Bigger isn't always better....

[Glenn]

There's been a "discussion" if a 30mm pump is needed vs a 26mm pump. And does it steal power?

Watching Engine Masters and while they were tested 3 pumps on a LS engine, I wonder if their testing applies to the VW world.

Discuss....

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Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"

Member #1009

#BlueSquare

[Vanapplebomb]

It certainly applies.

Engines I have taken apart with big pumps tend to show more wear on the drive tank and cam slot, suggesting more load needed to drive the pump. Granted, the pumps are much smaller than the pumps in the test, but the same concept is still present.

Also, oil temps rise because the pump pushes more oil through the bypass around the oil cooler. This is compounded by many running oil that is too thick.

For whatever reason the air cooled VW community, more than any other I have found, has a really bad habit of running oil pumps that are too big and oil that is too thick.

I agree, bigger isn’t always better.
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1800 Type 4 Berrien 295

http://www.thesamba.com/vw/forum/viewtopic.php?t=487021

[Glenn]

^^^^^^
This is also what i've seen.

Too much pressure causing the bypass to be open and higher oil temps.
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Glenn
74 Beetle Specs | 74 Beetle Restoration | 2180cc Engine
"You may not get what you pay for, but you always pay for what you get"

Member #1009

#BlueSquare

[J-Gaz.]

i wonder if everyone just started running the 30mm pumps because a lot of racers and buggies were running coolers - and in that scenario, it made sense.

But if your running stock or close to stock, and not full flow etc, the 26 is the way to go?

I've got a stock build 1600 single port in my 70, but put in the 30, because all the forums and articles said I should "upgrade" my oil pump 🤷‍♂️
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1970 Beetle | Basically Stock 1600 SP

[Glenn]

[94touring]

I have a 26 on a full flow with external cooler and don't have any pressure issues. At least my pressure light isn't coming on at idle like the old worn out engine I replaced without full flow or external cooler.

[Janne71]

Then we talk about oil pressure/pump there is maybe someone that’s known what thickness of the 3 pieces of shims under the oil cooler. I have the one with flat bottom and need the new shims/trays under. Not the doghouse cooler
//Jan

[Alstrup]

I´m no V8 expert, but why would you want 150 lbs oil pressure?????

Back in 2005 I think it was, i did a test on a 2 liter type 4, from a stock 24 mm. to a 30 mm pump and also synthetic 15w40 to mineral 15w/40 to mineral 20w/50. At 5000 rpm there was a 5,5 hp increased drag on the mineral 20w/50 compared to the synthetic 15w/40.
Naturally. 24 mm pump w. synthetic 15w40 to a 30 mm pump and mineral 20w/50.
But. Do not use this as more than a rough guideline, since some engines need a large pump due to large tolerances or parasitic losses through a turbo or a crappy aluminum case or something else.
for instance, a 356 engine needs its giant 38 mm pump due to tolerances about an inch, - or thereabouts so the bearings need a lot of oil to uphold a good film.
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https://www.thesamba.com/vw/forum/viewtopic.php?t=435993

[b-man]

If one were putting together a 2180 street engine (6500 max rpm, 9.2:1 approx 160 hp) for an early beetle using a CB Autolinea aluminum case with Hoover mods would a 30mm pump be advisable or would a 26mm pump be sufficient?
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1956 Dove Blue Panel
1966 Velvet Green Single Cab
1957 L41 Black Oval Window Beetle

[Glenn]

[Brian_e]

[b-man]

[Wreck]

the oil pump is the second biggest parasitic loss after piston rings from what I've read .

[Dan Ruddock]

Maybe a 30mm if you running Porsche check valve piston oilers and a spray bar in the rocker box along will all the hoover stuff, but don't hold me to it. Also could be argued you don't need all that spraying stuff anyway.

[modok]

I agree.
The cooling fan is also -a drag-, and most of you think bigger is better on that, which is true some of the time.

[Wreck]

[rayjay]

On a SBC build I managed to put the relief piston in backwards which basically resulted in no relief at all. The first sign that something was amiss was the Milwaukee 1/2" 120v big HD drill motor trying it's best to break my wrist. I got a better grip and hit the trigger again and heard a pop and suddenly oil is running down the outside of the filter. The cast alum filter adaptor had broken. I took the pan off and pulled the pump and found the issue and all was well after that.

On this motor I had the "High Volume - High Pressure" pump because of slightly loose bearing clearances. I actually used .001" undersized bearings to get .003 to .004. Probably would have been ok with my normal 1967 Z28 pump which had shorter gears than the HV-HP.

[modok]

I rebuilt an old racing engine that had a big oil pump and a extra heavy relief spring because.....that's how it was, and I'm just supposed to restore it to how it was.

got a call back about.... why it has over 150 psi oil pressure when they started it up the first time.

I think they changed at least the spring back to standard, to not sure never heard back, that was just what we decided was next step

[Bruce Amacker]

Ditto on above, I just dropped the pan on my '63 Chevy, removed the 80lb spring that someone put in and installed a stock 45psi spring.

It's not just the VW crowd that thinks too much oil pressure is not enough. IMO, 45psi is fine for almost any street engine. I recently took the 80lb spring out of a stock 1600 and replaced it with a stock spring.

Decades ago I ran Castrol 20w-50 in many Ford engines and had nothing but problems with bearing wear. Later in life I think I caused my own problems and 10w30 would have been better..... (Ohio)
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'66 Deluxe Bus
'65 Standard Bus
Build threads:
'66- http://www.leakoil.net/forum/viewtopic.php?f=23&t=2888&sid=54d8dedfb3822f99c7f2ea430cb4e856
'65- http://leakoil.net/forum/viewtopic.php?f=23&t=4263

[oprn]

The last engine I rebuilt, 1641 with new crank, all new bearings and align bore, used cam and lifters and ALL the Hoover mods. When it came time for an oil pump all I had on hand that wasn't used was a brand new Bugpack cast iron 30mm oil pump. I thought to myself - I am NEVER going to have a need for a 30mm pump! So - I cut it down to 26 mm and installed it. I put 5W20 oil in it because it was late fall. Well, things happened as they do and I never got it started up until the next summer. After a reasonable break in time and some ripping around on the back roads the hot oil pressure settled into 23 psi idle and 55 psi at 3000 rpm cruise. This was still with the 5W20 winter oil in the middle of summer!

Did I even need a 26 mm pump? Nope! A stock 21 mm would have been just fine!
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We had the stone age, the bronze age, the industrial age and now we are in the age of mass deception and mind control for corporate profit. (The mass media age)