I have an Amc 401 running an electric fuel pump, so the port for mechanical pump is sitting unused on the timing cover, which would convenient and easy to weld a fitting on, since my oil pan is already installed.

It's a ceramic ball bearing turbo, so not alot of oil will be going through it. Any thoughts on this? I know they sell LS timing covers with drains for turbos now. I don't think it'd drain enough oil to backup or be an issue.

 

It'll be fine as long as the drain can run downhill the whole way.

 

Sounds good to me, thanks. i was also thinking of plumbing in a turbosmart oil pressure regulator, it only allows 40psi to the turbo, bypassing the rest. Would that be fine to weld that return fitting into the same area? Or should it be returned elsewhere as it will probably see higher flow?

 

Can't you just run a restriction orifice and save the excess plumbing? I would assume this is favorable since the AMC V8 is know to have oiling issues.

 

What Ben said. I never understood dumping oil back to the pan when it could be needed elsewhere. A restrictor is much simpler, and works.

 

I read that restrictors aren't really ideal because they also limit flow. Whereas the regulator keeps pressure and flow constant.

Amc's main oiling issue is that it works too well. And without a big pan. They are known to suck the pan dry and have poor drain back from the heads. I have an 8 quart canton, and edelbrock heads. So it shouldn't be an issue. An oil cooler is getting put in somewhere too.

 

Restrictors are a bandaid, and bad on a journal bearing turbo. Ball bearing turbos require substantially less oil volume, and are a totally different animal.

 

If the regulator allows for enough oil pressure at rpm, then there's no harm in it, but plenty of bb turbos run a restrictor.

 

You are correct, restrictors limit flow, that is exactly what they do. I think there is something in the definition of the word restrictor that implies this.

When using a restricted orifice; as oil pressure increases flow to the turbo increases. As your RPM increases flow to the turbo increases, seems optimal as long as you have the right size orifice in it.

You do not need pressure in a ball bearing turbo, you just need enough flow to keep the ball bearing wet and cooled (cooled is a relative term, as long as you are below the smoke point of the oil). At low speeds this doesn't take much, at high speeds (say 70,000 rpm) it takes more.

In a journal bearing turbo the bearings are riding on the hydrodynamic wedge created by the oil, you need pressure to protect the bearings, and you would never want to restrict the flow or pressure. People do it, because they can't properly plumb a drain.

 

But in a journal bearing if it only needs 40 psi.. You wouldn't want more than that or it's going to push oil past the seals and begin smoke/blow oil, correct?

And if the ball bearing only needs a low volume of oil but as pressure increases, along flow, then at some point its going to be throwing way more oil than the ball bearing needs?

Seems like a garden hose vs pressure washer for journal bearing/ball bearing. Both should have regulated pressure but the journal bearing needs high volume

 

It doesnt push oil past the seals. If the oil doesnt drain properly, it submerses the drain area below and to the side of the bearing and saturates the rings. I look at the drain area the same as the oil pan on an engine. As was said above, a journal bearing is the same as an engine bearing. Rpm goes up, it needs more flow to increase the strength of the hydrodynamic wedge, and carry heat away. If flow goes up, so does pressure. No way around it.

 

It doesn't hurt to over oil a bb turbo as long as the drain is adequate, in fact it helps in cooling. It's beneficial to turbo life to give either type excess oil (within reason).. as long as your drain is good.