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Pedal Smasher
1973 Opel GT
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Discussion Starter · #1 ·
Howdy Everyone,

I randomly came across the below video on YouTube and immediately recognized the similar style of oil pump...


While the test to show an improvement is hardly scientific, if the different design improves oil flow it could be worth looking into. The lobe design is similar to superchargers.
 

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Super Moderator
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Except how many people need a better pump than OEM?

With normal blueprinting procedures the OEM pump has proven itself reliable at 8500-9000 rpms. Only above that rpm level would I consider changing things, and at that point a dry sump starts to make more sense, especially when hard cornering is encountered.
 
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Pedal Smasher
1973 Opel GT
Joined
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2,613 Posts
Discussion Starter · #4 ·
Except how many people need a better pump than OEM?

With normal blueprinting procedures the OEM pump has proven itself reliable at 8500-9000 rpms. Only above that rpm level would I consider changing things, and at that point a dry sump starts to make more sense, especially when hard cornering is encountered.
Bob, what about a pump that works more efficiently? Better oil pressure at start up, better scavenging, etc. So this isn't about high RPMs. I think a more efficient oil pump can be worth it.
 

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Bob, what about a pump that works more efficiently? Better oil pressure at start up, better scavenging, etc. So this isn't about high RPMs. I think a more efficient oil pump can be worth it.
Again, I’m not sure what you are actually attempting to gain. If you change the pump type (at considerable cost), only to gain efficiency at lower rpms you might see on the street, what is gained?

A normally functioning CIH pump works just fine. Forgetting what you may see on a high mileage set of gears, or a worn out timing cover, or a bad pressure relief valve…the stock pump works fine, and has proven to be able to handle about 50% more rpms than original design intent, and at least double the original power levels.

Let’s say you spend $400 machining the timing cover and procuring/installing a different set of gears. On a 100 hp engine…what is gained? 1 hp? Higher oil pressure? Or???

I can see cavitation being an issue at high rpms with the stock gears. But if you are not going to run up to 8500+rpms the point is moot.

I wouldn’t want a higher volume pump on a stock engine. That just eats more HP. it also empties the oil pan faster, which is a scary thought. An alloy oil pan holds just 3:2 quarts of oil, a steel pan holds 3.8. This includes the filter. So statically (engine not running, oil in filter), you have either 3 quarts or 3.6 quarts of oil in the pan.

A running engine has about a quart of oil filling the oil galleys, splashing around in the head, running down the oil returns, or wrapped up around the crank/rods in the form of windage. Leaving 2 - 2.5 quarts of oil in the pan. A wet sump pump which scavenges better than stock may suck oil faster than it can return under gravity. Throw in a few high speed corners and this would be bad, what with under 2 quarts of oil in the pan.

I just don’t see the benefits.
 
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