themechanic
Oklahoma is OK
I recently saw a tip on Nick's Garage's video on new oil pumps. The entire video is worth watching but the clip starts at the oil pump tip. You learn something every day.
Oil Pump Trick by Nick's Garage
- Thread starter themechanic
- Start date
Mopars & Missiles
Well-Known Member
Yes, that is an important check when building an engine. Been doing that for years now. Here's a couple before & after photos of an oil pump on an engine I rebuilt a little over 10 years ago.
Mopars & Missiles
Well-Known Member
This partial obstruction is pretty common on these oil pumps, here's a before & after comparison on another engine I built about 5 years ago.
68 HEMI GTS
Well-Known Member
I always work mine also. Gotta check every detail.
vintage chromoly
Well-Known Member
Yep, did the same thing to mine when we went through it.
BeepBeepRR
Well-Known Member
Glad this video was up. I just took mine off and did this. I purchsed a cheap set of burrs off amazon. I have to say I was impressed with the little things. Did a nice job doing this modification. Also used a dremel to do the work. I think the set was like 14 dollars. If you are cheap like me they fit the bill. HERE
![IMG_1747[1].JPG](https://www.forbbodiesonly.com/moparforum/attachments/img_1747-1-jpg.582509/ "IMG_1747[1].JPG")
![IMG_1748[1].JPG](https://www.forbbodiesonly.com/moparforum/attachments/img_1748-1-jpg.582510/ "IMG_1748[1].JPG")
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Check the alignment between the two pump body halves. I have 4 Melling pumps here where the misalignment is so bad it probably blocks 25% of the cross sectional area on the pressure side. I elongate the bolt holes, twist and roll pin the two halves, then enlarge the smaller of the two holes to match the larger one.
IMO, the aftermarket pumps are very poor. I now buy used OEM for $5 instead.
BeepBeepRR
Well-Known Member
I have the OE pump that was on the engine when i got it. I can install it on the engine just to see if it was any closer to the aftermarket pump as far as alignment. I will post pictures of that. I confirmed it is an actual mopar part number.
OE was no better than aftermarket.
OE Pump.
![IMG_1757[1].JPG](https://www.forbbodiesonly.com/moparforum/attachments/img_1757-1-jpg.582545/ "IMG_1757[1].JPG")
![IMG_1752[1].JPG](https://www.forbbodiesonly.com/moparforum/attachments/img_1752-1-jpg.582546/ "IMG_1752[1].JPG")
Aftermarket Pump.
![IMG_1749[1].JPG](https://www.forbbodiesonly.com/moparforum/attachments/img_1749-1-jpg.582547/ "IMG_1749[1].JPG")
![IMG_1759[1].JPG](https://www.forbbodiesonly.com/moparforum/attachments/img_1759-1-jpg.582572/ "IMG_1759[1].JPG")
OE was no better than aftermarket.
OE Pump.
Aftermarket Pump.
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BeepBeepRR
Well-Known Member
Umm the pictures are posted.
OEM
![IMG_1757[2].JPG](https://www.forbbodiesonly.com/moparforum/data/attachments/510/510727-823181cacb619b106a936f0943641b20.jpg "IMG_1757[2].JPG")
![IMG_1752[1].JPG](https://www.forbbodiesonly.com/moparforum/data/attachments/510/510728-245b17bc63741b3ba4b3d944891dfc9c.jpg "IMG_1752[1].JPG")
![IMG_1755[1].JPG](https://www.forbbodiesonly.com/moparforum/attachments/img_1755-1-jpg.582579/ "IMG_1755[1].JPG")
Aftermarket.
![IMG_1749[1].JPG](https://www.forbbodiesonly.com/moparforum/attachments/img_1749-1-jpg.582578/ "IMG_1749[1].JPG")
OEM
Aftermarket.
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Right. The pressure side hole between the halves, not the suction side between the pump body and block. Maybe Melling has fixed it, but the alignment was so bad, about half the width of the o-ring was exposed to the cover half hole.
And if you are truly interested in improving the flow, or flow efficiency of the pump, you need to start with the block suction side, and at least remove the square inside corner. That is a far greater flow hindrance than that suction block to pump alignment. There are probably 5 places that can use some work in the pump including the pressure side pump to block, although that one is not too bad. But the block and pump passage are on different angles so I enlarge the blend an inside radius. I think even the threaded filter adapter in the Melling had a slightly smaller ID than the original, IIRC.
At the end of the day, thousands, if not millions of these pumps are in service without issue, so they are clearly over engineered enough to make up for it all. But if you are actually interested in making an improvement, correcting that one misalignment is not doing much of anything.
And if you are truly interested in improving the flow, or flow efficiency of the pump, you need to start with the block suction side, and at least remove the square inside corner. That is a far greater flow hindrance than that suction block to pump alignment. There are probably 5 places that can use some work in the pump including the pressure side pump to block, although that one is not too bad. But the block and pump passage are on different angles so I enlarge the blend an inside radius. I think even the threaded filter adapter in the Melling had a slightly smaller ID than the original, IIRC.
At the end of the day, thousands, if not millions of these pumps are in service without issue, so they are clearly over engineered enough to make up for it all. But if you are actually interested in making an improvement, correcting that one misalignment is not doing much of anything.
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BeepBeepRR
Well-Known Member
OK I guess I wasn't understanding what you were saying. I will have to check that out too.
68 HEMI GTS
Well-Known Member
That’s a must on any build, the suction side has a lot of room for improvement.
Along with working the turn I enlarge the passage to the pump as well as open up the pickup to 1/2” not on anything that’ll see rpm.
On more serous builds people use external lines to avoid the restrictions inside the block. I use a single -12 on my hemi as well as a few wedge motors I’ve built.
External set up, not something most need.
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I have mad respect for you OEM guys!
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