3/8 vs 1/2 inch oil pickup. Do I even need 1/2?

I was swapping my oil pan from a Moroso 7 qt to a Hemi 6 qt and my new oil pickup tube is too small. Turns out, my 440 block was drilled and tapped to accept a 1/2 inch oil pickup tube which is what I had on there apparently.

My 440 is very mild, Edelbrock heads, stock sixpack pistons, a MP 484 cam and headers. Do I really need to run the 1/2 pickup on this motor or can I simply get a bushing/reducer and use the 3/8 pickup? I assume I would need to trial/error the height to make sure it sits properly on the bottom of the pan first.

Has anyone done this before?

not needed 3/8 will work fine

Any time you incorporate a larger size on the suction side of the pump is better. I would get a 1/2" pick up pipe since the block is opened up.
Whitch straw is easier to suck thru, small or big one? Your oil pump is trying to do the same thing. HP!

Your app wouldn't need it right now but as said since it is already tapped & I would get a 1/2 pickup & bend/mod it to get the pickup at the height you prefer. there has been mention of the block pickup threaded boss being too thin on one side after drilling along the original CL so you might check that. I like to have the pickup touching the pan with some added spacers so there is no restriction down there & the pickup is supported on both ends to avoid potential vibration cracking tho likely not a dealbreaker, just my OCD talkin.

Your Moroso pickup probably has just 1/2 threads and a 3/8 tube anyway. I’d get the 1/2 pickup though. Also look into if the turn has been opened up in the block. Should be pics or diagrams on the interwebs on that.

I don't think I have ever seen a 3/8 pickup, I would find a 1/2..

3/8 was standard.Imade my 440 1/2.But there were other mods needed to utilise all the advantages.I had the things here but lost them over the years.Rocky

Thanks for all of the great feedback guys, its appreciated.

Get the stock 1970/71 street hemi oil pickup, they are 1/2 inch
In the future don't let any one talk you into modding any stock B or RB to 1/2 inch pickup
The bypass spring in the pump determines how much oil goes into the pump and block, not the internal size of the oil pick up

Thank you, that is exactly what I ended up doing yesterday.

I bought the engine about 20 years ago and it was already modified by the previous owner who had much larger plans for it than I ended up using it for.

There is, the 440-4 and 440-6 in 70 and 71 used the hemi pan and had a 3/8" pickup. The pickup tube was available , now ?

I used a moroso 1/2" pickup threaded end, its a separate part welded to the tube, to neck down to the 3/8 pickup tube for the original A body 383 pan, the block had already been drilled when I was building it for a different application.

Have to disagree, the suction side of the system is the critical limiting factor. Even with the bypass fully closed, if you can't get it to the pump the volume output will suffer.

In practice, the 3/8" pickup has worked fine on my B based 496 run on road track up to 6,500 RPM and street. I do not think the bigger pickup has practical benefit in a relatively mild engine... though I agree less restriction in theory is better. The bigger pickup has drawbacks also like potential for block cracks and stroker clearance.

From your starting oint, I agree with Cab and others... you are already tapped for 1/2" so get a hemi re-pop 1/2" pickup and call it good. A bushing is just another potential failure point and I would avoid that.

I'm wrestling with this same question on a "street only" 440 I'm starting to build.... Is the 1/2" pickup necessary?

One thing I did find out (the hard way) is to match the pan with the pickup (same manufacturer). I put on a "hemi/six pack" Milodon pan & my 70/71 Hemi pickup tube (1/2") didn't fit. I had to buy a Milodon 1/2" pickup.

Also, fyi, I still have that 70/71 Hemi pickup in one of my boxes of parts.

Plus Mopar didn’t use 1/2 for no reason. The outer limit of a 3/8 might be beyond nascar needs, which wouldn’t apply to many doing this, but they did it nonetheless.

I run real loose (.0035+)bearing and lifter clearances(.002+) on all of my street and strip builds with 5W20 Wt. oil now with the high volume oil pumps with 65 Lb. + pressure at or above 2300 RPM with hot oil No bearing or other oiling issues using the stock type 3/8 oil pickups with 1/8 inch or less pick up clearances to the bottom of the oil pan by checking that clearance through the drain plugs on the last 12 motors
I use to use 1/2 inch pickups with 50Wt racing oil I have ruin several stock blocks while modding them for the larger 1/2 thread sizes and had to block the stock oil passage off in the blocks under the oil pump and use a Milidon swinging external oil system
No more

right again john.

I never have, so is your anecdotal experience more valid than mine?

Are you a machinest? I'm not
Maybe your luckier than I am on some things pertaining to modifying engines

3/8 is fine....

If you can't eyeball the edge distance of the existing hole and tell if it's a candidate for increasing the bore...

All my blocks are drilled with a hand-held drill and the correct tap, even the mundane daily driver blocks. I drill 'em all the way to the intersection and then use a rotary burr to smooth out the sharp corner. (easier with the larger hole)

I figure I gotta get a new pickup anyway and the 1/2" price isn't that bad when included in a complete overhaul.

I do it the same way,
except I first use a die grinder to remove the threads 180* opposite the thin side. This moves the drill center point over, leaving more material at the thin area and reducing the chance of cracking.
Another advantage with 1/2", it takes less power to turn the pump.

I did my 440 the same way, back in 85, a lot of passes at the track. I might finally pull the pan this spring just to look.
If you think the big blocks are to small, check out a small block pipe. I made a new one up for the 340 from the 3.0 Mitsubishi engine (a full 1" ) attached off the cover into the rear sump Magnum pan. Has that nice bell on the bottom too.

Mike would you have a pic (or a part # to search for a pic)? EDIT found one on eBay, that would be a nice piece & an easy mod especially if you have a rear sump pan.

I had to section, shorten, then tig it back to get it in the right direction, like making a header. If you still need a pic i'll send you a pm to show how it came out.

When I've tried moving the hole outboard the pickup pipe hits the pan side wall....have to dimple it. Might depend on who makes the pan.

So at a given RPM the oil pump will pump "x" volume of fluid
The 2 sizes of tubes have a different volume
The smaller sized tube would fill up faster and therefore recover from being "empty" quicker

There possibly would be a very small HP difference (1/2, 1hp?)that I doubt anyone on here could accurately measure as the bigger tube is easier to pull through

At some stage the small sized one would not keep up with a high volume pump and or rpm's, very much dependant on the bearing clearances and top end oiling system used

Its often said on here that our oil pumps are bypassing the regulator most of the time anyway

Simple enough, How long is a piece of string?

Question? At what point should a larger pickup tube be used?
Also, how much of a restriction is the hole in the oil pump?
I guess this leads to, how much better is an external line connected to the pump cover?

FWIW, both of my 400 and 440 stroker engines have 1/2" pickups. I'm just curious if they are really needed? My Jensen project 440 stroker (505") should be about 600 HP, and I have not decided which size pickup to use?
I picked up one of the 440 Source oil pumps (on closeout sale) that have the connections for the remote oil filter, and also an inlet for external oiling. I am thinking of plugging the external inlet so it will pull from the block pickup as normal. I really just wanted the remote filter fittings as that is how the Jensen is configured originally and I'm not sure what condition the original pump is in.