I really want to know what was causing this issue, it's such a one-off...

Fuel makes sense, I've been thinking it all along, but the OP seems confident that it's oil.

C

They both kinda make sense.

It could have been fuel that was initially the problem, and that helped pop the headgasket, which let in a bunch of oil.

I assume that's where the oil came from, because previously working rings usually don't just give up for no reason.

IDK like I said I know little about this stuff, but that's what my neighbor (who is a block design engineer for Cummins) thought when I told him about it.

oil and injector seals don't interface in this engine, no need to check those seals for oil leakage

Here's a picture of what came out of it. (remember I'm using royal purple) Also when I use a white rag to wipe the mess the fluid shows purple on it. Then there is the smell and the may it moves and feels when it gets on your hands. If this is my fuel I have bigger issues...

https://www.miataturbo.net/attachmen...ine=1375219184

Frank, it does make sense that a fuel hydrolock was the initial cause of the problem. It is hard to tell if oil is contaminated with fuel. Also, when you think about the fact that there was no oil smoke when it was running, it makes sense. I am starting to think that a fuel hydrolock injured something in the motor causing oil to enter the cylinders. Fuel hydrolock is a common issue.

Put that fluid in a pyrex glass and see if it will ignite. BTW fuel hydrolock bends rods real nicely! i had a 5 series keep an injector wide open at work a while back. luckily the piston wasn't collapsed

Is it possible you somehow don't have the 4 spark plug bore gaskets installed with the vcg?

Idk if I missed something in my reading, but this engine ran fine just before the kit was installed right? You said you did an oil change and added another 4.5q, are you sure you remembered to drain the pan first? Check your dipstick to see if it's ridiculously over-filled.

This would fill the plug wells with oil, and the OUTSIDE of the spark plugs (and plug wire boots) would be coated in oil.

But this would not admit any oil into the combustion chamber so long as the plugs are installed in the head.

I guess if he wasn't paying attention and didn't notice the bores were filled and just removed the plugs it would all drain into the cc.

Something just doesn't add up with the story here. How can a perfectly running engine suddenly have this issue from just bolting on a manifold and a turbo?

Turbo hit block too hard?

C

Okay, that is a viable theory. I guess I could see fuel being the initial cause. I ran till it died ( not being in the car or recording the AFR maybe it was drowning in fuel from the 750cc injectors. Then when I went the crank the motor back up, the pop could have been that abundance of fuel igniting and then blowing what ever is leaking oil into the motor.

Quite true.

But he's also talking about lots of smoke when running, and I assume he'd have said "Oh, and my plugs were all totally drenched in oil."

But I could be wrong.

OP: were your plugs totally drenched in oil (on the outside)?

Its an EFR, it can spool 20 psi at idle and make 300 ftlbs at 500 rpm.

No, they were covered in oil from the inside at the tip. If it was the valve cover leaking then I feel it would be kind of hard to ignore or not notice oil on the coil/plug wire, my tools and the plug.

Sometimes gaskets blow. It is a maintenance item.
Maybe it was going bad. Then when you changed to the EFR, oil lines or coolant bubble? Pressure?
Just seems like a freak accident compiled of multiple things?


Or like everyone else. Huge EFRboner and your motor couldn't handle it.

The coolant did bubble which added to the initial "oh shit! It's coolant" thought I had.

How many miles on the engine? and do you know if's ever been taken it apart/rebuilt?

My newly built engine should be going in the car tomorrow. If this happens I'll never forgive you :P

It has 90,000 miles on it and I severely doubt it's ever been apart.

I have a Mazdaspeed mx5. I accidentally overfilled my engine with 5 quarts of oil thinking it was a 4 quart container & oil came out the rear main oil seal & leaked out on to the clutch a little bit then leaked out of the small drain hole on the transmission housing below the clutch on to my garage floor a little. Oil also a lot came out the turbocharger compressor seal filling the intercooler & piping with oil. It messed up the turbocharger. I caught my error in time, blocked the turbo & I am running the engine naturally aspirated for now.

Overfilling the engine more than 4 quarts can cause excessive pressure in the crankcase causing oil seal leakage at the compressor end of the turbocharger. Mazda MX-5 Miata & MAZDASPEED 2004 workshop manual 01-03-09.

I seen you say you put more than 4 quarts of oil into the crankcase.