So I went to change my oil today and upon removing the drain plug (magnetic) I noticed what looks to be a woodruff key of some sort. I have approximately 3300 miles on the engine I rebuilt, and it has been there for at most 2000 miles. I've included pictures of it, and the units on the ruler are in inches. Does anyone know where this thing might go? I'm thinking it's oil pump related. It has had no effect on the drivability of the car.

 

The only one I can think of that small is the oil pump drive.

 

yup, oil pump drive key is what it looks like.

they have a habit of slipping out when putting the gear on.
I wouldnt drive the car until it is replaced...

 

Thanks for the responses. I definitely won't be driving it until I put it back. It's going to be a chore to put back it, but hey, beats a blown engine. I just find it strange that it fell out after I had over 1000 miles on the car.

 

Definitely the oil pump key. Mine fell out when i lifted my newly rebuilt block with the hoist. Luckily I hadn't put on the oil pan yet and noticed it before I drove around.

 

It can't "fall" out with the gear installed. The only way for it to move from the pump shaft is to be pushed off while installing the gear, then drop into the pan.

 

I never said it did. I am well aware that it got pushed out when installing the gear and that it would be unable to fall out of its slot with the gear installed. Which is why it was pushed out when the gear was installed then fell out of the bottom of the front cover when the block was set flat then lifted.

 

That is not what you said now is it? You said you lifted your engine with a hoist and the key fell out.

 

Yes the key fell out of the bottom of the engine. I never said the key fell out of the gear either.

 

Does anyone have any probable idea as to how it fell out? Cause it wasn't there at my 1000 mile oil change. And wouldn't some sort of catastrophic, noticeable, measureable, driveability issues result from it falling out? The pan was used on another engine I have, but I haven't pulled off the front cover to see if it could have came from that engine.

 

I hate that key. After you get it re-installed turn the eshaft/flywheel and make sure that the omp chain spins the pump shaft to ensure engagement.

What did your oil pressure look like while you've been driving it without the key in lol

 

yikes thats a scary thing to find! lol

 

Well at least it gives me an excuse to throw in some 850cc primaries and replace an oil return line gasket while it's apart.

 

That key is a bitch. It even gets worse when the key gets nicked. ALWAYS ALWAYS ALWAYS triple check it's position from under neath the oil pump gear during installation. If not installed right, it will get pushed down and out of it's groove when you put the gear on. Sometimes it will just sit on top of the oil pump hidden from view (which is what happend to the OP). The last time I put my 20b together, it took me 30mins because it kept popping off. I never had this problem before but, I was getting pissed! LOL!

 

So I guess I have driven 3200+ (including a few race events) miles without that key installed. You would think having something like that not being installed would cause the motor to fail in nothing flat.

 

That still doesn't mean it's not slipping. Once the gear really starts slipping, it's gonna wear away some of the metal on the flange making the gear lose. You need to pull the engine so you can pull the front cover apart for inspection sooner than later. If the key-way is still lined up when you remove the gear, call your self lucky. I've seen situations where too low of oil pressure has caused spun bearings and damage to the e-shaft. Don't risk it!

 

Don't worry, I parked it. Is it necessary to pull the engine though? I was thinking of just chocking the pressure plate with a block of wood to keep the torrington bearings from moving, and just pulling the front cover off while it's in the car.

 

The work can be done in the car. It is not very easy or fun, since the hub bolt is at such a high torque and should have thread sealer. You really only need to worry about the bearings falling when you are removing the front hub but not removing the front cover. Since you are going to have the cover off and half the front stack, you can just check that the bearings are in place.