IDI REBUILD

KR69IDI · Oct 11, 2007

Ok, I have never had this properly explained to me. 6.9 and 7.3IDI's do not have cyl liners from what I understand. So, how are these engine's actually rebuildable without replacing the shortblock. I've heard terms such as sleeving, and others I don't recall, but how is an engine without liners rebuilt? Are they just bored out like a gasser, or is something else done? Someone with experience please educate me. :dunno

Thanks

LittleBlue · Oct 12, 2007

If you haven't read the IDI Tech Articles http://oilburners.net/forums/forumdisplay.php?f=80, I highly suggest you do so. Cavitaion is the $$$ problem with the IDI and boring it thins the cylinders. You’re taking a big chance and may find yourself ******* a lot of cash down the drain and having had to rebuild it again. I do see long blocks from PROMAR on fleabag for 3099.00 shipped. Haven't used one yet so can't comment on the quality. They do install sleeves and boring to STD size.

And yes us a good machine shop and sleeve all the cylinder if you plan on saving the block and doing it yourself (It's your motor and money only you know what works for you). You can search the IDI section and read post with the same questions your asking.

Hope this helps and good luck with the rebuild.

Diesel JD · Oct 12, 2007

With a 6.9 cavitation is rarely a problem. Most will do an overbore or even just rebuild with standard pistons. Usually the rings wear out, the piston tops take abrasive damage and sometimes from a foreign object or too high egts. Also on any 6.9 or 7.3 with any mileage there's going to be that ridge at the top of the bore. I would prefer to dry sleeve or use standard size bore and pistons but the dry sleeves must be done by a very good machinist. It would be great if he had some experience with 6.9/7.3 engines or at least maybe CAT 3208s which were parent bore and also dry sleeved often to be saved from the scrap heap. This does not come cheap, expect to pay 50-100 bucks per hole for dry sleeves at a good machine shop. If you want to do an acceptable rebuild, boring a 6.9 is completely acceptable. You could go .010, .020 or even 030 over and you wouldn't even be close to what a brand new 7.3 was bored out. Just use a good diesel ELC or low silicate green coolant and SCAs to keep the cavitation worm away. You should do this anyhow IMO,
JD

82F100SWB · Oct 12, 2007

Yes, it is entirely safe and acceptable to bore a 6.9, a 7.3, in essence is a 6.9 bored .110 over, so a normal .030 over re-build is not even scratching the surface.

Gotta-B-Ford · Oct 12, 2007

Have a promar long block sitting in the garage as we speak,going in this weekend.It looks great very good people and super quick shipping,all 8 cyl bored and sleeved. ;Sweet

Let you know how it goes

Agnem · Oct 12, 2007

KR69IDI said:
Ok, I have never had this properly explained to me. 6.9 and 7.3IDI's do not have cyl liners from what I understand. So, how are these engine's actually rebuildable without replacing the shortblock. I've heard terms such as sleeving, and others I don't recall, but how is an engine without liners rebuilt? Are they just bored out like a gasser, or is something else done? Someone with experience please educate me.

Thanks

I'm not sure anybody actually answered his question yet, and I'm probably not qualified to do it because I don't really understand the difference between a cylinder liner and a wet sleeve myself. What I can explain is that parent bore engines are what we are used to looking at. That is, the block is cast, and the cylinders are bored out of the same metal the block was made from. In a wet sleeve design, the cylinder is a stand alone part, that is held in by the bottom of the block, and the top of it, and is sealed with O-rings. I've never actually seen one apart, so I can't explain it any better, but the DT-466 is a wet sleeve engine, and they are cheaper to rebuild because you don't need any machining to recondition a cylinder. With our parent bore blocks, you have to make the cylinder larger, then install a sleeve which is basically a pipe if you will, that is machined on the outside to be just a hair larger than the hole in the block so it can be press-fit into the original but now larger cylinder, and the inside is machined back to the original dimension of the cylinder, leaving behind a thin but sturdy "liner". Hopefully I've confused everyone enough that somebody who knows what they are talking about will now come in and correct this jibber jabber. LOL

KR69IDI · Oct 12, 2007

Thanks to everyone for their input. This does make more sense to me now.

dwaymar · Oct 13, 2007

Mel you hit the nail right on the head there

Kevin 007 · Jan 15, 2012

I hear that wet sleeves also have a better wear resistance factor in the fact that they expand evenly upon cold starts, where as a regular block wont as some section near the cylinder are thicker/thinner than others thus expanding faster upon start up than other parts of the cylinder. I can see long term wear benefits here no doubt

FoMoCo · Jan 15, 2012

Question about the 7.3 factory turbo motor. Is the factory turbo block better than a regular 7.3 idi? I read the article about the differences in the 6.9, 7.3 non turbo, and 7.3 factory turbo, and International really upgraded the parts for the factory turbo (piston, rods, crank, etc) did they also beef up the block?

icanfixall · Jan 15, 2012

About the turbo 7.3 block being beefier... Nope... There is a "claim" that the main webs are 110 thousands wider but... Nobody has ever been able to see or find that. All the cranks in any 6.9 or 7.3 engine are the same. Alll that might be differant is the balance drilling because of the particular crank ... Al non turbo rods are the same in any 7.3 or 6.9 engine as is the cam too. The big differance in the turbo 7.3 is the pistons have a larger pin diameter at 33mm where all other rods are 28mm. So of course the turbo postons are differant too. Now the turbo block has 1/4 inch national pipe thread plugs in all the main oil galley ports where all 6.9 and 7.3 non turbo blocks are 1/8 inch plugs. The turbo exhaust valves are inconel material and resist the heat from the turbo. And finally the oil cooler bundle has more fins per inch for cooling but thats all we can buy these days. No longer can we buy a oil cooler bundle with fewer fins per inch. Its cheaper for international to just stock one size that works for all.

bbjordan · Jan 15, 2012

Crankshafts

icanfixall said:
All the cranks in any 6.9 or 7.3 engine are the same. Alll that might be differant is the balance drilling because of the particular crank ...

Well...mostly the same. They will physically interchange, but there is a difference. The 7.3 crank is 3 lbs. heavier! The casting numbers are also different.

Weight
6.9 weight