Or engine kits?
I have a tired 7.3 turbo with a bunch of blow-by. After looking at the (electronic) problems with newer trucks---as well as gas engines with issues---I ight just keep the old truck and install some fresh power. Any rebuilders to recommend? or avoid?
Same for engine kits in case i decide to go that route.
Does anyone sell just the cartridge for the turbo, or do you have to buy the whole thing?

 

First off, why do you think it's tired, just because of blow by?
Does it use a bunch of oil?

IDIs produce a massive amount of blow by, when newly rebuilt. No need to worry about that. And yes, you will end up with bits of oil getting into the intake/turbo through the CDR valve and hose.

Is the turbo worn out? Check for shaft play. in/out is a problem, side to side is only a problem if it contacts the housing when you are spinning it.

Your power problems are fuel related. By this age, your injection pump is probably worn out, and your injectors are shot. Get a new injector pump(I'd recommend a RD2-90 from R&D IDI Performance for you), good injectors and an EGT gauge. You'll probably have about double the HP with just that.

I really want to make sure it actually needs a rebuild before you go down that road. It's just not needed in a lot of cases.
I'd definitely recommend talking with R&D IDI Performance if it comes to that, though - I do know they rebuild motors for whatever power level you want, but they aren't going to be the cheapest out there..

 

That's a good question as it seems since most builders do not know these engines there are a lot of sloppy rebuilds out there. I'm sure you'll get some feedback soon.
But let me throw this out there, be sure of your diagnosis; by design the 6.9/7.3 has a lot of blowby, even new. So don't let that be the sole factor in deciding the engine's tired. Even only marginally taken care of it can go 400K, they don't tire easily.

 

Ha! Rob types faster!

 

Im sure Jasper is still doing them, not that id ever run one.

 

Thanks for the replies.
Yes, the only real problem is the blow-by. I am not new to IDI--been driving one for about 20 years.
Injector pump was replaced about 10,000 miles ago--it starts and runs fine.( except for 2 or 4 bad glow plugs--but thats another story.
I measured the oil consumption over the last 1000 miles or so, and it was using a quart about every 250 miles.
Then I saw a LOT of oil under the engine--both sides. I found a little oi around the turbo oil supply line--that could account for oil running over both valve covers. The fitting on the oil line took a full turn to feel snug enough--I haven't checked it since---bad weather ---and another project on the lift that can'y be moved for a few more days.
I have a boost gauge--but I bought the wrong one. I missed that it was a vacuum/ boost gauge and it goes to 3 atm....My turbo only puts out about 7 psi or 1/2 atm--so i think that is all good .EGT will get right up to the 1200-1250 range and then hold constant. I know some say you must stay below 1200, but I haven't seen anything definitive from a manufacturer. I have heard that aluminum melts around 1250, but the alloy in pistons likely has a higher melting point. Also, remember that aluminum transfers heat VERY rapidly, AND that hot exhaust gas is quickly replaced by cool, outside air, AND there is a constant stream of cool (?) or relatively cool oil directed at the underside of the piston's top. I would love to know the correlation between EGT and the actual temperature of the aluminum piston crown. I've read stories about EGTs buried well past 1250 while climbing a long 1-2 minute mountain grade with no apparent damage.---Sure would be nice to have that confirmed. I don't want to toast my engine, either.
I should get out and check the oil problem this week. NOT replacing the engine would be a very good thing.

(I was actually beginning to look at a newer truck--2005 and newer F250, and 2009 F150--lots of nice features especially that trailer brake controller....then I began reading about cam phasers needing to be replaced, and spark plugs that come out in 2 pieces and coil packs ( whats a spark plug??). I have a friend that works at a local LARGE auto auction, and he says he sees some newer vehicles where the doors won't open from the inside due to electrical issues--no way I want any of THAT. The old truck is in really pretty good shape--just a little rust, and the paint is dull--but all that is fixable, and won't leave me stranded. It rides firm--not loose at all; a few clunks in the front end, but I will eventually figure that out, too. Of course there is always cavitation to worry about, but I have maintained the SCA level during my 12 years or so of ownership--right now it is at 2.2 SCA units per gallon, and the freeze point is around -45. All in all, I'd like to keep it--if you guys can talk me off the ledge, I might be able to.)
Oh--one more thing--does anyone around Gettysburg have a timing light for these engines? I had it timed right after i replaced the injection pump--and I have no reason to believe it has moved--but IF I decide to replace the engine that becomes a issue.)
Thanks all.

 

If you want good performance, you can definitely do it. Not sure where your injector pump came from, but if it was a cheapy one(auto parts store, Diesel Care or like Pensacola), go check with R&D IDI Performance.
If you check my sig, I've got the same truck as you(with an '88 model 7.3 engine, so no upgraded bits), and I'm able to push 250 at the wheels(around 320 HP at the crank)vs about 125 stock(190 at the crank), and yes, it makes a huge difference.
Part of this is more boost - the turbo you have can put out about 15 PSI max. Unplug the wastegate(or at least adjust it) so you aren't 'wasting' below 10; more air in there = a leaner burn = lower EGTs burning the same amount of fuel.
The second part is a good IP. a RD2-90(or decent stock pump turned up to max) can push about 200-220RWHP(260-280 crank); a RD2-110 can push over 300 but needs studs for that(and a better than factory turbo).


With rebuilt engines for IDIs(and other engines) being pretty cheap(especially compared to new engines), you can take a small amount of risk if you want a bunch more performance out of it.
IDIs are really tough motors, and the factory turbo ones are even more underrated... do it right(and you have the EGT gauge to watch), and you can push quite a bit of power through it without issue.

 

Going over 1200* WILL erode the top of the piston, ive seen it. Secondly, running EGTs that high is really hard on the rings. If you run at 1200 alot that could very well account for the blow by and oil consumption. With all things in order, 1200 should be very hard to get to. With a 110 pump i can barely hit 800 without a load on, lugging, WOT up hills etc. few miles wot up a 6% grade for instance. 1200 is the safe maximum, you can go over, just briefly but it will pit the pistons. I personally dont go over 1000 unless i absolutely must (old engine with leaky turbo).

To your original question, i would have yours rebuilt by a reputable shop, or find a donor to rebuild, or just drop in. You will likely need valves and guides, and probably a bore and pistons. Aside from the pistons, everything else is relatively cheap. My machine work was around $2200, but i had them do everything, this also included milling and helicoiling 5 headbolt holes which was 850 if i remember right. If you dont care for the blowby, i have gapless rings and have almost NO blowby.

 

hairyboxnoogle--Yours is the first info I have seen that attributes erosion of the piston to high EGT. Not doubting it--just saying there are a lot of opinions and not a lot of hard data. thanks for that. ( But....how come aluminum pots do not melt in a propane flame around 3600 degrees F?)
Of course there is always the question of what is the real EGT? My probe is in the exhaust manifold right, but there is no way to know how accurately the gauge is calibrated--nothing NIST-traceable, if you know what I mean.
Waste gate vacuum line is plugged and still only about 7 PSI. More boost would drop EGTs, right?
Oil is cheaper than a rebuild, at least short term.
As for the IP, I don't know. That was one of the very few times I paid a shop to do any work for me, and it has run well since. The original pump was really bad ith mpgs, empty around 7-8. The new pump gets me right around 18 empty and holding max speed to 62-65 mph.
At the time, I just couldn't afford a "Moose" pump from Agnem. I live close enough that a pump from him is always possible, and maybe now financially possible....)


Thanks for the replies.

 

I know this one, relief from heat and maximum heat transfer. The pot in this situation is not totally saturated in 3600 degrees, and also most likely has multiple surfaces to radiate that heat away from the heated section. Conduction and Convection will create radically different results. Also, over all stress must be considered in both applications. Heat up a pan and its going to probably survive, heat that same pan up then subject it to a sledge hammer 30 times a second and it may start to erode. Don't have to melt it to break it down, just need to give it enough stress for long enough.

 

I'll point out that my '88 ran into the 1100-1150 degree range for a couple minutes on end, a number of times. When I took it apart, I didn't see any real pitting.
I have seen small amounts of pitting at one edge of the piston before, perhaps .030" in size by 1/2" long, but that was on old, N/A engines. Either way, it wasn't critical or anything.

My EGT gauge was in the turbo up-pipe, right before the turbo(banks kit stock EGT probe).

 

That temperature was probably a little cooler than what the pistons were seeing simply based on the distance the gases traveled before reaching the temp probe. Any guesses on what EGT were at the piston surface?

 

Do the google thing, theres tons of pics of IDI pistons with erosion at the bowl, a bunch with the top of piston looking like it has a wicked case of dandruff, and even a few where the crown is cracked between the top and the first ring land. As far as the ring thing, ask a diesel shop. As far as egts, whats in your exhaust manifold really isnt close to whats going on in the combustion chamber, its not under compression for one which massively cools the air, on top of that, the piston is under crazy pressure on top of the heat, and is only cast aluminum.

 

I had never considered the ring issue. That was new info--at least to me.
I'll look at some pics.

 

Lots of pictures of damaged pistons. Many from Power Strokes, and VW, even some IDi. I wish they had documented the causes better....but some people are running some very bad pistons, for sure.