need rebuild info

[pauls painting]

well since i am using 2 gallons of oil every 476 miles i am planning a rebuild and want to know should i stay with my 7.3 turbo or go with 6.9 turbo? also in 30 days will need to find a good core for the motor i use. also where can i get info on rebuilding these motors. what mods should i do besides studs and sleaves . should i lower compression and ceramic coat pistons. i am building this to put in a crew cab so if anyone knows where a good crew cab body is let me know. darin tosh i am still interested in turbo so let me know.thanks for any info or ideas. also would c-6 with gear vendor o/d be better than my 5 spd

 

[icanfixall]

You can sleeve it from a 7.3 down to a 6.9. Buy everything you need from Diesel direct. They have the big pin 6.9 turbo pistons and also the 7.3 big pin turbo pistons. They are Mahle and are hard anodized tops. They can get the low compression (shaved 10 thousands) pistons too. They have all the bearings for the cam and crank and the big pin turbo rods for $42.50 each no core charge either. The rest of the parts I buy from Ford Parts Online. Pushrods $83.84 a set. Rocker arms $251.68 a set. Rear main seal and speedy sleeve $45.86. Northern Autoparts for the gasket set, about $150.00 with the valley pan. The cam is usually just needing a cleanup grind. Lifters are the same for the chevy diesels and most powerstrokes so shop around or I'll sell you a new set I have. Oil pump is about 150.00 from Nappa. part number Balkamp 601-1959. Or a Melling will do fine. Check yours first and if you can get a 4 thousands or larger shim stock between the internal gears it needs to be replaced. Any other items just ask...

 

[pauls painting]

icanfixall what should i know about the diffrent ways of sleveing the engine ,and what is the pre cup mod in your sig? thanks again . will start ordering parts on thursday. any other mod ideas ? i will be adding a inner cooler , do they make air to water inner coolers for idi s? i saw a article in diesel mag amonth ago about these on power chokes.

 

[Diesel JD]

Hypermax and ATS have intercoolers for IDI engines. I think they are air/water, not 100% sure, they are out of my price range, but they are a real good idea if you want to go for high performance. The turbo pistons and rods are a great idea. I would also go with head studs. No difference between a turbo for a 6.9 and a 7.3. You have a '94 so its probably an ATS factory wastegated turbo. A better flowing downpipe will make that a different turbo. ATS still supports the wastegated turbo. I'd keep it unless you want a non gated turbo.

 

[ttman4]

What's the purpose in lowering compression on the 7.3 IDI? I thought higher comp. was better performance etc.
And what does playing with the precomb chambers to get these IDIs to act closer to a DI engine get us?
Just asking, curious. I keep seeing reference to these ever now & then.

Inquiring minds need to know....

Another thought in relation to pre comb chambers, folks running WVO, from what I've gathered the IDI run it better than DI engines. Or at least less trouble running WVO in the IDI, for what ever reason.
Coking of rings etc apparently can be an issue running WVO & such. In my mind, if there was coking problems in rings, then probly coking & crud build-up in pre-comb chambers.
Way I understand coking, short trips, not getting that iron hot enough & long enough to keep things burned out helps lead to coking....ampng other things.

 

[tonkadoctor]

What's the purpose in lowering compression on the 7.3 IDI? I thought higher comp. was better performance etc.

Higher compression for performance is for naturally aspirated gassers.

High performance turbocharged & supercharged diesels as well as gassers need lower compression so you can cram more air and fuel in them without preignition. More fuel & air means more power when it ignites. The more boost you have the higher the cylinder pressures go to the point of lifting the heads and puking coolant and oil as well as the engine.

Watch how far some of the diesel pulling and race truckscan spew their smoke, many of them can shoot a stream of smoke, not just a cloud, 40 - 50 feet or so and it takes extreeme cylinder pressures to do that.

Another thought in relation to pre comb chambers, folks running WVO, from what I've gathered the IDI run it better than DI engines. Or at least less trouble running WVO in the IDI, for what ever reason.

The IDI is a bit more used freindly to run WVO. IIRC (and I'm sure somebody will correct me if I'm wrong)...The PSD needs mods to the fuel return to be able to properly purge the system of WVO before shutting it down because WVO needs to be heated to flow properly

And at $1100 - $3000+ and core charges for a set of injectors vs $150+ for a set of IDI injectors it gets a weeeeeee bit pricey to ****** them up not to mention the royal PITA of changing them when they are buried under the valve covers.:***:

 

[ttman4]

...The PSD needs mods to the fuel return to be able to properly purge the system of WVO before shutting it down because WVO needs to be heated to flow properly

Yeah, all the systems start better if they're purged before shutdown. Especially in cool weather.
& it does bigtime to heat the fuel/WVO & system before IP.

 

[pauls painting]

well scored on good running 6.9 4x4 for 500 . so i will build that and sell my 7.3 after i pull her out. how do i get ahold of ken? will be going with stage 1 pump and injectors. what do i need to do to 6.9 for it to be reliable w/turbo?

 

[icanfixall]

Paul, What I did to my precups and the precup chambers is this. I had a custom ball end mill made up to 1.168 and "cleaned the chambers up in the heads plus I lowered them 60 thousands. Ford had the injectors pulled up out of the heads 60 thousands to run cleaner for the EPA. Didn't do us any good so I "restored" them to OEM. The ruff looking chambers in my new set of offshore heads wasn't going to work for me so I machined them out and polished them for better matched compubstion balancing. The neded up being about 2 thousands differance between all of them and the CC volume was spot on. I cleaned up the precups too. I opened up the flame port some. The width was widened to about 0.625 and raised to 0.400. The inside of them had a small lip in them so I cleaned them out and blended the flame port. I feel I should have left in the lip because these precups need turbulance for better burn of the fuel squeaking thru them. I wont do that again. The entire hot a cold air path was ported and polished. Thats the intake manifold, heads intake & exhaust ports & exhaust manifolds. Any place I could smooth out the ports I did. These motors can run very well with highly polished ports. They aren't like a gasser that will bead up the gas on the polished ports. We inject into the heads and not the intake runners.

 

[pauls painting]

icanfixall are you a machineist? thanx for the info. where in so cal are you ? i grew up all over from san diego to up north . i go to pick up 6.9 truck later this week .

 

[pauls painting]

bought the 85 f250s/c 4x4 6.9 c-6 . the engine sounds strong .should i rebuild this to put in my 94 or run this and sleve the 7.3?
can the 6.9 be built up for turbo and stage 1 injectors ,i am hoping to
build this to be a reliable work truck. thanks for all the info i have learned
from this site.

 

[pauls painting]

will my luk flywheel bolt up to 6.9? plan on putting in 6.9 till i get 7.3 rebuilt . how hard is it to rebuild turbo? where can i getr a turbo rebuild kit?

 

[tonkadoctor]

IIRC the 7.3 is basicly just a bored 6.9, should be a bolt in swap. I've never done it so others will have to help you on this one.

For the Turbo rebuild kit give Ron a call at 801-842-9186, He has a good reputation on many forums. I got parts from him to rebuild the turbo on my PSD and it was a pretty easy job. Very fast shipping too.

 

[pauls painting]

need some help on hooking up oil pres. pyro, boost gages this will be in a pillar
mount ,any articles on easy way to install? also should i use c6 or keep 5 spd?
also looking to go with dual fuel filters is this possible and how do i do it?and
is a bypass coolant filter a good idea? any info and part # would be a great help thanks
will be pulling 7.3 this week so will have pics soon.any thing i should do in engine compartment while engine is out? headlight mod
or any other mods would be easier with engine out. will be making cool air intake once engine is out.