7.3idi Rebuild Cylinder Wear

F350Will

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I’m a new member although I’ve been viewing for about 2 years. I own several IDI Fords. I’m rebuilding a 7.3IDI (with ATS turbo and baby moose IP installed by PO) out of my 1993 F250 with about 240,000 miles. I’m at a stand still because I believe a couple cylinders are too worn to just hone. There are ripples at the lower quarter of 2 cylinders that can be felt and seen in the right light. Most cylinders have a slight ridge but not enough to keep pistons from coming out. Piston skirts look great but I don’t think it’s a good idea to just rering it with this kind of cylinder wear. I don’t think it’s worth a few grand of machine work and new pistons on top of having thinner cylinder walls. Any ideas would be appreciated. I’m just wondering if I should find a used engine and risk the same problems, risk it with this block and hone and re-ring it, or drop a 12 valve Cummins in it. Thank you for any advice.
 

F350Will

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In the second pic you can see how the light is distorted.
 

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ihc1470

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One way to go if the pistons measure within specs would be to sleeve the block. Not a cheep option but should get you away from cavatation issues and you would not have to buy pistons. Only you know how much money you wish to spend.
 

IDIBRONCO

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There are ripples at the lower quarter of 2 cylinders that can be felt and seen in the right light.
In this case, yes they are too worn to rering.
or drop a 12 valve Cummins in it.
That's the LS swap of the diesel world. I like being different that the majority/popular opinion. I don't recommend a Cummins swap because of the popularity and the Cummins fan boy crowd. Again, that's just my opinion.
 

IDIBRONCO

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I also forgot to mention that these are probably #7 and #8 cylinders. Those are the ones that will have the most wear when people have a turbo and don't have the means or the knowledge to use it. IE monitoring the EGT's is a HUGE one.
 

F350Will

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Yeah it’s #7 and #1. I’ve always watched the egts carefully but when I bought it the fuel screw was turned up way too much and I think it was ran hard like that.
 

F350Will

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The reason I mentioned the Cummins swap is because I have a VE pump 5.9 in a junk truck. It’s just a thought. I’ll keep an eye out for a used IDI for now.
 

KansasIDI

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The reason I mentioned the Cummins swap is because I have a VE pump 5.9 in a junk truck. It’s just a thought. I’ll keep an eye out for a used IDI for now.
There is still a Dodge/Cummins guy, deep inside me, who eeks out from time to time.

The 5.9 Cummins is a great engine. A little overrated but still a fantastic engine. If the Cummins you have on hand is good, the swap would cost the same or less than what it would cost to rebuild an IDI anyways. But if the Cummins itself also needs rebuilt, then it’s probably not worth it.

Both options are good options, the Cummins are great but there’s not much wrong with an IDI.

5.9 Cummins - overrated but still great

6.9/7.3 IDI - underrated but still great

Best of luck to you whichever path you choose.
 

Black dawg

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I wouldnt say the 12v is overrated.....over used, put in stuff that is just not practical and stupid.....yes.

If it can be put in for reasonable cost, and truck will get used in a way to take advantage of a diesel engine, 12v valve is a pretty easy yes for me. Especially if the truck is torn apart and the idi needs a significant amount of work.
 

KansasIDI

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I wouldnt say the 12v is overrated.....over used, put in stuff that is just not practical and stupid.....yes.

If it can be put in for reasonable cost, and truck will get used in a way to take advantage of a diesel engine, 12v valve is a pretty easy yes for me. Especially if the truck is torn apart and the idi needs a significant amount of work.
Whether or not the 12V is overrated really boils down to opinion. Personal preference.

I have had a lot of experience with them, and while I do like them for the most part, there are plenty of things about them that I don’t like.

I’ll leave Ford vs Dodge out of this, once again a matter of opinion.

I also have been around them in paving machines, tractors, irrigation pumps, gensets, and other equipment.

The old 12Vs are f**king loud. You cannot escape the noise. A good muffler will quiet down the exhaust plenty, but the rattle and engine noise persists. And while from a distance their sound is generally pleasant, being near one, especially in a piece of machinery rather than a truck, may cause disdain. It has for me.

I am not the best about wearing hearing protection, especially after a particular incident, but regardless, I am certain that the 12V Cummins has played a part in my hearing loss, which I have all too much of at too young an age.

That is probably the main reason why I consider them overrated, but truly, many of their positive traits can be found with plenty of other engines. The 12V is a neat package, but still has some drawbacks.

The killer dowel pin is probably a bigger scare than an actual issue, but still a potential fail point nonetheless.

They are great engines, and especially if circumstances are less than ideal, they start far better than an IDI, but in reality, while they have more potential, in both performance and reliability, and are certainly an excellent engine, they are not perfect. Nor is any other engine.

I certainly wouldn’t be opposed to putting a 5.9 Cummins in an older Ford truck, and it’s possible that I might even be interested in doing so myself someday. But they aren’t perfect, and there are plenty of people who talk them up to be.

In short, the 5.9 Cummins won’t solve all your problems. But they are excellent engines.

Oh and the VE pump engines are gutless. Shoot me if you want. I think they’re gutless. Stock to stock a 6.9 could run circles around one. With the same upgrades to each (both intercooled with the fuel screw turned up) they are probably comparable, but a hopped up 6.9 isn’t exactly setting the bar high…

P pump engines can make easy power, and yes it’s possible to make power with a VE pump, but also possible to make power with an IDI. The level of difficulty in doing so is probably similar.

I have had a well maintained 24V (farm feed truck) let me down more often than any of my IDIs. I am not particularly fond of those engines, although not entirely scarred from them. I wouldn’t be entirely opposed to owning one, but I do think I would prefer a 12V. Neither one is quieter than the other anyways in my experience…

I have very little against the common rail engines.

The 5.9 and 6.7s all seem to be more prone to gelling than an IDI… they use the same fuel so perhaps that doesn’t make sense, but that has been my experience. It probably helps that the DB2 injection pumps return so much more fuel than really any Cummins pump does.
 

Nero

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Well put. As someone who works on the big C every day, you've outlined well what I think too.
 

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