Correct oil pickup position?

[4C FED]

I was tinkering in the garage today and installed the oil pump pickup.

I then mounted the pump to the rear main cap to see if the pickup was positioned correctly.
If I try to run the pickup parallel to the pan mating surface, the back of the pan sticks up off of the gasket by about 1/4", maybe a little less.
If I rotate the pickup (closer to crank/farther from the pan) just until the pan sits begins to sit on the gasket, this puts the pickup at a tilted angle.

What is the correct angle to position the pickup?

Thx,

 

[myclone]

Which oil pump are you using?

 

[4C FED]

It's a Melling HV.

I tried to position the pickup like the pump I removed, but it doesn't seem to be right.

I was just reading in my "How To Build The SB Chevy" book that you position the pickup so that it hits the bottom of the pan. Then, push the pan down until the pan sits flat without a gasket (pickup bottomed out on pan). Measure the height of the pickup on a stick or ruler relative to the pan surface then move it down another 1/4" (increasing the space between the pickup & the bottom of the pan).

Wadda ya think?

 

[jwaller]

I never use a HV oil pump but thats your call. I position the pickup screen parallel to the pan rail. then tack weld the pickup to the pump

 

[myclone]

It's a Melling HV.

I tried to position the pickup like the pump I removed, but it doesn't seem to be right.

I was just reading in my "How To Build The SB Chevy" book that you position the pickup so that it hits the bottom of the pan. Then, push the pan down until the pan sits flat without a gasket (pickup bottomed out on pan). Measure the height of the pickup on a stick or ruler relative to the pan surface then move it down another 1/4" (increasing the space between the pickup & the bottom of the pan).

Wadda ya think?

The high volume pumps are slightly longer than the stocker and this lowers the pick up into the pan further which is prolly whats causing your probs. Personally I want the pick up parallel with the bottom of the pan. If I were you Id shorten the pick up tube by cuttting/rewelding it instead of pushing the pickup further away from the bottom and it no longer being parallel with the bottom of the pan.

FWIW.. IMO the Melling M55A (early LT1/Z28) pump is plenty adequate and doesnt require any pick up mods. I put that pump in just about every V6 or V8 I screw togeather and it only costs ~$30.

FWIW part II... I personally set my pick ups no more than 1/4" from the bottom of the pan (measured at the pick up screen) WITH the gasket installed. IMO putting it 1/4" from the bottom without the gasket is too close but thats just my opinion.

HTH

 

[nightdiver]

My pick up was in contact with the pan and i had lub problems a few years ago. This happend cause i asked my mechanic to see if the clearence was ok and he said "yes yes ill do it "The SOB didnt
I welded the pick up about 5 mm away from the pan
With the HV pump i needed to hit the MF just a little bit :2gunfire:

 

[Sy769]

It's a Melling HV.

I tried to position the pickup like the pump I removed, but it doesn't seem to be right.

I was just reading in my "How To Build The SB Chevy" book that you position the pickup so that it hits the bottom of the pan. Then, push the pan down until the pan sits flat without a gasket (pickup bottomed out on pan). Measure the height of the pickup on a stick or ruler relative to the pan surface then move it down another 1/4" (increasing the space between the pickup & the bottom of the pan).

Wadda ya think?

The high volume pumps are slightly longer than the stocker and this lowers the pick up into the pan further which is prolly whats causing your probs. Personally I want the pick up parallel with the bottom of the pan. If I were you Id shorten the pick up tube by cuttting/rewelding it instead of pushing the pickup further away from the bottom and it no longer being parallel with the bottom of the pan.

FWIW.. IMO the Melling M55A (early LT1/Z28) pump is plenty adequate and doesnt require any pick up mods. I put that pump in just about every V6 or V8 I screw togeather and it only costs ~$30.

FWIW part II... I personally set my pick ups no more than 1/4" from the bottom of the pan (measured at the pick up screen) WITH the gasket installed. IMO putting it 1/4" from the bottom without the gasket is too close but thats just my opinion.

HTH

What he said

 

[hrodgmc]

According to Reher-Morrison,(NHRA pro-stock builder) the pickup can be positioned anywhere from 1/4" to 1/2" above the bottom of the oil pan. The hv pump has been proven to rob a couple horsepower.

 

[4C FED]

Yeah, my pickup is resting/pushing on those 3 raised nubs on the bottom of the pan.

When you guys run the stock pump, do you change out the pressure relief spring to run a little more pressure when hot?

 

[TyMeUp]

When you guys run the stock pump, do you change out the pressure relief spring to run a little more pressure when hot?

Don't do that! Too much oil pressure will cause more oil to spray off of crank and onto cylinder walls. Oil control rings can't handle that much oil so you end up burning it. Not good for octane.

Also use the LT1/Z-28 pump (has correct spring for 50-60 psi) with a 'new' pickup, tack welded - as several here have suggested. Save the HV pump for when you build your 630 cid Big Block Chev.

(What? doesn't anybody want to build one of those?)

 

[4C FED]

I guess I'll buy another fricken pump.
Which one do I want this time? PN?

I was going to run the Moroso rear pan baffle.
Anyone want to comment on that?

Thanks guys,

 

[myclone]

I guess I'll buy another fricken pump.
Which one do I want this time? PN?

I was going to run the Moroso rear pan baffle.
Anyone want to comment on that?

Thanks guys,

The Melling Z28 pump from Jegs is part #689-M55A and is $29.99.

The pan baffle youre talking about..... is it the one that goes between the oil pump and main cap? If so then it prolly wont hurt. Ive used it and the only real issue was it had to be trimmed to fit the pan every time. Not a big deal but be prepared to do some tinkering with it to get it to fit.

You have an after market "one piece" oil pump drive? Yes?... If not get one as theyre only a few bucks (ARP, Moroso, etc make them).

According to Reher-Morrison,(NHRA pro-stock builder) the pickup can be positioned anywhere from 1/4" to 1/2" above the bottom of the oil pan.

Those guys have prolly forgotten more than I'll ever know but..... how long has it been since a pro stock engine was wet sump? If/when they were Im sure they were turning ungodly RPM and needed the extra clearance so the oil could get to the pick up. So, it prolly had to be a little further off the bottom of the pan.

Our engines are the oposite of a pro stock. Low RPM grunt motors that do not come close to needing the oil capacity into the pick up a pro stock motor would. A steady supply of clean oil from a Z28 pump will suffice for all but the most radical builds IMO.

You could write novels on oiling systems and the different theories but I personally stick to what has worked for me in the past and suggest accordingly here.

 

[4C FED]

The Melling Z28 pump from Jegs is part #689-M55A and is $29.99.

Thanks

The pan baffle youre talking about..... is it the one that goes between the oil pump and main cap? If so then it prolly wont hurt. Ive used it and the only real issue was it had to be trimmed to fit the pan every time. Not a big deal but be prepared to do some tinkering with it to get it to fit.

Yep, that's it. And I already trimmed it. Just need to make some holes in it to clear the main studs.

You have an after market "one piece" oil pump drive? Yes?... If not get one as theyre only a few bucks (ARP, Moroso, etc make them).

Yep, going w/ARP drive.

Thanks.....again.

 

[4C FED]

The Melling Z28 pump from Jegs is part #689-M55A and is $29.99.

Our engines are the oposite of a pro stock. Low RPM grunt motors that do not come close to needing the oil capacity into the pick up a pro stock motor would. A steady supply of clean oil from a Z28 pump will suffice for all but the most radical builds IMO.

OK, I ordered the pump.
So I know what to expect, what kind of oil pressure should I see with this pump when the oil is warmed up?

 

[myclone]

OK, I ordered the pump.
So I know what to expect, what kind of oil pressure should I see with this pump when the oil is warmed up?

It depends on a lot of things.... Tight bearing clearances will give you high oil press, heavier oil will give higher pressure hot or cold, and lastly is wheather youve modded the oil bypasses in the block and external filter thingy.

To ans your question is an educated guess at best but here is the norm I see. On 4.3 V6s Ive built I would normally see ~80 psi cold on 10-30 dino oil at idle (cold) with a shimmed filter bypass in the block (no external oil filter thingy as this was a block mounted filter). Keep in mind this is with ZERO miles on it.... That 80psi would drop down to 45-55psi at idle when the temps came up. At steady state cruise (~2k RPM) with temps hot the oil pressure would be 60-70psi.

At ~8200 RPM oil pressure would approach 100psi but I doubt anyone here would need to twist a V6 that high so even though thats a tad high IMO its not really applicable for us.

Anyway, IMO its a situation of seeing what kind of oil pressure you have and adjusting your oil weight to where the hot and cold pressures make you happy. I personally like more oil pressure than some ppl as I have yet to see slightly high oil pressure hurt a street SBC/4.3 but have seen low oil pressure kill a few. That tells me that higher (to an extent) oil pressure is WAY better than too low oil pressure.

I also dont even think of using 40 or 50w oil in a fresh/new street motor until it gets ~50k or so miles on it and the clearances have opened up. After ~50k miles I might switch to 40/50w or I might not depending on wheather the miles have lowered the oil pressure due to wear. If the oil pressure is still close to what it was when the engine was new I stick with 30w until I start to see it dropping then I switch it over to either 40w or 50w. That make sense?? :-?

Myclone has ~73k and it had 68k when I bought it (bone stock engine). I didnt like the hot oil pressure so I switched over to 50w synthetic which brought the hot idle pressure up to ~40psi which made me somewhat happy. The cold idle will burry the gauge with 50w so needless to say I dont beat on it until the oil gets some heat in it. I suggest doing the same to you about being aware of the cold temp pressures and adjusting your driving habbits accordingly (no WOT blasts till the engine has had a chance to at least warm the oil).

Now, before anyone gets all over me about how high oil pressure heats the oil, pushes the oil past the bearings too fast, and all that I want to make it clear Im not talking about insanely high oil pressure here. We're only talking about ~20psi over stock on a fresh engine anywhere but approaching 9K RPM and none of us that I know of are going to try that with a wet sump engine (except me and it failed miserably :roll: ). Thats using an aftermarket gauge to read the pressure not the crappy stock gauge either.

Prolly more info than you needed but Im in NO hurry to go out and finish cutting grass in 92 deg heat. :wink:

 

[ed hess]

fwiw

myclone told me to use the same pump.

I had 20/50 valvoline in it for initial startup. when priming it the gauge hooked to the remote filter port was reading 70psi, using a drill and arp adapter to spin the pump.

ed

 

[4C FED]

Well it's amazing how well things go together when you have the right parts. :roll:

Melling (std. volume) oil pump, ARP pump drive & ARP pump stud showed up yesterday. Now the pan fits like it should. 8)

All I need to do is clean the block & maybe I can get the lower end together this weekend. YAY!

Thanks guys.

 

[myclone]

Well it's amazing how well things go together when you have the right parts. :roll:

Melling (std. volume) oil pump, ARP pump drive & ARP pump stud showed up yesterday. Now the pan fits like it should. 8)

All I need to do is clean the block & maybe I can get the lower end together this weekend. YAY!

Thanks guys.

Couple of things just FYI...

Since youre using a stud on the oil pump check the main cap to see if the hole that it threads into has been drilled all the way through or not. If it has been (Ive seen rear mains both drilled through and not through) then make sure you dont screw the stud in too far so it contacts the main bearing. Running the stud in too far until it hits the bearing will close up the rear main clearances and wipe out the bearing in no time.

The studs for mounting oil pumps sometimes end up hitting the pump housing so mock everything up before putting bearings in, cleaning, etc as you may have to slightly grind the pump body to clear. Saves you the hassle of cleaning everything, trying to install the pump, finding you to have to grind it, then having to reclean everything after grinding. BTDT :roll:. Also once youve verified the pump doesnt hit the stud (or clearanced it if it does) reinstal the pump with that ARP drive shaft and check it out. Ive had that steel "collar" on the one piece drives that replace the stock plastic piece rub on the main cap. You may need to touch up the main cap with a die grinder for clearance. BTDT also :roll:

Submerse the pump in a pan of kerosene or the like and rotate it by hand a few times in both directions. This helps wash out any garbage that managed to get in there during packing or whatever. You can also feel any binding or what have you in the pump action through your fingers while turning it. If you feel anything that seems like its "catching" or the rotation seems rough disassemble pump and look it over for burrs or the like. If you find any knock them off with a file or whet stone, clean parts, then reassemble.


HTH

 

[myclone]

The studs for mounting oil pumps sometimes end up hitting the pump housing so mock everything up before putting bearings in, cleaning, etc as you may have to slightly grind the pump body to clear. Saves you the hassle of cleaning everything, trying to install the pump, finding you to have to grind it, then having to reclean everything after grinding. BTDT :roll:.

Wait... I forgot youre using that slosh shield that goes between the pump and main cap. That might raise the pump just enough you dont have to grind the pump to clear the end of the stud. Itd be best to check before the final instal but that sheild might just save you the stud/pump housing clearance probs...

Yeesh Im getting rusty at bottom end stuff but in my own defense its been eons since Ive used one of those sheilds.

 

[4C FED]

10-4

Thanks again. 8)