what can i do with a 6.9 IH

[Ladman]

i might be purchaseing an 1985 ford F250 4x4 with a 6.9 in it. i know that the 7.3 is pretty much a 6.9 but bored out. so my question is what can i do to it perofrmance wise??? can i do upgrades to the 6.9 that i could do to the 7.3, being that they are almost the same ish.

 

[FordGuy100]

Yes, I cant really think of any performance mod that you cant do to a 6.9 that you can do a 7.3. How much money do you plan on dropping into performance?

The best thing for our IDI's is a turbo. That being said, it is pretty much the most expensive thing you can do. My turbo install cost me roughly $1500-1600, for a used ATS turbo rebuilt by Russ, 4 gauges boost pyro water and oil temp, and 4" exhaust. Then turn the pump up to accomidate for the increased air flow through the engine. After that, the mods become more expensive.

 

[Diesel JD]

The turbo is really the best bang for your buck, and yes anything you can do to a 7.3 IDI you can also do to a 6.9. The 7.3 PSD of course is a whole different beast. Aside from the turbo, headstuds, an intercooler compound turbos, a DPS or Moose Pump, water/methanol injection, propane. Many things. As Justin said they get expensive...they can also crater the engine if you're not careful. A turbo shouldn't if you have a healthy engine, but the headgaskets should be upgraded unless they have been done in the last few years and studs are a good idea if you want to push more than 12-13 pounds of boost.

 

[The Warden]

Is the truck in your sig the one you're thinking about buying? Any more detailed pics?

Almost looks like a twin to mine, as far as color's concerned...

 

[Mr_Roboto]

Honestly if you want "performance" you are best off buying a gasser or a 94+ truck with the PSD diesel. Our engines were made to be workhorses, not race horses.

 

[Ladman]

I thought about geting it bored out to a 7.3, adding the banks turbo kit, and maybe upgradeing the pistons. the 6.9 did come with a 3 speed auto, so i would like to swap it out for a E4Od auto. I heard a few things about the 6.9 block cracking if you use the block heater though? i guess the design of the block back in the day was not as good. if i do any of these upgrades, manly the turbo, would i risk cracking the block? i obviousley would be getting better head gaskets and head bolts to with hold the PSI.

 

[Ironman03R]

your not gonna notice a difference with a turbo 6.9 to a turbo 7.3. Sutd the 6.9, turbo it turn up the pump and be happy with it.
The C-6 is a cheaper stronger trans than the E4od, plus the E4 is computer controled so you lookin at 2-4K for a built trans PLUS the controler and wireing for it.
As far as the block cracking, I think it was just the early ones (1/2 of first year)and it only hapens if you use the block heater.

 

[Diesel JD]

Actually the "problem" blocks ended some time in late 84 or early 85. Someone somewhere has the serial #s for the "problem" ones and the upgrades. Personally I'd look it over and if the block doesn't look to have been repaired right around that block heater I'd buy it and call it good. I use the block heater in my 86 and no worries with it. I doubt the turbo will crack the block. Anything is possible if you get too crazy with boost and EGTs, cause a lot of stress on everything, but usually the heads or head gaskets are the weak points. So is the valve train. Block and bottom end are strong as a brick "you know what" house. The E4OD is no upgrade from the C6. True it will give slightly better fuel mileage due to the O/D and it also has a lockup torque converter unlike a C6, but the failure rate is very high unless all the computer and electronic calibrationis perfect and the trans is very well maintained, and even that is no guarantee. Either be happy with the C6, use the C6 and some sort of aftermarket o/d or swap to some kind of manual, but that's my .02. You'll find people here who like the E4. It really is reliable if you get a built one by Brian's Truck Shop or one of the other reputable builders. The 97 and later upgrades I'm told help on a stock unit.

 

[FordGuy100]

Dont bore it out to 7.3 liters, you run the risk of having your block cavitate later on down the road. Just bore it to 7.0 liters which I would think is .030" over, but it might be .060" over.

And as JD said.......unless you build up that E4OD, then its not really worth it to swap the C6 out for it.

 

[6.9poweredscout]

i think there's only like a 10 hp ft/lb difference between the 6.9/7.3. the 6.9 has more meat in the cyl walls so it'll last longer, and when it wears out you don't have to sleeve it, just clean up the cyl walls and re-ring it. on my 6.9 there was rust in the cylinders from sitting, so the machine shop bored it .020 over.i can't wait to get mine done, i never drove a IDI diesel before!

-Jon

 

[MUDKICKR]

im one of those guys who like an e4od but id rather have an auto over a 5-speed. maintance is the key to anything but a c6 will last longer without proper maintance, i remember i had a 78 bronco with a 400/c6 in it and went 4-wheeling, got stuck in a really deep mudhole, neutral dumped it in drive and reverse for like 10 minutes straight and finally got out of it. when driving it home it started slipping bad, got home and it had no reverse and the fluid was black. next day i drained the fluid and looked at the filter and the buddy of mine that was helping me bet me 50 bucks if i put a new filter in it and new fluid it would be fine (it was slipping the day before and bad + the fluid was black and smelled burnt) i said ok, put a new filter in it and fluid and drove it 4 months and it didnt even slip, or shift funny, and i lost 50 bucks. the c6 is nearly bulletproof, leave it in there and go with a overdrive unit, it will be the same money as an properly built e4od swap, but a lot easier on you