Welp, I blow'd er up. Time for a new build!

[Hink]

Hey all,

I've finally had the time to sit down and start getting a condensed version of what led up to my current build and I'll add more as I get further along.

So to start, I have been running an Optimizer that I added all the improvements that you see in my signature. All of which were added to make the truck run strong for many thousands of miles.
Well, basically, I can break pretty much anything.
At the end of this last summer, I was hauling my RV to Eastern Washington to see friends for a end of summer trip. I needed to get under the hood to do something and in doing so, pushed a plastic fitting in the heater core line up against the turbo which decided to melt and explode right when I was cresting a hill under full power.



Result; head gasket blown out about 1/2" out from under the head at the #8
After getting it home, I pulled the motor and found further carnage.
Let me tell you this, don't let anyone tell you that Optimizer blocks don't crack.

- I had main web cracks at the outside bolts on the three inner webs with the #2 web cracked so bad that it likely would have fallen into the oil pan in short order.



- I also had spider cracks on all 8 piston tops with pitting and large erosion at the edge where it scuffed the cylinder wall.



- My DSG timing gears also self destructed and lost a snap ring that ended up in the oil pan.

So what the hell happened to this motor?
Me. I'm what happened to this motor.

Again, a condensed version...

The motor was a military take out from Ted's and was in great shape, I would buy another from them again (as a matter of fact, I plan on it). But who knows what kind of life it had before I got it?

I removed the heads to install ARP head studs and was reminded of a couple things that I didn't like...

- This motor came out of a naturally aspirated HMMWV. The concern here was that the pistons were not coated like the turbo versions are. After a bit of research, I found the consensus was that they would would be fine. And in truth, they would be fine in an otherwise stock motor, but this thing wasn't going to be very stock.

- Also being naturally aspirated, the heads had some of the smallest precups made for these
motors. I believe the theory that they run hotter and certainly don't allow for as much power as the later design precups.

There were several other major issues that all conspired in the destruction of my block and pistons.

- I had bumped up the timing quite a while ago. But, a few pictures of some other's failed pistons caught my eye. They looked a lot like mine with spider web cracks and they had obviously been heated to an extreme degree.

Advanced timing was identified as the culprit.

- This was all before I solved my overheating issues with so all the heat attacking the piston tops wasn't able to be removed.

- The first day I had it running, the upper radiator hose comes off and I subject my motor to it's first thermal shock.

- The injectors I ended up using were rebuilt by a local shop and I was always unhappy with them and we all know that bad injectors can destroy a motor.

And let's not forget that this motor was hydrolocked at one point.

The water/meth cools everything down and helps prevent pre ignition so that likely actually helped.

The last bit of damage was when installing timing gears I couldn't get the idler gears in so I installed a smaller gear.
Some time after getting the truck back on the road, I realized what I had done wrong during install which meant that I likely had an idler gear that was too small.
Sure enough, when I removed the oil pan at the start of the teardown, there was that ear to a circlip at the bottom of the pan.
The gears had fit so loose that they wobbled around in there and eventually broke the clip, allowing the gear axles to ruin the housing they ride in and some metal to get into the bearings.
Luckily, no damage to the crank, rods, or any other hard part could be found.

I am pretty surprised at the amount of cracking the block showed though. But with all the abuse that I put it through, and how horribly out of balance these engines are normally and the fact that I had no opportunity to magnaflux this block to check for cracks before the build, I guess it's not too hard to accept.


So now, the plan...

- I'll reuse the cam, crank, and rods.
- I went into the new block and smoothed all sharp edges to remove any stress risers and beveled/smoothed all main bearing bolt holes that could aid in the start of any cracks.
- I'll fix the problem areas and improve others while I'm in there.
And I did something that I'm really excited about and that is balancing. I got the whole rotating assembly balanced so it'll run super smooth! I firmly believe that this will go a long way to help prevent any block cracks.
- I went with a GM OE piston and a full complement of the best ceramic coatings that can be found from @Twisted Steel Performance .
- I had a set of double square "T" precups on hand from a turbo '93 that are a big improvement over the old NA precups that I was running.
- I will still have the timing advanced, but only just a bit.
- I had already completely solved my heating issues starting with the standard heating upgrades and ending with Twisted Steel's thermal dispersant coated Champion radiator.
- In place of the crappy injectors, I got the best ones that I know of for the 6.5 that you can get from Kris Stratton.
- I tracked the hydrolock issues to Faulty AEM nozzles so I replaced them with much better Devils own nozzles and solenoid to completely eliminate the possibility of it happening again.
- I'll install Leroy's timing gear set. Properly this time.

Tonight I painted the block, and tomorrow I hope to start with assembly!!

 

[MrMarty51]

Sometimes there is blessings beyond the destruction. It sounds to Me like You are going to have one sweet enjun when it is finished.
I had the rotating assembly of My 1976Harley FLH electra glide balanced. That old critter was smooth and a joy to ride.

 

[WarWagon]

I would start out at stock timing because a quick way to ruin a diesel engine is with too much timing. We are talking instant hot oily parts embedded in the pavement from shattered cylinder liners, bent rods, melted pistons... It's a real fine line between advance for power and pre-ignition that melts things in seconds. Yes, advance brings on power as is known from Olds 5.7 Diesel days and shattered cylinders resulted. Sometimes the advance was from water in fuel and rusty IP internals. (IP locks up and then snaps free making a late timing event then an advanced timing event that broke stuff.)

So many things add up that it's hard to say, but, that piston also looks melted. Erosion is melting... 6.5 pistons are not coated all the way to the edge so you could have melted a 6.5 coated piston anyway.

The smaller precups would keep more fire/fuel in the chamber longer and or centrifugally separate the fuel air charge. Black smoke is not burning and the biggest PIA I had with NA precups. Possible the a charge that can be still burning when the exhaust valve opens for high EGT readings. The small precups when pushed out of their range cause so much to go wrong that you should start conservative on the timing and advance it later after you get the feel for proper precups with your other mods. Simply put the small precups are causing so much trouble that larger turbo precups doing away with this can blow your engine on settings you used to overcome the small precup limitations.

 

[Hink]

I would start out at stock timing because a quick way to ruin a diesel engine is with too much timing. We are talking instant hot oily parts embedded in the pavement from shattered cylinder liners, bent rods, melted pistons... It's a real fine line between advance for power and pre-ignition that melts things in seconds. Yes, advance brings on power as is known from Olds 5.7 Diesel days and shattered cylinders resulted. Sometimes the advance was from water in fuel and rusty IP internals. (IP locks up and then snaps free making a late timing event then an advanced timing event that broke stuff.)

So many things add up that it's hard to say, but, that piston also looks melted. Erosion is melting... 6.5 pistons are not coated all the way to the edge so you could have melted a 6.5 coated piston anyway.

The smaller precups would keep more fire/fuel in the chamber longer and or centrifugally separate the fuel air charge. Black smoke is not burning and the biggest PIA I had with NA precups. Possible the a charge that can be still burning when the exhaust valve opens for high EGT readings. The small precups when pushed out of their range cause so much to go wrong that you should start conservative on the timing and advance it later after you get the feel for proper precups with your other mods. Simply put the small precups are causing so much trouble that larger turbo precups doing away with this can blow your engine on settings you used to overcome the small precup limitations.

Yeah, I'm definitely going with low timing. And I forgot to even mention the water that got pumped into the tank at one point so who knows how much got into the motor or caused damage to the ip. The ip is likely fine since it doesn't sit for long and had steady fuel running through it.
But you're saying water in the fuel will advance the timing? Because I have had, at times, a sound that I didn't like that sounded very much like too much timing but then it went away within a few seconds.

Funny thing, I remember what you wrote about the smoke from the small pre cups but... I never had any.
I never understood it. I have my IP maxed out right now with the small cups and I would very rarely see any smoke. And my EGTs were never really an issue. Weird.

Thanks for the input, WW, I've had a hard time getting my head wrapped around the whole thing.

 

[Hink]

Sometimes there is blessings beyond the destruction. It sounds to Me like You are going to have one sweet enjun when it is finished.
I had the rotating assembly of My 1976Harley FLH electra glide balanced. That old critter was smooth and a joy to ride.

Oh yeah, that's one of the things that I'm most excited about. For the quiet and the smoothness, but as much as that, the likelihood of helping to prevent the cracking.

 

[EWC]

That's one of the reasons I had mine balanced . $200 in heavy metal but I think it will be worth it . Part of my thinking was the stock balancer is overworked . Bring it back to where the balancer can do what it was designed for and you might not have all these problems . You are the first one , that I have seen , to post about balancing .

 

[Will L.]

That's one of the reasons I had mine balanced . $200 in heavy metal but I think it will be worth it . Part of my thinking was the stock balancer is overworked . Bring it back to where the balancer can do what it was designed for and you might not have all these problems . You are the first one , that I have seen , to post about balancing .

If so, I feel like crap never talking about it.
These engine all SUCK from factory, yes GEP too. How they think the amount off this far is ok for such high compression amazes me. I just take it as standard practice that any engine a person is rebuilding that has higher than 10:1 compression or goes over 6,000 rpm NEEDS balanced.

That is so massive of an improvement. Even as teenagers rebuilding sbc’s in the late 80’s with a $250 budget- we would balance the pistons and rods to all match each other and couldn’t afford the crankshaft to be done- but even that helps alot. One time we went down the street to a 7-11 deli and paid the gal there to let us use the meat scale, with butcher paper of course. Haha.

All the cracked mains imo are because of the imbalance. I have never seen a block damged where the balancer was in perfect condition. In the fleet once we figured it out -I have seen so many blocks of all castings go over 250,000 with NO cracking but the balancers were changed out under 100,000 miles.
Many people think it is a waste on money, but I have learned that at 100,000 miles- new balancer, pulley, injectors, are a must. I do other things at same time, coolant hoses and coolant, fuel hoses, belt with tensioner and idler, imitation wmi with spray bottle for cleaning if not equipped.

 

[WarWagon]

The water advance is from an IP that is Rusty and about to lock up anyway from WIF. The details of this are lost with the Olds 5.7 diesel info sites that have gone away. Regardless water settles in the advance piston area and stays there due to low fuel flow in that part of the pump.

More advance keeps more of the EGT in the engine. More time for burnt fuel to heat up engine parts. Look at the deep fried Chicken pistons... So when I ran 1550 EGT it wasn't in combo with lots of advance. I could have advanced the timing and cooled the EGT down. And likely burned the engine down. Somehow the small precups wouldn't allow this in the range of timing we did try.

You get more power with advance because the cylinder pressure is higher. To a point it can't take it or the advance to the point of pre-ignition melts a hole in a piston.

Turbos spool up faster with retarded timing because that puts the heat in the exhaust. Consider a flat spot of retarded timing in a tune to spool the ATT up. I noticed this with a spool valve as that RPM already had the ATT spooled up.

 

[WarWagon]

Percups. You had a 6.5 NA engine. I used a 1986 6.2 NA engine that had even smaller precups. Only civilian 6.2 NA or econo precups were smaller. AC/fan and derate for 117+ temps make smoke esp with taller gears. You can see the smoke videos under the Spool Valve ATT videos around here somewhere. Not proud the smoke and spent real cash to fix it via Spool valve and then Yank converter...

The 6.5 NA precups I am pulling out of Patch now smoked less than the 6.2 precups.

 

[Hink]

If so, I feel like crap never talking about it.
These engine all SUCK from factory, yes GEP too. How they think the amount off this far is ok for such high compression amazes me. I just take it as standard practice that any engine a person is rebuilding that has higher than 10:1 compression or goes over 6,000 rpm NEEDS balanced.

That is so massive of an improvement. Even as teenagers rebuilding sbc’s in the late 80’s with a $250 budget- we would balance the pistons and rods to all match each other and couldn’t afford the crankshaft to be done- but even that helps alot. One time we went down the street to a 7-11 deli and paid the gal there to let us use the meat scale, with butcher paper of course. Haha.

All the cracked mains imo are because of the imbalance. I have never seen a block damged where the balancer was in perfect condition. In the fleet once we figured it out -I have seen so many blocks of all castings go over 250,000 with NO cracking but the balancers were changed out under 100,000 miles.
Many people think it is a waste on money, but I have learned that at 100,000 miles- new balancer, pulley, injectors, are a must. I do other things at same time, coolant hoses and coolant, fuel hoses, belt with tensioner and idler, imitation wmi with spray bottle for cleaning if not equipped.

This is great to know!
I agree with you that balancing should be commonplace and I had always wanted to do it from building motors 30 years ago till now but I was also in the same boat and couldn't afford it. While I still don't have money to throw around, I think that it will be standard practice from now on.

One thing that bothers me about the extensive cracking that I saw is that it was an Optimizer motor with stronger steel, thicker main caps, etc, and had a balancer that was in perfect condition when I got it. And I even put a Fluidampr on it myself but it still cracked massively.
That is why I am shotgunning every process that I can to help prevent any cracking on this one including balancing.

 

[Hink]

The water advance is from an IP that is Rusty and about to lock up anyway from WIF. The details of this are lost with the Olds 5.7 diesel info sites that have gone away. Regardless water settles in the advance piston area and stays there due to low fuel flow in that part of the pump.

More advance keeps more of the EGT in the engine. More time for burnt fuel to heat up engine parts. Look at the deep fried Chicken pistons... So when I ran 1550 EGT it wasn't in combo with lots of advance. I could have advanced the timing and cooled the EGT down. And likely burned the engine down. Somehow the small precups wouldn't allow this in the range of timing we did try.

You get more power with advance because the cylinder pressure is higher. To a point it can't take it or the advance to the point of pre-ignition melts a hole in a piston.

Turbos spool up faster with retarded timing because that puts the heat in the exhaust. Consider a flat spot of retarded timing in a tune to spool the ATT up. I noticed this with a spool valve as that RPM already had the ATT spooled up.

It's sounding like retarding the timing is going to help this motor survive as much as anything else. And considering that EGTs were never really an issue with me (I'd only see 1100 if I was REALLY pushing it while towing and accelerating up a grade and then it was easy to control to keep it lower), I think allowing them to raise a bit is a good trade off.

If retarding the timing will put the temps into the exhaust, and therefor spool the ATT quicker (which spooled quite fast anyway in my opinion), it seems that would compensate for some of the power lost from not being as advanced and still have plenty of pep?
We will certainly find out.
I'm actually good either way. I had enough power in the old motor that if I end up with a motor with slightly less power but was incredibly reliable and lasted forever, I'm good with that.