[hyper1]

Ok, I posted this picture a weeks ago and someone told me they have never seen a marine engine with valve covers like this. I have the numbers off of the block. They are as follows:

10114182

Can anyone tell me what this is? It has a mercury marine plate glued to the side of the block and it has a knock sensor on the side. I dont under stand how a knock sensor works on a carb boat? No ecm??

any help would be a big help. I just want to make sure this is a marine engine!

thanks

 

[ProbableCause]

The knock sensor is linked to the ignition module which retards the timing when it senses a knock. My 96 454 carb. has one too. It looks like someone put some custon valve covers on. They appear to have been painted

 

[obnoxus]

PC is right,, all a knock sensor is, is a piezo electric generator. It actually creates its own electric pulse so it doesnt need power from an ecu to work.

 

[BajaIceBreaker]

I don't know what year that is, but my 454 Mags in my 88 baja are
C326319
C326327
I don't recall ever seeing a letter in a serial number of an automotive engine, but don't take that as the rule.

Besides, if someone was trying to disguise an automotive engine as a marine engine, they would probably use the marine valve covers. They probably changed the valve covers because they didn't like the painted covers from Mercury.
Are they aluminum?

 

[hyper1]

They mercury marine plat looks to have been ribbited to a engine at one time, But now it is glue to the side of the block.

I hope it is a marine engine. It has MSD and K&N breaters on it.

 

[BajaIceBreaker]

By what you have said so far, I would say no... it's not the original motor. I would bet that if you ask some others, there will always be at least one letter in the serial number. But I could be wrong.

Joe

 

[BajaIceBreaker]

Here's the serial numbers on a 90 Aronow w/ 500's
1203010B
1003010B

Notice the letter in the Serial Number

 

[hyper1]

I wonder what it is then, I know it is a heavy boat and it will run 72@4700 rpm on GPS. that is not bad for a single engine 25.5 foot boat that is 8'6 beam.

The engine is so strong it planes out with very little effort. And the mid accel will plant you in the seat.

It also has a lope to it at idle and around 1600 rpm's sound like a race car.

Carb is polished on the inside, but is a AFB without a choke, It had a volisty stack on it.

There is a small 1 1/2 inch plate under the carb but it all has thick black paint on it.

the valve covers are metal but look to be a factory power coated .

Boat was used to run drugs in Fla.

Was taken by the DEA and resold.

it is for sale for 14,500, I paided 17,000 for it in December of 2003.

lot of history, and very nice!!

 

[f311]

454 mags, 89 Formula 311

OC607347, OC533582

This info right from my survey, can't confirm - boat not here.
(surveyor screwed up on the HP and saved me some $ on insurance, he listed as 340hp each and kept it under some magic number with insurance companies, probably 700hp combined. first year I paid $1800 using 365hp, last year paid $818 going by survey numbers)

 

[BajaIceBreaker]

If it's not a marine engine, but it sounds built, then it probably has forged pistons and rods, but the big concern would be the crank. Although a good CAR engine builder would use a forged steel crank, a marine engine uses a billet steel crank. Much stronger. You might want to consult a professional boat motor builder on that one. I may not be totally correct about this. And a forged steel crank may be strong enough to withstand the abuse of boating.

 

[OldMagicfloat]

Check out Mortec inc. web page

I looked for your engine # and it said it was a 1991 & up 454, 4 bolt main, Gen V

Whenever we have to change out a block, we silicone the Mercruiser engine plate back on the new block, just for future parts reference.

 

[hyper1]

Ok cool because the plate is silicone to the engine block.
the whole engine has thick black paint on it all over.

I beleive this is a marine engine as it was 6months old when the dea took it.

It was in a chase and loss the engine in fla, the owner paid 41,000 for the boat. It was listed as a Cheetah and is built by sea sprite as they bought the molds after Cheetah when out of business.

It has ship to shore radios and is us coast guard registered. The person I got it from from said the whole boat has under 300 hours on it.

how long does a 454 last in hours? it runs like new and is really a fast boat.

65 gallon tank.

 

[OldMagicfloat]

You are probably never going to know exactly what you have unless you pull the engine and tear it down. I would be more concerned about if it had the marine starter, carb, etc. You say the carb is an AFB, is it the Mercruiser Carter with the extended float bowl vents? If the engine blew before they probably used the original stuff that came with it new, but who knows? You say it has an idle lope so it sounds as though it has been hopped up a bit and that's always cool. I would also be concerned with what grade of gas you need to run. If it has higher compression and you are filling it up with 87 that may not be a good thing. We can probably assume that your engine is much hotter than stock because of the speed you are getting out of it. It's too bad you can't find out who built the engine in between the DEA and the guy you got it from. It has been a long time since I have played with BBC's in a boat but I seem to remember that 1000 hours or so seems to be the bench mark of getting tired in a STOCK application. It's probably like everything else, depends on build, maitenance, etc. I know some kids on this lake that can take daddy's boat and screw it up faster than you can believe!