[dmac]

If I'm not worried about parasitic power loss, is there any reason NOT to use an 80 lb pump? Or are there any definite benefits of using an 80 lb pump?

[grivera]

This is a good read referencing Butler Performance:

http://www.hotrod.com/articles/hppp-...-observations/

"Oil Pressure Requirements

A common question from many Pontiac hobbyists is about oil pressure and just how much is required. “We generally feel at least 10 psi of oil pressure for every 1,000 rpm is the minimum requirement for reliable operation,” says Butler. “We recommend 20W-50 oil for our high-performance engines, and like to see hot-idle oil pressure between 30 and 40 psi. Pressure as low as 15-20 psi doesn’t necessarily present a risk as long as it isn’t a sign of other problems, but the amount of time it takes pressure to climb to 60 psi or more can put the bearings at risk on a quick-revving, high-performance engine.”

Butler says that since an engine with smaller-diameter main journals (3-inch) and shorter-stroke crankshafts (4.21-inch or less) is generally less stressful on the bearings, a 60-psi pump may provide adequate lubrication in a modified engine, but an 80-psi pump is a better choice. He says any performance engine with 3.25-inch-diameter main journals and/or a stroker length greater than 4.21 inches should use an 80-psi pump. “The greater oil pressure associated with the 80-psi pump improves the strength of the oil film, and better protects the bearings in large journal and/or long-stroke applications,” he adds.

Common hobbyist concerns when using an 80-psi oil pump in a street engine include excessive parasitic loss, bearing wash, and premature distributor and/or cam gear wear.

“We’ve never seen a noticeable performance loss from the added load,” says Butler. “Racers will sometimes run a 60-psi pump to reduce parasitic drag and free up a few horsepower. While that’s acceptable in a dedicated race engine that’s frequently torn down, it’s certainly not something we recommend for all engines.”

He continues: “We’ve run as much as 100-psi on some engines and have never experienced any bearing wash issues. Excessive distributor or cam gear wear can result, particularly with a bronze gear, but we consider positive cam-gear oiling a must when running a roller camshaft, and we found that it significantly improves distributor gear life.”

One area that many hobbyists overlook when selecting an oil pump for a particular engine is camshaft type. “Some of the aggressive hydraulic- roller-lobe profiles available today and the high-pressure valvesprings required to effectively maintain valvetrain stability can cause the roller lifter’s hydraulic internals to bleed down too quickly, and that can create a performance loss. In these instances, additional pressure (75 psi or more) is required to keep the hydraulic lifters working properly,” states Butler."

[chiphead]

Risk of significant cam/distributor gear wear above 70PSI. Risk of oil filter collapse, case rupture or filter gasket pushout, risk of excessive oil throw-off from crank causing oil control issues, possibly pumping too much oil topside.

Are you running over 7000 RPM?

[Steve C.]

Pressure Requirements

A common question from many Pontiac hobbyists is about oil pressure and just how much is required. “We generally feel at least 10 psi of oil pressure for every 1,000 rpm is the minimum requirement for reliable operation,” says Butler. “We recommend 20W-50 oil for our high-performance engines, and like to see hot-idle oil pressure between 30 and 40 psi. Pressure as low as 15-20 psi doesn’t necessarily present a risk as long as it isn’t a sign of other problems, but the amount of time it takes pressure to climb to 60 psi or more can put the bearings at risk on a quick-revving, high-performance engine.”

Butler says that since an engine with smaller-diameter main journals (3-inch) and shorter-stroke crankshafts (4.21-inch or less) is generally less stressful on the bearings, a 60-psi pump may provide adequate lubrication in a modified engine, but an 80-psi pump is a better choice. He says any performance engine with 3.25-inch-diameter main journals and/or a stroker length greater than 4.21 inches should use an 80-psi pump. “The greater oil pressure associated with the 80-psi pump improves the strength of the oil film, and better protects the bearings in large journal and/or long-stroke applications,” he adds.


Common hobbyist concerns when using an 80-psi oil pump in a street engine include excessive parasitic loss, bearing wash, and premature distributor and/or cam gear wear.

“We’ve never seen a noticeable performance loss from the added load,” says Butler. “Racers will sometimes run a 60-psi pump to reduce parasitic drag and free up a few horsepower. While that’s acceptable in a dedicated race engine that’s frequently torn down, it’s certainly not something we recommend for all engines.”

He continues: “We’ve run as much as 100-psi on some engines and have never experienced any bearing wash issues. Excessive distributor or cam gear wear can result, particularly with a bronze gear, but we consider positive cam-gear oiling a must when running a roller camshaft, and we found that it significantly improves distributor gear life.”

One area that many hobbyists overlook when selecting an oil pump for a particular engine is camshaft type. “Some of the aggressive hydraulic- roller-lobe profiles available today and the high-pressure valvesprings required to effectively maintain valvetrain stability can cause the roller lifter’s hydraulic internals to bleed down too quickly, and that can create a performance loss. In these instances, additional pressure (75 psi or more) is required to keep the hydraulic lifters working properly,” states Butler.

Source with additional info:
http://www.hotrod.com/articles/hppp-...-observations/


.

[dmac]

Originally Posted by chiphead

Risk of significant cam/distributor gear wear above 70PSI. Risk of oil filter collapse, case rupture or filter gasket pushout, risk of excessive oil throw-off from crank causing oil control issues, possibly pumping too much oil topside.

Are you running over 7000 RPM?

No. Might get to 5000 rpm once every few years.

But the first reply with info about 455 with longer stroke and bigger bearing surface makes sense. The oil filter rupture issue was something that came to my mind, but someone could refer me to 'stronger' filters. I was thinking that I could use thinner oil and more pressure to keep moving parts well covered.

[Skip Fix]

Remember also when Pontiac used them they used a different sized distributor gear.

A 0.060 hardened shim will get you 70-75psi.

[dmac]

Originally Posted by Steve C.

One area that many hobbyists overlook when selecting an oil pump for a particular engine is camshaft type. “Some of the aggressive hydraulic- roller-lobe profiles available today and the high-pressure valvesprings required to effectively maintain valvetrain stability can cause the roller lifter’s hydraulic internals to bleed down too quickly, and that can create a performance loss. In these instances, additional pressure (75 psi or more) is required to keep the hydraulic lifters working properly,” states Butler.

Source with additional info:
http://www.hotrod.com/articles/hppp-...-observations/


.

Good info. Makes me wonder of some of the lifter ticking issues that seem so common may just come from the higher pressure springs some are using combined with 60 lb pumps.

[Steve C.]

Sorry for the duplication of the same material grivera posted. I knew it was out there and was searching for it while he posted and did I not notice.


.

[grivera]

Originally Posted by Steve C.

Sorry for the duplication of the same material grivera posted. I knew it was out there and was searching for it while he posted and did I not notice.


.

good minds think alike...

[64speed]

I just traded out my 60 pound pump for the 10541 80 PSI pump but rockauto only gave me the same melling part number for the drive rod. Do I need to buy a hardened one from butler or is the melling one a solid unit. I bought the pump drive when I bought the 60 psi pump

[glhs#116]

Well I'm going down to 60 after losing a cam gear and about six months of having the engine out of the car only a few years after an 80psi pump went in. I have the factory manual for 71 and in there they say that 50psi was for standard motors and 60psi on the HO. I can see the case for high pressure for more "race" builds but I'm thinking for street guys like me who want to put on a lot of miles there's a strong case for the "standard" pressure pump...

Sam

[Cliff R]

ZERO benefits anyplace using an 80lb pump in a street/strip Pontiac engine build.

I've built more of these engines than most who will read this, and we've spend more time making sure that everything associated with the machining is spot-on and parts used up to the task at hand. This includes getting the cam bearings in straight, main and rod bearing clearances, crank journals round and correct size, balancing dead on the money, bores round/pistons correctly fitted, ring end gaps on the money, etc, etc.

I don't use the 80lb pumps in full race builds and have several out there over 700hp that have survived many years of severe duty with zero issues related to oiling.

The only Pontiac engine we've ever lost had a lifter bore cave in (with brace) and at that point it was being pushed beyond the mechanical limits of a factory block. The owner knew it and I even advised against the last cam upgrade to push the HP up over 700 so he could run consistent 9 second runs with it.

Not only did the engine loose the lifter bores and "grenade" it, I found a couple of main cap dowel pins in the oil pan and the bearings fell right out of the caps and had a "black" look to them indicating they weren't very happy at that power level.

It was replaced with an aftermarket block, same 60lb Melling oil pump, and it has lived now for over 10 years with zero issues related to the crank/rods or engine oiling......and it makes close to 750hp!..........Cliff

[HWYSTR455]

Well, if you shim a 60 pump to get 70 or so as SOP, the 10 lbs difference is nominal. Depending on the oil you use, there may not be much of a difference at all. Like if you use 10-30 with an 80 pump compared to 20-50 with a 60 pump.

There may be additional dizzy gear wear with an 80, but there too, nominal. Let the oil warm up to proper temps before hammering it, easy fix. Especially if you run 20-50.

Benefits, I can see where it could help in HYD roller apps in keeping the noise down. And Butler does make a valid point of fast revving engines. Not to mention folks who prefer/run bigger bearing clearances.

Filter collapse? Not a concern as long as the filter and/or OE bypass is not disabled. Only time the OE bypass should be disabled is in a full race app, and IMO, not even then.

I dunno, this just seems like common sense stuff to me, and to a degree is personal preference. As long as you know, you can compensate.

.

[HWYSTR455]

Originally Posted by 64speed

I just traded out my 60 pound pump for the 10541 80 PSI pump but rockauto only gave me the same melling part number for the drive rod. Do I need to buy a hardened one from butler or is the melling one a solid unit. I bought the pump drive when I bought the 60 psi pump

IMO, if you're building an engine, replace the shaft with a upgraded/hardened one, just make sense. I personally recommend one that has the 'ears' too, to prevent the dreaded 'fall-into-the-pan' syndrome.

.

[PAUL K]

Originally Posted by HWYSTR455

IMO, if you're building an engine, replace the shaft with a upgraded/hardened one, just make sense. I personally recommend one that has the 'ears' too, to prevent the dreaded 'fall-into-the-pan' syndrome.

.

The ears are on the pump side of the shaft (relative to the driveshaft support).... They're there to keep the driveshaft from falling out of the distributor hole while the engine is upside down without a distributor installed.

[HWYSTR455]

Originally Posted by PAUL K

The ears are on the pump side of the shaft(relative to the driveshaft support) they're there to keep the driveshaft from falling out of the distributor hole while the engine is upside down without a distributor installed.

Exactly, but the shaft falling out doesn't always happen when the engine is upside down. It can happen when you remove the dizzy, it sticks to the gear, until you get about 2/3 of the way out with the dizzy, THEN it falls back in, falling all the way to the pan. Not fun.

.

[PAUL K]

Originally Posted by HWYSTR455

Exactly, but the shaft falling out doesn't always happen when the engine is upside down. It can happen when you remove the dizzy, it sticks to the gear, until you get about 2/3 of the way out with the dizzy, THEN it falls back in, falling all the way to the pan. Not fun.

.

Oh, okay gotchya.....never had that happen. The only need I've ever heard for removing the ears is if the engine was mistakenly assembled without the driveshaft.

[Navy Horn 16]

All of my interntals came through Butler, so I've got the 80psi pump with all the necessary rods, cam gear etc. The only problem that I had was that my local engine builder felt that Jim's advice on threading in the oil galley plugs wasn't necessary so he "staked" them. After the 2nd time they blew out, he threaded them in.

[PAUL K]

Originally Posted by Navy Horn 16

All of my interntals came through Butler, so I've got the 80psi pump with all the necessary rods, cam gear etc. The only problem that I had was that my local engine builder felt that Jim's advice on threading in the oil galley plugs wasn't necessary so he "staked" them. After the 2nd time they blew out, he threaded them in.

WOW! That'd be disappointing!

[tom s]

This is another of those deals where a 80lb pump is being recommended in the STREET section!I cant think of any reason to have one if your not building a race engine?JMO,Tom