How many miles on this engine?
Was the problem always there?

 

 

That shop going to make it right on their dime?

 

"What's a torque plate?"

 

I think it is from the crank being able to move in and out as you can see in the video I posted. The bottom end is in the back of my car and I will be taking it up to the machine shop tomorrow.

 

Missing thrust bearing will play havoc on your oil pressure.

 

Yeah, that would be quite the hemorrhage.

 

Ouch! Damn, sorry to see that Lars.

What caused those cylinder wear marks? Oil pressure fluctuation/loose piston to bore specs?

 

my vote is piston slap due to the thrust bearing failure.

 

wouldn't thrust related problems cause vertical wear marks on the fore-aft portions of the bore and not the sides?

 

This is one reason why I build my engine myself. Though I admit it was terrifying the first few days "**** did I put the bearings in correctly? did I torque everything down right? **** **** ****"

 

So I have dropped the bottom end off at the machine shop and talked to them about it. Currently they are in the middle of building 3 motors so we could not start the tear down now. When they have the space to tear mine down I will be there for it.

First I explained to them what was going on with oil pressure and why I pulled the motor. Then we pulled the motor out from the back of my car and I showed them how the crank moved in and out. Then I showed them the wear marks in the cylinders. Once they saw the crank moving in and out they knew something was up with the thrust bearing. When they looked at the cylinder walls they say those patterns generally come from oiling issues. So what the machinist thinks happened is some how during the initial trying to build oil pressure the throw out bearing some how spun or got worn down. Then with that out of place and the crank being able to move it possibly wore down some of the bearings. This could explain the oil pressure issue once the oil is warm.

As soon as we get to tearing down the motor I will be taking pictures and posting what we find. In the mean time I am just going to seam weld my engine bay.

 

I have a bone stock 01 bottom end just sitting in my garage for now.

 

slap on a few extra head gaskets and go to town.

 

The hone job on those cylinders looks like **** as well.

to compare...

 

I was thinking the same thing when I saw that.

 

Every single engine I've ever had, in every car, builds pressure off turning the key for 10-30 seconds, then I can start the car. Every, single ******* time. I'd like to know what this machinist's suggested procedure is for an oil prime on Miata. This is starting to reek of ****.

 

It is not how I tried to build oil pressure, but the length of time trying with actual oil flow not happening. It took a while to locate that is was the sandwich plate that was blocking the flow of oil. I probably had about 3-5 minutes of cranking time spread over several dozen attempts to get oil pressure.

The plan as of now is to swap over an oil pan that is already fitted for an oil drain line. Then put my absurdflow setup on the stock 01 engine and just run whatever I currently have wastegate at which should be 6-8psi. Engine should be fully put together by the end of this week and the actual install of the motor should happen Sunday morning.

 

I like this plan.