No thrust bearing?
 

I value this forum's knowledge on these matters so here goes...

Once this thing started knocking i drove it straight home, maybe 8 miles. It then sat for about a year while I used the suspension on another autoX car. It then refired and ran for a few minutes when i drove it onto the trailer. We just pulled this lump out and dropped in a 00 motor last weekend. Yesterday we pulled the oil pan:

"a-central-ohio-performance-shop" built 1.9l 94 shortblock:

I FINALLY got the nerve to pull the pan off this motor...Looks like i was right to be worried :vash:

Thrust bearing floating around in there...


Looks normal so far...
https://www.miataturbo.net/attachmen...ine=1330308238

what the..
https://www.miataturbo.net/attachmen...ine=1330308238

you gotta be ------- kidding me...
https://www.miataturbo.net/attachmen...ine=1330308238

Heres the other half and the hole it was punched through...
https://www.miataturbo.net/attachmen...ine=1330308238

Here is a short video of the crank endplay present with no thrust bearing...
http://s20.photobucket.com/albums/b2...t=94403c26.mp4


#1 rod cap is discolored. There is obvious crank end play. There is stubble on the underside of #4 piston, from the bearing banging around. Im not taking anything else apart/off until I hear back from the shop that built it. Is there a chance the crank is junk?

I have sent the shop an email with these pics and video.
Do you have any advice on how to handle this?

For roughly $2500 in engine I guess you can ask for them to build it again or give you money back in some capacity. However they don't have to do either and for $2500 you're not going to hire an attorney to deal with it. It sucks, but that's the reality. I've been here before.

There is a chance that everything in that block is junk, and you can't really tell until you inspect and measure all the parts.

I would measure the thickness of those thrust bearings. I don't see any way of them falling out unless they wore out super-thin.

Generally when the thrust bearing falls out on these motors the head and cams are toast in short order. I’m not sure how it works but the cast iron that gets warn off the block ends up in the cam journals and it chews them up pretty quickly. Oil pump gets toasted pretty quick too. The side load on the oil pump might be the big source of the catastrophic nature as well. I think the oil pump becomes the thrust bearing.

There was a short production run where Mazda had an issue with some tolerances on some early NB cars 99 or 2000 where the thrust bearings would fall out from the factory. They replaced a bunch of engines under warrantee. I thought this might be a source for cheap heads but every one I have seen all the bearings were toast including the cam journals in the head and the cams themselves.

Bob

That sucks, but the reality is that this is over a year later and nothing will probably come of it from the shop. Did you voice a concern for it when you drove the first 8 miles? It is obviously their error, but time is not on your side here.

Everything needs to be disassembled and checked to make sure they are still usable. Hopefully any imperfections are minor and workable.

If you don't walk in to the shop with your chest all bowed up ready to fight, then I would be willing to bet they would work with you. Be calm and respectful, but ask if there is anything you guys can work out. I would stop taking it apart any further, and see if they want to see it. Maybe if you source a new engine, they'll do the labor and machining for free.

Hustlers right, they don't have to do anything, but most people do take pride in their work.

Had this exact thing happen in a built motor. The crank milled the block, the iron filled oil milled the head and cams. I can only figure the builder knocked the thrust bearing out when he set the crank, he did note that it "took forever" to build oil pressure when he was bench spinning it. I don't think I'd ever pay someone to build a motor again, unless there was a specific warranty.

You need to pull everything apart and examine everything to check for useability. My piston skirts were so nicked up that I tossed the 10 hour old pistons, too.

I'm not saying the thread-starter would be rude, but I think most people do this. I think a good machinist knows that "---- happens". Sometimes a valve-spring goes in backwards, sometimes there are arithmetic errors, and other times they can simply make mistakes. I don't know about you but if I own this business, I'd see this as an opportunity to have a customer for life by making good on the work.

Add me to this list. I just bought a 2000 with a recently rebuilt motor and the same problem. Only lost one rod but the block and crank are junk.

I just heard back from the shop. They want the motor as is. They say they are willing to work with me. We shall see what that ends up entailing.
I am going to take it up to them tonight or tomorrow.

Good to hear it, Dan. I hope they take care of you. This might go a long way in influencing my tuner decision.

Keep us posted.

I think it was a run of the 2000's blocks that were machined wrong from the factory. they came out with a thicker thrust bearing to keep it from falling out. Im not sure of the whole story.

Bob