Bad News & Advice Needed...

[typ4]

There is nothing wrong with a bored 6.9.
Now ,there is a place called Hubler engines over your way and they have good parts. Talk to Matt and tell him Russ from Russ's repair in newberg sent you.

 

[david85]

A 7.3L IDI block is essentially a 6.9 block bored over by 110 thou. This means that a minimum bore on a 6.9 will still be very reliable. I think the smallest size of oversize piston that is available is 20 thou over. I have 30 in mine if I remember right.

Sleeving a 7.3 doesn't seem to be reliable and I have yet to hear of such an engine lasting a normal lifespan (300k miles or more).

 

[Diesel JD]

I'd say you should do the rings and bearings at least and pistons too if there's any doubt if they are in spec or not. Russ said he used some old pistons that were in spec but worn with new rings and had piston slap right away. You could just fix whatever is broken and call it good. The bolts vs. studs is a debate here I doubt very much you'd ever lift a head at 10 psi boost but maybe you would. You could be sure with the ARP studs and they're not that expensive. It appears it can be hard to install them right though.

 

[k_williams1982]

What town is Hubler Engines in? Are they open tomorrow or do I need to wait until Monday? Do you guys know what the max I'd ever want the boost at with a 6.9 if I just used new head bolts? I have plenty of power for pulling my trailer in the 6-7 psi range up the grades. It shows about 1 psi at 35 mph and about 3-4 psi at 65 mph. At lwast I think those are the numbers... been a few months since I drive it last now

 

[160k87F250]

I would strongly reccomend testing the oil cooler the way Mel said. I would hate to see you rebuild it for no reason, or worse, rebuild it, use the same oil cooler and have the exact same problem. Just trying to save you some grief in the long run.
John

 

[k_williams1982]

NAPA says that they can pressure test the cooler for me for just a few bucks. The guy said that they "plug" it and charge it with a specific PSI and then check to see if the PSI leaks off either right away or over an amount of time. Is this possible? I'd like to have it checked, but is NAPA correct on the way to do it?

 

[punkmechanic]

I suppose you could do it that way but it takes out the seals between block and cooler as possible suspects. It may sound "redneck" but I would get a regulator and shop air, regulate it down to 15 psi and then pump the system up and see where you hear air leaking. Its off the same principle as a cylinder leak down test for the cooling system. if you listen with a stethoscope (or long piece of vacuum line for that matter) you can isolate where the air is leaking and then localize the tear down

punk

(btw before I get flamed for it I use the term "redneck" as I represent that remark)

 

[typ4]

dieseljd, On an update the piston slap wasnt immediate and I found that one piston had shrunk after going back in the engine also I completely spaced out the fact that they are select fit at the factory, so I way have swapped one, well 2 i guess, anyway the hole that was noisy had 12 thou clearance.
Nice and quiet now, well as quiet as it gets

 

[Brimmstone]

A 7.3L IDI block is essentially a 6.9 block bored over by 110 thou. This means that a minimum bore on a 6.9 will still be very reliable. I think the smallest size of oversize piston that is available is 20 thou over. I have 30 in mine if I remember right.

Sleeving a 7.3 doesn't seem to be reliable and I have yet to hear of such an engine lasting a normal lifespan (300k miles or more).

Are you sure on the overbore size. I seem to remember it being 140 thou for some dumb reason but then again I'm getting older which means senile isn't far off.

 

[FordGuy100]

but then again I'm getting older which means senile isn't far off.

That reminds me of the movie "Waiting" that old guy was so fricking funny

 

[hesutton]

Are you sure on the overbore size. I seem to remember it being 140 thou for some dumb reason but then again I'm getting older which means senile isn't far off.

6.9's bore and stroke are 4.00 x 4.18 inches.

7.3's bore and stroke are 4.11 x 4.18 inches.

If your bore is 4.14 it is 30 thousands over standard for the 7.3.

Heath