7.3 rebuild questions

[Brimmstone]

Ok here are the issues as they lay right now. Customer bought 94 F350 IDIT truck with knocking noise. Cracked injector lines and noise is still there but gets real loud with injectors tightened down. Compression was also low on those cylinders when doing a test. Here is issue. Customer found an engine on eBay for 1000 dollars. After being assured engine had not been bored or sleeved and had been sonic-tested engine was purchased. Engine is sitting in my garage currently in limbo because when pulling the heads to make sure correct valve seals had been used and to upgrade to studs it was discovered engine had been bored .030 over. I'm not real fond of 7.3s to begin with due to their thin cylinder walls and in my personal opinion an overbore on a 7.3 basically makes it a boat anchor. What is everyone else's opinion on this issue? I've got a call into a guy I know who does diesel engine machine work everyday but haven't heard back from him yet. Will be calling the shop I used to have do all my work in Ohio tomorrow morning when he opens up and check with him.

 

[OLDBULL8]

First thing I would do is put a complaint into Ebay that the engine is NOT as advertised and was lied to by the seller. Hope he did all his communication thru Ebay messaging. That engine should be guaranteed/warranted thru Ebay. He has nothing but a boat anchor as you say. Bored .030 OS, it won't be long for cavitation. Inspect the bores real close, those knocking cylinders, low compression, I'll bet they have pin holes in them already. I would say the only way to save that engine is to sleeve it since it almost bored to sleeve diameter, then a set of standard pistons for $800 plus sleeves and boring for another $1000 +.

 

[Brimmstone]

To clear some things up they are two different engines the one in the truck is still in it and knocking. The new one is sitting in my garage with the heads off of it. It was rebuilt by supposedly the number one rebuilder in NY. I just real leery about this engine especially on the fact it was bored. I don't see any sleeves which is a good thing but still.

 

[OLDBULL8]

To clear some things up they are two different engines the one in the truck is still in it and knocking.

You had better pull those injectors you said were loose, the copper washers won't seal anymore if injectors are tightened down again. See if they are wet on the end, that means a leaking injector, which will cause knocking at idle, sometimes disappear when speeded up. A badly retarded IP will also cause knocking and a lot of blue/white smoke. Just timed one today with similar problems and it was retarded 10-12 degrees, reset it at 8.5-9 degrees BTDC and runs just fine and no smoke.

 

[Brimmstone]

This isn't a knock from a leaking injector. This is deeper into the engine. As to loosening the injectors where I loosened them is the lines. I can hear a metal ringing sound in the engine when I use my stethoscope to listen to while it's running.

 

[racer30]

I agree with OLDBULL8 a 30 over 7.3 is not a engine that will last long due to the thin cylinder walls flexing with every power pulse of the engine. It will cavitate verry soon. I am having my turbo block sleeved in all 8 holes with top quality parts just for the fact that I will be running more power than stock and want the block to have less chance of problems. I would also check with ebay on the warranty or refund

 

[plowboy444]

^^If you don't mind me asking, how much is it costing you to sleeve all 8?

 

[OLDBULL8]

^^If you don't mind me asking, how much is it costing you to sleeve all 8?

What did I say?

 

[idiabuse]

I sonic tested my 7.3 it is .020 over thinnest spot around .170 thickest are about .300
When sleeved all 8 holes you may rid yourself of cavitated block, but sleeves will dance and move around.
Either way it is a big risk we throw cash at...


Javier

 

[racer30]

My machinest says he only uses top lip style sleeves and cryo treats the sleeves when installed for a realy tight fit then just kisses the deck, tork plate bores the cylinders, to size and line bores the mains, cleans the block and all the oil gallerys, installs the correct freeze plugs and cam bearings all for 1400.00 I am still saving up for this, He wants 700.00 to start the job, and I dont want the block to sit around to long after the work is done because it will start to rust in all those places you cant see or treat with oil.

 

[plowboy444]

Whats the name of that shop? I see your in my general area....

 

[icanfixall]

A properly installed sleeve will not "dance around" in the cylinders. Now finding someone that can install them correctly is going to be tuff. My next engine build will be with the flanged sleeves. They are much more dificult to install because of the need for the flange to be seated at the top of the block but... A good machine shop can do it easily. Most sleeves are nothing more than a thick tube of cast iron that sets in the overbored block. They need to be frozen in liquid nitrogen and then dropped into the block. Then help in place with threaded stock and cross bars till they normalize to the block. A 2 thousands press fit is about the norm. That means the sleeve is that much larger than the hole bored in the block. When the sleeve is frozen it will shrink enought to just drop in without any force. Some shops put these sleeves in a refirgerater freezer and then super glue them in the block... Not the correct way at all. Super glue acts as a non heat transfer agent. Our engines hve three choices for sleeve hardness from L.A. Sleeve. Soft, medium or hard. Remember we have a hard high nickle block material so don't use the soft sleeve. The rings will seat much faster in a soft sleeve but the sleeve wears faster too. A hard sleeve will outlast the rins and it takes a long time for the rings to seat...

 

[jonathan]

A properly installed sleeve will not "dance around" in the cylinders. Now finding someone that can install them correctly is going to be tuff. My next engine build will be with the flanged sleeves. They are much more dificult to install because of the need for the flange to be seated at the top of the block but... A good machine shop can do it easily. Most sleeves are nothing more than a thick tube of cast iron that sets in the overbored block. They need to be frozen in liquid nitrogen and then dropped into the block. Then help in place with threaded stock and cross bars till they normalize to the block. A 2 thousands press fit is about the norm. That means the sleeve is that much larger than the hole bored in the block. When the sleeve is frozen it will shrink enought to just drop in without any force. Some shops put these sleeves in a refirgerater freezer and then super glue them in the block... Not the correct way at all. Super glue acts as a non heat transfer agent. Our engines hve three choices for sleeve hardness from L.A. Sleeve. Soft, medium or hard. Remember we have a hard high nickle block material so don't use the soft sleeve. The rings will seat much faster in a soft sleeve but the sleeve wears faster too. A hard sleeve will outlast the rins and it takes a long time for the rings to seat...

what hardness do you prefer?

 

[hesutton]

Two things....

1st. I had my 7.3 bored 20 over BEFORE I knew better. It was too late when I realized that was a mistake. So I have just been running it with the proper DCA-4 in the coolant ever since. It currently has 30+K on the rebuild and so far so good. UOA has not shown oil/coolant mixing. But, would I do it again.... NO! However, it hasn't killed my 7.3 yet. I do have two core blocks just in case it does cavitate.

2nd. Melling also offers sleeves for these IDI's and they have a standard sleeve for the 7.3 and a "heavy duty" sleeve as well. I've heard good things about their HD sleeves. But, like Gary said, the outcome of sleeving the block is solely dependent on the quality of the machine work.

Heath

 

[icanfixall]

My sleeves are the medium hardenss L.A. sleeves. Melling is another great builder for sleeves.