Best 7.3 idi build.

steve07spirit

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Hey all, I hope everyone is well during these trying times. I would like to build the very best 7.3 idi that I can. I have an engine to start with which came out of a 93 f350 n/a but yet has all the turbo internals. Here is what I propose, list all the weakness of this motor and address, or better yet upgrade them. Commentors start dreaming , i plan on taking all the best options.
 

Booyah45828

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One thing for sure:
You can have all the best parts in the world but if you don’t have a competent machinist you have nothing but misery.
If you don’t have a relationship with a machine shop, be sure to do your research carefully. Engine machine work is a shrinking field.

I could not agree with this more. Good machine work can make or break any build. And rebuilding an engine isn't something you want to have to do more then once.
 

lotzagoodstuff

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......Engine machine work is a shrinking field.

I think finding a competent machine shop to build IDI stuff shaves an already small number down even further. My suggestion is asking the open ended question of "how familiar are you with pre-cups and how do you determine if they've been installed properly?" If the shop isn't familiar with the pre-cup design, you'd better consider another shop or maybe just be prepared to walk them through everything and watch them like a hawk. Simple things that are common in gassers like decking a cylinder head can become much more complicated (spelled detrimental) on an IDI.

Good luck: properly built IDI's seem to last quite a while.
 

Blackascoal

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You want to have Wes at Classic Diesel Design rebuild it. R and D also rebuilds them. I see your in Arkansas. Wes is in San Antonio, TX.


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rhkcommander

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The bottom end is stout. The top end flows well but a new cam will help. Dont really need any head work, they flow better than PSD heads.

The head bolts or studs are a weak point, the heads will lift above 10 or 12 psi in short order. Recently Wes or somebody floated the idea that 7.3 head gaskets were stronger than the 6.9 because of the filled coolant channel.

Soot getting in the oil can bother some, you can set these up for longer oil life with bypass filtration, and run bigger oil filters. Rebuild the oil cooler, they love to leak after a while.

Fuel was always the limiting factor for power on these, other than head lifting issues. Conestoga, R&D, and CDD all do bigger pumps. 80CC is about stock, 2.2 hp per cc to the wheels is a decent rule of thumb, so buy accordingly. You might need an electric lift pump, if your engine ever loses prime or you have fuel leak down issues the mechanical lift pump will drive you nuts.

Add a nice intercooler and make a custom intake for better flow, and get a 3 inch dow pipe and run 3-4" exhaust after that.

The old radiators are OK if you find a solid one. Otherwise you can get a cheap 3 or 4 row on ebay, or sacrifice your next child for a rodney red aluminum radiator.
 

IDIoit

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the very best IDI, will need 2300 in connecting rods, and then 700-ish to modify ;)
not to mention the decompressioning, and coating, and total seal 2nd fire ring.

promar's long block run about 3500$

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Thewespaul

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Thanks for all the recommendations, if you have any questions about your projects let me know! FYI... Stock pumps are actually calibrated to 67cc peak and 58cc at hp peak, so even an 80cc pump is a good upgrade from stock.
 

rhkcommander

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Thanks for all the recommendations, if you have any questions about your projects let me know! FYI... Stock pumps are actually calibrated to 67cc peak and 58cc at hp peak, so even an 80cc pump is a good upgrade from stock.
Gotcha, thanks for the clarification. The older I get the more I forget!

Another popular upgrade is 921 valve springs, stiffer than stock.

Everything everyones said covers most of the engine upgrades that I can recall.
 

typ4

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First to do is find a turbo block, stronger then a NA one.
Not true
Ive measured all the things that are supposed to be different, oil galleys are about it.

I have 15 years and 100k + on my engine build. If you want reliability and good torque and power pm me.

Same pump and injectors FYI, needs injectors now. But thats about it.
It just made a 4500 mile round trip to WI at about 85-90 everywhere I could.
Added no oil.
 
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