Engine Time

YJMike92

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Last Friday morning at 1:30 AM I pull into a gas station in Durant OK and the old truck (1993 F350 turbo) is obviously running on seven cylinders. I'm too close to my destination to turn around so I spend the weekend in the Dallas area. Driving home approximately 350 miles I use four quarts of oil. I will try and do a compression test this evening to narrow down which cylinder. Unless I come across something strange to explain this. I think a Rebuild is in my future. I have several options.
Rebuild the engine in the truck (turbo engine) or rebuild a non-turbo spare engine. It would be easier to rebuild the spare motor and then swap it out along with some of the parts for my 4x4 conversion.
My questions are,
  • Besides the rods what are the differences in the engines?
  • Does anyone have some used rods they would like to part with?
  • Does anyone have any other input?
 
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riphip

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You can rebuild another engine since you only have a 7.3 with turbo & not a "turbo engine" (IDIT). You may be able to find another 7.3 with low enough mileage that only needs a hone job on the cylinders. May also do a bottom end balance on it also. You should have all the internal parts you need with a running block.
Or you can put a running block in the truck & rebuild the present one and take your time. If you go this route, rework the oil cooler and oil pan, lower end gaskets + block drains before you put the replacement engine.
A motor is electric driven & engine is combustion driven.

7.3 & 6.9 engines share all internals except pistons & headbolts
 

Thewespaul

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Before you pull the engine I would pull the injectors and pop test all of them to be sure it wasn’t an stuck injector causing it not to run on all 8, but the oil consumption does suggest otherwise.

7.3 idit, 7.3 na and 6.9 have different rods, pistons and cranks. The idit has unique exhaust valves, flywheel and balancer.
 

YJMike92

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Before you pull the engine I would pull the injectors and pop test all of them to be sure it wasn’t an stuck injector causing it not to run on all 8, but the oil consumption does suggest otherwise.

7.3 idit, 7.3 na and 6.9 have different rods, pistons and cranks. The idit has unique exhaust valves, flywheel and balancer.

I pop tested the injectors a week ago because the truck seemed like it had a bad injector. The last injector passenger side (not sure how they are numbered) was sticking initially and then was all over the place as far as pressure 500-2000lbs. It is that cylinder I am concerned about. I put all new Stanadyne injectors in about three days before this trip. I'm wondering if the bad injector caused a failure. I am going to do a compression test and pull the valve cover and take a look. It is the oil consumption and increased blowby that makes me think it's engine time.
I guess that it would be pointless trying to make an NA block work for the IDIT?
 

Thewespaul

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That could be a possibility. If the injector was hanging open it could burn a piston or an exhaust valve.

Its possible but its a lot easier to keep the block with the bottom end it came with. I would swap a spare engine in if you cant find another idit to build, and rebuild your current engine.
 

YJMike92

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I've talked to the machine shop that I use for my shop about the costs of possible machine work. They seem to think that sleeving the two rear cylinders is a good idea because "those are the cylinders most prone to cavitation". Is anyone able to verify that?
 

Randy Bush

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I would rebuild the turbo one , IMO a stronger engine. It is always better to rebuild a running engine unless there is a major problem with it.
 

Randy Bush

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I've talked to the machine shop that I use for my shop about the costs of possible machine work. They seem to think that sleeving the two rear cylinders is a good idea because "those are the cylinders most prone to cavitation". Is anyone able to verify that?

I have also read that the turbo block where less prone to that problem , I can't verify that though. I little more money , but there is nothing wrong with sleeving an engine. I had a N/A the I did three of the rear ones. Didn't cost me much being we had a machine shop.
 

YJMike92

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I would rebuild the turbo one , IMO a stronger engine. It is always better to rebuild a running engine unless there is a major problem with it.

Rebuilding the turbo engine seems to be the direction I am heading. I checked with a friend at the Ford dealer about a factory rebuild kit but the IDIT kit is discontinued. I believe NA kits are still available.
 

YJMike92

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A good engine rebuilder should be able to supply you the parts need for a turbo engine.

They quoted me about $2000.00 for parts I've got wholesale connections I can do better than that. I just liked the idea of a genuine Ford kit. My price would have been around $1000.00
 

Randy Bush

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The thing about a "Genuine kit is that a lot of the parts are not made by Ford . There are only a few lifter makers, bearing makers and such that Ford has built and stamped for them.
 

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