bbjordan
Snow Monkey
Redneck 6.9 Rebuild (don't try this at home)
History:
I bought this 6.9 L engine from a guy who said that it a good strong engine that had been rebuilt not that long ago. Well, I needed an engine while I rebuilt the 7.3 that had been overheated (a whole other story). Well, about 6 months later after I was just getting it running good, it blew a head gasket.
The 7.3 was ready to put back in, so I pulled the engine. Good thing too. As I started disassembling, it I realized how bad it really was. It was standard bore,and the rod and main bearings were also standard size, but the bearings were shot. Even the crank mains and rod journals were damaged. It looks like the engine had been run dry of oil! Even the fuel cam eccentric was worn.
The pistons had some melting done on them too.
The BB code injectors were said to have been replaced, but they were crap. I think this engine had been worked like a Mexican donkey.
The piston to bore clearance and the bore taper was just in spec, so I could have gotten by with a set of rings, but if I was going that far, I might as well go .010 oversize on the bore and get new pistons and rings. Machining work is expensive tho, as are new pistons and rings. I already had a '93 7.3 with cavitation, a cracked piston and a badly scored crank. I had picked it up for parts for $200. It had a brand new DMF and clutch on it when I got it! I got my money's worth out of it right there. The other engine was a 7.3 out of an '88. I got this one free with the parts truck that I got along with the 1986 F-250 4x4 that I bought. This one was a leaker and it looks like it had been driven into the ground. It had a burnt up rod journal, which probably caused it to let go of the rod cap. So now I've got 3 crap engines.
Rebuild:
At the depth of my despair, I noticed that the top ring thickness on the '88 7.3 was the same as the 6.9. Which got me thinking. Why not put the 7.3 rings in the 6.9 and just trim the end gap to minimum specs?
The end gap on the top rings of the 6.9 were about .065! Specs call for .014-.024
The end gap on the second rings was bigger than my gauge went: about .090. Specs call for .060 to 0.070. So the old top rings are going to be demoted to second rings. The expanders on the oil rings were in bad shape, but between all 3 crap engines there were plenty for a working set.
I took the crank into the machinist to get the mains and rods turned down .010. He said he thought he had a std. size 6.9 crank in the back that had been saved for a rebuild that never happened. He did, and $250. later it was mine. Don, my machinist, mentioned that a standard size factory crank was better than a turned down crank for a number of reasons:
1) Its marginally stronger because of the extra metal.
2) It has the factory heat treating on the journals.
3) Its really hard to match the factory fillets.
4) It cost less than turning down the crank.
Works for me!
Ok, so now I have a marginal block, a good crankshaft, some marginal pistons. Time to order some main and rod bearings and put the bottom end together!
The crank sat on the new standard bearing that had a coating of a mix of oil and STP. The STP is nice and sticky and will stick around until the fresh oil gets to it. Same oil-STP mix for the wrist pins, and rod bearings. I reused the rear seal, and the front seal from the 1991. The rear teflon seal was in good condition and fit snugly over the crankshaft. The seal did not match previous seal wear groove in the crank. Same with the front. Awesome! The Teflon seals get installed dry. Its says so right on the seal.
No oil for the piston rings! I just used some biodiesel. Since I was using used rings, I felt this would help them seat faster. Biodiesel has pretty good lubricity properties as well.
I disassembled the hydraulic roller lifters and cleaned them thoroughly. Same with the rest of the valve train parts. Lots of cleaning. That is what took the most time.
The heads were another matter. This engine had been worked/abused as evidenced by the wear on the valves. The valves had a groove of about 0.010 where the valve seats had worn them away. Surprisingly, the valve guide clearance was in spec. Since this is a Redneck rebuild, I chucked the valves into my drill which I had clamped in the vice and took the grinding stone to the valves. I cleaned all the buildup and crap off the stems and ground the valves down until there was no more pitting. I even had to grind the tops down on some of the valves they were so bad. The key to getting the valve seating angle correct was to grind the valve down slowly and evenly. I had lots of light and my 2.75 magnifier glasses on. It took a lot of time; hours and hours. I takes a steady hand and lots of sand paper too. I used a 40 grit to cleanup after the grinding stone, and a 100 grit to clean up the 40 grit. I am actually amazed at how well it turned out. After lapping the valves and seeing how well the valve matched the seat, I was truly proud of my Redneck rebuilding ability. BTW I don't buy the 2 Degree valve to seat difference. The valves transfer most of their heat through the valve seat, and the more contact area you have, the more heat you can move! Sure, the 2 Degree difference will provide a tighter seal on the valve seat, but so what, the valves will just burn up until they get the minimum contact area that they need, and by then your valves will have grooves in them. A good machinist should be able to provide a good contact area with good sealing without any difference in valve angle.
I was able to blend the contact area back to the stem and provide a nice radiused edge from the margin to the face of the valve. No sharp edges to glow on the valve. The seats were in amazingly good condition considering the hard life this engine had. Its the kind of thing that makes me respect the engineers that designed and built this engine.
It is an amazingly tough engine! That is probably why there are so many running 25 years later!
I was so happy with the way the valve job turned out, that I was inspired to port the heads. Nothing major, just clean up the casting flash and do a little bowl blend, and smooth out the transtions between the casting and the machining. After putting the heads together, the valves even held methyl alcohol.
I had already bought the head gaskets when I thought that was all it needed.
The 6.9 got the cam, lifters and valve train from the '93 7.3. It also got the oil cooler from the '93 after I replace the o-rings. I should have bought the oil cooler o-rings when I bought the head gaskets, but since I didn't, I went to the International stealership to get them. Would you believe $43.98 for the set? That is $11. per o-ring. You would think they are made of unobtainium. Why do I always walk funny when I leave the stealership?
I made my own gaskets too. I bought some gasket paper and used the set that I bought as templates. I took my time and used a sharp razor knife to cut the gaskets out. I cut out the big shape first, then the little holes, then finally the largest cutout. This turned out to be the best way to make the gasket without messing it up. I used these home-made gaskets on the engine. It took a long time to cut the gaskets, and I lost the feeling in my index finger on my right hand for 2 weeks from pressing so ******* the razor knife!
I reused the best looking valley pan. When I put the heads on, before I torqued down the heads,I installed the valley pan and intake manifold and snugged up the intake manifold bolts. I remember the last 7.3 engine that I put together. I was unhappy with the way the valley pan and intake manifold fit on after bolting on the heads, so I thought I would try this method. I'm happy with it.
The engine also got ARP head studs. Since this engine had already been "rebuilt" once before, I did not want to reuse the head bolts again. Besides, the original head bolts were too small to begin with. That is why IH went with the bigger head bolts on the 7.3.
The dual mass flywheel was pooched. Most of the plastic pucks in the springs where pounded out, so I used my old one from the previous 7.3 rebuild, The new DMF that I got with the '93 7.3 got used on it, so I used the least worse one. At least the plastic pucks weren't pounded out. I repacked the throw-out bearing too. Normally this is not something that is repackable, being a sealed bearing, but I just unsealed it, cleaned it, repacked and resealed it.
After getting the engine all bolted back in, I filled up a PowerStroke oil filter and screwed it on. I filled up the crankcase with oil, radiator with coolant and cranked the engine over without the glow plugs until it built oil pressure. It takes more time then you might think for the oil pressure to build. 3 long cranking sessions with enough time to let the starter to cool down, This also doubles as crank time to bleed the injectors. The injection pump was one that I picked up at the local Pick-n-Pull off an '88 van. It cost me a whole $20.32 including core charge! I wound up getting the whole engine (6.9l with ventilated oil pan). (But that is another story) I knew it worked because I had swapped it out earlier and it worked great. The glow plugs were then put in and the second cranking session it roared to life. I love this engine already.
The next weekend I set the timing at 7 degrees BTDC (I run 100% biodiesel) and drove it around a bit up some big hills to see how it performed. It worked great! The injectors got a new fuel line return line kit too. The injectors where a set of E code injectors that I had reshimmed up to 1800 PSI for use on my 1991 two years ago. The 1991 got a new set of BB code injectors because I wanted to see if they were as good as they're made out to be. The 1991 runs better now, but it also got a new fuel return line kit and the timing was also set. Anyway, I pop tested the E codes to see if they had changed much. They had not. They still had a good spray pattern and all popped at 1800 PSI, so in the 6.9 they went.
I am very happy with the engine so far, but have not put very many kilometers on it yet. I got caught with my pants down so to speak. As I mentioned earlier, I run 100% biodiesel in the summer, and the temperature dropped suddenly from 10C to -7C! Summer is over. My biodiesel clouds up at about 0C so I've been waiting for some warmer weather so I can fire it up and get some #2 diesel to put in it. Well it hit +2C today, I was able to fire up both the '92 and the '86 and get some dino diesel in them.
So far it runs good and no leaks. Folks must wonder when they see me driving down the road in an big old noisey diesel truck with a big smile on my face. Most people don't smile when they drive. I do, but I have something to smile about.
Total cost:
Item Date Qty. Description Unit Extended
1 2011-03-30 1 ARP Head Studs 263.51 263.51
2 2011-09-16 1 Head Gasket set 104.49 104.49
3 2012-01-14 1 Crankshaft Std. Mains & Rods 250.00 250.00
4 2012-01-20 1 FLP3046 Gasket paper 13.56 13.56
5 2012-01-20 1 FLP3045 Gasket paper 6.76 6.76
6 2011-09-16 8 Connecting Rod Bearing 10.16 81.28
7 2011-09-16 1 Crankshaft Main Bearing Set 138.50 138.50
8 2011-09-16 1 Oil Cooler Mounting Kit 3.25 3.25
9 2011-10-02 1 4 cans Paint 24.62 24.62
10 2011-12-27 2 1804414C1 O-Ring 9.52 19.04
11 2011-12-27 2 1807563C1 O-Ring 12.47 24.94
12 2011-12-27 1 1804136C3 Water Pump Gasket 19.48 19.48
13 2011-12-27 1 1804480C92 34.90 34.90
14 2012-01-14 1 CDR 52.50 52.50
15 2012-01-24 1 Fuel Line Return Kit 42.00 42.00
16 2012-03-16 1 Wix Oil Filter 51734MP (Powerstroke filter 21 Micron) 17.97 17.97
17 2012-07-14 1 Fuel Injection Distributor 20.32 20.32
Total 1117.12
The grampulator.
History:
I bought this 6.9 L engine from a guy who said that it a good strong engine that had been rebuilt not that long ago. Well, I needed an engine while I rebuilt the 7.3 that had been overheated (a whole other story). Well, about 6 months later after I was just getting it running good, it blew a head gasket.
The 7.3 was ready to put back in, so I pulled the engine. Good thing too. As I started disassembling, it I realized how bad it really was. It was standard bore,and the rod and main bearings were also standard size, but the bearings were shot. Even the crank mains and rod journals were damaged. It looks like the engine had been run dry of oil! Even the fuel cam eccentric was worn.
You must be registered for see images attach
I suppose it may have been from the oil being diluted by fuel in the past. I found some fuel pump parts in the oil pan! So what I thought was going to be head gasket replacement was now starting to get more costly. The ring end gaps were way beyond spec. Judging by the look of the pistons this engine had never been rebuilt. It had eaten at least a couple of glow plugs and one piston had clipped a valve.
You must be registered for see images attach
You must be registered for see images attach
The pistons had some melting done on them too.
You must be registered for see images attach
The BB code injectors were said to have been replaced, but they were crap. I think this engine had been worked like a Mexican donkey.
The piston to bore clearance and the bore taper was just in spec, so I could have gotten by with a set of rings, but if I was going that far, I might as well go .010 oversize on the bore and get new pistons and rings. Machining work is expensive tho, as are new pistons and rings. I already had a '93 7.3 with cavitation, a cracked piston and a badly scored crank. I had picked it up for parts for $200. It had a brand new DMF and clutch on it when I got it! I got my money's worth out of it right there. The other engine was a 7.3 out of an '88. I got this one free with the parts truck that I got along with the 1986 F-250 4x4 that I bought. This one was a leaker and it looks like it had been driven into the ground. It had a burnt up rod journal, which probably caused it to let go of the rod cap. So now I've got 3 crap engines.
Rebuild:
At the depth of my despair, I noticed that the top ring thickness on the '88 7.3 was the same as the 6.9. Which got me thinking. Why not put the 7.3 rings in the 6.9 and just trim the end gap to minimum specs?
You must be registered for see images attach
You must be registered for see images attach
You must be registered for see images attach
The end gap on the top rings of the 6.9 were about .065! Specs call for .014-.024
The end gap on the second rings was bigger than my gauge went: about .090. Specs call for .060 to 0.070. So the old top rings are going to be demoted to second rings. The expanders on the oil rings were in bad shape, but between all 3 crap engines there were plenty for a working set.
I took the crank into the machinist to get the mains and rods turned down .010. He said he thought he had a std. size 6.9 crank in the back that had been saved for a rebuild that never happened. He did, and $250. later it was mine. Don, my machinist, mentioned that a standard size factory crank was better than a turned down crank for a number of reasons:
1) Its marginally stronger because of the extra metal.
2) It has the factory heat treating on the journals.
3) Its really hard to match the factory fillets.
4) It cost less than turning down the crank.
Works for me!
Ok, so now I have a marginal block, a good crankshaft, some marginal pistons. Time to order some main and rod bearings and put the bottom end together!
The crank sat on the new standard bearing that had a coating of a mix of oil and STP. The STP is nice and sticky and will stick around until the fresh oil gets to it. Same oil-STP mix for the wrist pins, and rod bearings. I reused the rear seal, and the front seal from the 1991. The rear teflon seal was in good condition and fit snugly over the crankshaft. The seal did not match previous seal wear groove in the crank. Same with the front. Awesome! The Teflon seals get installed dry. Its says so right on the seal.
You must be registered for see images attach
You must be registered for see images attach
No oil for the piston rings! I just used some biodiesel. Since I was using used rings, I felt this would help them seat faster. Biodiesel has pretty good lubricity properties as well.
I disassembled the hydraulic roller lifters and cleaned them thoroughly. Same with the rest of the valve train parts. Lots of cleaning. That is what took the most time.
The heads were another matter. This engine had been worked/abused as evidenced by the wear on the valves. The valves had a groove of about 0.010 where the valve seats had worn them away. Surprisingly, the valve guide clearance was in spec. Since this is a Redneck rebuild, I chucked the valves into my drill which I had clamped in the vice and took the grinding stone to the valves. I cleaned all the buildup and crap off the stems and ground the valves down until there was no more pitting. I even had to grind the tops down on some of the valves they were so bad. The key to getting the valve seating angle correct was to grind the valve down slowly and evenly. I had lots of light and my 2.75 magnifier glasses on. It took a lot of time; hours and hours. I takes a steady hand and lots of sand paper too. I used a 40 grit to cleanup after the grinding stone, and a 100 grit to clean up the 40 grit. I am actually amazed at how well it turned out. After lapping the valves and seeing how well the valve matched the seat, I was truly proud of my Redneck rebuilding ability. BTW I don't buy the 2 Degree valve to seat difference. The valves transfer most of their heat through the valve seat, and the more contact area you have, the more heat you can move! Sure, the 2 Degree difference will provide a tighter seal on the valve seat, but so what, the valves will just burn up until they get the minimum contact area that they need, and by then your valves will have grooves in them. A good machinist should be able to provide a good contact area with good sealing without any difference in valve angle.
You must be registered for see images attach
I was able to blend the contact area back to the stem and provide a nice radiused edge from the margin to the face of the valve. No sharp edges to glow on the valve. The seats were in amazingly good condition considering the hard life this engine had. Its the kind of thing that makes me respect the engineers that designed and built this engine.
It is an amazingly tough engine! That is probably why there are so many running 25 years later!I was so happy with the way the valve job turned out, that I was inspired to port the heads. Nothing major, just clean up the casting flash and do a little bowl blend, and smooth out the transtions between the casting and the machining. After putting the heads together, the valves even held methyl alcohol.
I had already bought the head gaskets when I thought that was all it needed.The 6.9 got the cam, lifters and valve train from the '93 7.3. It also got the oil cooler from the '93 after I replace the o-rings. I should have bought the oil cooler o-rings when I bought the head gaskets, but since I didn't, I went to the International stealership to get them. Would you believe $43.98 for the set? That is $11. per o-ring. You would think they are made of unobtainium. Why do I always walk funny when I leave the stealership?
I made my own gaskets too. I bought some gasket paper and used the set that I bought as templates. I took my time and used a sharp razor knife to cut the gaskets out. I cut out the big shape first, then the little holes, then finally the largest cutout. This turned out to be the best way to make the gasket without messing it up. I used these home-made gaskets on the engine. It took a long time to cut the gaskets, and I lost the feeling in my index finger on my right hand for 2 weeks from pressing so ******* the razor knife!
I reused the best looking valley pan. When I put the heads on, before I torqued down the heads,I installed the valley pan and intake manifold and snugged up the intake manifold bolts. I remember the last 7.3 engine that I put together. I was unhappy with the way the valley pan and intake manifold fit on after bolting on the heads, so I thought I would try this method. I'm happy with it.
The engine also got ARP head studs. Since this engine had already been "rebuilt" once before, I did not want to reuse the head bolts again. Besides, the original head bolts were too small to begin with. That is why IH went with the bigger head bolts on the 7.3.
The dual mass flywheel was pooched. Most of the plastic pucks in the springs where pounded out, so I used my old one from the previous 7.3 rebuild, The new DMF that I got with the '93 7.3 got used on it, so I used the least worse one. At least the plastic pucks weren't pounded out. I repacked the throw-out bearing too. Normally this is not something that is repackable, being a sealed bearing, but I just unsealed it, cleaned it, repacked and resealed it.
After getting the engine all bolted back in, I filled up a PowerStroke oil filter and screwed it on. I filled up the crankcase with oil, radiator with coolant and cranked the engine over without the glow plugs until it built oil pressure. It takes more time then you might think for the oil pressure to build. 3 long cranking sessions with enough time to let the starter to cool down, This also doubles as crank time to bleed the injectors. The injection pump was one that I picked up at the local Pick-n-Pull off an '88 van. It cost me a whole $20.32 including core charge! I wound up getting the whole engine (6.9l with ventilated oil pan). (But that is another story) I knew it worked because I had swapped it out earlier and it worked great. The glow plugs were then put in and the second cranking session it roared to life. I love this engine already.
The next weekend I set the timing at 7 degrees BTDC (I run 100% biodiesel) and drove it around a bit up some big hills to see how it performed. It worked great! The injectors got a new fuel line return line kit too. The injectors where a set of E code injectors that I had reshimmed up to 1800 PSI for use on my 1991 two years ago. The 1991 got a new set of BB code injectors because I wanted to see if they were as good as they're made out to be. The 1991 runs better now, but it also got a new fuel return line kit and the timing was also set. Anyway, I pop tested the E codes to see if they had changed much. They had not. They still had a good spray pattern and all popped at 1800 PSI, so in the 6.9 they went.
I am very happy with the engine so far, but have not put very many kilometers on it yet. I got caught with my pants down so to speak. As I mentioned earlier, I run 100% biodiesel in the summer, and the temperature dropped suddenly from 10C to -7C! Summer is over. My biodiesel clouds up at about 0C so I've been waiting for some warmer weather so I can fire it up and get some #2 diesel to put in it. Well it hit +2C today, I was able to fire up both the '92 and the '86 and get some dino diesel in them.
So far it runs good and no leaks. Folks must wonder when they see me driving down the road in an big old noisey diesel truck with a big smile on my face. Most people don't smile when they drive. I do, but I have something to smile about.
Total cost:
Item Date Qty. Description Unit Extended
1 2011-03-30 1 ARP Head Studs 263.51 263.51
2 2011-09-16 1 Head Gasket set 104.49 104.49
3 2012-01-14 1 Crankshaft Std. Mains & Rods 250.00 250.00
4 2012-01-20 1 FLP3046 Gasket paper 13.56 13.56
5 2012-01-20 1 FLP3045 Gasket paper 6.76 6.76
6 2011-09-16 8 Connecting Rod Bearing 10.16 81.28
7 2011-09-16 1 Crankshaft Main Bearing Set 138.50 138.50
8 2011-09-16 1 Oil Cooler Mounting Kit 3.25 3.25
9 2011-10-02 1 4 cans Paint 24.62 24.62
10 2011-12-27 2 1804414C1 O-Ring 9.52 19.04
11 2011-12-27 2 1807563C1 O-Ring 12.47 24.94
12 2011-12-27 1 1804136C3 Water Pump Gasket 19.48 19.48
13 2011-12-27 1 1804480C92 34.90 34.90
14 2012-01-14 1 CDR 52.50 52.50
15 2012-01-24 1 Fuel Line Return Kit 42.00 42.00
16 2012-03-16 1 Wix Oil Filter 51734MP (Powerstroke filter 21 Micron) 17.97 17.97
17 2012-07-14 1 Fuel Injection Distributor 20.32 20.32
Total 1117.12
The grampulator.
You must be registered for see images attach
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You must be registered for see images attach
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Timed it up to about 9.5 degrees advance @ 2000, and off they went.
When my son got back from Prince George, The truck was running like crap. I had a devil of a time trying to get it timed up right. It was way too retarded. I wound up advancing the IP gear by two teeth to get the timing right! Something is definitely wrong. Fortunately, Jbevs sold me his Baby Moose injection pump. It just hadn't arrived yet, so I avoided driving the antique until it arrived. It ran, but it was horrible to drive.
I just regret not having done the Lucky Mod on the DMF while I had it apart. Oh well...
