What to consider when building a 7.3 IDI?

[Isaac Ristow]

I built a 7.3 for my international s1654 medium duty truck over the winter the engine is in and running I'm waiting on my driveshaft to be done then it needs exhaust. I used a 92 NA 7.3 I tore it down to the bare block inspected everything. It had never been opened up before and was in very very good shape internally. I ran a dingleball hone though it then washed the whole block with hot soapy water and the pressurewasher. I built my own turbo kit and fitted a water to air intercooler to it. I used a pulsar 63.5mm billet ball bearing borg warner knockoff turbo. I sent my heads into my local machine shop he installed my comp 910 valve springs and shimmed them along with planed all surfaces, grinding valves and seats, replacing exhaust valve guides that ran me around $800 that was the only machining I had done. From R&D I ordered stage 1 injectors, 110 pump, total seal piston rings, turbo performance camshaft. I got a full felpro engine sealing kit and rod+main bearings on rockauto (plus other small external things) I also got ARP head studs on it. Justin at R&D told me I'd be in the neighborhood of 350/700 for flywheel power/torque. I do have a build thread on this project in this forum I'll be updating in the near future. My bullnose is a 84 also has a 7.3 with a zf5 instead of a 13 speed, I did my bullnose years ago not nearly indepth but its a 7.3 that had been rebuilt at some point I was told by the military but have no proof. I tore the heads and pan off inspected bearings inspected heads I then put all new gaskets and seals and studs in. Only mods it has is the studs, a period correct Rajay turbo kit, Russ injectors and a almost maxed out NA ip. My bullnose will get down and scoot it only weighs 5800lb it has 4.10 gears and that zf5. I pulled on a tuned stock LB7 with it on a 40 roll and I've put 14,000lb gooseneck behind it with no complaints. As for lifters on my international build I disassembled inspected and cleaned all the original lifters as I have a hard time trusting new aftermarket lifters these days. Pushrods and rockers will handle about anything you throw at them unless your pockets are super super deep which it sounds as your on a budget like the majority of us are lol.

 

[The_Josh_Bear]

I built a 7.3 for my international s1654 medium duty truck over the winter the engine is in and running I'm waiting on my driveshaft to be done then it needs exhaust.

Where's the write-up?!

(I could have missed it...but I don't remember anything about custom turbo kit and stuff.)

 

[Isaac Ristow]

Where's the write-up?!

(I could have missed it...but I don't remember anything about custom turbo kit and stuff.)

I just put a update on it figured it was time it is on this forum

 

[MasterChiefIDI]

Thank you very much again this has been very very helpful. Been doing lots of research and comparing and I am REALLY liking the bank's turbo kit for its completeness and price point.

If using the banks turbo kit, would a 90cc IP be the way to go? Or turn up the stock unit? Should I also do a new cam since I'll have the engine apart or will I have no added benefit since I'm not going larger than a 90cc IP?

Did not know the water to air intercoolers existed. Very cool and looks like the way I will approach adding an intercooler to the bank's kit.

 

[IDIBRONCO]

Russ's cam was designed for low RPM torque and was designed for N/A applications. Justin's cam is designed for higher RPM use. I've seen some people say that a bigger cam isn't really needed with a good turbo set up. I'd recommend asking Justin what he thinks would be good for your goals.
Honestly, with a Sidewinder turbo, you could probably get away with a turned up 80cc pump. I wouldn't recommend any bigger than 90cc. Just remember that pumps and injectors wear at the same rate and should be replaced as a set.

 

[MasterChiefIDI]

Hey guys,

Spoke to Joe at CDD and this was his recommendation for my NA 7.3 build:
- Stage 1 turbo kit w/ 61mm Turbo, Ceramic coated pipes, non intercooled
- Head studs
- 90cc pump or 110cc pump w/ an intercooler (says the 110 w/ intercooler is the max safe IP for stock NA 7.3 lower)
- Stock cam is perfectly fine
- Don't have to but consider CDD's COMP 910 valve springs
- Russ' stock injectors are perfectly fine

Also spoke to Justin. he could not give me a specific lead time for his stage 1 turbo kit and could not take pre orders. Basically to keep an eye on the site. He recommended the 90 pump, his stage 1 turbo kit, and said his cam would definitely be beneficial.

I like CDD's price point and could ship in 6-8 weeks with preorder.

I am thinking I will go with CDD at least for the turbo kit as he has a good price point compared to all the kits I have seen out there.

Questions before I move forward:

1st what do y'all think of using the 110 IP instead of the 90? If i do the 110 I will have to figure the intercooler now rather than add later.. still looking into the water to air and air to air options.

2nd, are the stiffer comp springs really necessary for the build I've listed above whether I run a 90 or 110 pump?

Thank you,
Douglas

 

[Nero]

In my opinion, comp springs are a must. They help the valves close faster and prevent valve float.

As for the ceramic coated pipes... The ceramic part is strictly cosmetic. I have CDD's plain pipes and intercooler kit, works just fine.

As for 90 vs 110cc, that is only at wide open throttle you'll get max fueling. Can tell you from experience with my 90cc, my egts get high on steep grades at wide open throttle.. I'd imagine it'll be hotter with a 110. Just some food for thought. Curious how you'll go about it.

 

[MasterChiefIDI]

Nero, thank you. I will consider the comp springs then.

Looks like I'm not the only on that has asked this question before ha. I will plan to go with 90cc and intercool eventually once I decide how to approach. Seems there are concerns with heat soaking for water to air.

90cc or 110cc injection pump for a 6.9idi

Hey guys, I want some opinions on which pump to put on my 6.9idi. I was taking to Joe over at CDD and he said a 110 is at the limit, but still safe. Justin at R&D said it was too much. I’m looking for some real world experience. I don't plan to tow with the truck, just haul camping gear and the...

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Seems I finally have a plan coming together. Really appreciate everyone's input here!

 

[IDIBRONCO]

Seems there are concerns with heat soaking for water to air.

It uses it's own radiator to cool the water. I'm not sure that there's much greater chance of these heat soaking than an air to air set up.