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5.7 reman mystery....

sandkicker

Outstanding Contributor
My YC had one of its boats ( 24 ft Privateer inboard) "re-engined" last spring ( May 2021 commissioning). The boat was used during the season for about 100 hours. It was winterized by a different yard than the one that did the engine swap.

Several days ago the yard that winterized the engine, recommissioned the boat. Their report was 150 psi in one cylinder, 0 in another. Cylinders #2 and 4 involved. The engine has a full "fresh water" cooling system. The yard that did the swap claims "bad winterizing".
I think the engine was shot at install. See pix of removed plugs... and no, I don't know which plug or cylinder is which. Any ideas how this kind of damage could happen in one season on a FWC engine... BTW... no record or indication of coolant loss.

Note condition of center electrode in lower plug.
Roberta Plug side view.jpgRoberta Plugs 2 and 4 .jpg
 
What year is engine/boat and what are the plug part numbers?

The center electrodes, one is missing...........

Looks like a lot of deposits on that one on the inside.

Possible blown head gasket leaking antifreeze into that hole.??

Also those plugs dont look like 100 hours..........I have removed plugs with a years of use that look better than those
 
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Boat.... 1987 Privateer 24 Ft Renegade...
Engine.... "5.7 Reman opposite rotation base engine" w/..... additional parts. "New".... 3/26/21
Plugs...MR43LTS New 3/26/21

BTW.... when launched ( April 2021) after reengine, boat exhibited somewhat lower than normal power response during first normal ( sailboat race management) use in late June 2021. At the time this was attributed to "engine is tight and needs break in"
 
5.7 Reman opposite rotation base engine What is that? Is it a standard rotation or reverse rotation.

Other question, what engine is it? Standard 350 or Votec (8 intake manifold bolts)



Those dont look like 43LTS LTS plugs are Long reach and have almost twice as many threads. I think these are used in Vortec engines

They look like standard 43T if they are 43's These are used in the non vortec older 350's

MR43LTS
mr43lts_spark_plug.jpg


MR43T

b55745ac-347a-4f62-b9fa-24a8981e69a7_1.178ce7ed962ea215b17d6caaae76c5a8.jpeg
 
You are correct about plugs... my fingers had "run on" typing :) definitely 43's will double check exact flavor .
Re: intake... not @ boat now ( 20 mins away) will check when I go there tomorrow.
Thank you for your time...

/Bob
 
Ayuh,..... Is this a carbed motor,..??

Detonation will do that sorta thing, easily in 100 hrs,.....
Probably tuliped the valve is where the compression went,..... Pressurize that cylinder at Tdc, 'n listen,.... you hear whether it's a valve or rings,....
A bad carb tune, or crap in the fuel filter is where I'd start,....
 
Sandkicker, have to agree with bondo in the detonation .Will touch base with you wed . in the am
Locate #1 in the cap and go clockwise. 18436572 is a standard motor. If you go CCW it will be the same just opposite rotation engine if you go clockwise it will be this 12756348
 
Ayuh,..... Is this a carbed motor,..??

Detonation will do that sorta thing, easily in 100 hrs,.....
Probably tuliped the valve is where the compression went,..... Pressurize that cylinder at Tdc, 'n listen,.... you hear whether it's a valve or rings,....
A bad carb tune, or crap in the fuel filter is where I'd start,....

They rebuilt the 4 bbl carb from the original engine and put it on the reman.
 
5.7 Reman opposite rotation base engine What is that? Is it a standard rotation or reverse rotation.

Other question, what engine is it? Standard 350 or Votec (8 intake manifold bolts)



Those dont look like 43LTS LTS plugs are Long reach and have almost twice as many threads. I think these are used in Vortec engines

They look like standard 43T if they are 43's These are used in the non vortec older 350's

MR43LTS
View attachment 28581


MR43T

View attachment 28582




You are correct... plugs are 43T plugs...
Rotation... CCW looking from the front when starter bumped, i.e. RH ... Decal on splash shield on flame arrestor from original engine says RH .


Robereta Engine ID.jpg

And.... 12 bolt intake so... not Vortec.
 
Is this a twin engine boat?

I dont understand why a RH engine is needed when a Counter rotation lower unit.

Anyway is it a twin engine boat?
 
Last season, the first season of this current engine, the boat was used as normal. At the end of the season, with both 40 gal tanks just below 1/4, I dumped 1/2 of a "256 gal" STARTRON enzyme fuel treatment bottle in each tank since the tanks had been let to sit at that low level for several weeks. A fast moving storm front coming in from the west dissuaded me from running the boat up bay to the fuel dock. I ran the engine at idle until it warmed up and shut it down The following Saturday a number of "club volunteers" who needed to use the boat to pull the race marks, seeing the low fuel, emptied all the fuel left in a number ( 6 to 8) jerry cans that had been used as back up fuel for the YC's other 9 OB ( 4 stroke) powered boats. The engine started, the boat got about 1/2 miles ( mostly a no wake area) from the club and stalled... would not restart. It got towed back to the club and they called me. I dumped the fuel filter and it was full of water. I made two attempts to restart the engine but it would not start. When I found out how the boat had been refueled @ the club, I had the boat towed to a local marina and had their mechanics drain and refill the tanks and restart the engine. The boat was hauled and blocked @ the club's yard, and later that month, the marina that worked on the boat, winterized the engine. This was not the same marina that did the engine work.
 
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I have a couple of thoughts and although I am not a professional I am on my third 5.7 reman. It seems obvious that water got in and stayed in the system. Perhaps someone even put lots of water in the fuel tank during that last of the season refill. Everything inside got wet and then it got stored and corrosion set in. I've lost a block to freeze up even though it was well winterized. The theory being sediment had built up in a 6 year old motor and so the anti freeze never got to the low spots in the block and they cracked both sides near the motor mounts. This led to my latest new 5.7l reman.

Also, my latest, 2020 5.7L Alpha reman, came with NGK plugs. These are markedly better than any of the other plugs I have used in my boat or in any car I have ever owned. Motor just runs better with NGK BPR6EFS came from the factory with those in it and I will keep those going back in forever. AC and Champion are just not as good quality and if compounded with any issue like you have, they don't function well. I'm not sure on the gap, I would have to pull one to check it.
 
Personally, over the years, I've re-engined two personal boats.... One in the 1980s and one in 2006. Both times I was advised to "save money" and get a reman. Both times I did my engineering due diligence and found that any cost saving was minimal and was outweighed by the lack of finger pointing opportunities and the factory all up warranty ( and all new parts). Unfortunately, my YC did not consult with me when they did the re-engine and was charged $12,450 plus tax for the engine including related labor ( to reuse 35 yo parts). I just got a quote from Michigan Motors for an all up 100% brand new 5.7L 315 HP carbed FWC rev rotation engine @ $12,647 (plus shipping).
 
I have a couple of thoughts and although I am not a professional I am on my third 5.7 reman. It seems obvious that water got in and stayed in the system. Perhaps someone even put lots of water in the fuel tank during that last of the season refill. Everything inside got wet and then it got stored and corrosion set in. I've lost a block to freeze up even though it was well winterized. The theory being sediment had built up in a 6 year old motor and so the anti freeze never got to the low spots in the block and they cracked both sides near the motor mounts. This led to my latest new 5.7l reman.

Also, my latest, 2020 5.7L Alpha reman, came with NGK plugs. These are markedly better than any of the other plugs I have used in my boat or in any car I have ever owned. Motor just runs better with NGK BPR6EFS came from the factory with those in it and I will keep those going back in forever. AC and Champion are just not as good quality and if compounded with any issue like you have, they don't function well. I'm not sure on the gap, I would have to pull one to check it.

I have been winterizing boats for over 30 years and have never has a failure. Method my be the issue. Not the build up of crudd in the block. It takes years of use for any substantial crudd to build up.

I run AC MR43T;s in my 1987 original motor in my boat with no issues. I use NGK in my motorcycle and AC platinum in my GM truck. They all work just fine!
 
Personally, over the years, I've re-engined two personal boats.... One in the 1980s and one in 2006. Both times I was advised to "save money" and get a reman. Both times I did my engineering due diligence and found that any cost saving was minimal and was outweighed by the lack of finger pointing opportunities and the factory all up warranty ( and all new parts). Unfortunately, my YC did not consult with me when they did the re-engine and was charged $12,450 plus tax for the engine including related labor ( to reuse 35 yo parts). I just got a quote from Michigan Motors for an all up 100% brand new 5.7L 315 HP carbed FWC rev rotation engine @ $12,647 (plus shipping).

At this stage, I think the conversation is over.

The valve covers should be removed to make sure all the valves are moving properly but in the end, I feel the engine has to come out and the heads have to be removed to diagnose all the problems.

Note: I have replaced OEM engines with Remans and have had great success! My last was a 350/5.7 Long block heads and timing cover only, Had to transfer oil pump and crankshaft oil shield and main cap bolts for shield etc....so just the block.

Engine went almost 1000 hrs in an inboard ski boat used religiously every day during the late spring, summer and early fall for skiing. Then had a head gasket failure which I fixed and the boat was back in service and lasted another 5 years before the heads needed rework.

Reman cost ~$1800 and supplies another $400 and my labor..............All said and done ~$4000.00 and agreement to keep my boat at his dock all summer every summer.


Of course the source of the reman is the key. Mine came out of Rhode Island and I purchased through a distributor/seller not direct. There is a large engine reman company there.

If you cant do your own work, and you have the money then it is always better to buy new. Always!
 
Personally, over the years, I've re-engined two personal boats.... One in the 1980s and one in 2006. Both times I was advised to "save money" and get a reman. Both times I did my engineering due diligence and found that any cost saving was minimal and was outweighed by the lack of finger pointing opportunities and the factory all up warranty ( and all new parts). Unfortunately, my YC did not consult with me when they did the re-engine and was charged $12,450 plus tax for the engine including related labor ( to reuse 35 yo parts). I just got a quote from Michigan Motors for an all up 100% brand new 5.7L 315 HP carbed FWC rev rotation engine @ $12,647 (plus shipping).

I did look at Michigan Motors, they did seem to offer a very compelling high quality product. In the end, I purchased a Mercruiser reman from a dealer who had just gotten it in. Fortunately I was able to work with them to get things going. One of my issues turned out to be the wiring harness. I had a 9 pin harness and the new motor came set up for 10 pin. Turns out when "my boat yard" had installed the motor 6 years earlier, they just forced the harness together even though there was a pin issue. It took me hours to figure out what the issue was. Back to the new boat yard and they sold me a used wiring harness that plugged right in at both the front and back and I was good to go. Basically I have had lots of issues relying on others to do work for me. FYI my 357 alpha was $7,499.00 June 14,2020. I picked it up and installed it myself. Carb, and no FWC, I added that after.
 
At this stage, I think the conversation is over.

The valve covers should be removed to make sure all the valves are moving properly but in the end, I feel the engine has to come out and the heads have to be removed to diagnose all the problems.

Note: I have replaced OEM engines with Remans and have had great success! My last was a 350/5.7 Long block heads and timing cover only, Had to transfer oil pump and crankshaft oil shield and main cap bolts for shield etc....so just the block.

Engine went almost 1000 hrs in an inboard ski boat used religiously every day during the late spring, summer and early fall for skiing. Then had a head gasket failure which I fixed and the boat was back in service and lasted another 5 years before the heads needed rework.

Reman cost ~$1800 and supplies another $400 and my labor..............All said and done ~$4000.00 and agreement to keep my boat at his dock all summer every summer.


Of course the source of the reman is the key. Mine came out of Rhode Island and I purchased through a distributor/seller not direct. There is a large engine reman company there.

If you cant do your own work, and you have the money then it is always better to buy new. Always!

RE: "If you cant do your own work, and you have the money then it is always better to buy new. Always!" YES !!!!
 
And the Envelope Please!!!!


Thanks to Bt Doctur, the following "items" were identified.

1) Plugs for #2 and #4 were never installed correctly, i.e. tightened. This was confirmed by a conversation with the mechanic who had pulled them the week before.
2) A leakdown test showed leaky intake and exhaust on #4 and slight leak on #6 exhaust
3) A low spot on the exhaust manifold flange that allowed sea water to intrude. Apparently the face of the exhaust elbow flange was not filed (dresssed) before using.
4) Instead of using a stainless blocking plate sandwiched between two composite gaskets between the elbow and the manifold, only a single composite gasket was used.
 
Impressive diagnostics, I appreciate the info. Never would have guessed the exhaust gasket issue would have caused this failure, but man the details always get you, so much more so than on a car. This is consistent with what I have experienced around Boston North shore. Not enough boat mechanics, the ones that are working are way over booked and they get sloppy, making all sorts of mistakes which you get to pay for and then figure out how to fix on the water.
 
Did the 'guilty' yard own up to the mistakes?? Agree to make the YC 'whole', in a finite period of time?


The guilty party was supposed to "look at" the boat three days ago and didn't make it, then two days ago and don't know if he made it today.

Re: Finite period of time.... we need that boat running by mid June the latest !!!! Fortunately, this is now in the hands of the Officers of my YC...
 
Thankyou ,Bob.
Ryan Machine is very good with reworking GM heads.
  • 80 Freneau Ave, Matawan, NJ 07747
  • Phone: (732) 566-9538
Can be available in about 3 weeks if needed for R/R
 
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