Back on the Hemi project. 4.5 stroke and Callie’s Compstar 2.200 rods. BMP thought it wouldn’t be an issue, but it is. Anyone here done this? After grinding the pickup adaptor I think I might have enough clearance on that, but the pickup tube is the real issue. How much do I need to be safe what would be the thinnest I can have on the pickup tube wall thickness. Trying to make enough clearance without getting too thin on the tube wall. Any ideas?

Eeek that's tight. Is moving to an external pickup an option?

That was my original plan, but with all the reports on losing prime after setting, I decided internal would be better since it will be primarily a street car.

I'd be concerned about the tube cracking.

Have you thought about using an Accusump for priming? Since my car can sit for a month at a time, I use one as a primer. Fully oiled before I hit the key. In your case, it would kill two birds with one stone. Priming the pump AND the entire engine.

Just a thought.

No, never gave that a thought. Sounds like a good option. Really want to keep things simple with the inter oiling.

I'd fab a different adapter with the threaded hole pointing towards the skirt of the block. Then put a bend in the tube. This would allow the tube to hug the inside of the block skirting.
Doug

Yes, I called Bill Mitchell and asked him if he had a different adaptor. He does not. Where do I look?

I like your original plan better. It is a 4.5" stroke and probably a big powerful motor. Go external like you planned on and quit thinking about losing prime. Hemi's have been using external pickups for over 50 years. Do you know why every Hemi Super Stocker in the country had external 50 years ago? It's because they had big powerful engines (not as powerful as yours) and they wanted it to have good oiling. BMP sells a block-off plate.

The right pump doesn’t need the block off (no hole in pump body) loop the external line higher behind the pump so there’s always oil laying in it when engine is not running. My first system I made in the early 70s was a static single line that ran behind the deep pan sump, took awhile to prime till I put the line up under header( above pump) instant prime after that. I also used the big Teflon lined line (same size as the rubber line 14?)

After having another episode of no prime, after custom clearanncing my oil pump to minimum specs, i am thinking of a way to put vacuum draw on the inlet side of the oil pump pickup, right up by the pump. If i could draw oil up by the pump, it should then prime quickly. I have an accusump, and despite a full pre oil, it refused to prime. So if this idea has merit, you might be able to use it on your Hemi.
I am tired of pulling the distributor and gear on my motor, as at times it has taken a lot of trys to get the pump gear to go back in. So drilling and tapping a 1/8 pipe plug port , and using a small vacuum pump to pull oil is what i am considering. If my idea works it would save me a lot of messing around. One of those tire deflater things comes to mind, since i have a compresser in my race trailer. My last fail to pull prime was on a cold morning at the track.

HI

my 4.5 in stroke hemi has stock type internal oiling . miladon pan

never a oiling issue , been together sense 2012

should have app .060 clearance .

get out the tourch and heat it red and put a small dent for clearance at closest point . done !

Think about this, internal pipe is below pump same as external so inside I’ve never heard of a priming problem, why is external NOT priming? I’m sure the oil drains back into sump with internal pipe. Sounds like it’s sucking air at some place

I have heated and dinged the pick up tubes also in the past also. However, I am currently running the dual line external system on the street with no lose of prime issues with a slight loop. Here is the loop in the picture.

Inabiliy to prime comes from the pump clearances hindering the pump to pull oil, the volume of the system, viscosity and temp of oil. At somewhere around 50 degrees temp with 20w50 oil and an external pickup,(big volume from oil to pump in the external line) the pump has to spin a ton of rpm to pull oil, and for more time than you dare run without pressure.

What block is that? Wonder if a 528 crank would be that bad? I'm thinking about a 4.50 stroke and I don't like the looks of that on the street.

I always used to prime my engine with an electric drill if the car had been standing for any length of time, (it would hold prime for a week or so). It always took a couple of seconds before you could feel the oil pressure load the drill. I switched to a 3 qt Canton accusump when the car started to do big wheelstands and now just use that. I can leave the car for months with the accusump pressurized, pull the release cable and the engine is primed. I've done it whilst under the car, you can hear the oil flooding the engine and draining back to the sump. There is a technique to re-filling the accusump when the engine is started, I shut the accusump off and gently open it to allow the oil to re-fill it, while watching the oil pressure gauge. Fill it too quickly and you can see the oil pressure drop excessively.

If the pickup clearance issue and the fragility of the tube has you worried, just go external oilingand run one of these. Granted not the cheapest way but work like a charm.

Pre oil your engine before every fire up.

Done.

I had a Milodon aluminum pump on my wedge. It would loose prime every time i changed the oil. The air leak was on the snout of the pump at the oil ring. A little rtv fixed it, but maybe a gob of grease would be better. If you use too much rtv, a wad of it can fall off and get into the pump and shear the oil pump shaft. Ask me how i know.

I do appreciate your options and may have to use one, but i'm set on internal oiling this thing if i can make it happen. It will never see over 7000rpm. I want as little hassles as possible, just easy start up and drive away.

Not many options here, i understand, but once i dent the tube, i lose the benefit of the 1/2" tube.

.060 is recommended but .020-.030 is fine.

Don’t just dent the pipe, make oval shape, a press or vice will work, heat to cherry red then squeeze it. An oval or squareish pipe will flow same as a round one

Yes, was just thinking that. Like oval exhaust same area.

Come to think of it. That is what I did was oval the tube in a bench vise while cherry red. I didn't just ding the tube.

Here is an idea to modify the factory Bill Mitchell part, so you can move it a little.
Use locktite on the bolt threads, and a touch of some sealant (not RTV) on the flat part after milling off the round part sticking out (into the block).
I might even be able to mill an O-ring recess after milling off that part, so sealant would not be needed.

instead of milling that completely off, i could shave a little off one side and drill the holes bigger. I will have to contour the inside a bit for even flow. That might get me enough, if not, a little squeeze in the vise should do it. Thats.

I agree don't grind it. Mine cracked after a few years in stock stroke and condition.

No kidding, it cracked on the thread? That is the thicker part of the tube.

Finished. I will mail this today (Fri). Give it a try.

Any worries about it "sliding" over, now that there's nothing to register it?

Thanks Jim, i will certainly give that a try. I think Indian Head gasket shellac would seal and hold that a long time.

hi,

you are over thinking it if you dimple the tube .060" there should be plenty of oil still .

i have 1 449 that the owner has ran with a stock street hemi oil pan 3/8 tube for 7 years without any refrish of engine .

verry consistant 10,40 1/4 mile .

my hemi runs 60 /65 psi hot 10/30 valaoline .

New adaptor on the way by 440Jim. No dimpling required.

Yes

They crack like that from not enough thread engagement . The pipe thread used is tapered when you just grab 3-4 threads your sill on the part of the tube that is on the minor dia of the thread die, so its cut deeper into the tube, you need to open up the thread in the block with a tap to get more thread engagement.

Thanks for that a will do. Mine was only getting 4 threads.

with my Milodon pickup I actually used a taper die to recut the thread as it wouldnt go more than about 1 1/2 turns . Once recut went in a lot further . Did this on 2 different road race pan pickups . One went into my World block one into a stock block .
Almost seemed like it was cut parrallel thread .

Tex

Will recut that adaptor when i get it.

x2. I'd have no problems denting one but I wouldn't want to grind it in an area where it has the potential to crack. That's a lot of leverage from the end of the pickup to the threads for it to crack over time due to vibration.

Make a strap tied to top of a main cap to stop vibration,

Please keep updating this so I know what to do on mine... I am not going to use an external line so whatever solution you find will be very helpful.

I really wanted 4.5 stroke to keep the dome size down.

for sure. i see about getting some pics this weekend.

After clearancing the pan rail a bit for the tube, I have .055” between the tube and the rod shoulder and .040 between the adaptor and the rod. A bit more grinding on the adaptor and I’ll have it.

Well... it looks like my 572 just turned into a 540. But good to know before buying the rotating assy... Bummer for me, but thank you for sharing...

Those clearances are wider than what I have race with in the past

x2

Start it up and let the rod make its own clearance.

if the rod touches that your going to have lot more than that that it going to touch. The only way its touching that at .020-.060, something is coming apart.

It will save you some trouble.

Yep, just a bit more grinding and a tapered tap to get the tube to screw in all the way. I think i will use a thin paper gasket under the adaptor, glued on with Indianhead . That should keep it in place. Anyone know the torque spec on the adaptor screws? Thanks to 440Jim, it will be internal oiled.

Just what i hoped to hear cab. Thanks

From my build notes, I used Loctite on the ¼ allen head bolts (socket head cap screws) and torqued to 100 lb-in.
572 B1 org Part 5 - Build Notes [block oil pickup hole]

No more than 120 lb-in (10 lb-ft).