I've read plenty here that rebuilt 7.3's with sleeves are crap. Fortunately mine is still running strong at 225,000 miles. However, I'm a planner and want to be prepared when the time comes to replace my engine. I don't have the knowledge, tools, or time to rebuild myself. Therefore is there an engine source for bomb proof long blocks? I don't take short cuts and don't mind paying for quality. It's generally cheaper doing something correct once than two or three times.

basfire

 

Look for a 6.9.

The problem with 7.3 engines is cylinder wall thickness.
The cylinder wall is thin enough that cavitation is a very real issue on the stock engine block.

So when it comes time to rebuild the engine, boring the block only makes a bad problem even worse if in fact they don't cut into a cavitation pocket when the bore the block.

So the remedy was over bore the block, then sleeve it back down to the original bore.

That is exactly hat the do in big diesels, the press the cyinder sleeve out and replace it with a new cylinder sleeve, these are called wet sleeve engines.

Where the problem arises though, the block was not designed to sleeve like the big ones, the 7.3 sleeves are dry sleeves, basically glued and pressed into the overbored block.

But under heat of the engine running, the glue gets soft, the fire ring on the head gaskets rests on the end of the sleeve and it slides down in the block.
Then the engine cools, bang.



Between the black lines you can see the 6500 dollar crack on an engine that has 2700 miles on a reman complete drop in 7.3 turbo.
Replaced under warranty, but the next one looked the same at 9700 miles.
Replaced under warranty again, looked the same after 17,000 miles again.

In case you are not counting, that is three 7.3 turbo reman engines in under 30,000 miles.

They sent me a fourth engine, but my warranty was about out, so I tore it down before I unbolted it from the shipping pallet.
The sleeves were already dropped below the deck on an engine that had never been started and I refused to install the engine.

I got a buyout on the engine, but that took about 2 months.

So I bought a 6.9 salvage yard engine, built it myself and have never been happier.

 

Who was the rebuilder on your 7.3's? Just curious.

Jason

 

Reviva is the new name, was Dealer Diesel.

Still makes no difference, the way the sleeves go in is the problem.
Glued in is the second part of the problem.

A sleeved engine is a ticking time bomb.

None of the local rebuilders will touch a 7.3 because of sleeve problems.
Just to much money for someone to eat, even if it is only a problem on 1 out of 10 blocks.
Since I was running 4 for 4, I think most rebuilders just hope the warranty runs out before their luck does and the sleeves move.

My position is the 7.3 is a fine engine right up till it needs overhauled.
The 6.9 does not have that problem.
You can go 20, 30 or 40 over and still have thicker cylinder walls than a stock 7.3 does.

At the final rebuild, take the 6.9 110 over and run 7.3 pistons.

 

Is there a source for a new 'crate' engine?

 

Years ago, I worked for a company that was contracted to work on UHaul equipment. We replaced several 7.3's in that time using our own engine supplier, without a failure. I know that most of them were sleeved blocks.

UHaul decided that our supplier was too expensive and they started supplying us with engines from one of their national accounts. After that, we had the same issues as you were experiencing. It was determined that the bores were being cut improperly and the sleeve installation was very sloppy and were not being checked. They were not from Dealers Diesel though. Are DD's engines built by Ford or a 3rd party contractor?

I've found that a lot of mass rebuilders tend to specialize in certain brands. We had different engine suppliers for GM, Ford,Dodge and even another couple for import engines. Find a builder that was great with a GM 350 or 455 but they couldn't get a 351W right to save their life.

Jason

 

I've heard some more recent developments of new sleeves that are interferance fit with a tapered shoulder to prevent them from falling down in the bore.

The glue in method sounds pretty scary no matter how its done though. I also heard of the idea of doing a minimum bore on a 7.3L block, then installing a sleeve to turn it into a 6.9 displacement. If there was surface area on the whole height of the sleeve then it would hold much better than just boring out the sleeve completely.

I'm still holding out hope that sleeves can be done right because it means keeping IDIs running for that much longer.

Engines that have sleeve pressed into a full height bore are actually very common. Any aluminum block has that but some cast iron blocks do too.

 

I was wondering myself, why someone hasn't come up with a sleeve that has a shoulder on top. It would require a little more machining, and you probably need to make sure the deck has enough meat to counterbore on top for the shoulder to sit. I wonder if the cracking between the cylinders was caused by too much of a interference fit between the sleeve and the block, possibly caused by wanting to make sure the sleeve didn't slide down.

The more I think about it, the clearer it becomes why they haven't improved the rebuilds on this engine. I am going to assume they do not make this engine anymore, and most equipment or school buses that used them are long off the road, and trying to keep a few Ford truck nuts happy is not worth the hassle.

Am I right? They did quit making this engine correct?

 

As far as I know they are not being made anymore but there are off shore jobbers that are making some castings now. I know that there are chinese sources for new chevy 6.2L engine blocks. I think they are made with the same tooling and everything. From what I understand, GM doesn't even own the engine anymore so anyone that wants to can make and market parts for them.

I also heard that 6.9/7.3 IDI head castings are being made offshore, so maybe there will be blocks as well in the future.

Yeah, I know, the chinese make nothing but junk and bla bla bla..... but you might be supprised how much quality has improved over the years with SOME products.

Lets put it this way, I'm going to be very nice to my engine.....

 

Has anyone run into these engines in something other than a pickup and a e series van? I have seen in this forum they were in u-hauls. I believe I have heard they were in international school buses, and possibly some international straight trucks.

You know unless there is a big demand, someone is not going to the trouble to make parts, especially the Chinese. I am surprised there is enough demand for the 6.2 engine to remake it. Was that a Isuzu engine?

 

I believe the 6.2 was a GM/detroit joint venture. The engine is cheaper and easier to build than anything that the EPA demands in our part of the world these days, so rest assured there is a market for them in developing countries.

The IH IDI diesels were also used in some larger 5 ton HD trucks, school busses, and maybe some other commercial vehicles, but the vast majority would be found in ford pickups.

 

You can find them in step vans made by several companies, things like bread trucks, International had them in many trucks, Ford was probably the biggest user with F and E series.

Do be aware, the International versions were a little different on the externals bu the block was the same thing.
Also the International versions did not have fuel settings as high as Ford did, and International never did turbo an IDI engine.

Dealers Diesel was a Ford authorized rebuilder, but they lost that long before the name change to Reviva.

A shoulder on the top that limited how far down the sleeve could go would be a help.
So would a shoulder on the bottom.
What I see as still being a problem with going that way is a looser fit in the cylinder area would stop the block cracking, but it would also hamper heat transfer to the coolant.

From what I have seen, the system that is in use right now leaves a lot to be desired.
After my experience with them, I would not give you 100 dollars for a complete reman 7.3 with sleeves in every cylinder.
Changing engines is something I got way to good at thanks to Reviva.

 

I have 4 6.9 blocks and a cavitated 7.3 with rotating assembly. why not bore out the 6.9 blocks and install the 7.3 rotating assembly

 

You could do that, but be aware most 6.9's never had SCA's run in them.
So when you bore it out to a 7.3 bore, you could bore into a cavitation pocket which means the block is trash.

When I had my 6.9 done, I specified the absolute minimum bore that would give me clean fresh cylinder walls.
30 over is what I wound up with.

And on the plus side, the cylinder walls are still thicker than a stock 7.3 had.

 

a couple of years ago up here in canada my local dealer had a listing for "new" long blocks for 5000 bucks... went to ask again about 6 months ago and they said they didn't have them any more, only a listing for a ford reman... might try the local dealer and see if they can find ya one... but be prepared to pay if they can... I'm going the ctd rout...