Dirt Missile rebuild begins

[carbuff]

Originally Posted by GregWeld

Mister “I’m a race car builder” put a 2 gallon tank on it — along with a PCV system.... LOL

Several of you have commented on this, but someone educate me please...

Why don't you use a PCV system with a dry sump?

On TOW I don't run a true PCV, but I do have my valve covers plumbed to fresh air inside of the air cleaner. I also have an overflow / breather tank on the side of my oil tank. Oil should never get in there, but I do get some puffs of smoke out of it.

Am I doing something wrong here?

[MtotheIKEo]

The dry sump should be pulling a vacuum on the crankcase, any breathers or leaks in the system are just fighting to equalize that vacuum.

[CJD Automotive]

Dry sumps are sealed systems. Good pumps can pull over 20” of vacuum on the crankcase, literally pulling in gaskets and seals. Most use a vacuum regulator installed on the engine to limit that to 12-15”. If you do have an air leak, you are pulling and mixing the oil with a large quantity of air. That makes foamy aerated oil. The tanks are designed with screens and steps that deareate the oil as it settles from the top to bottom. With an air leak, especially as big as a PCV hole, the amount of air is so excessive the tank simply can’t remove it from the oil. The air expansion in the tank, normally handled by the TANK breather, is being overwhelmed by the excessive air, the oil is not deareating, and gets puked out the breathers. The aerated oil provides little to no bearing film, and consequently bearing scuffs or failures result. The tiny size of the tank and capacity only exaggerated the issue.
They were running this engine at 10/10ths for two lap stints, with less oil capacity than required and massively aerated. Can’t understand how they did this multiple times for multiple days knowing they were causing damage. I simply don’t understand that thought process.

[Peter McMahon]

So let me get this straight, he was either ignorant about dry sump systems, or he is knowledgeable about them and understood what he was doing so it was intentional damage? Flipping coin hits floor...

[randy]

Miss educated post like this. Thank you for the knowledge

Originally Posted by CJD Automotive

Dry sumps are sealed systems. Good pumps can pull over 20” of vacuum on the crankcase, literally pulling in gaskets and seals. Most use a vacuum regulator installed on the engine to limit that to 12-15”. If you do have an air leak, you are pulling and mixing the oil with a large quantity of air. That makes foamy aerated oil. The tanks are designed with screens and steps that deareate the oil as it settles from the top to bottom. With an air leak, especially as big as a PCV hole, the amount of air is so excessive the tank simply can’t remove it from the oil. The air expansion in the tank, normally handled by the TANK breather, is being overwhelmed by the excessive air, the oil is not deareating, and gets puked out the breathers. The aerated oil provides little to no bearing film, and consequently bearing scuffs or failures result. The tiny size of the tank and capacity only exaggerated the issue.
They were running this engine at 10/10ths for two lap stints, with less oil capacity than required and massively aerated. Can’t understand how they did this multiple times for multiple days knowing they were causing damage. I simply don’t understand that thought process.

[GregWeld]

Originally Posted by Peter McMahon

So let me get this straight, he was either ignorant about dry sump systems, or he is knowledgeable about them and understood what he was doing so it was intentional damage? Flipping coin hits floor...

Sometimes even if a guy is a supposed “genius” (self described) - doesn’t mean he can hang a picture..... or understand a dry sump....

The funny part — you should have seen the “monkey F’n the football” when the car would come off track and they’d begin their “clean up in aisle 3” routine — in other words — ABSOLUTELY CLUELESS.

The guys that were there for this “outting” so wanted me to fire him right there and let them take over — because we mostly had the “issue” figured out.... but by that time it was me still wanting Mister Secret Sauce to be able to save himself..... dumb on my part in retrospect — but we all have 20/20 hindsight....

Oh well.... it shall all be fixedededed right up shortly.

[carbuff]

Originally Posted by CJD Automotive

Dry sumps are sealed systems. <snip>

Thanx for the explanation. I may block the ports on my valve covers, although everything looked good when we did the rebuild last year given my current setup. I don't have any method of de-aerating my oil, so I can see where this would be a potential problem for me...

[GregWeld]

Originally Posted by carbuff

Thanx for the explanation. I may block the ports on my valve covers, although everything looked good when we did the rebuild last year given my current setup. I don't have any method of de-aerating my oil, so I can see where this would be a potential problem for me...

To be sure Bryan — there is a connection between the top of the oil tank and your PCV system (vacuum)..... so be sure you learn about these systems to fully understand them.

[Flash68]

Originally Posted by carbuff

Thanx for the explanation. I may block the ports on my valve covers, although everything looked good when we did the rebuild last year given my current setup. I don't have any method of de-aerating my oil, so I can see where this would be a potential problem for me...

What tank are you running? My understanding is that most all tanks have some internal baffling for de-aeration purposes.

[CJD Automotive]

Originally Posted by Flash68

What tank are you running? My understanding is that most all tanks have some internal baffling for de-aeration purposes.

Sounds like a stock GM setup, which is a hybrid dry sump. If so, you need your breathers, but can be plumbed through Petersons breather can, and then to the tank.

As Greg said, if you have a pump with scavenge stages and are pulling vacuum on the crankcase, you need two additional pieces. A vacuum regulator to limit the amount of vacuum pulled on the crankcase, and a pressure pop off. Most pop offs are plumbed back to the tank. This is just a safety valve for a sealed crankcase. If the pump has an instance when it can't pull a vacuum, with the crankcase sealed, the pressure has no where to go, and usually pushes past a seal. The pop off, lets that pressure be evacuated to the tank, while still allowing the crankcase to be sealed.