What oil pump to use.

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furz4

furz4

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it looks like I will need a new oil pump for my build, the one I had in a box was obviously used and I don't remember where it came from. I was going to run standard volume Melling M72 with high pressure spring as I am running stock clearances and will see some RPM on occasion. Build is pretty standard .030 over 9.2 compression magnum headed LA block, crank turned 10/10 ARP rod bolts with a re-balance flat tappet cam. Since I am oiling the rockers through the push rods I was thinking maybe a hi volume would be better since I have to buy one. I have used both high volume and standard pumps in the past with no problems but am wondering what people are using when going to oiling through the push rod set up. Am a little disappointed it looks like Melling pump is mad in China now.
 
My understanding is a high pressure pump is nothing more than a regular pump with a high pressure bypass spring installed. That spring come standard in high volume pumps I believe.
 
If running the high pressure pump and the by pass valve fails on the oil filter, it causes one heck of a mess. Ask me how I know.
 
Where did you see Melling pump is made in China? summit still lists Melling M-72 as made in USA. There are lots of Chinese copies using the same part number, especially on eBay and Amazon.

There is also a kit K-72 if you want to rebuild your old standard volume pump.
 
No reason to use anything but a stock pump.

My oval track 7,000 rpm motors ran stock pumps
(with oiling mods) without issues.
 
Amazon showed the Melling pump as made in China, might be a knock off for all I know. I doubt I need the high volume pump with standard bearings and clearances, the lifter bores were tight on this block also. My main reason for not using high volume would be to eliminate excess heat build up as I have installed modern air conditioning and I don't want to induce extra heat that is not needed. I don't know how much heat the high volume pump adds but I saw a poster somewhere say that at highway speeds his temps went up 10 degrees, seems like a lot to me. My main concern is valve train oiling through the push rods. I was thinking of using the high pressure spring in a stock pump because of 10 PSI per 1000 RPM rule of thumb. Motor could see above 6000 RPM.
 
mopowers said:
My understanding is a high pressure pump is nothing more than a regular pump with a high pressure bypass spring installed. That spring come standard in high volume pumps I believe.
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I thought so, but no it does not. Mopar Performance used to sell a HP version of both big and small block oil pumps. They were HV pumps modified with the HP spring. High volume and high pressure. You can do the same since the high pressure springs are still available.....for now. The big block spring fits the slant 6.
 
Ordered a standard melling pump from Amazon will see where it's made and see if it's a knock off and report back.
 
Super-Cuda said:
Can I ask why not use HP pump?

Just curious.
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Standard pressures are plenty- it's debatable if the high volume is even necessary, but I usually run one.
There were issues years back with the high pressure units actually snapping the intermediate shafts, which led to higher strength DC/MP shafts with more rounded machining to reduce stress points, etc. etc...
The lack of availability of ANY intermediate shafts right now, let alone any high strength ones; coupled with the lack of need for higher pressures, would make me not recommend a high pressure pump for any build.
 
I see it now. On Amazon the country of origin is listed as China. And one review said the same thing. Not happy about that.
 
Brooks James said:
Hi pressure
Hi volume

Take more HP than std pump
Get some free hp
Click to expand...


How much extra power does it take?

I know of an example where dropping the oil pressure was a power loser.

And I mean dropping from 100 to 85 pounds. And the power went down every time we tried to lower it.
 
If using a standard capacity pan, I would stay with a standard pump.
 
townsend said:
Melling warns about counterfeit pumps.

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This is what I was originally wondering about. Anything bought off ebay or amazon where it is a third party seller is always suspect these days. When I looked at the supposedly Melling M-72 on Amazon, it says sold by and ships from Amazon, which is usually safer, but still says country of origin is China.
I usually only buy the pumps from Summit and a they are still saying made in USA, which is more in line with what we expected.
 
Bobzilla said:
This is what I was originally wondering about. Anything bought off ebay or amazon where it is a third party seller is always suspect these days. When I looked at the supposedly Melling M-72 on Amazon, it says sold by and ships from Amazon, which is usually safer, but still says country of origin is China.
I usually only buy the pumps from Summit and a they are still saying made in USA, which is more in line with what we expected.
Click to expand...
Yep - stick to an authorized dealer. Amazon and Ebay are not the places to buy new automotive parts anymore, unfortunately. There are too many counterfeits out there.
 
Why order thru Amazon? That's where the counterfeits are, as SHOWN here lol.
$10-15 savings vs something that could ruin your motor?
furz4 said:
Ordered a standard melling pump from Amazon will see where it's made and see if it's a knock off and report back.
Click to expand...
 
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