347 questions

BKM48198 · May 2, 2021

Getting my 1st 347 built and I don't know if I should go with stock oil pump or high volume, I'd like opinions from others that have had 347s. Are there any parts needed for a 347 you would recommend, this is a cruiser and NOT a racecar, not looking for 400 hp, just a dependable engine. Thanks

7991LXnSHO · May 2, 2021

Opinions on this are like belly buttons. Everyone has one, but you do not want to see them all.
How many rpm are you going to spin this engine to? By your description so far, a stock pump and an ARP pump drive shaft will serve you well.
The stock pump shaft is the weakest link in my experience. They do not work well once they twist up like a Twizzler and snap.

BKM48198 · May 2, 2021

7991LXnSHO said:
Opinions on this are like belly buttons. Everyone has one, but you do not want to see them all.
How many rpm are you going to spin this engine to? By your description so far, a stock pump and an ARP pump drive shaft will serve you well.
The stock pump shaft is the weakest link in my experience. They do not work well once they twist up like a Twizzler and snap.

I had one twist up in an Explorer so the hardened shaft is going in which ever pump I go with, as for RPM's I don't plan on being over 5500 very often, I'm about to turn 59 and this is a 1 owner car, the cam drops off about 5500rpm so no need to push it beyond that, most of the time I will be driving it easy with mostly highway miles. I am leaning towards the stock pump from everything I have read.

7991LXnSHO · May 2, 2021

Then there is no need for the Hp drain in this build. A Melling or TRW stock replacement will be good.

WhiteCobra95 · May 2, 2021

I agree with 7991LXnSHO. If it's a street or street / strip car, you don't need the high volume pump. From my experience and experiences with friends' engines, high volume or high pressure oil pumps do more harm than good in most cases. You have to be running serious race engine specs rather than a normal or mild performance rebuild before those types of pumps are necessary. A good quality stock replacement pump with a shaft upgrade is probably the way to go.

Mustang5L5 · May 3, 2021

I agree, no need for high volume. If your bearing clearances are tight it's going to be a high pressure pump and put such a load on the oil pump drive that you run the risk of twisting them up.

Definitely upgrade to the ARP oil pump shaft, but stick with a standard output Melling.

TOOLOW91 · May 3, 2021

Bearing clearances really determine what you need . I have a big bore 347 that’s makes a little hp and has seen upward of 7k rpm . It has a standard melling pump in it and has no issue making 60plus psi at full tilt

revhead347 · May 4, 2021

I have a high volume pump in mine with no issues. Honesty, I don't think it puts out much more than a factory volume. The general consensus is that it is totally unnecessary. Factory pump should be fine.

Kurt

CarMichael Angelo · May 6, 2021

I guess the experts that teach us that high pressure vs high volume are completely different, are entirely wasting their time then.

A high pressure pump isn't the same as a high volume pump. The one that moves oil through the existing passages at a higher pressure, will not move volume

The one that moves volume won't necessarily move it at a higher pressure..
As long as the existing passages don't act as a restriction.
When existing passages haven't been modified ( i.e. passages enlarged, bends and turns are smoothed/radiused, bearing Clearances are increased) ,bad things happen. Horsepower is robbed, oil pump shafts twist, bearings starve, oil pans get sucked dry)
Dont be a weiner.. Put a stock pump in it. Run at least a 30w oil.
Be happy for ever after.

347 questions

BKM48198

7991LXnSHO

wanna catch the space herp

BKM48198

7991LXnSHO

wanna catch the space herp

WhiteCobra95

Mustang5L5

That is…until I whipped out my Bissell

TOOLOW91

If you're the village idiot what's that make me?

revhead347

Apparently my ex-husband made that mistake.

CarMichael Angelo

my rearend will smell so minty fresh,

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347 questions

wanna catch the space herp

wanna catch the space herp

That is…until I whipped out my Bissell

If you're the village idiot what's that make me?

Apparently my ex-husband made that mistake.

my rearend will smell so minty fresh,

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