-
Welcome to The Truck Stop! We see you haven't REGISTERED yet.
Your truck knowledge is missing!
- Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
- We have tons of knowledge here for your diesel truck!
- Post your own topics and reply to existing threads to help others out!
- NO ADS! The site is fully functional and ad free!
Problems registering? Click here to contact us!
Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!
Bringing 1993 Patch back from the dead...
- Thread starter WarWagon
- Start date
@Burning oil Now here is something you don't see every day.
@Twisted Steel Performance
Shots of the piston. Rings were free on the piston and gaps were still 180 degrees off like I set them.
Note the wear on the inner spring from the broken valve spring on the side of the pic.
@Twisted Steel Performance
Shots of the piston. Rings were free on the piston and gaps were still 180 degrees off like I set them.
Note the wear on the inner spring from the broken valve spring on the side of the pic.
Last edited:
ak diesel driver
6.5 driver
Is it just the rag or is the top edge of the piston missing some material?
Just the rag. Pistons are fine other than the surface cracking.
MrMarty51
Well-Known Member
Is that timing gear set something that You had installed ?
Those pistons have been overly hot. And with no oil squirters it shows.
Will L.
Well-Known Member
Oh yeah- that is a heat soaked piston.
So is the broken valve spring the only one that hit the piston, or did others? Intakes or exhausts?
So is the broken valve spring the only one that hit the piston, or did others? Intakes or exhausts?
ak diesel driver
6.5 driver
That's an aftermarket set. Leroy's timekeeper
MrMarty51
Well-Known Member
Nice. Going to take a lot of time to get such nice upgrades for the enjun in Mine truck. Next on the list is the Kennedy diesel fan clutch, then the fluid dampener system.
People rarely name engines although they name vehicles. I dub thee 6.2 engine in/out of/around Patch: "Christine"
Never underestimate the fury of a military 6.2, particularly one that just…won’t…die.
Stephen King said he chose a 1958 Plymouth Fury as the story’s central figure because it was a “forgotten car.” Well, the 6.2 is a "forgotten diesel".
The 6.2 came out of a military rig, was rebuilt, and continued to be used in the military. The rig it was in got sent to the range as target practice. The rig I put this 6.2 in got more Elk than most hunter's guns that same month. 2 trucks made 1 and this engine wound up in it after a uh... a time out. It ate a worm clamp, piston set, and a set of heads. Out and back in. Now this: just…won’t…die. Seriously the all-out effort shown above is conclusive evidence. We have tried everything and can say over-advancing the timing is the closest we have come along with over-speed. (It needed the over-advance to run on low compression.)
So I had a long chat with @Twisted Steel Performance . Literally got a dose of my own medicine about rings. I tell people to do rings all the time due to overheating and blowby. Because *No Budget* here and having zero blowby I was figuring on reusing them. We have overlooked how hot the rings must have been on the "well done" pistons, OOPS! Chris was like 'use the coating money for rings and run uncoated pistons.' In context of a retired rig and worn engine. This is a in town runabout and towing on "The Real Highway IN Hell" is no longer in it's future like it was in the past. Chris pointed out the luck I had: Camshaft failures are worse than crankshaft failures. I am lucky the engine didn't simply go "BOOM!" at high RPM during the said snap test. With the ATT and Moose Jr. the top coating can do some good. Lower compression is said to be better.
Bottom line is pistons are on the way to get coated.
(I will also be running thicker head gaskets to cheaply lower compression.)
My next call was to Total Seal Piston Rings. I told them what was going on with this engine and the results of how clean the Gapless were keeping the engine oil. Total Seal agreed that I should use new rings.
Site vendors now carry gapless rings both in the send your own in to be made gapless and I believe sell the Total Seal Brand. Regardless Total Seal is looking for oil samples of "before and "after" installing Gapless rings: Let me clarify. They want the actual oil sample bottle to do their own testing. I am NOT going to run conventional rings again so I can't provide a sample. Get in touch with me on this and I will post elsewhere not buried in here.
Bottom line new Total Seal Gapless Rings are on the way.
Looking at the valves I see where they are contacting 3/4 of the face and then have carbon spots on the rest indicating slight bend. Just enough to loose compression. I am not going to bother the *experts* head shop with these valves but will be using new valves and springs.
Never underestimate the fury of a military 6.2, particularly one that just…won’t…die.
Stephen King said he chose a 1958 Plymouth Fury as the story’s central figure because it was a “forgotten car.” Well, the 6.2 is a "forgotten diesel".
The 6.2 came out of a military rig, was rebuilt, and continued to be used in the military. The rig it was in got sent to the range as target practice. The rig I put this 6.2 in got more Elk than most hunter's guns that same month. 2 trucks made 1 and this engine wound up in it after a uh... a time out. It ate a worm clamp, piston set, and a set of heads. Out and back in. Now this: just…won’t…die. Seriously the all-out effort shown above is conclusive evidence. We have tried everything and can say over-advancing the timing is the closest we have come along with over-speed. (It needed the over-advance to run on low compression.)
So I had a long chat with @Twisted Steel Performance . Literally got a dose of my own medicine about rings. I tell people to do rings all the time due to overheating and blowby. Because *No Budget* here and having zero blowby I was figuring on reusing them. We have overlooked how hot the rings must have been on the "well done" pistons, OOPS! Chris was like 'use the coating money for rings and run uncoated pistons.' In context of a retired rig and worn engine. This is a in town runabout and towing on "The Real Highway IN Hell" is no longer in it's future like it was in the past. Chris pointed out the luck I had: Camshaft failures are worse than crankshaft failures. I am lucky the engine didn't simply go "BOOM!" at high RPM during the said snap test. With the ATT and Moose Jr. the top coating can do some good. Lower compression is said to be better.
Bottom line is pistons are on the way to get coated.
(I will also be running thicker head gaskets to cheaply lower compression.)
My next call was to Total Seal Piston Rings. I told them what was going on with this engine and the results of how clean the Gapless were keeping the engine oil. Total Seal agreed that I should use new rings.
Site vendors now carry gapless rings both in the send your own in to be made gapless and I believe sell the Total Seal Brand. Regardless Total Seal is looking for oil samples of "before and "after" installing Gapless rings: Let me clarify. They want the actual oil sample bottle to do their own testing. I am NOT going to run conventional rings again so I can't provide a sample. Get in touch with me on this and I will post elsewhere not buried in here.
Bottom line new Total Seal Gapless Rings are on the way.
Looking at the valves I see where they are contacting 3/4 of the face and then have carbon spots on the rest indicating slight bend. Just enough to loose compression. I am not going to bother the *experts* head shop with these valves but will be using new valves and springs.
Last edited:
To those that are following this, this is what happens when a bigger turbo, more fuel, small cups, high compression etc is done without the supporting mods.
JayTheCPA
Well-Known Member
Mods, shmods . . . We are just waiting to see how long Christine lasts! 
Better yet, how about we put it in Will's rig and let WW drive for a while
Better yet, how about we put it in Will's rig and let WW drive for a while
I have always said I can serve as a bad example. In no way do I disagree that one can build a better engine for the mods.
This engine and truck is a product of "the day" and The Great Depression V2.0. Only reason it's still rolling is because it's cheaper than getting anything else as a spare vehicle.
I understand, that's one reason i'm doing the 18.1 standard bore pistons.
I wanted to expand on an observation as to the limits of these engines: EGT related to timing. Looking through the carnage here one could question me saying high EGT alone won't kill a 6.2 6.5 engine even with uncoated pistons. Yet I have torn this engine down three times and the first two times there wasn't this kind of damage. High EGT means you have a rich mixture and may not have enough air for the fuel. In context of this engine it isn't something you need to get heartburn over and drive with one eye on the EGT gauge like other engines. No, that eye had better be on the ECT gauge!
The first time this engine was torn down was after towing 7000 miles through the 6.5 killer grades with a GM3 ignoring the 1400+ EGT with a turned up 6.5 IP. I popped a head off after we pulled the engine out of the elk wrecked truck. Then the engine went into the 2 trucks to 1 good one. Then towed some, but, not as much as before.
Add ATT turbo and a bunch of bad biodiesel. Went from 15 PSI from the ATT (18 during a shift or towing) to 12 PSI with 6.2 pumps. Ate a worm clamp and pulled the engine apart. Found cracked mains, but, pistons were fine in context of the cracking shown here. Maybe lower compression could have helped the GM cracking design defect of 12mm outer main bolts. I tossed a set of heads on from a worn out engine and new slugs with gapless rings. As far as engine builders go I am running scrap metal at this point.
High EGT then tear down:
And since the above overhaul I have been running fuel screw turned all the way in 6.2 pumps that deliver slightly more fuel than a stock setting 6.5 pump. I have had to run slightly advanced timing to keep the white smoke down due to high-pop injectors. Last couple years we have had an injector knock due to the hi-pop injectors and need for advanced timing. Possible the injectors were hurt somehow to cause the knocking. One of the only mods I really hated was going high pop injectors esp. because it took so long to figure that part out. Hard starting cold with a misfire till the precups could get hot. I tried a used 6.5 pump that apparently had a failing governor. It ran good for awhile although still hard to start. Emissions testing I expected it to pass. It accelerated once to over 4200 RPM and then for the rest of the snap emissions testing was slow to accelerate with lots of white smoke. (Luck I didn't have to be towed then and there.) New Moose pump and then near stock or lower pop injectors were put in. Easier starting but still having trouble with misfire after start till the precups get hot. I had to really advance the timing: I pushed the truck another 3000 miles or so before tearing into it. Glow plug erosion indicated too much timing. Gamble on cracked mains paid off for years and nearly 40K miles more service.
The first time this engine was torn down was after towing 7000 miles through the 6.5 killer grades with a GM3 ignoring the 1400+ EGT with a turned up 6.5 IP. I popped a head off after we pulled the engine out of the elk wrecked truck. Then the engine went into the 2 trucks to 1 good one. Then towed some, but, not as much as before.
Add ATT turbo and a bunch of bad biodiesel. Went from 15 PSI from the ATT (18 during a shift or towing) to 12 PSI with 6.2 pumps. Ate a worm clamp and pulled the engine apart. Found cracked mains, but, pistons were fine in context of the cracking shown here. Maybe lower compression could have helped the GM cracking design defect of 12mm outer main bolts. I tossed a set of heads on from a worn out engine and new slugs with gapless rings. As far as engine builders go I am running scrap metal at this point.
High EGT then tear down:
And since the above overhaul I have been running fuel screw turned all the way in 6.2 pumps that deliver slightly more fuel than a stock setting 6.5 pump. I have had to run slightly advanced timing to keep the white smoke down due to high-pop injectors. Last couple years we have had an injector knock due to the hi-pop injectors and need for advanced timing. Possible the injectors were hurt somehow to cause the knocking. One of the only mods I really hated was going high pop injectors esp. because it took so long to figure that part out. Hard starting cold with a misfire till the precups could get hot. I tried a used 6.5 pump that apparently had a failing governor. It ran good for awhile although still hard to start. Emissions testing I expected it to pass. It accelerated once to over 4200 RPM and then for the rest of the snap emissions testing was slow to accelerate with lots of white smoke. (Luck I didn't have to be towed then and there.) New Moose pump and then near stock or lower pop injectors were put in. Easier starting but still having trouble with misfire after start till the precups get hot. I had to really advance the timing: I pushed the truck another 3000 miles or so before tearing into it. Glow plug erosion indicated too much timing. Gamble on cracked mains paid off for years and nearly 40K miles more service.
And "Christine" Died on the operating table last night.
You see with Gapless rings the old trick of turning the engine over and letting the soot show the mains cracks doesn't work very well, because, Um... just not enough black in the oil to make the cracks show up. Yes, having a very hard time seeing the old cracks.
So looking at the mains, last time, 2 of the 5 main webs had cracks. This time on final inspection I found a "new" crack on the #2 main. So this is #2, #3, #4 mains all have cracks with the #4 being the worst cracked on both sides on the outer main bolt clear to the relief cut in for the cylinder. These are the ones I can see without any crack detection tools.
IF and only IF I was rerunning the old rings etc. it would still be a very bad gamble to find out when it's going to let go. Further with the new parts coming it wouldn't do the said vendors any justice to run this. Combined with needing a different cam and, oh yeah, that bad cam scratched each and every bearing on the way out due to having a sharp raised ridge on the side. No Thanks on the "Procedure to remove 6.2 crankshaft": Remove mains bolts from #1 and # 5 mains and then lift out crankshaft in (x) number of pieces.
So Black-Friday Cyber-Monday, whatever, sale... Hey Ted's Trucks: Send me the "rest of the 6.2 engine" with that used camshaft I ordered, eh? And make sure it's a standard bore 6.2 not an OS for whatever dumb bad luck I got reason. No, the paint doesn't make it "go fast"... but if you want to paint it, yeah, will be the newest matching paint on the truck...
The next $600 "heartburn" I have to get over: Do I send out the 6.5 heads to be rebuilt or put the diamond precups in the 6.2 heads?
You see with Gapless rings the old trick of turning the engine over and letting the soot show the mains cracks doesn't work very well, because, Um... just not enough black in the oil to make the cracks show up. Yes, having a very hard time seeing the old cracks.
So looking at the mains, last time, 2 of the 5 main webs had cracks. This time on final inspection I found a "new" crack on the #2 main. So this is #2, #3, #4 mains all have cracks with the #4 being the worst cracked on both sides on the outer main bolt clear to the relief cut in for the cylinder.
These are the ones I can see without any crack detection tools. IF and only IF I was rerunning the old rings etc. it would still be a very bad gamble to find out when it's going to let go. Further with the new parts coming it wouldn't do the said vendors any justice to run this. Combined with needing a different cam and, oh yeah, that bad cam scratched each and every bearing on the way out due to having a sharp raised ridge on the side. No Thanks on the "Procedure to remove 6.2 crankshaft": Remove mains bolts from #1 and # 5 mains and then lift out crankshaft in (x) number of pieces.
So Black-Friday Cyber-Monday, whatever, sale... Hey Ted's Trucks: Send me the "rest of the 6.2 engine" with that used camshaft I ordered, eh? And make sure it's a standard bore 6.2 not an OS for whatever dumb bad luck I got reason. No, the paint doesn't make it "go fast"... but if you want to paint it, yeah, will be the newest matching paint on the truck...
The next $600 "heartburn" I have to get over: Do I send out the 6.5 heads to be rebuilt or put the diamond precups in the 6.2 heads?
Plan B. Yeah, the old made in Japan air powered one that will sheer off lug nut studs.
Are the Red threadlocker head studs going to come out of the block peacefully or are we going to war? Snap the studs off, break the block, or come on out? Directions are like heat the red threadlocker area up to 550F degrees Blah, Blah, Blah. For the $200 in studs I am not going to work around something that hot. So double up the nuts and see if the will come out with hand tools, an impact, or a big impact.
I have worried about this very day for years by saying this block is going to the scrap yard with the red threadlocker studs in it. I have enjoyed zero leaks from the studs with the heads off 3 times. I don't have so much as a rusty thread on the studs.
They waved the white flag and although stiff all the way out: came out with a long ratchet. This side anyway.
Are the Red threadlocker head studs going to come out of the block peacefully or are we going to war? Snap the studs off, break the block, or come on out? Directions are like heat the red threadlocker area up to 550F degrees Blah, Blah, Blah. For the $200 in studs I am not going to work around something that hot. So double up the nuts and see if the will come out with hand tools, an impact, or a big impact.
I have worried about this very day for years by saying this block is going to the scrap yard with the red threadlocker studs in it. I have enjoyed zero leaks from the studs with the heads off 3 times. I don't have so much as a rusty thread on the studs.
They waved the white flag and although stiff all the way out: came out with a long ratchet. This side anyway.