Fuel's Winter Project: Build It Before It Blows

[weather man]

It would depend on how long from pump failure to shutdown and if it had any partial pressure. It wasn't because it was lean, you would have seen something on the piston crown.

Danny said the 4V guys breaking the oil pump at the strip used to look exactly like this failure. He was really surprised Josh hadn't upgraded the pump at this power level. Water under the bridge on that, the blower guys always seemed to have more problems with the pump than turbo guys.

 

[BruceH]

It would depend on how long from pump failure to shutdown and if it had any partial pressure. It wasn't because it was lean, you would have seen something on the piston crown.

Danny said the 4V guys breaking the oil pump at the strip used to look exactly like this failure. He was really surprised Josh hadn't upgraded the pump at this power level. Water under the bridge on that, the blower guys always seemed to have more problems with the pump than turbo guys.

Or the other motors had issues that caused failure and caused the pump gears to break as part of that failure.

Just because the pump broke doesn't mean it's the culprit. I do think that the pump breaking helped to cause the cam journal issues but after the fact.

If oil pressure was lost for long enough to cause the piston galling it would of had to be lost through the bearings first. Once the bearings lose the oil wedge things go south fairly quickly for the crank and rods.

Josh, you said there were no hot spots on the crank and that nothing was seized, what about the rods, are they discolored? Did the bearings just have wear spots or are there serious grooves in any of them?

 

[JoshK]

i am going to grab some pics for you real quick guys

 

[weather man]

Or the other motors had issues that caused failure and caused the pump gears to break as part of that failure.

Just because the pump broke doesn't mean it's the culprit. I do think that the pump breaking helped to cause the cam journal issues but after the fact.

If oil pressure was lost for long enough to cause the piston galling it would of had to be lost through the bearings first. Once the bearings lose the oil wedge things go south fairly quickly for the crank and rods.

Josh, you said there were no hot spots on the crank and that nothing was seized, what about the rods, are they discolored? Did the bearings just have wear spots or are there serious grooves in any of them?

Discussion is good Bruce, never know when something will pop out.

 

[BruceH]

Discussion is good Bruce, never know when something will pop out.

It's too bad we have to have this discussion. Poor Josh.

 

[JoshK]

Things happen. I am bummed yes, but to be honest we all know that this is a likely possibility at these power levels.

I should have had a billet oil pump in the car. I thought i could get away with the ford billet backplack oem gt500 pump though. There are more than one places I skimped a little the first time that i wont this time

 

[JoshK]

These are the two melted pistons







Rear two journals



Front two journals



Two sets on the left are 4 and 8, two sets to the right are 1 and 5



Picture of the rods, remember #4 was melted the worst

 

[weather man]

I think I will stick with Danny on this one.

 

[BruceH]

So are the bearing markings just wear marks or are they more significant? The crank looks pretty good from here.

Did the pistons gall on just the sides that are perpendicular to the crank or all the way around? I'm wondering if there was a little mismatch between the pistons and bore.

 

[JoshK]

Only melted on the sides with skirts. The slight markings you see on the crank are just visual, there are scratches or anything of that nature

 

[BruceH]

Only melted on the sides with skirts. The slight markings you see on the crank are just visual, there are scratches or anything of that nature

The bearings themselves, they always look beat up in pictures but quite often it's just wear marks on the coating. I'm wondering if the bearings are scratched up or if they are showing the "coating" rub mark wear that's normal.

 

[JoshK]

The bearings seem to have deposits on them if that makes sense

 

[BruceH]

The bearings seem to have deposits on them if that makes sense

It's something you can feel?

 

[JoshK]

On the bearings, definetly yes. But nothing on the journals of the crank.

 

[BruceH]

On the bearings, definetly yes. But nothing on the journals of the crank.

That's really interesting. It's also odd imo that the two back pistons had the problem. Oil goes from the front to the back. All of the bearings had the deposit, correct?

Going from front to back and then to the top means that anything going bad along the way would kill or reduce the flow of oil to other components.

The piston walls are basically splash lubricated from oil that comes out of the bearings. What would be in common with both of the back pistons besides the engine oil galleries and crank oil holes? This is a reach but is there any chance that the crank holes were partly blocked?

Do you think that the buildup on the bearings could be some of the piston skirt material? It would stick to the bearings, the top bearing layer on a coated bearing is designed to catch and hold debris.

By any chance did you keep the oil filter and cut it open?

 

[JoshK]

Oil filter is still on the car and I plan to open it up. To settle any confusion, #4 is the rear most cylinder on the passengers side and #5 the front most on the drivers side. These are the two pistons that are damaged. If I had to say, the material in the bearings is definetly aluminum from the pistons.

The main bearings are king high performance uncoated, which u have yet to check. The rod bearings are uncoated clevite h series bearings

 

[05stroker]

What was the piston to bore clearance used with those pistons?

 

[JoshK]

What was the piston to bore clearance used with those pistons?

I will have to ask my machinist when I take the block back. I let him handle that. Told him to set it up for 25+ lbs of boost though. He has done a lot of modular stuff so I didn't worry about it.

 

[eighty6gt]

Probably riding such a fine line that as the pistons expand with heat under dyno loads they either wipe out the oil film in the bore or actually begin to contact the bore. Once this happens, the heat goes up exponentially and instantly to metal melting levels. Aluminum is shot into the pan, goes into the oil pump, breaking the gears - all in a moment, game over. Fuel distribution may be different between cylinders leading to combustion temperature and cylinder temperature differences.

 

[JoshK]

Probably riding such a fine line that as the pistons expand with heat under dyno loads they either wipe out the oil film in the bore or actually begin to contact the bore. Once this happens, the heat goes up exponentially and instantly to metal melting levels. Aluminum is shot into the pan, goes into the oil pump, breaking the gears - all in a moment, game over. Fuel distribution may be different between cylinders leading to combustion temperature and cylinder temperature differences.

This is exactly what I think as well. There are tiny bits of aluminum all over in the block. The material in the bearings look like aluminum as well