . AND THAT ALTERNATOR

I'm not a "boat" mechanic. But, the internals of the engine are the same as a car. If you're hearing a knocking, that's bad. You could start by pulling the pan and taking a look. Once you have it out, it's not much more work to just rebuild it. I wouldn't fool around with just replacing bearings. Usually when the bearings start going bad, so does everything else.<br />The minimum I would do is pull the crank and have it mic'd to make sure it doesn't need to be ground. Why replace bearings if the crank is bad?<br />I rebuilt my 67 mustang last year. Granted, I did a full rebuild (including heads) and only reused the crank. You probably don't need that kind of work. Your's should be a bit cheaper if you go this route.<br />The bill looked like this:<br />Labor: $1,100<br />Hot tank, rebore block, r&r cam bearings, r&r pistons on rods, grind crank, complete valve job (magnaflux, install valve guides and seats, resurface).<br />Parts: $640<br />pistons, rings, main/rod/cam bearings,oil pump, timing chain and gear set, freeze & galley plugs, exhaust/intake valves & seats, valve guides, valve springs, mild camshaft, lifters.

 

[tommays]

Re: warm boat awfully loud noises . . . AND THAT ALTERNATOR

with and old volvo i would look into price and if you can get parts before i did anything<br /><br />they are rare and volvo marine only on many things and it makes the prices shocking<br /><br />tommays

 

[RubberFrog]

Re: warm boat awfully loud noises . . . AND THAT ALTERNATOR

good point

 

[peacekeeper6]

Re: warm boat awfully loud noises . . . AND THAT ALTERNATOR

uhg, damn boats. the thing is i thought when rods went out and things of that nature it knocked whether hot or cold. mine only knocks when its hot. i threw a rod in an old camry i had and it burned oil like it was nothing and knocked as soon as started up. also i noticed around the stern dirve under the locking mech. there is some sorta brownish sluidge. also i forgot to mention that when it starts knocking and i bring it to idle it stalls out.

 

[peacekeeper6]

Re: warm boat awfully loud noises . . . AND THAT ALTERNATOR

well i think i am going to take the engine out and tear into it and see what exactly is going on. maybe i will find something clogged or dirty.

 

[Nos4r2]

Re: warm boat awfully loud noises . . . AND THAT ALTERNATOR

Just a thought-check out whether your engine is common with any volvo car engines. Some of the old volvo's were just a marinised car engine- a decent one from a wrecker won't cost much.

 

[peacekeeper6]

Re: warm boat awfully loud noises . . . AND THAT ALTERNATOR

it is, its a b20 block i cant remember which car engines they came out of though

 

[Nos4r2]

Re: warm boat awfully loud noises . . . AND THAT ALTERNATOR

I've got a manual for that-hang online and I'll be able to tell you.

 

[Nos4r2]

Re: warm boat awfully loud noises . . . AND THAT ALTERNATOR

volvo b20 block was in Volvo 140 series 2 liter cars from 1966 til end of run in 74ish, then in the first few volvo 240 series. for a haynes manual for the engine get the 240 series from 74 to 84,ISBN 0 85696 963 X<br /> or IF they still publish it the one for the 140 series ISBN number is 0 85696 129 9

 

[peacekeeper6]

Re: warm boat awfully loud noises . . . AND THAT ALTERNATOR

i have a marine engine manual for the aq115, but now that i know the cars it'll be good cause i can buy the new gaskets.