450hp 340 oil pump suggestions ?

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64whiteghost

64whiteghost

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Whatsup guys. What oil pump do you recommend for my 450hp 340 build ? Its going into a 1964 plymouth valiant
 
I run melling HV pumps but I also do anything else that can increase flow. From full grove bearings to smoothing out all casting in the block to glyptal in the block.
 
RustyRatRod said:
Wow. I see they have them bad boys back in stock. With an inflated price, too!
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yeah, it seems like the sealed power and the mahle jumped up too. the melling was out of stock for so long, the last two i wound up using a MP one and a summit house brand. wasn't super concerned on the MP piece, but the summit one got the hairy eyeball before going in.
 
junkyardhero said:
yeah, it seems like the sealed power and the mahle jumped up too. the melling was out of stock for so long, the last two i wound up using a MP one and a summit house brand. wasn't super concerned on the MP piece, but the summit one got the hairy eyeball before going in.
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I have a collection of used slant 6 pumps and a couple or three new ones. They're ridiculous new, too.
 
Honestly a stock pump is fine. It depends on a few factors not HP.
1) clearances- how loose is the motor? The looser it is, the more oil you need to fill those gaps.
2)rpm- are you dropping oil pressure the faster it spins. Most pumps “blow off” excess oil pressure out the by pass valve.
3)cost- as mentioned above, these prices are going higher and higher as child labor in Chy-na and delivery fees are increasing.
4) added power boosters like turbos need oil and that to me is where you need “extra” oil flow to compensate for the loss of oil flow/pressure.
Syleng1
 
I believe there are only 1 or 2 places the manufacture and cast these SB pumps.
 
Syleng1 said:
Honestly a stock pump is fine. It depends on a few factors not HP.
1) clearances- how loose is the motor? The looser it is, the more oil you need to fill those gaps.
2)rpm- are you dropping oil pressure the faster it spins. Most pumps “blow off” excess oil pressure out the by pass valve.
3)cost- as mentioned above, these prices are going higher and higher as child labor in Chy-na and delivery fees are increasing.
4) added power boosters like turbos need oil and that to me is where you need “extra” oil flow to compensate for the loss of oil flow/pressure.
Syleng1
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Agree, don’t give up on perceived HP. Concentrate on all of the above. You really don’t know what the actual hp until you get it on an engine dyno. Even the it depend a lot of fine tuning.
 
Syleng1 said:
Honestly a stock pump is fine. It depends on a few factors not HP.
1) clearances- how loose is the motor? The looser it is, the more oil you need to fill those gaps.
2)rpm- are you dropping oil pressure the faster it spins. Most pumps “blow off” excess oil pressure out the by pass valve.
3)cost- as mentioned above, these prices are going higher and higher as child labor in Chy-na and delivery fees are increasing.
4) added power boosters like turbos need oil and that to me is where you need “extra” oil flow to compensate for the loss of oil flow/pressure.
Syleng1
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Your number 2 is incorrect the excess oil pressure does not blow out the pressure relief valve. The valve opens inside the pump in order to drop the pressure. Once the pressure drops the valve closes and the pressure increases until the next time it needs to open up to allow the pressure to drop.
I agree with you that a stock pump is fine. Personally I pull them apart clean them up put in a high pressure spring and put them back together using as big inside of a pickup tube as I can.
 
autoxcuda said:
I believe there are only 1 or 2 places the manufacture and cast these SB pumps.
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The SealedPower NAPA ONES I got had a paper and same casting as Melling and had a Melling paper inside box. M-72 as well as HV 72 ones
 
autoxcuda said:
I believe there are only 1 or 2 places the manufacture and cast these SB pumps.
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if i had to take a guess melling would be one and seeing sealed power as another option that would be my second guess in that they're part of federal mogul. mahle probably buys it from one of them and just reboxes it.
 
340six said:
The SealedPower NAPA ONES I got had a paper and same casting as Melling and had a Melling paper inside box. M-72 as well as HV 72 ones
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i stand corrected, then. thanks for the insight!
 
See my post above, these guys will blueprint your milling pump, top shelf work.

Blueprinted Melling M-72HV SB Mopar High Volume Pump. Will fit all 273, 318, 340, 360 engines.
MELLING HIGH VOLUME OIL PUMP,Blueprinted by PRECISION OIL PUMPS. The pump is a brand new Melling HV Small Block Mopar pump #M72HV. Will fit all 273, 318, 340, 360 engines. Each pump is disassembled in groups of ten, The passages have the casting flash removed, polished, radiused and blended by hand. The Housings & gears are Deburred by a Vibratory -Polisher then cleaned. The Gears are then sprayed with TECH-LINE moly-coating and oven curred. Three Critical Clearances are checked on reassembly: (1) Gear to Housing,(2) Mesh or Backlash, (3) Gear to Cover-Plate. With Ten gear sets to choose from, One set with Optimal clearances will be installed. The relief valve is deburred with emmory-cloth and is re-installed with the existing spring & new hardware, Each cover plate is also Vibratory -Polished, cleaned and is fastened with safety-wired aircraft bolts. All pumps are bench tested. Buy with confidence
 
I've used Precision Oil pumps for years. I did have a poor experience with them on the newest SBM motor I built.

When I hand tightened the oil pickup into the pump, 1/2 of the threads snapped off the housing. I never even put a wrench to it. After examining it under my magnifying light, it appears to have been a casting defect.

I called Precision and they claimed it was installation error, which really irked me because the threads were cleaned and prepped before screwing the pickup tube on.

Just make sure that before any oil pump is installed to inspect for hairline fractures and defects. Trust but verify.

20230803-123238.jpg
 
Just Send It said:
I've used Precision Oil pumps for years. I did have a poor experience with them on the newest SBM motor I built.

When I hand tightened the oil pickup into the pump, 1/2 of the threads snapped off the housing. I never even put a wrench to it. After examining it under my magnifying light, it appears to have been a casting defect.

I called Precision and they claimed it was installation error, which really irked me because the threads were cleaned and prepped before screwing the pickup tube on.

Just make sure that before any oil pump is installed to inspect for hairline fractures and defects. Trust but verify.

View attachment 1716122723
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Did they step up to fix? They have been really good for me so far.
 
Heywodja said:
Did they step up to fix? They have been really good for me so far.
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No sir they did not. Never gave a refund. $170.00 down the drain. I ended up just reusing the old stock HV Melling. Works fine.
 
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