Best platform for rebuild

[Old blue_83]

Hey fellas, I hope this is the site that can point me in the right direction. I'm new to this site, but not new to diesels.
The thing is, I don't know which engine to build from. I really want to make this truck as true to stock(6.9L) as possible, but it will have a turbo and possibly anything else that will add power. Would you build from a turbo'd IDI or put hypermax parts in a 6.9L? Would low compression pistons allow for more boost from the non-wastegated Banks turbo? I read something about rebalancing the crank if you put in different pistons? If you had $5000 for an engine what would you do? I have a 6.9, a 7.3, and the Banks turbo to build from. Don't tell me to put a cummins in it.

 

[icanfixall]

Welcome to the forum. The 6.9 or 7.3 each have there issues but will both build nicely some great power. We do not recommend boreing out a 7.3 because the cylinders are too thin as it is on a standard bore. They actually expand in the cylinders during combustion. This causes cavitation and eventually eats a hole thru the liners and coolant leaks into the cylinders. Not good at all. Usually the pistons hydrolock and a rod bends or goes thru the cylinder wall. You can't compress fluids so something has to give. Resleeveing the 7.3 block is the norm but. Some have bored them 20 over without issues. Thats not the norm. The 6.9 has the smaller head bolts at 7/16 inch where the 7.3 has 1/2 inch head bolts. We usually recommend installing a set of ARP head studs. The added strength is a welcomed advantage over the stock bolts. A new 7.3 head bolt is 153,000 psi and the studs are 220,000 psi. Plus reuseing the studs is fine compared to reuseing stock head bolts. It can be done but its a risk of head gasket failure on the 6.9 engines. The 7.3 has low compression pistons available from the oem company called Mahle. They are 10 thousands lower in the bores. All these engines run with the pistons as much as 31 thousands up out of the cylinder bore. Mostly any turbo from the big three (banks, hypermax or ats ) will encrease you power. Adding a type4 torquer cam is a great idea. Couple that with a built Mooes Pump and a matched set of BB code injectors from Typ4 or Agnem who makes the Moose pump Products is a good way to make hp and mileage. Usually hp and mileage don't go together but they do here. I have driven my rig with two differant Moose Pumps and when I drove home from the 2009 ralley in Bowling green ky I got 18.9 mpg average driving 75 to 85 mph. That was with the latest Moose Pump. Balancing the rotation parts is a needed item. So is line boreing the crank webs. When you remove the main bearings look at them. If they show wear on one edge more than the other then that main bore is machined off center and needs to be cleaned up. The rod bearings may show the same thing but if they do thats because the cylinder bore was not cut square with the crank. Decking the top of the block is important too but only 4 thousands can be removed and still be in factory tollerance. All V8 blocks are twisted some and the pistons will be at differant heights in the bores. That causes a differant compression in each cylinder. The engine will run fine but the power from each cylinder will be a little differant. Balancing the rotating parts and the power from each cylinder smooths out the power pulses to the crank. That releases mor lost hp in the engines. Barnett Performance offers porting in three differant specs. They have a great website so give them a call. Great people to talk with. If you plan boosting past 13 lbs you will need an intercooler because the boot air temp will be up around 300+ degrees much higher than 13 lbs. No real good idea putting 15 or 18 lbs of 300+ degrees air charge into these engines. No real hp gain will be achieved doing that but ego will be telling you I have 18 lbs of boost and I screaming down the road doing it. Stock,these engines are not a powerhouse but they live a long life. They can be trusted to get you there and back with very little maintance. A pump is around 500 to 600.00 and a set of Bb code injectors is about $325.00. A rebuilt injector for a powerstroke is $350.00 just for one. And having a set installed in a psd is going to cost you about $4000.00 and thats on the cheap side. You can replace your own idi injectors for $400.00 easily in one afternoon. So 10 times cheaper works well for a lot of owners here. The realy hp differance from the 6.9 and 7.3 ingine is about 10 hp. Really not a true way to decide which engine to build but that what it comes down to.

 

[Devon Harley]

Im restoring my 7.3 89 idi and im on a budget got the 088 ats kit non gated and i would order a typ4 cam from here on ob from russ and would build the 7.3 deck the block balance it coat the pistons with heat stuff names slipping mind use the stock pistons re sleeve cly.7&8 and you can turn your fuel pump up a few flats and get a pyro should be super reliable and have some nice power later a aluimunum rad. and water/**** and she will run long and strong im doing that and getting a moose pump and injectors two!!!! Cummins goes in a dodge not and classic idi lol

 

[bike-maker]

What year is the 6.9L? And is the 7.3L by chance a factory turbo engine?

 

[snicklas]

No 6.9 factory turbo

part of 93 and 94 there were 7.3 factory turbos

 

[FordGuy100]

Another East Texan

I would go with the 6.9 as there wont be as much of a problem with cavitation.

 

[Old blue_83]

Wow. Thanks for all the info and time, icanfixall. Looks like I'll be rebuilding a 6.9. I have 3 donor trucks and all are '85 or '86. The 7.3 that's in it is not a factory turbo, bike-maker.

So hypermax offers rod and main bearings, exhaust valves, exhaust and intake valve seats, rings, rebuild gasket kit, and piston pins. Are their products really "high performance" and which of these things would be necessary if I plan on having a turbo, moose pump, moose injectors, and intercooler on this truck? Are the rods not a weak link on these trucks?

I'll be looking for you around Tyler, FordGuy. That beautiful red paint should be easy to spot