4.3l Block Crack - repair or replace? [Decided to Replace - Adventures begin]

[Struc]

Re: 4.3l Block Crack - repair options, or replace?

Re: 4.3l Block Crack - repair options, or replace?

What a shame. I tore down the old motor completely tonight. Camshaft, pistons, rods, crank, bores - all perfect. The bores barely even have a ridge on them. Rod and crank bearings look *barely* worn. Such a shame that the block cracked. This thing would have run for another 23 years without a problem. [sigh]

Oh well - it's all stripped down so I can move the new engine onto the engine stand this weekend now.

 

[Struc]

Re: 4.3l Block Crack - repair options, or replace?

Re: 4.3l Block Crack - repair options, or replace?

Was searching for information on wiring in the electric fuel pump and found a post with a wiring diagram from 2007, and thought I would repost here to keep this thread informational for future info seekers.

The wiring to the "D" post on the starter provides power to the fuel pump during cranking. The switched power through the oil pressure switch while the engine is running.

 

[joewithaboat]

Re: 4.3l Block Crack - repair options, or replace?

Re: 4.3l Block Crack - repair options, or replace?

Good work!

 

[Struc]

Re: 4.3l Block Crack - repair or replace? [Decided to Replace - Adventures begin]

Well guys, I stripped down the new engine today. Nothing too alarming, but the rebuilt motor was already bored out .060". As such, if there is any problems with the cylinders being out of round or anything, I'm going to have to go out to .080" oversize, and that concerns me a little bit. Any opinions on pushing it out that far?

On the bright side, it doesn't look like I'll need any cylinder work. They look great, although I haven't pulled the pistons out yet. Oh, and another plus is that it looks like during the rebuild they already used brass core plugs.

From what I can see, the cam in it looks OK, so I probably don't have any reason to pull it. The lifter retainers are different on this engine, compared to mine. It has a retainer along each side rather than the one in the center for both sides. The head castings are different too, but look identical to my heads from what I can see.

Heading out to clean up, and maybe pull off the oil pan before I finish. Will post some pictures up later tonight.

 

[Struc]

Re: 4.3l Block Crack - repair or replace? [Decided to Replace - Adventures begin]

Sorry for the delay - pictures as promised.

Started the day with the old engine on the stand, and the new engine on the cherry picker. Needed to swap that around.

Pulled off the clutch, flywheel, and one exhaust manifold, and got it mounted on the engine stand.

Last remnant of parts from the original boat engine:

Started pulling all the accessories off the new engine

 

[Struc]

Re: 4.3l Block Crack - repair or replace? [Decided to Replace - Adventures begin]

That leaves me with the long block

Got the ID number on the new heads

As was said earlier, this block has differnt lifter keepers

And one head off

And, the keynote of the teardown. Finding out the block was already bored .060"

 

[Struc]

Re: 4.3l Block Crack - repair or replace? [Decided to Replace - Adventures begin]

Not 100% sure what all these mean, but I'm guessing it was the original serial number of the engine.

The tag that was added after the rebuild

Parts ready to be sold or reused.

I did manage to get the oil pan pulled before the end of the day, but didn't take any more pictures. Not much to see - things look pretty good. I didn't do anything on Sunday but watch the Packers continue their phenominal season, and clean up some of the parts so I can get my car back in the garage.

I have some bore gauges ordered so I can check the cylinders for any taper, out of round, etc. If all that checks out I'll have to decide to either leave this thing the way it is, and just rebuild with new gaskets, or take it to the machine shop for a good cleaning, hone, and eventually, new bearings and re-ring job. Not sure which way I'm leaning at this point.

 

[joewithaboat]

Re: 4.3l Block Crack - repair or replace? [Decided to Replace - Adventures begin]

So.... was that running when you bought it? I guess you can sell all of the accessories including that centerforce dual friction clutch and pressure plate to get your money back.
Make sure and keep your rod caps with their original rods...

 

[Struc]

Re: 4.3l Block Crack - repair or replace? [Decided to Replace - Adventures begin]

So.... was that running when you bought it? I guess you can sell all of the accessories including that centerforce dual friction clutch and pressure plate to get your money back. Make sure and keep your rod caps with their original rods...

Yes, it was running, and running pretty well. And yes, I plan on selling off a bunch of the parts. Since the flywheel is the same as a 305/350, that Centerforce should go pretty quick. I recognized it right away too, since I have one in both my Mitsubishi cars.. I have to think the intake manifold / TBI unit are worth quite a bit to somebody too.

And yes, all the rod caps were marked, so they are all mated back up. I haven't pulled the rods/pistons out of this thing yet. Going to wait to measure the cylinders and decide if I want to re-ring and re-bearing or not.

 

[Bondo]

Re: 4.3l Block Crack - repair or replace? [Decided to Replace - Adventures begin]

Since the flywheel is the same as a 305/350, that Centerforce should go pretty quick.

Ayuh,... If I'm not mistaken, the 4.3l flywheel is balanced differently than the 305/ 350 flywheels...

 

[Struc]

Re: 4.3l Block Crack - repair or replace? [Decided to Replace - Adventures begin]

Ayuh,... If I'm not mistaken, the 4.3l flywheel is balanced differently than the 305/ 350 flywheels...

Ah, no doubt true. I should have said they were the same size, not necessarily the same. The clutch will bolt to either, however.

 

[vincechig1975]

Re: 4.3l Block Crack - repair or replace? [Decided to Replace - Adventures begin]

I am curious ... aren't these vortech engines reverse rotation, and the one that was in it standard rotation? what was the year of change?

 

[Scott Danforth]

Re: 4.3l Block Crack - repair or replace? [Decided to Replace - Adventures begin]

Ayuh,... If I'm not mistaken, the 4.3l flywheel is balanced differently than the 305/ 350 flywheels...

agreed the balance is different, however the clutch assembly is the same.

 

[Struc]

Re: 4.3l Block Crack - repair or replace? [Decided to Replace - Adventures begin]

I am curious ... aren't these vortech engines reverse rotation, and the one that was in it standard rotation? what was the year of change?

As far as I know, all the 4.3's (Vortec or not) were standard rotation. If there were any reverse rotation engines, I'm sure they were marine application specific.

 

[netting one]

Re: 4.3l Block Crack - repair or replace? [Decided to Replace - Adventures begin]

nice thread, i followed this all the way. going through the same thing. thanks for all the help so far.

 

[ssb33r]

Re: 4.3l Block Crack - repair or replace? [Decided to Replace - Adventures begin]

I am curious ... aren't these vortech engines reverse rotation, and the one that was in it standard rotation? what was the year of change?

Auto engines are clockwise rotation and marine is counter clockwise, difference is in the auto world rotation is seen from the water pump side and the marine world rotation is seen from the flywheel side

 

[tpenfield]

Re: 4.3l Block Crack - repair or replace? [Decided to Replace - Adventures begin]

Auto engines are clockwise rotation and marine is counter clockwise, difference is in the auto world rotation is seen from the water pump side and the marine world rotation is seen from the flywheel side

Wouldn't that make them the same rotation?

BTW - to the OP, I am enjoying this thread and watching the progress.

 

[Scott Danforth]

Re: 4.3l Block Crack - repair or replace? [Decided to Replace - Adventures begin]

Auto engines are clockwise rotation and marine is counter clockwise, difference is in the auto world rotation is seen from the water pump side and the marine world rotation is seen from the flywheel side

Marine engines and industrial engines come from the same stock as truck engines. reverse rotation engines have gone by the wayside years ago.

 

[Struc]

Re: 4.3l Block Crack - repair or replace? [Decided to Replace - Adventures begin]

Wouldn't that make them the same rotation?

Pretty sure that was the point he was trying to make.

BTW - to the OP, I am enjoying this thread and watching the progress.

Thanks! I guess I should really update the thread, although there isn't too much progress on the engine itself right now.

I had a quandry of faith in the engine I picked up, so I started another thread about it. You can read about it here: http://forums.iboats.com/showthread.php?t=523399

In the end, I decided to run this engine I picked up as-is. It's already bored .060", so it's not going any farther, and it was running well, so I'm planning on running it for a season at least. I cleaned it up with some engine degreaser and a small wire brush for the thick stuff. I threw a couple coats of paint on it as well. Went to work with a wire wheel to the head mating surface and pistons to clean everything up there.

Next step is to take in a set of my 4.3l heads (I have 3 sets currently), and have them worked over, cleaned up, valve stem seals replaced, and then start throwing the engine back together.

I'll keep the thread updated as I start doing the engine work.

I also picked up a 1997 4.3l Vortec engine out of a Astro Van for $200. This will be the long term rebuild project engine that I'll play with in my free time.

 

[300sflyer]

Re: 4.3l Block Crack - repair or replace? [Decided to Replace - Adventures begin]

Good job! Here are a couple of pictures showing my "spare" truck engines, just in case I happen to run accross a inexpensive boat with a cracked block. There are usually quite a few of them in the spring up here in Canada EH!