[ScottP]

A bunch of years back, I fuel injected my 70 Bonneville and swapped in a 4L80E. I've been tweaking the combination and getting it dialed in over the past few seasons, and am finally ready to make another big change.

To that end, I ordered up a Vortech V7 YSi and all of the needed brackets and hardware from Mark at Luhn Performance. I spent last weekend starting the mock-up, and thus far it all fits great! I can't say enough good things about the work that Luhn does.

One of my tasks will be to address the oil return on the blower. I'm leaning heavily towards reworking the passenger side of the timing cover to keep the return plumbing short and clean. Has anyone else here used this approach and would like to comment on it, or share pics of their work?

Anyone have any other approaches they have used and are willing to suggest?

I've attached a few pics of where things stand today. I'll add more as I make progress over the coming weeks.

-Scott

[Scott65]

Way cool! Do you have boost level in mind? Or are you gonna find the limit as you go? Keep us updated.

[ID67goat]

I think a lot of people just drill and tap the timing cover for an AN fitting for the oil drain back.

Really cool project, keep the updates coming!

[firechicken]

Many years ago I added a turbo oil drain to the passenger side of the timing cover and redirected the lower rad hose as well to clear it.

Drilling and tapping would probably be simpler.

[ScottP]

My plan is to keep the boost levels modest to start - I'm thinking in the 7-8 PSI range initially. From there I'll assess the fuel system, get the boost regions of the
spark and fuel tables dialed in, and just generally see how it drives.

For the oil return, I'm envisioning something like what firechicken shows, except keep the lower radiator hose as-is, and have the oil return come in at an angle. I'm still noodling over how I want to do that. Tapping the side of the timing cover and adapting to an AN fitting is where I'm leaning at the moment using something like this:

https://www.jegs.com/i/JEGS+Performa...SABEgKnU_D_BwE

-Scott

[Tom Vaught]

Just remember the oil drain line/hose must ALWAYS be GOING DOWNWARD.

No "U"s in the drain line.

Tom V.

[JC455]

My experience with Jeg's AN stuff- use a name brand. I bought a bunch of fittings from them and ended up replacing all of them with Earl's piece.
The fit and finish was too poor for me to trust the parts. When I mocked up the Earl's, things just glided together smoothly... kinda like using generic carb studs vs. ARP.

[ScottP]

100% agreed on the line routing Tom - care will be taken to ensure that it is a continuous slope downward from the blower oil drain to the side of the timing cover.

I would be interested in hearing thoughts on the sizing of this line. At the moment, I have the parts to do this in both 3/8" stainless tube, as well as 1/2". I'm leaning towards the 3/8" just for ease of routing and bending.

[Tom Vaught]

Just a thought for you to consider.

The oil/foam coming out of the Vortech Supercharger can, at times, restrict oil from FROM the supercharger with too small of a return line diameter.

The bubbles created by the oil and gears inside the supercharger drive unit will almost always break and the oil will flow with the larger diameter return line.

When I did Belt driven Vortech and Paxton supercharger testing at my job, we always ran the larger rubber hose vs the smaller 3/8" hose because of the wall friction.

Now if you were running a aluminum or steel tube the walls are much smoother and the bubbles ability to block the drain of oil is greatly reduced. We ran the minimum of rubber hose at the two locations, out of the supercharger nipple and into the oil pan nipple.

Just something to think about.

Some "self contained oil" superchargers can get very hot in the oil/gear case.

Tom V.

[charlie66]

I wouldn't run anything smaller the a 10 line ..