Inliners International Forums General Discussion Blown and Injected 250 / 292 oil return to pan or block?

Just wondering if a fitting attached to oil pan is only option, or is it safe to drill and tap block for oil drain?
Thanks

Go through the pan.


MBHD

why would you WANT to drill and tap the block?

I thought the pan would be the right answer.
I was thinking I'd like the look of the line entering the block as on the older engines.
Thanks

as on the older engines?

Pete,
I found it easy to put it in the pan. Welded a threaded fitting on a angle, then screwed a nipple in it.

You going to turbo your chevelle?

panic:
I thought the 235/261 bypass filters dumped back into the sump.
I think I was wrong on that.

tlowe:
The confession:
I'm putting a 6 micron bypass filter on the 292 for my 61 Panel truck.
Removed from some industrial size air compressors, they're big!
I figured this was a good forum to ask about the plumbing.
Thanks.

If this is a remote filter set up there are adapters to do that and you can use any filter you want. You are thinking of the conversion of the older GMCs and Chevys to full flow oil filtering. In that process the main oil passage is blocked and oil is diverted to the filter and returned to the main passage through a fitting in a hole drilled and tapped in the block. This is not needed on the newer engines as they were full flow from the beginning. The hole in the pan thing is for returning oil from a turbo to the engine. Beater

I thought the 235/261 bypass filters dumped back into the sump.
I think I was wrong on that.

No, you're right - I was thinking of a much bigger line.
A turbo drain has to be at least 1/2" ID (bigger is harmless), because the oil leaving the bearing is aerated. The drain can go anywhere that connects to the pan, but it must be below the turbo bearing, and should go only down-hill (no up or level stretches).
If it goes to the pushrod cover it's going to overburden the drains there. The front cover is a possible, but that's a "busy" area with no advantages.
In the pan: has to be above the oil level, so if it's toward the rear it should be a bit higher to allow for oil surge on acceleration.
There's no pressure, so any high-temp hose and clamps is OK as long as it doesn't come off!
I like a bulkhead fitting in the pan wall, since you can install it without welding (I can't weld, so I try to work around it just for my own convenience). You can take off the line or change the angle without disturbing the pan.

This filter looks just like something GM used to sell, but larger yet.
see below for good article on bypass filters:

http://www.stovebolt.com/techtips/engines/oil%20filters/index.html

Amsoil is selling this modern version:
http://www.amsoil.com/a/By-Pass-Filters-Mounts

There is the cool factor in play here plus I want to see if the oil does run much cleaner than with just the stock filter, which I'm leaving in place.

I do wonder if a separate, lower micron rating, filter might be an idea for supplying a turbo bearing.
Thanks for the help guys.

The turbo bearings are pretty durable, but cleaner oil can't hurt.
Were you thinking of using the bypass as the sole source for the turbo feed?
How are you going to run the plumbing, in parallel with the B-P as a T off the feed from the pump?
I'm not sure how much oil pressure you have, or can afford to lose, so restricting the size of the bypass will still be needed, unless its output goes back into the main gallery like the F-T.

I had started telling tlowe that this was for a bypass filter setup, but never got to mention that I have no turbo.
At least not yet. Though that manifold on ebay is tempting.
(I'd have to figure out the t3 or t4 part first)
So anyway, this has been all about the plumbing for the time being.
Is it a problem robbing oil from the engine for the turbo bearing? I know the high volume oil pump is out of favor but this sure seems like a good use for one.(In my 194 the Hi-vol pump took out the bushings in the old dist, but the HEI seemed ok- btw: that engine went 180K on a rebuild for total of 320k miles, I think the hi volume pump helped)

If using the oil sender hole as a source can you really rob that much oil from the engine?
It has to go through the plumbing and a 6 micron filter.
Probably a pressure gauge at the turbo bearing would be in order.

IIRC Garret used to reccomend puting a restrictor in the turbo supply line, .016" IIRC.

I don't know if they do or not anymore (check their site).

Point being, that's not much oil flow.

The early Chevys and GMCs, up to '62, bypass filters took oil from the main gallery, filtered it, then returned the oil (thru' a restrictor) either to the rocker arm shaft or a fitting in the crankcase. The later Chevy 261" had a filter that could be used either as a bypass or full flow.

With the '63 and up engines having full flow filtering, why don't you just use them to filter all the oil?

Tim