Engine replacement help…

Ogbign

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Apr 16, 2023
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76
Pretty sure this isn't true. Though I used the flywheel that came with the block, I don't recall which balancer I used

These things are a dime a dozen in the scrap yards. I got mine for $180. IMHO, you're much better off with a truck engine than a 30 year old Marine engine. Almost by definition, a boat with a rotted Hull is going to have a neglected engine (btdt). I did almost the same swap, you can definitely learn from my mistakes 😂
I have found several 4.3 truck engines non that I can hear run tho… an yes most these boats here are badly neglected, maybe it’s our weather, one day it’s 80 next it’s freezing, but these rotten boats look scary, I just really would rather do a v8 I found a 350 mercury older 4 bolt main and I can watch it run also … My mounts don’t look like theyl move much do they ?
 

stresspoint

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Unless I can hear an see the used engine run I’m not gonna buy it
yes exactly , i got caught out on that one , seller said it was removed as a running concern ,YEA!, problem was and he neglected to tell me , it was a running concern 2 years earlier.
more rust than the titanic when i pulled it apart..

my 4.3 fiasco was just one thing after another and costly since parts are not readily available here in AU,
like yourself i was going to go the V8 route but after inspection of the V8 motor i have , i needed new manifolds and risers + numerous other things to make it work + not forgetting hull mods and drive ratios, so i was committed to the 4.3 V6 at that point.

as the boat was built for the motor .i persevered with the 4.3 , learned a lot along the way and since i new nothing about the 4.3 , i got well educated hands on :) them ,.3 motors later and lots of mods i have what i have now (y).
things some said could not be done i managed to make work , in turn i have a very powerful and reliable 4.3 that kicks asss and sips fuel , it will rev well over the 6000 rpm mark if i let it .( 6500 + a bit ) 60 mph + is IMO not bad for a heavy assedd boat like the Maxum SR 1800 its in.

i am glad persevered with the 4.3 and not gone the V8 ,even with all the BS i went through , so my advice is to stick with it and get it right , your half way there with a good solid hull.
 

Ogbign

Petty Officer 3rd Class
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Apr 16, 2023
Messages
76
yes exactly , i got caught out on that one , seller said it was removed as a running concern ,YEA!, problem was and he neglected to tell me , it was a running concern 2 years earlier.
more rust than the titanic when i pulled it apart..

my 4.3 fiasco was just one thing after another and costly since parts are not readily available here in AU,
like yourself i was going to go the V8 route but after inspection of the V8 motor i have , i needed new manifolds and risers + numerous other things to make it work + not forgetting hull mods and drive ratios, so i was committed to the 4.3 V6 at that point.

as the boat was built for the motor .i persevered with the 4.3 , learned a lot along the way and since i new nothing about the 4.3 , i got well educated hands on :) them ,.3 motors later and lots of mods i have what i have now (y).
things some said could not be done i managed to make work , in turn i have a very powerful and reliable 4.3 that kicks asss and sips fuel , it will rev well over the 6000 rpm mark if i let it .( 6500 + a bit ) 60 mph + is IMO not bad for a heavy assedd boat like the Maxum SR 1800 its in.

i am glad persevered with the 4.3 and not gone the V8 ,even with all the BS i went through , so my advice is to stick with it and get it right , your half way there with a good solid hull.
Good advice Ty,
 

stresspoint

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Sep 19, 2022
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Pretty sure this isn't true. Though I used the flywheel that came with the block, I don't recall which balancer I used

These things are a dime a dozen in the scrap yards. I got mine for $180. IMHO, you're much better off with a truck engine than a 30 year old Marine engine. Almost by definition, a boat with a rotted Hull is going to have a neglected engine (btdt). I did almost the same swap, you can definitely learn from my mistakes 😂.

not here to argue , I'm positive you cant fit a FW with balance bulge IE: early FW , on a internally balanced crank..
FWIW i fitted a internally balanced rotating assembly into a pre vortec motor, not strait forward but can be done , many said that motor should not work , however the let down was it kept getting water in ( long story) , the day it was going to come out of the boat , i cracked it to 7000 rpm and held it there for a good 2 km of the river , still was able to drive it onto the trailer .
 
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Ogbign

Petty Officer 3rd Class
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Apr 16, 2023
Messages
76
not here to argue , I'm positive you cant fit a FW with balance bulge IE: early FW , on a internally balanced crank..
FWIW i fitted an internally balanced rotating assembly into a pre vortec motor, not strait forward but can be done .
If I keep the 4.3 I probably need to find another boat , both my manifolds are trash ,and my gears are 1.47 , I could fit 2 people in it an still pull a skier barely any more than that an it won’t come out the water, with just the 2 people tho I could stomp it an it would stand up an launch, boat also only seats 4
 

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stresspoint

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If I keep the 4.3 I probably need to find another boat , both my manifolds are trash ,and my gears are 1.47 , I could fit 2 people in it an still pull a skier barely any more than that an it won’t come out the water, with just the 2 people tho I could stomp it an it would stand up an launch, boat also only seats 4
i know it is frowned upon in some circles , if i was in your position , i would chase down some used manifolds and risers to get you by.

i went to AM HITEK performance manifolds , my OEM ones were not too bad slightly used but ok , with all the hype about not using used risers and manifolds i could not get my asking price , so i have kept them pickled in grease and oil paper for when the stainless AM ones rot out.
no doubt someone here could direct you to some decent ones for a good price that are available in your area..

? any progress on the examination of the motor you have , dye penetrant test kit will be your friend.
 
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Scott06

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Apr 20, 2014
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I’m lookin at one from Michigan motors don’t think I’m gonna find one at a salvage near me
My experience was good there, but this was a new partial engine not reman.

Yes there are cheaper ways to do it but if you want to buy and engine and enjoy the boat spend for the new GM base engine. After 8 trouble free years I am glad I spent the extra money on it given how much we use our boat.
 

Scott06

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i know it is frowned upon in some circles , if i was in your position , i would chase down some used manifolds and risers to get you by.
If they are from a freshwater location no issue using used. We are on an inland lake and unless you don't winterize the manifolds last the life of the boat- our and our friends boats have lasted 25-40 yrs.
 

Lou C

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Yep in freshwater they last forever here in the salt they are wear item. The elbows are good for 5 seasons maybe 7, manifolds can last longer if filled with good no tox antifreeze over the winter to cut down on corrosion. The cyl heads will eventually rot out too but it takes like 15 years depending on the salinity of the water. Blocks don’t seem to rot out at least I haven’t heard that.
If redoing mine I might see if I could get a local machine shop to build me one from a good core.
 

Ogbign

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The block is cracked 😭😭😭😭 an my cam looks like poo too, rods a crank probly just as bad … this is worst case scenario I guess…. 😭😭😭😭
 

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stresspoint

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nasty !, where to go from here is to find a boat with a later vortec motor, due diligence should get you a decent motor.
make sure you can run whatever you find up to temperature , pull the rocker covers and look for any sign of water after it has been ran .

people in your parts sat rotted boats go cheap and are out there for the taking .
 

Scott06

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The block is cracked 😭😭😭😭 an my cam looks like poo too, rods a crank probly just as bad … this is worst case scenario I guess…. 😭😭😭😭
At least you can save the starter bolts...

Seriously it always amazes me how much damage can be done for lack of ten minutes pulling drain plugs.

Was the crank bent or broken or what ever ?
 

Ogbign

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nasty !, where to go from here is to find a boat with a later vortec motor, due diligence should get you a decent motor.
make sure you can run whatever you find up to temperature , pull the rocker covers and look for any sign of water after it has been ran .

people in your parts sat rotted boats go cheap and are out there for the taking

At least you can save the starter bolts...

Seriously it always amazes me how much damage can be done for lack of ten minutes pulling drain plugs.

Was the crank bent or broken or what ever ?
I’m sure it’s not bent but, I’m in process of putting it on the stand, gonna flip it over an see if it spun a bearing or rod or whatever, really no excuse to not drain the water either way would still be fixable if they had , I’da bought a crank an stuff
 

Lou C

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People who know me know what I'm gonna say:
Just say NO to raw water cooled inboards! There is an increased cost factor but if that boat even had just a half system on it, all you'd be doing now is changing the exhaust & heat exchanger.
I would never ever put a new or reman engine in my boat without a heat exchanger. GM designed it to have pressurized antifreeze going thru it not nasty salt water, river water, mud and sand!
 

Ogbign

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People who know me know what I'm gonna say:
Just say NO to raw water cooled inboards! There is an increased cost factor but if that boat even had just a half system on it, all you'd be doing now is changing the exhaust & heat exchanger.
I would never ever put a new or reman engine in my boat without a heat exchanger. GM designed it to have pressurized antifreeze going thru it not nasty salt water, river water, mud and sand!
By heat exchanger you mean like some sort of radiator? When I pullled this apart I did find small rocks and mud our lakes here are rough and our mud is red mud thick nasty stuff, speaking of cooling I wanted to ask, I have a power steering cooler it looks about useless . Do I need to keep it .?I think it’s bad …
 

Bondo

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By heat exchanger you mean like some sort of radiator? When I pullled this apart I did find small rocks and mud our lakes here are rough and our mud is red mud thick nasty stuff, speaking of cooling I wanted to ask, I have a power steering cooler it looks about useless . Do I need to keep it .?I think it’s bad …
Ayuh,... If you run p/s, you need the cooler,.......

Lookin' at yer motor mount picture, it would be pretty easy to glass in new ones for a V8,....

With the destruction I see, yer best option is to find another drop-in, ready to run motor, out of a rotten hull,.....
V6, or V8,....
 

Lou C

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Yes you need the PS cooler, they sometimes self drain but they can freeze and crack just like the engine if not drained. You can get them aftermarket in some cases, look for Mr Cool's website, they sell them, or depending if it froze, it might be repairable, depending on what the damage was.
 

Ogbign

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Yes you need the PS cooler, they sometimes self drain but they can freeze and crack just like the engine if not drained. You can get them aftermarket in some cases, look for Mr Cool's website, they sell them, or depending if it froze, it might be repairable, depending on what the damage was.
Doesn’t look cracked or anything I figured inside rotted out looking it tho looks fine but it’s brass so that’s probly oem old stuff , an I wonder why my freez plugs didn’t pop…
 

Ogbign

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Ayuh,... If you run p/s, you need the cooler,.......

Lookin' at yer motor mount picture, it would be pretty easy to glass in new ones for a V8,....

With the destruction I see, yer best option is to find another drop-in, ready to run motor, out of a rotten hull,.....
V6, or V8,....
I would love to just stick in a v8 there’s a lot more ofem around , I don’t much about fiberglassing tho, I’ve repaired some oilfield tanks but that’s it
 

Scott06

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I would love to just stick in a v8 there’s a lot more ofem around , I don’t much about fiberglassing tho, I’ve repaired some oilfield tanks but that’s it
Looking at the pic would be and easy job to glass in a block of wood at same height, you can do the V8 and have no issue.
 
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