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-   -   Vortech boosted '70 Bonneville convertible (https://forums.maxperformanceinc.com/forums/showthread.php?t=856928)

ScottP 02-26-2022 06:29 PM

Vortech boosted '70 Bonneville convertible
 
2 Attachment(s)
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 02-26-2022 07:48 PM

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

ID67goat 02-26-2022 08:00 PM

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 02-26-2022 08:07 PM

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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 02-27-2022 09:55 AM

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 04-23-2022 08:44 PM

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

No "U"s in the drain line.

Tom V.

JC455 04-25-2022 11:15 AM

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 04-29-2022 05:57 PM

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 04-29-2022 06:58 PM

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 04-30-2022 10:08 PM

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

ScottP 07-06-2022 02:49 PM

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I'm long overdue for an update, but its summer here in New England, so I'm out
cruising more than wrenching!<g>

One of the issues I encountered in my install that seems to be unique to the
fullsize cars is an interference with the front crossmember. I've attached some
pics to show exactly where the 8.6" diameter crank pulley interferes, and the
cut that I made to eliminate the interference.

It looks closer than it really is in the pics. The belt fits nicely, and there's no less
than 5/16" clearance on all sides.

ScottP 07-06-2022 02:57 PM

2 Attachment(s)
In addition to getting the front crossmember clearanced, I also had some time
to test-fit the boost-side plumbing. The setup is going to be non-intercooled
for now while I get things sorted.

I'm also going to heed Tom and Charlie's advice to go big on the oil return. The
weld-in -10AN fitting will be here Friday, and I'll get that TIG'd into the side of
a spare timing cover.

The long pole in the project is now the supercharger mounting bracket front
plate. I'm waiting on that from Mark before I can get the rest of the belt drive
hardware fit-checked.

ScottP 12-20-2022 06:18 PM

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I'm long overdue for an update on this. I finally got the reworked timing cover
back from the welder, and I'm really happy with the results. A -10AN fitting
was added to the side of a spare timing cover, and a custom line was made
to connect the bottom oil drain on the blower to the new fitting. Care was
taken to ensure that the drain is downhill the entire way. It gets close to
horizontal at the cover, but even there I was able to maintain a few degrees
of downward pitch.

Waiting on Mark for the last machined component (front plate for the
supercharger mount), and then its time to fire it up and begin tuning.

-Scott

Tom Vaught 12-21-2022 02:19 PM

Glad you are happy with your fabrication to date.
Luhn made ~ 863 HP with a 455 engine at 5300 rpm years ago.
Should be a fun vehicle to drive and very easy on parts.

No more than 27 degrees of total timing under boost.

Tom V.

ScottP 12-21-2022 07:32 PM

Thanks for the input Tom, that touches nicely on the next phase of the project,
which I'm working on in parallel - tuning the PCM for boost.

With the naturally aspirated tune I have in the GM PCM now, I'm running
~12.6-12.8:1 AFR at WOT, and 33 degrees max timing (3300RPM on up)

The motor uses Edelbrock aluminum heads ported and prepped by Butler
back in 2007 when I built it. SCR is ~9.85:1. Cam is a hydraulic roller with specs
nearly identical to Old Faithful.

Are you recommending 27 degrees max based on my initial target of 7-8PSI?
I have a timing adder (retard) vs MAP table so that I can progressively pull
timing as boost builds.

Similarly I have a commanded AFR vs MAP and RPM table so I can bring the
AFR into the low 12's and even high 11's as boost builds. For 7-8PSI, I'd tend to
not go much richer than ~11.5, but would love to hear from others on both the
question of timing as well as desired AFR vs boost for this combination.

-Scott

Tom Vaught 12-21-2022 09:07 PM

27 degrees with no retard in the box.

Find the happy point for the timing (less than 27 degrees) or computer retarded for the
different boost levels. You will find it very hard to stay at 7-8 psi once you are driving the car, LOL!

John Clegg's 64 Pontiac Race Car used a simple "box" with timing pulled in 3 degree steps. You should be able to do much better with your electronic timing capability.
11.5 is a great Air/Fuel ratio to get dialed in initially.

Tom V.

ScottP 12-24-2022 07:36 PM

2 Attachment(s)
Made more progress in the garage today. The air intake side of the blower is
now plumbed, and I made some tweaks to the boost side as well. Still a few
vacuum lines to run and a bit of wiring to tidy up, but its getting there.

KEN CROCIE 12-28-2022 03:56 AM

WE -h-o, supplied the modified timing cover with our Turbo kits. we filled the void below the bottom timing cover bolt with weld and drilled an tapped for a fitting.
As low as you can go without putting a bung in the pan.

blueghoast 01-04-2023 10:23 PM

Man this is such a cool project. Keep the pics coming.

GT

ScottP 05-08-2023 08:30 PM

4 Attachment(s)
The front supercharger mounting plate finally arrived, so I was able to wrap up
the install and get the belt installed. Pics of the final install are attached. I have
the initial 2-bar tune in the PCM and will try to get it out to log some data this
weekend. Really looking forward to seeing how it pulls!


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