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Time for a rebuild...

Croz

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I’ve got a ‘92 454 mag in my 210 that’s carbureted with about 900ish hours on it, I want to rebuild it before it goes boom because it’s slow and not snappy to fire up, pings in a higher RPM, and is just all around tired. So I would love some input please..


Was thinking of adding a Holly Sniper EFI system to replace the carburetor so my starter doesn’t get put through hell every trip, does anyone have experience with this product yet?

Also what would it cost(ballpark) to have it rebuilt at a shop? I’m hoping to add some horsepower but not trying to break the bank.

Anyone have a rebuilt or new motor for sale? Thanks in advance
 

Bigbore500r

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I’ve got a ‘92 454 mag in my 210 that’s carbureted with about 900ish hours on it, I want to rebuild it before it goes boom because it’s slow and not snappy to fire up, pings in a higher RPM, and is just all around tired. So I would love some input please..


Was thinking of adding a Holly Sniper EFI system to replace the carburetor so my starter doesn’t get put through hell every trip, does anyone have experience with this product yet?

Also what would it cost(ballpark) to have it rebuilt at a shop? I’m hoping to add some horsepower but not trying to break the bank.

Anyone have a rebuilt or new motor for sale? Thanks in advance

Running a sniper EFI setup would be simple, except for the 02 sensor placement. You will need to have a 02 sensor location in your exhaust stream that stays dry. That might require a different exhaust manifold setup, or possibly yours can be modified by somebody who knows how to set it up properly to keep the 02 sensor happy. You will need an electric fuel pump and regulator to run the required fuel pressure, and to route a return line back to your tank(s)

A stock rebuild for a 454 in decent shape can be done for $2000 and up, assuming your crank, rods and block can be re-used. The sky is the limit once you get in there.... Forged pistons, better heads......etc are all gonna crank that budget up exponentially.
 

D19

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I wouldn't do the EFI. Too much money and hassle for not enough reward. Put an electric pump on it if you want better fuel pressure when cranking. You'll need an electric pump if you go EFI anyways, might as well start there.

The pinging could have something to do with the ignition system or bad fuel.

Like BB500 said, you'll need to run returns for an electric pump. Your tanks might need to come out if so to weld in the ports. You also want to return fuel to the same tank you're currently drawling from. You'll need a electric valve or two manual ball valves dedicated to each tank.
 

mesquito_creek

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I just have to ask.... Is it really "tired" or you have just changed your impressions of how it runs. Slow start and some high rpm detonation is not nessesarily anything to do with the rotating assembly. Also is 900 hours on that motor about 1/2 way done and not finished? I am all about building it for more HP, but unless your wife reads the forums and you want your story to be consistent is it really a rebuild problem?
 

Bigbore500r

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I just have to ask.... Is it really "tired" or you have just changed your impressions of how it runs. Slow start and some high rpm detonation is not nessesarily anything to do with the rotating assembly. Also is 900 hours on that motor about 1/2 way done and not finished? I am all about building it for more HP, but unless your wife reads the forums and you want your story to be consistent is it really a rebuild problem?
I've heard the old carbed Merc 454's practically run forever with care. They don't rev high, or run big spring pressure. I'd do a compression and lead down test, and if it's good have the distributor timing and curve checked, fresh plugs with correct gap, new wires, and get that carb running proper
 

Cole Trickle

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Keep it simple shit snowballs really fast....Bigger engine and more hp and you are now going external steering,extra cooling , drive issues,etc....

Barry would be a good place to go for a rebuild if you can pull and reinstall the motor. After that perhaps a trip to see Alexi at boostpower for a prop dyno/Tuning session.

Go through everything make it fresh perhaps a new cam and some head work , dial it in and go enjoy.
 

D19

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I've heard the old carbed Merc 454's practically run forever with care. They don't rev high, or run big spring pressure. I'd do a compression and lead down test, and if it's good have the distributor timing and curve checked, fresh plugs with correct gap, new wires, and get that carb running proper

Yes. All of this should be step one unless he just wants to rebuild an engine merely for the sake of rebuilding it. Rebuilding should be the last resort lol
 

HST4ME

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The sniper kit is nice since they offer a Rochester kit. The 02 sensor isn't terrible to do. Start with exhaust for parts . it's not difficult to make 450 hp with stock cruiser hard parts and a cam with exhaust upgrade.
 

OLDRAAT

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One of my boats has an '88 gen 4 big oval port with 1362 hrs. Never been busted open, just sensible maintenance and a few replacement parts.
Runs within 2 to 3 mph as it did 32 years ago :)
 

Shrub Lurker

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How fresh is that carburetor. I have had great luck with Edelbrocks marine units. At 900 hours and that age, I’d throw $500 at a new unit from summit or other internet source (there are small model 1409, and big block model 1410 units offered). They require minimal adjustment once installed and this time of year you can find deals.
 

Shlbyntro

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How fresh is that carburetor. I have had great luck with Edelbrocks marine units. At 900 hours and that age, I’d throw $500 at a new unit from summit or other internet source (there are small model 1409, and big block model 1410 units offered). They require minimal adjustment once installed and this time of year you can find deals.

Keep the original carb on it and rebuild it. It drives me crazy when people nonchalantly just throw another carb on it. That factory carb is jetted and setup for your engine.
 

Trash

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EFI is a significant improvement. Biggest downside is the initial cost. But...once you have the EFI system it can be used on virtually any motor should your tastes change down the line.
 

Riverbottom

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Did anyone mention Barry. I would give him a call, all around good guy.
 

Riverryder

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Run it till it blows. Buy another motor in mean time and build it. That’s what I’m gonna do! I have a 454 in mine with some work. But I am gonna do a efi motor next
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obnoxious001

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Barry @ Obnoxious recommendation X5

Thanks Jason and all others who mentioned me. My first thoughts are that a properly tuned engine will fire up easily with a carburetor, so as mentioned above it would make sense to test and see if the engine is truly worn enough to justify pulling for a rebuild.
 
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