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Suggestions on building a hi performance 7.3

I have acquired a banks turbo'd 7.3 for my f 600 fire truck re-power. It has the pump calibrated for the turbo. It is coming out of a 90 f250. While it runs very strong the motor has over 200k on it and is ready for a tear down and build

I know that using studs is one good build up trick but I am clueless what other modifications would be worthwhile during a reman of the motor

Does anyone have some suggestions?

Thank You

notme
 

Fellro

Moderator
Staff member
It depends how far you want to go. Actually, 200,000 miles isn't that much on these motors. You can shave the pistons and jump the boost, or stay mostly stock mechanically and just play with the fuel and intake/exhaust systems. The head studs are more of an insurance policy on the head gaskets.
 

1970Custom

They call me Spuds
14,107
447
Middleton, ID
I was going to say, I've seen many with 1,000,000+ before needing a rebuild...
 
I cant say Ive ever seen a 7.3 with a million miles on it.... I think these are good for about 250k.... they dont have the durability of a cummins... but I selected it to keep the truck "fordish"

I was thinking... a careful rebuild,maintain stock compression, stud it, ceramic coated pistons, g injectors, maintain the turbo and pump setting.. which I think is already up 1/8 of a turn...
Exhaust... I was thinking the 3 inch banks downpipe to a 5 to 3 reducer to a single stack 5 inch open.. its a commercial truck anyway...

Pistons... are there better pistons than what the factory has?

thoughts?

thanks

notme
 
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Fellro

Moderator
Staff member
I would disagree with the durability, as my dad's 84 6.9 has 350,000 and is still going, just needs some maintenance done, which I have been doing, He has let the whole truck go... The main thing is taking care of the unit properly. It's a diesel, they all wear pretty well.If it hasn't been overfueled and run hard all the time, it should be fine.These motors serve long time periods as tow trucks and the like in medium duty applications. They are detuned pretty well and can be brought to life with some simple stuff. Since you already have the turbo, that is one thing. The main issue these motors have is more the high compression they run makes it harder to get effective mods on them without popping head bolts, hence the studs. If you were to mill the pistons down to lower the compression, then have the turbo make more boost, and crank up the fuel, they change their nature a bit. The ceramic pistons are to deal with higher temps in the cylinder, so aren't really needed unless you are pouring the fuel in with not enough exhaust flow and the like to keep the exhaust temps down. They are intended for the firebreathers at the pulls and the insane levels some people push their motors, which then shorten their service life.
 

flareside_thunder

Florida Chapter member
7,812
246
If you feel the pump won't give you the performance you need PM me and I'll hook you up with a guy that does performance rebuilds on these injector pumps. Another route you could go is propane injection. I had a buddy make his own injection system in his 97 PSD and that thing will throw you in the seat and not let you up.....I woulda also recommend the necessary gauges however. Boost, pyrometer, coolant. One of the 7.3's biggest issues is what they call the block worm, or cavitation. I'd go ahead and throw new sleeves in there while I'm at it then run the appropriate coolant. here's a link to an aftermarket coolant alot of guys are running. www.evanscooling.com Also, if you intend to go the propane route as well as run your turbo, I'd definitely upgrade to ceramic coated pistons.....
 
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Some information being floated to me .. generally about reman'ing 7.3s is that sleeving it may be problematic..and boring is not an option... that the sleeves are put in with loctite and when the setup gets hot they can move and drop out... obviously if this is in fact an issue it would be catastrophic..

Im also told most people go for the 6.9 block and bore it instead

The learning curve gets steep when I have two 7.3's sitting in my shop yard

Im interested as to what others think about reman'ing the 7.3

thanks

notme
 

flareside_thunder

Florida Chapter member
7,812
246
No doubt guys love the 6.9...they never had the cavitation issues because they have thicker cylinder walls...it's not that difficult to do the sleeves whatsoever, you could even have a machine shop remove and install them if you'd like. Also, the sleeves to not "drop out" they are installed from the top. However, Like I stated in my last post the main reason for the issues with the 7.3 is the block worm but new sleeves and that coolant link I gave you or a coolant like it will keep that from happening.
 

Fellro

Moderator
Staff member
These blocks were never intended for sleeves, and the ones that get installed don't have the lip at the top to keep them from sinking. It would make a hell of a motor to have them sleeved from the factory though. The sleeves they use are no different than what would be used in a gas motor, but gassers take to it better due to less vibration.The sleeve don't actually drop out, but sink in the cylinder, but don't necessarily come all the way out, just down enough to cause big trouble. A quality machine shop might be able to pull off the sleeve job, what the individual he speaks of got was reman motors. he had problems multiple times with that particular reman company. While each was covered under warranty, doesn't matter when your livelihood depends on that truck to be running, and it keeps cashing in motors, several were to dropped sleeves. It was to the point he tore down the last one just to inspect things and found one down already, as well as intake bolts loose and the like. He had to fight the company to get his money back, but finally did and build a monster 6.9
 

Fellro

Moderator
Staff member
6.9 and 7.3 are practically the same motor, there were some upgrades on the 7.3 like larger head bolts and improved valve design, but the block on the 6.9 has the better wall thickness.
 
So.. other than the block and pistons is everything pretty much interchangeable between the motors?

thank you for the links btw... they will be very helpful getting me up on the learning curve
 
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Fellro

Moderator
Staff member
Heads can be swapped, but you need the special head bolts to do so, as the 7.3 uses larger head bolts. Otherwise, they are essentially the same.
 

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