New OBS owner

[wyndnra1n]

Hello everyone, I am new to the forum, and a new OBS owner (finally). I had been waiting to find a good bullnose, and finally picked one up, should be here in the next few weeks. 1986 F350 crew cab long bed dually with a 460 and 141k miles from CA. Truck is complete, but does not run. My end goal is a 7.3 idi swap, and I found a good core I snagged last week from a 94. Got a set of IDI frame brackets as well. Do not know if it is a turbo block yet, need to start tearing it down. I also grabbed a set of 8 NIB rocker arms and set of 30 over pistons and rings for it part no K1577(8)030 from the seller. That being said, I had a question about pistons. Im planning on selling that set I got and buying a set of Mahle 224-3512HA and going turbo. What is the consensus on rotating assembly on these things? I was figuring that set of pistons, set of converted PSD rods, stock crank. Going to do a full rebuild on the core engine I got and I want a bulletproof bottom end that is going to last me a long time.

I am not totally new to the OBS scene. Been working with my best friend who I think is a member on here on his old broncos and his 86 6.9 350 since high school. That being said, any good info that can be imparted is extremely appreciated!

Rob

 

[IDIBRONCO]

The bottom ends of these engines were pretty bulletproof straight out of the factory. They will hold up to a pretty good amount of power just as they are. If you go with anything other than the rods that are in the engine now, you'll want to have the entire rotating assembly balanced to eliminate vibrations. Since it sounds like you're wanting to make a lot of power with your rebuild, you'd better be ready to invest in a big turbo, an intercooler, a big injector pump, and possibly bigger injectors too. Of course you're going to stud the heads. Don't forget all of the aftermarket gauges to keep an eye on your engine's vitals. Congratulations on the Bull Nose CC dually. They aren't easy to find.

 

[testlight]

Fummins

I love my IDIs, but if you want to trade money for performance it's repower time.

 

[wyndnra1n]

Well I have partially tore down the 7.3 I got, and it looks like I struck gold. block s/n 7.3DU2U1227167* So I have a 1994 factory turbo short block. Was a steal for $270! Came out of an E4OD truck. Valvetrain all looks good and is tight and no sludge in the valley yet. Hopefully nothing crazy once I get the heads and pan off. I have a feeling there might be water in a cylinder though.

 

[IDIBRONCO]

Not too bad, but it's not a Factory Turbo block. The s/n would start out 7.3TU2U if it was a Turbo block.

 

[wyndnra1n]

The block also has the 1/4 npt oil feed at the rear of the block. Would make a lot of sense to have a T in the s/n though. From the information I found here, I was assuming I had a turbo block.

Rebuilding the International 6.9/7.3L Powerstroke Engine - Engine Builder Magazine

One solution to that problem is the diesel engine with more torque, horse power and better fuel economy. This applies not only to heavy duty applications but small displacement turbocharged inter-cooled diesels as well. The diesel engine will play just as important part of the future of the...

www.enginebuildermag.com

Then I have found information here saying my s/n is denoting a N/A block.

engine block serial # location

i'm double checking the location of that all-important number that tells if you have an old or newer style 6.9 (and if the block heater area is weak or not) from what i know, this number is located on the top of the block, near the timing gear cover, on the right side. it looks like this...

www.oilburners.net

Any clarification on this would be great. Tomorrow I will continue to tear the engine down and hopefully find the block casting number.

 

[IDIBRONCO]

Someone could have drilled and tapped that oil port to 1/4" NPT. There's actually some debate on whether or not there's any significant differences between the blocks themselves other than the serial number and that oil port. I haven't seen anything definite one way or the other, but I don't think there is. It's in the crank, rods, pistons, oil cooler, balancer, and flywheel/flexplate where the biggest differences lie.

 

[wyndnra1n]

Turbo Block Casting Numbers

As I understand it the turbo blocks have a casting number of 10809000C3 and the non turbo blocks are 10809000C1. Can anyone confirm this with their turbo block and non turbo blocks? Thanks.... I know the 7.3 block serial numbers started at 500,079 and up to 1,116,330. Then the turbo blocks...

www.oilburners.net

Very strange. Would not surprise me if international just used the turbo block for everything at some point even for N/A motors?

 

[Old Goat]

Here is some good info in the Factory IDI Turbo Engine.

https://mid-atlanticema.org/wp-content/uploads/93-94-7.3-IDI-Turbocharged-Diesel-Engine.pdf

Goat

 

[wyndnra1n]

Here is some good info in the Factory IDI Turbo Engine.

https://mid-atlanticema.org/wp-content/uploads/93-94-7.3-IDI-Turbocharged-Diesel-Engine.pdf

Goat

Wow, this is an amazing resource. Thank you! From this manual, and other information found, this is 100% an N/A 7.3. However, it does have the turbo block casting number ending in C3 and the 1/4 in oil feed in the rear with an adapter down to 1/8. Navistar must have just been using the updated block for everything at that point. Once I tear into the short block I will report back with what rotating assembly is in it regarding piston pin size.

 

[IDIBRONCO]

I saw no mention of the supposedly thicker main bearing webs in the block here. I don't really think that they were, but I may be wrong. The article from enginebuildermag.com that says that they were doesn't rate too highly in my opinion. I have a hard time putting a lot of faith in a reference that tries to lump the IDIs and the 7.3PSD into the same category. I feel that just about anyone can put up something like that and say just about whatever they want to. It doesn't mean that that person is correct. As far as the different blocks, I won't believe that until some trustworthy actually measures them both. Russ was going to at one point, but I don't remember seeing any results.

 

[DrCharles]

Here is some good info in the Factory IDI Turbo Engine.

https://mid-atlanticema.org/wp-content/uploads/93-94-7.3-IDI-Turbocharged-Diesel-Engine.pdf

Goat

Thanks for the link Turns out I already downloaded that, but it's very useful indeed.

Has anyone removed the turbo according to the procedures in that document (pg. 41-46)? It looks simpler than trying to unbolt the turbo from the pedestal while it's on the engine, for example...

 

[IDIBRONCO]

From my experience, there just doesn't seem to be enough room the remove or install them together. I always removed and installed them separately. I could be wrong on that one.

 

[wyndnra1n]

Been getting ****** around by my auto transporter so still do not have my truck and have not had any time to continue tearing into this IDI. Will attach some photos once I finally get the truck.

 

[wyndnra1n]

Finally got the truck a while back, very pleased with the condition besides the interior. Working on getting the engine running. Got it unseized, but found it had a broken distributor gear and the weights and springs had broken off. Took it apart and am going to try and drive the oil pump to see if its seized or not then go from there. Wiring also needs some work due to rodent damage. Body is straight, only issues is the bed is a little beat. No rust. Looking forward to getting to it. Got the idi on a stand finally, only took me 2 months to find a place with one in stock.

Also I have a set of new in box idi pistons in the for sale section if anyone is interested.

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