Oil pump.... reuse or buy new?

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dartfreak75

dartfreak75

Restore it, Dont part it!
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I had planned on buying a new one they are only about 40 bucks but I was looking and my old one and took it apart just to see how it worked and I don't see a whole lot that could go wrong or wear out. Should I just save the 40 bucks and reuse the old one?
The old one came off a 318 at they the same pressure as a 360 pump?
 
dartfreak75 said:
I had planned on buying a new one they are only about 40 bucks but I was looking and my old one and took it apart just to see how it worked and I don't see a whole lot that could go wrong or wear out. Should I just save the 40 bucks and reuse the old one?
The old one came off a 318 at they the same pressure as a 360 pump?
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If a mild street engine, and I know it worked good, I've re-used them without worry. I've put new ones in also. A new melling oil pump is never a bad idea.
 
Krooser said:
If it looks good without any wear or slop use it. Every car runs on used parts.
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We put a new oil pump on one of my hemi`s once, ( roller cammed super stock motor) , started it w/ no oil pressure, partner was sitting in the drivers seat, I ask him how the pressure was, he sat stunned for a couple of seconds, and said the isn`t any, I told him to kill it.
It had ran for about a minute, we pulled the pan and had no bearing damage . Was running either Valvoline or Quaker State 50 weight at the time ----- put original oil pump back on-----draw ur own conclusion.
 
dartfreak75 said:
I had planned on buying a new one they are only about 40 bucks but I was looking and my old one and took it apart just to see how it worked and I don't see a whole lot that could go wrong or wear out. Should I just save the 40 bucks and reuse the old one?
The old one came off a 318 at they the same pressure as a 360 pump?
Click to expand...


When you took the old one apart, what did the wear pattern look like on the inside of the cover? Any scoring on the lobes of the pump, or signs that foreign matter went thru the pump? Those are the signs that you look for when making the new/reuse decision. You can replace/shim the pressure relief spring on your pump, be it ( the pump ) new or used.
 
After reading the comments I decided Its worth 40 bucks to clean it and see what it looks like. I'm not sure what normal wear or a normal oil pump looks like I took photos. But I'm kinda leaning towards a new one some of the scoring on the rotary part looks pretty deep to me. What do you guys think?

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Just buy a new one.
If you can get a new Melling one for 40 bucks, that's money well spent for peace of mind.
The old one is pretty scored up, i wonder what the bearings looked like on this engine that it came off?
 
Those wear and score marks on the insides and outsides of lobes is where a lot of the flow/pressure capacity gets lost. I'd replace that, no question. I know the budget is constrained but, as said, it is good insurance.

Service limits (which tend to be on the sloppy side):
- Pump cover flatness variation: no more than .0015"
- Minimum inner and outer rotor length: .825"
- Minimum outer rotor diameter: 2.469"
- Maximum clearance between outer rotor and body: .012" (but scoring will effect this)
- Maximum clearance between inner and outer rotor lobes: .010"
 
Dartnut said:
Just buy a new one.
If you can get a new Melling one for 40 bucks, that's money well spent for peace of mind.
The old one is pretty scored up, i wonder what the bearings looked like on this engine that it came off?
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The crank bearings looked good but then rod bearings had alot of scoring the engine had low miles. I think the guy never changed the oil or ran sand in the oil or something lol.
 
nm9stheham said:
Those wear and score marks on the insides and outsides of lobes is where a lot of the flow/pressure capacity gets lost. I'd replace that, no question. I know the budget is constrained but, as said, it is good insurance.

Service limits (which tend to be on the sloppy side):
- Pump cover flatness variation: no more than .0015"
- Minimum inner and outer rotor length: .825"
- Minimum outer rotor diameter: 2.469"
- Maximum clearance between outer rotor and body: .012" (but scoring will effect this)
- Maximum clearance between inner and outer rotor lobes: .010"
Click to expand...
Dartnut said:
Just buy a new one.
If you can get a new Melling one for 40 bucks, that's money well spent for peace of mind.
The old one is pretty scored up, i wonder what the bearings looked like on this engine that it came off?
Click to expand...
Yea I thought the same after I cleaned it up and saw how much scoring was on the inside.
 
Looks like some junk has moved thru it... but it looks great compared to the one in my race motor. Cam and con rods parts make a mess.
 
Krooser said:
Nice little video...

Click to expand...

Thanks for the video! I will do that for sure!!

Has anyone used engine tech oil pumps? Rock auto has one for 21 bucks. I'm a little hesitant about buying cheaper parts now tho! Check out my lca bushing thread.. :BangHead:
 
dartfreak75 said:
Thanks for the video! I will do that for sure!!

Has anyone used engine tech oil pumps? Rock auto has one for 21 bucks. I'm a little hesitant about buying cheaper parts now tho! Check out my lca bushing thread.. :BangHead:
Click to expand...
Don’t skimp on the oil pump, not worth the risk.
 
new oil pump is first on my engine build list. new bolts are last on my list.
 
I've cut corners before, but places I will not cut corners are bearings, rings, oil pumps and timing sets.
 
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