G'day all,

I remember when I disasembled my engine (over 5 months ago) there what appear to be an oil restrictor in the block.

I can't seem to find any reference in the service manual or on Toyodiy for one.

Does anyone have any knowledge on whether there's supposed to be one?
And a part number if there is one?

Gen 3 3SGTE

Thanks.

Maybe someone put it there after a rebuild? 3s engines flood the head with oil and this is a trick done on these engines to hold more of the oil where it is needed in the bottom end.

Is it worth running one?

The car is mainly used on the road but it will be seeing some trackdays and hillclimbs.

Yes

Information seems pretty hard to find, evem MR2OC doesn't have much on it.

What have people here ran? What diameter hole?
Bearing in mind that the car will see prolonged times at idle at traffic lights etc.

Why have you not found the information on MR2OC? because those guys all follow each other like sheep and fit high volume oil pumps that only add to the problem. People have been restricting oil flow to cylinder heads on engines since the early racing drag racing days. Old tricks are sometimes the best tricks.
 
Is this something you would do to a daily driver? I do not see why not, there really is no downside unless you do not change your oil regularly. This is the reason the factory chose to set it up like this, as people have a tendency not to change their oil on time and the top end generally is the first failure point.
 
I cannot remember the sizing of the one i have used in my engine, but it is a hollow screw such as this.