What is the TPI of a 440 Oil Pickup?

[Gscyrkel]

I recently acquired a 440 for my 1966 Coronet and took the pan off to see if the pickup tube was 3/8 or 1/2. Only it wasn't either of those it appears to be 5/8-24 which I can't seem to find anything on that even being an option? Obviously I'll need a reducer to take it down to 1/2 inch but I don't know what the threads per inch is on the 1/2 pickup tube? Does anyone know or have some ideas.

Thank you

 

[R/T Boy 67]

The thread in your block is 3/8" pipe thread, which is close to 5/8" NF, but isn't. You will have to drill and tap your block to fit the 1/2" suction pipe. The stock 3/8" is fine for most lightly modified engines.

 

[Bird 426]

I do not understand, why would you remove the pan to see what size the oil pick up is? The pick up tube that screws into the block is 1/2" pipe, pick up tube itself is 3/4". Milodon pick up. Are you changing something,?

 

[R/T Boy 67]

Big blocks are 3/8" pipe. Hemis are 1/2" pipe.

 

[Bird 426]

Okay, I do have a Hemi.

 

[Gscyrkel]

I do not understand, why would you remove the pan to see what size the oil pick up is? The pick up tube that screws into the block is 1/2" pipe, pick up tube itself is 3/4". Milodon pick up. Are you changing something,?

I removed it because the 440 came from a truck so I need a new pan and pickup

 

[Gscyrkel]

The thread in your block is 3/8" pipe thread, which is close to 5/8" NF, but isn't. You will have to drill and tap your block to fit the 1/2" suction pipe. The stock 3/8" is fine for most lightly modified

Sorry I don't understand. The thread on the pickup I took out is 5/8 and looks like it's -24 which is larger than 1/2 or 3/8. Don't I need to reduce it down to either of those for it to fit?

 

[rickseeman]

If this is a real posting, I'll answer. Pipe threads are not bolt threads. In addition, they are tapered, not straight. To make a hole for a 3/8" pipe you start by drilling a hole 37/64ths in diameter. (That is .578".) Do you see that is much larger than 3/8"? (.375") Your wedge should have a 3/8" pipe thread pickup. (3/8" pipe is 18 threads per inch.) If by one in a million chance your car doesn't have this, you can drill it out to a 1/2" (Hemi) pickup, which is what all wedges want anyway.

 

[69Bee]

NPT pipe threads are larger than USS NC/NF dimensions, so let me break it down for you:

1) 3/8"-18NPT has a dia of 0.621" at the bottom of the hole and a dia of 0.627" at the top of the hole

2) 1/2"-14NPT has a dia of 0.758" at the bottom of the hole and a dia of 0.778" at the top of the hole

 

[rickseeman]

Sorry I don't understand. The thread on the pickup I took out is 5/8 and looks like it's -24 which is larger than 1/2 or 3/8. Don't I need to reduce it down to either of those for it to fit?

If you measure the pickup threads that screw into the block and they are around .660" then you have a 3/8" pipe thread pickup.

 

[RemCharger]

..... and in all my experience the 3/8 pickup works well into the 10 second motors

 

[padam]

For reference:

 

[rickseeman]

No disputing that.

 

[rickseeman]

View attachment 1703006View attachment 1703007For reference:

All pipe threads in our Mopar blocks are NPT. (Tapered.) Not NPS (Straight.)

 

[padam]

I wish i knew where I posted it, cause I went through this a couple years ago.
I installed a Miladon pan and pickup and I’m pretty sure the pickup had straight threads.

 

[Gscyrkel]

If this is a real posting, I'll answer. Pipe threads are not bolt threads. In addition, they are tapered, not straight. To make a hole for a 3/8" pipe you start by drilling a hole 37/64ths in diameter. (That is .578".) Do you see that is much larger than 3/8"? (.375") Your wedge should have a 3/8" pipe thread pickup. (3/8" pipe is 18 threads per inch.) If by one in a million chance your car doesn't have this, you can drill it out to a 1/2" (Hemi) pickup, which is what all wedges want anyway.

Pardon my ignorance in this. I was not aware they aren't the same. I do not come from a mechanically inclined family so everything I'm trying to do with this car is involving lots of browsing these forums and watching some YouTube. It would never have occurred to me that pipe thread and bolt thread aren't the same. I won't forget that.

 

[rickseeman]

No problem. There are lots of people out there needing answers and I understand. My father was a school teacher. A good man but I didn't learn how to work on engines from him.

 

[Gscyrkel]

Thanks everyone,

I've got my answer now.

 

[rickseeman]

I wish i knew where I posted it, cause I went through this a couple years ago.
I installed a Miladon pan and pickup and I’m pretty sure the pickup had straight threads.

If it had straight threads, basically, it would never tighten up.... unless it had a shoulder and a gasket. Or bottomed out in the threads. And them we couldn't get the pickup turned where we need it in the bottom of the pan.

 

[coloradodave]

Ahhh, a teaching moment! Congrats to all of you who actually posted a correct, easy to understand answer to the OP's question. I was waiting for a wise*ss answer but it never came. Maybe we all are maturing? Naw...