Did a tear down for a friend of mine. Engine was running decently but starting hard when warm, had slightly low compression on all 3 faces of the rear rotor and was consuming large amounts of oil in both housings. Both front and rear housings look okay, end plates and intermediate plate have bad corner seal and oil control ring surface wear. Also noticed a small spot on the front rotor possible detonation? Wondering what caused this, lack of lubrication.. Should also mention it was a premix car with no oil metering pump. Why would the wear all show up on the irons and not the housings? Is that detonation on the rotor face? There were no signs of any apex seal issues and the engine only had about 3500k on it since rebuilt by aspec. Any input from you guys would be much appreciated.

 

2mm apex seals

 

Pictures Pictures Pictures, this thread is worthless without them.

What corner seals? 2 or 3mm? Solid Corners? What apex seals? Factory ECU? Need a lot more information to give you any real insight.

 

Sorry for the image delay had to upload them from my iPhone. Mild street port done by aspec tuning in Chicago

 

Stock ports, or street ported and by whom?

 

 

Had two different types of corner seals in it ? He was running a microtech ecu

 

 

All types of issues there. One, solid corner seals always cause more wear, secondly the Superseals always cause excessive wear to the rotor housings which is starting to happen(miles on rebuild?), third the rear iron looks like it was damaged by the rotor gear hitting the face. It is unlikely that damaged was caused by the oil control ring but when the iron is that badly scraped up it will cause the symptoms of failed control rings due to oil getting past the oil control rings. Please keep in mind those oil control rings are now unusable and damaged but doubt they were the cause. It is likely a bearing issue that caused the damage you see on the rear iron.

 

To add: that spot on the rotor is a casting defect and does not appear to be any sort of damage, it is common.

 

I've seen something similar before.... the engine had ingested media blasting material from some monkeys who polished the UIM and LIM and left it all inside the runners. New engine that failed (massive oil smokescreen) shortly after the owner started boosting it.

 

that's your problem right their you sent your car to a-spec.

 

Lol I've never personally dealt with aspec it's not my engine like I said its a friend of mines car. And he actually went the route of buying a good used short block after we found the extent of the damage so I had no intentions of reusing the control rings more at this point trying to investigate the failure and clean up and sell what parts are salvageable

 

ihavetwins...you're trolling buddy.

Crispy

 

I'm thinking the rotor housing are still usable there is no signs of any cracking and no grooves you can catch a nail on ill post some more pics later hopefully for an opinion on them

 

They need resurfaced. They look pretty rough in my opinion. But what do I know?

 

^Guys, this is Roger Mandeville's backup screenname. He's just being modest

 

Bump for any other ideas?

 

How do the rotor and stationary gear bearings look?

I'd like more details on the oiling system: Ever ran low on pressure or volume? what weight oil? changed how frequently?

 

Well the damage was done before the purchase of the car. So judging by the conversations with seller the oil more than likely was changed at close to correct intervals 5w-30. The real reason for this post Goodfella is the damage was done before the purchase with minimal miles on motor and we get her open and Wahhhh. Purchased anticipating engine was toast but when opened we couldn't believe to what extent. After speaking to the engine builder "EXTREMELY HELPFUL" gave few more clues as to where the damage came from. Low on coolant overheat!
Sorry for the rambling but truely we are investigating and trying to figure out what parts are salvagable, obviously the irons are already in the recycle pile LOL

 

Post pics of the bottom of the rotor housings, the underneath part. They usually turn brown if the motor is extremely over heated.

 

The front bearing for sure has issues, what would cause a front bearing to make only the rear rotor gear to be contacting the irons?

 

Here's the solution.

First, have the rotor housings resurfaced.

Second measure the rotor gear protrusion, the rotor gear can work it's way out of the rotor at high rpm. I'll bet that it's worked it's way out or the rotor. You can still reuse them if you have them race clearanced depending on the severity. If its .003" or less I would reuse it. .005" or more and I would start to worry.

We prefer to do CNC cutting as it keeps the balance of the rotor over other methods.

Third have someone competent build the motor, not that anyone is to blame here but many crucial items can be overlooked. I've seen oil issues cause housing contact but it's usually when both stat gear bearings are toasted.

 

/\ bingo.. rotor land protrusion.. suspect also there may have originally been an issue with excessive endfloat

have a motor pulled down this week with torrington fail and the similar wipes on rotor and plate and heavy step wear are obvious there too..

PS

premix engine.............. showing heaviest housing wear right in the middle...
as always, backs my argument for premix supplement..and not omp delete.. when over 300 rwhp or using aftermarket seals

 

Yup, Sean tells me the previous owner ran the car for an extended period of time with *no coolant* in the engine. Unbelievable.....