What do you see with my tore down motor?

[toolman4]

I finally got my motor home from tear down. I was wondering if you guys see anything different? He said it was a bad rod bearing and said the crank and cam were shot. He also said the motor looked tired and it is a 98. My boat is a 99 4.3l merc. The only pieces of metal in the pan were thin tin like pieces like you see squished out in the first picture. It is an automotive motor, don't know if truck or car. Should I label anything tearing it down further? I don't see any scuffing on the cylinders or pistons. What else do you see?

 

[Howard Sterndrive]

Re: What do you see with my tore down motor?

first pic = spun bearing - crank is likely toast
everything should be already labeled from the factory, but verify scribe marks and stampings as you disassemble to make sure the last guy matched everything
last pic has a block drain... looks like a boat engine from that, not car

 

[Bt Doctur]

Re: What do you see with my tore down motor?

Need some history on why you pulled it, funny noises, operator malfunction, etc.
low oil, no oil wiped the bearings. cranks can be repaired to stock or reground -.010- .010 on the mains and rods.

 

[zbnutcase]

Re: What do you see with my tore down motor?

first pic = spun bearing - crank is likely toast
everything should be already labeled from the factory, but verify scribe marks and stampings as you disassemble to make sure the last guy matched everything
last pic has a block drain... looks like a boat engine from that, not car

Block drains are EASILY added. The brownish residue on the pistons SCREAM used car motor, and the spun rod bearing is the reason you rebuild a used car motor if it has more than 20K on it BEFORE you put it in a boat!!!!

 

[toolman4]

Re: What do you see with my tore down motor?

It was making a bad knock sound and that's why it was pulled. I bought the boat last full and of course he told me it was the original low mileage motor and that he hadn't had to do anything to it. It has a block heater in one of the cast plugs which I missed when looking at the boat. Where can I find a serial # to check if it is from a car or truck and what site do you go to? What else will tell me this motor is high mileage?

 

[RogersJetboat454]

Re: What do you see with my tore down motor?

I don't know if the 4.3's have it, but their big brother small blocks usually have a suffix code stamped on the deck of the even cylinder bank. It would be a flat spot on the front of the block right in front of the head. There are several on-line sources to decode the suffix code if you can find one (assuming the 4.3 is like the small block, and the block hasn't already been decked). The suffix code will reveal what GM factory built the engine, and what the engine may have been installed in if not a boat. Unfortunately I have seen several 4.3's that suffered this fate. We had an Astro van in our shop that we went through 3 bone yard motors to finally get one that didn't have a rod knock (the van had 200K on it, and the customer didn't want to buy a new or reman engine).

 

[RogersJetboat454]

Re: What do you see with my tore down motor?

Actually.... one more question. Was this engine injected? If it wasn't the crank sensor hanging out of the bottom of the timing cover is a dead give-away it was out of a truck.

 

[toolman4]

Re: What do you see with my tore down motor?

Thanks for the replies. Nice catch rogers. It is carberated. That makes me feel a little better because a close enough cam was in there right? How much damage does a spun bearing usually do to other components besides the bearings?

 

[Bifflefan]

Re: What do you see with my tore down motor?

Thanks for the replies. Nice catch rogers. It is carberated. That makes me feel a little better because a close enough cam was in there right? How much damage does a spun bearing usually do to other components besides the bearings?

Minumum, replace or grind the crank, replace or resize that rod. Goes up from there.

 

[toolman4]

Re: What do you see with my tore down motor?

If I look at at a reman motor then do I get a 98 since this motor is a 98 or do I get a 99 which my boat is. It has v tec heads but I dont know if there is a big difference between a 98 long block and a 99 long block? If there isn't too much other damage to my block will my other parts be heavy enough for marine application?

 

[Bt Doctur]

Re: What do you see with my tore down motor?

If your close to NJ, I need block

 

[Faztbullet]

Re: What do you see with my tore down motor?

Try here as I have installed several for customers and they really look good...
http://www.cmengines.com/se/marine.aspx

 

[RogersJetboat454]

Re: What do you see with my tore down motor?

Shouldn't be much of a difference between a 98 & 99. I am assuming that Merc probably used the same casting # heads through those years. The truck cam in the engine you pulled may have been close enough, but at this point if you plan on reusing the block I would swap it out for the appropriate merccruiser unit. It would be piece of mind anyway. At this point, with machine work being needed on the lower end, and the rest of the engine having questionable mileage and parts, it would probably be the same price or cheaper to get a reman long block, then to spend time at a machine shop, and hunting down parts. Plus you will have a warranty with the remaned engine.

 

[toolman4]

Re: What do you see with my tore down motor?

I appreciate all the help. I will finish tear down this week and see what I have. I agree, it is probably going to be chaeaper and less hassel to go with a long block. I am in Minnesota so I'm a little way from NJ. If I have good parts I wood like to part it out to offset the long block. Is there a way to tell how much wear is on the pistons or cylinders for an indication of miles??

 

[Bt Doctur]

Re: What do you see with my tore down motor?

not really, have 300,000 on my truck and it is still perfect. measure the pistons and measure the cylinder bores. .020 or better and it`s seen some miles

 

[toolman4]

Re: What do you see with my tore down motor?

The .02 or better are you talking the gap between the piston and cylinder? If I replace with my motor with a long block are there any there parts that should be replaced like manifolds or flappers? My vortec heads should be replaced at the same time?

 

[RogersJetboat454]

Re: What do you see with my tore down motor?

.02 is in reference to how much the cylinder has enlarged due to high usage. A 4.3L or 5.7L engine start off life with a 3.99" bore (most people round it up to 4.00"). If you honestly intend on re-using this engine, a machine shop can measure the bores to determine if standard sized pistons can be installed after the cylinders are re-honed, or if an overbore is needed. You can usually get a visual for the condition of the cylinders by checking 2 things. Are there still crosshatches in the cylinder walls from the factory honing? Is there a ridge of metal at the top of the cylinders? In any case, if you really intend on reusing this engine, it will need a trip down to the machine shop for a professional check over. Here are the prices from my favorite machine shop. Your prices may be a little less since you have a V6.
Oven Clean, Shot Blast & Mag Block
$100

Bore & Hone Block with Torque Plate
$325

Deck V-8 Block
$150

Align Hone Main Line
$150

Resize V-8 rods (per 8)
$150

Install pistons on rods v-8 (8)
$50

Crank Work:

Grind V-8 Crank
$225

Balance V-8 Full Assembly
$350

That's a total of 1500 bucks for just the lower end work, even if you were to shave $500 off because its a V6, or you find a cheaper machine shop, that's still allot of money! That doesn't even cover the price of pistons, rings, bearings, oil pump, camshaft, lifters, timing set, core plugs, harmonic balancer, water pump, hardware, gaskets, etc.
Next after you have all that lower end work done, do you really want to bolt a set of worn heads with questionable mileage on the engine? Here is a ball park on head work cost;

Oven Clean, Shot Blast & Mag Heads
$40 Each

V-8 Three angle Valve Job, blend bowls
$225

Deck Head up to .010" cut
$75 each

Install New Guides V-8 Heads (16 guides)
$120

Assemble v-8 heads and set up spring heights
$80
That comes out to $655, again V8 prices, so say you take 150-200 bucks off. Your looking at 450-500 in head work, not including parts.
I don't know what you have seen for prices on a long block, but considering you may be dropping well into 2K if not 3K for parts and machine work to put this engine back together right with no warranty in the end, a long block with a warranty would be the way to go!


As for the manifolds, flappers, hoses, etc. If they are in rough shape, or questionable then replace them as necessary. A long block comes with heads. If you were getting a short block, that would mean it was a lower end with out heads.

 

[Kainon]

Re: What do you see with my tore down motor?

I'd go with a reman long block, sell the block and heads off to someone, but tell them it had a bad rod bearing because some of the material that was there, is also now in the rest of the oil system somewhere. Cam bearings, lifter oil galleys. I wouldn't use that block without a thorough cleaning, and I'd doubt it that crank will clean up to 10/10.

 

[toolman4]

Re: What do you see with my tore down motor?

Good info guys. Thanks for the breakdown rogers! I was curious what all the processes would cost which is good to know. I have been looking at the long blocks. I hate throwing stuff out, but I hate even more having to do things over. I am looking at rapido marine, michigan motorz, and a local shop. Seems like customer service and satisfaction is good with those companies. Do manifolds warp, I was reading a post that said replace them if you change engines? I should be able to put a straight edge agross them to see if they are still square for the gaskets right? Just curious, what's my block and other parts worth if there is minimal damage?

 

[RogersJetboat454]

Re: What do you see with my tore down motor?

I suppose its good common practice to replace the manifolds with a new engine. Reusing the old ones all come down to the condition they are in. Do you really know the history on the manifolds? Given the fact that the boats previous owner was willing to do a Busch league engine replacement, its plainly obvious that expenses were spared. It comes down to your call. You are the one who can physically look at the manifolds. If your not confident that you can detect any issues with them, maybe have a marine tech, or machinist take a look at them. Then again they will probably want their palms greased for their time (rightfully so), which is money you could be investing towards new manifolds. Again, its really your call. I would also check into what the warranty requires that comes with the crate motor you choose. There may be a requirement to use new intake and exhaust manifolds to keep the warranty.

As far as you blocks value, they are honestly a dime a dozen. The crank is most likely junk. The block and heads will need to be cleaned and checked to determine if they even still usable. I don't know if you ever ran it in salt, but if you did, the value on it is really no more than the price of scrap iron. You also may find that the company you buy your crate engine from will want the old engine back as a core anyway. So hang on to it until you know.