Oil orifice

[musthave]

I am preparing the block so that I can install the cylinder head. In the front corner of the block, there is a threaded hole where the Oil Orifice is supposed to be installed. The Oil Orifice P/N 11448-66010 is shown below.

The problem is, there isn't anything that I can find that says how far to insert this. Do you use Loctite? It can be installed so that it is flush with the block, or it can be about 1/4" above the block. But there is no direction on how it should be installed.


Here is where it is, the threaded piece near cylinder 1.

Here is a closeup of the piece

As you can see, it can be put in so that it is below the level of the cylinder block.

Or, it can be installed on about 2 threads and it looks like this:

This what the piece looks like:

 

[musthave]

This is where it mates up to on the cylinder head. (left corner slot)

 

[musthave]

And the FSM doesn't give much direction.

I really want to get this right, but I can't find any information on the installation. Threads here show the orifice but nothing more that I can find.

I'm sure that I am being overly OCD on this.

So, what have others done? Installed about 3 threads and used loctite?

 

[coax]

There is a torque value in the fsm. It’s like
48/in/lbs. I put it in until it hit the torque spec. I did not leave it above the block, should be below the deck surface afaik. I did not use any loctite.

 

[musthave]

@OTRAMM What have you done with this? Seems that you’ve done quite a few. I looked through your videos and don’t see mention of it, yet. Thank you

 

[coax]

Here’s the page from the Lexus manual.

 

[musthave]

Lexus gives the details Awesome!!! What a relief. I've got 2 Land cruiser FSM's neither show this additional information. Thank you so much!

 

[Irish Reiver]

I wouldn't mind knowing what the purpose of that screw is. If it is torqued down and sits flush with the head then why wouldn't toyota just have machined the orifice to the correct dimensions.

 

[Woofythewolf]

It's for manufacturability.
Drilling holes (even with a fancy carbide drill in a CNC machine) it gets very difficult when doing a hole that is a certain multiple of the diameter, so you can't just drill a 10 inch hole that's 1/8" in diameter. It's around 5x its diameter that things get hard according to Wikipedia? I've done deeper with carbide twist drills but those are pricey, and Toyota probably has set limits on how deep they'll drill with a certain bit type in a specific material based on probability of a mishap occurring. Over that, you have to use gun drilling which can get you up to an insane 300 times the diameter, but it's another machine setup.

So instead you just drill a bigger hole and put an orifice to restrict it the amount you originally wanted, which makes for faster manufacturing EVEN with having to do a larger drill operation for the step, a thread operation, make an entire plug, and have another assembly step with a torque wrench.

Now, I think they could have just put the restriction into the cylinder head, as aluminum is much easier to drill and not break bits, but again Toyota probably has set limits on how far they're willing to drill and I guess even that was too much.