HELP--Need Advice-454 rebuild/refurbish

R

Roch Speiser

Active Member
Sep 9, 2019
196
Tuckerton NJ
Boat Info
1995 SeaRay 370 Sundancer
Engines
2
Hello all.......Unfortunately found out today that my starboard engine that failed (blown cylinder) en-route to new marina in south jersey (little egg harbor area) needs refurbished/rebuilt. 1995 370 sundancer, engine is a 7.4 carbureted ....Rebuild quote between 9-12k including hauling in and out of water/transportation to shop etc....I am NOT an engine person but my son is somewhat knowledgeable....just don't know if I am better buying refurbished or having them rebuild it. Is this a reasonable price? Again I am stupid when it comes to engines, smart otherwise...lol...thanks in advance
 
For reference I rebuilt 1 of my carburetored 454’s. The rebuild was thorough in that it included boring out, new pistons, rings, lifters, cam, crank turned and new bearings, both cam and crank. Additionally, I had the heads rebuilt including hardened seats and bronze guides.
Except for the machine work I did all the work myself including buying parts, assembling the engine and engine removal and install.
The vessel was a Pachanga 32 on a trailer.
Total out of pocket was just shy of $2500.
The rebuild was due to a failed riser gasket that allowed water intrusion into cylinders 5 and 7.
 
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Wife says her list supersedes all others so I guess I am KNOT available.
Word of caution... most likely your 454 is a 4 bolt main block and those are getting rare. If you cannot find a rebuilt 4 bolt short or long block it is best to have yours rebuilt because a 4 bolt main block is strongly recommended for marine applications.
 
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Can you describe what they mean by "blown cylinder"? How many hours are the engines and have they been maintained fairly well? How long have you owned the boat? It is very possible the engine only needs a "top end" overhaul at a third or half the quoted prices.
 
Only had boat since September. Hours are around 800. Bad cylinder I believe is how it was described. Started with loud knocking coming from valve cover and engine shut itself down when underway trying to get on plane. Waiting on a full details of findings from test today and estimate. Supposedly oil pressure was low under 20psi I believe.
 
Sounds fishy. I would seek a second opinion. 800 hours is very little on 8.1s. Oil pressure "supposedly" low. I'm skeptical.
 
Starts and runs with loud knock on top around valve cover like a rod is bent or lose from what im told. Second opinion is a no brainer. Still waiting on report and i will post for all to review
 
We have twin 454s and have 3400 hours on them. I do not see why an 800 hour engine would fail. It may be the heads I would start by having the heads taken off that way you can see the condition of the cylinders.
 
My little 2 cents here is NO ONE can tell you exactly what the issue is without a certain amount of dismantling unless they have an X-Ray machine none of us know about.
If the engine runs, and they haven't even taken the valve covers off, run, Forest, run. There are honest people out there.
I am talking from what this post has provided, not personal observation of your particular engine.
 
update: got my insurance company involved and found some startling issues....captain who brought boat from marina A to marina B found sluggish performance underway...said the sea strainer cover was loose on starboard engine and used zip ties to fasten...15 minutes later engine shut down with the loud tapping...compression test done and found failed cylinder (even that is suspect at this point that they actually did it)...in short: insurance looking to subregate for rebuilt engine....what is a fair cost for a rebuilt 454? will look to do both engines.
 
Rebuild quote between 9-12k
so what did you do? a Jasper is 4 - 6K tops. and if someone is charging you $3K - $6k to install they are ripping you off, it is a 1/2 to 1 day job tops.
 
Wanderer 290 said:
Word of caution... most likely your 454 is a 4 bolt main block and those are getting rare. If you cannot find a rebuilt 4 bolt short or long block it is best to have yours rebuilt because a 4 bolt main block is strongly recommended for marine applications.
Click to expand...
Gen VI 454s are four bolt mains and are plentiful. Mark IV four bolts are tougher to find though. Gen VI is a better motor. Roller, oiling etc.
 
could simply be a stuck valve that bent/broke a pushrod/rocker arm too
 
I had a gen 6 that I bought running, but with a loud "tick." Turns out the moron that rebuilt it for the guy forgot to put the dog bones back in which allowed the roller lifters to spin 90 degrees on the camshaft... Two pushrods pushed through rockers and it completely canoed the cam.
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