1997 5.7l water in oil. replace?

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Jun 26, 2021
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O.k. I just got a 1997 deckliner (vip) with a 5.7l remanufactured block from Jasper. Previous owner didn't winterize correctly. Port freeze plug blew out the one at the engine mount-replaced with a rubber one from oriely"s . Starboard side had a hairline crack right where drain plug is. Ground down side of block with wire brush and JB welded over crack. (it wasn't open, just cracked, about three inches long.) Checked everything else, ran the motor on muffs for over an hour for 3 different heat/cool cycles. No leaks, ran great except for a stumble coming off of idle. Took it out on the lake . ran it for 2 hours at 3k rpm. Ran perfectly. Got back to home, checked oil, and it was milk, and about 3 inches higher than it should be. Any idea where it could still be pumping water in? Should I just replace it? If so, can I get any 1997 or so motor out of a truck? I was told truck engines would be cammed about the same, and mine is also a 2 barrel rochester carb. I have a serial number on the starboard side right by the starter . It is 696496. There are no cast numbers or letters on the block in front...only the Jasper sticker on the freeze plug. The rest of the boat is like new. I only paid 1500 bucks for it on it's trailer. Boat is trailered to fresh water only. There are 350 's out here in Iowa like crazy from dirt track racers, or rebuilds. thanks in advance for your help. I can assemble a short block myself, too. Options? where to look for blocks? help, please
 

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cyclops222

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If you have to ask these questions ? And more later ?
Love the boat. Get real help on ALL possible freeze cracks & damages .
 

Bondo

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I can assemble a short block myself, too
Ayuh,..... Welcome Aboard,...... Go with a long block, so that you won't have to deal with cracked heads,....
 
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Ayuh,..... Welcome Aboard,...... Go with a long block, so that you won't have to deal with cracked heads,....
Thanks. I kinda agree. I'm thinking of going with that. The boat is with it, I think, and it will last me till I die, as long as I winterize it correctly. Currently looking at 3700 to 5k to replace. Any sources you know of?
 
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Others have said that the block normally fails somewhere in the intake valley. I'll pull the manifold and check. Like I said, it runs great. Just makes pudding. I'm on a lake. I'll run it till it seizes, if I can JB weld it. But yes, if I gotta pull it, it's all gonna be new. I only want to do this once, and I planned on it when I bought it.
 

cyclops222

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In todays ......Maximum profits......... It is pure luck if you get a correctly built .......ANYTHING
Would love to be more positive.
More money no longer buys more quality. :(
 

cyclops222

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Years ago you could buy a G M Marine Crate engine with a warranty. Not sure if it is still available that way. Would need to bolt to your drive. Worst case should be buying a marine rated starter ?? Good luck.
 

kenny nunez

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You will find a crack in the valley, also look closely at the underside of the intake manifold under the thermostat housing area. Most times the exhaust manifolds crack also.
 

Scott06

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Thanks. I kinda agree. I'm thinking of going with that. The boat is with it, I think, and it will last me till I die, as long as I winterize it correctly. Currently looking at 3700 to 5k to replace. Any sources you know of?
Michigan motorz has new and rebuilt engines.
you could get a running truck engine strip it to the long block - swap head gaskets, freeze plugs and circulating pump to marine and go that route. This is usually the cheapest way.
I got a partial engine package from Michigan Motorz in 2015 , swapped if for the freeze cracked engine PO ruined… just finished our 9 th summer enjoying the boat. Was glad I spent the money for a new long block. Of course was cheaper then but even at what new 5.7 s cost now if you use it it’s worth the investment .
 
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You will find a crack in the valley, also look closely at the underside of the intake manifold under the thermostat housing area. Most times the exhaust manifolds crack also.
Thanks. I will remove that tomorrow and check it. If I can fix it, I will. If not, I'll maybe try a junkyard truck motor and put all of my stuff on it. I'll look at getting a short block, new. I'm not worried about crew plugs. It's trailered to fresh water only. What I really need to know is what years of blocks will fit.
 

Scott Danforth

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your freeze busted motor is junk.

get a 1996-2000 vortec motor from a truck. NOT ONE FROM THE CIRCLE TRACK GUYS
 
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your freeze busted motor is junk.

get a 1996-2000 vortec motor from a truck. NOT ONE FROM THE CIRCLE TRACK GUYS
I just meant that if I wanted someone to rebuild one, my race buddy's could easily put a short block together with the right cam. I know you guys are thinking wtf is this guy doing trying to JB weld a motor back together. I'm not... Unless I can. BUT... What is the difference between a vortec motor block, and my jasper?
 

Scott06

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I'll maybe try a junkyard truck motor and put all of my stuff on it. I'll look at getting a short block, new. I'm not worried about crew plugs. It's trailered to fresh water only.
In addition to what scott says worry about the core plugs even in fresh water. The steel ones will eventually corrode through in fresh water they are just steel. Doesn't make much sense to not replace them for $35-40 bucks while you have the block out as there are 2-3 behind the flywheel.

Some of the later truck engines have stainless ones that are good to leave in, otherwise would make sense to swap them.
 

Scott Danforth

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vortec motors are the 1996 and later GM motors with vortec heads.
 

Scott06

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I just meant that if I wanted someone to rebuild one, my race buddy's could easily put a short block together with the right cam. I know you guys are thinking wtf is this guy doing trying to JB weld a motor back together. I'm not... Unless I can. BUT... What is the difference between a vortec motor block, and my jasper?
A lot of people have JB welded cracks on the outside of the block no issue. The ones in the valley you wont be able to successfully jb weld to hold up for long.

Your jasper engine is a vortec block/engine. The term vortec (8 bolt intake / vortec heads) is just a street identifier for a 96 and up Chevy truck engine
 
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In addition to what scott says worry about the core plugs even in fresh water. The steel ones will eventually corrode through in fresh water they are just steel. Doesn't make much sense to not replace them for $35-40 bucks while you have the block out as there are 2-3 behind the flywheel.

Some of the later truck engines have stainless ones that are good to leave in, otherwise would make sense to swap them.
Thanks. I have now verified that I have a 350 from Jasper that is an 87 -95 block, with a12 bolt intake, and center bolted valve covers. If I can find a good truck motor, I'll do it. New long block is gonna run me 3500.
 

Jmunk

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in addition to the new engine consider at least testing the manifolds for cracks or replace. A new or good used intake wouldn’t be a bad investment as well so you can do it once and be done.
 
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Very true. I'm going all new. I only want to do this once. Presently, the motor runs great...except for turning the oil to pudding. I.m guessing my 2 barrel intake is toast, so I'll be getting a new one anyway. Going to a 4 barrel won't really help me much, but if it's cheaper, I might do it. The edelbrock 650 has always been my favorite carb. I'm thinking it would be o.k. as long as I keep the spark arrestor on top of it. we'll see. a lot of work brfor we get to that part. I'm pulling my outdrive tommorow. I'm getting a new long block from Michigan Motorz.
 
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