1957 RPO 684 big brakes

[Joseph T.]

Were the 1957 RPO 684 big brake inner fenders supplied with air tube holes from the supplier or were they template cut in St.Louis?

What about he unusual shape air entry cut to the airbox..when and where was that done?

Who was the supplier of the air box?

Who was the supplier of the elephant ears?

Who was the supplier of the metal rear dust covers and air scoops?

Who made the handfull of metal 37 1/2 gallon Sebring tanks?

Joe

[Mike E.]

Re: 1957 RPO 684 big brakes

And who made the 7 or so fiberglass 37 gallon tanks for the 60-62 cars?

[Tom P.]

Re: 1957 RPO 684 big brakes

The 57 AIM both illustrates and provides dimensions for the cutout in the panel to the left of the radiator support for the airbox intake.
One would think that maybe a template was placed on the panel (possibly before assembly with surrounding panels) and then the irregular opening was cut out.
But even if it was done after asseembly of the body, it isn't terribly difficult. Simply by using the dimensions and the radii shown in the AIM, I drew out a pattern on a piece of paper, cut out the pattern with scissors, then traced around the pattern onto the panel of the 56 and cut out the opening by hand. When I installed the airbox on the 56, the opening was a perfect mate for the front of the airbox.
So it couldn't have been too difficult to do on the assembly line.

But it would be nice if answers could be provided for all of Joe's questions. I'd like to know myself.

[Joseph T.]

Where are Dave Bartush and Ray Macierella when you need them?

The 57 AIM both illustrates and provides dimensions for the cutout in the panel to the left of the radiator support for the airbox intake.
One would think that maybe a template was placed on the panel (possibly before assembly with surrounding panels) and then the irregular opening was cut out.
But even if it was done after asseembly of the body, it isn't terribly difficult. Simply by using the dimensions and the radii shown in the AIM, I drew out a pattern on a piece of paper, cut out the pattern with scissors, then traced around the pattern onto the panel of the 56 and cut out the opening by hand. When I installed the airbox on the 56, the opening was a perfect mate for the front of the airbox.
So it couldn't have been too difficult to do on the assembly line.

But it would be nice if answers could be provided for all of Joe's questions. I'd like to know myself.

Tom..the reason I am particularly interested if the inner fenders were St.Louis plant template cut standard fenders or shipped by the inner fender supplier with big brake air tube holes is because the #775 Nassau car sports the big brake tunnels and inner fender holes and this of course would be before the 684 package was officially available on production cars around April of 57. I suspect the Nassau cars were prepared with these options at Engineering in November 1956 but the tunnel system must have been in the works for it to be done. Maybe just not yet implemented in St.Louis.

I have not studied or asked John if the SR car has air tubes. I don't think so. I think those 56 cars just had special brake scoops. Which would mean the special Nassau cars would have been the first big brake air tube cars..not including the Bill Mitchell SR2 which has a more elaborate built in air flow.

It would be nice to know what the documented history is on the early use and roll out of the big brake air tube system was.

Where is Dave Bartush and Ray Maceriella when you need them? Their old restorer article on big brakes was excellant!

Gary..maybe a monthly sticky of a great previous restorer article would be welcome by the TDB members.

I would think most recent members have no idea what a treasure of information has been published in the restorer. With special thanks to all previous editors..especially John Amgwert.

Joe

[Tom P.]

Re: 1957 RPO 684 big brakes

Joe,
I agree, the answers to those kinds of questions would also be of interest to me.
Once the later, regular production (57) cars were on the assembly line and scheduled to receive the Airbox/HD pkg (so far, no one has said if what WAS referred to as RPO 579E is now going TO BE changed ti RPO 579D per K. Kaysers revelations), there had to be 7 additional holes cut in the entire body:
Inlet hole for the airbox
2 holes (L&R) inner fenders for the air hoses
2 holes (front/rear) in each rocker panel (total 4).
Do you suppose all of these holes were added at the same time? Before or after panels were glued together? Good questions!

And last, it has been mentioned that Airbox cars (actually, I suppose HD brake cars would be more correct) DID NOT receive the metal reinforcing structure inside the rocker panels. Has anyone shined a flashlight into the rocker of a genuine HD brake car (or 2-3 cars) to verify if the metal structure was in there?

[Gary C.]

Re: 1957 RPO 684 big brakes

Gentlemen, John Hickley always reminds me; "if it's in the AIM then it happened at the St.Louis factory". That's my guideline for determining what happened where. Regards, Gary....

[Joseph T.]

Re: 1957 RPO 684 big brakes

Gentlemen, John Hickley always reminds me; "if it's in the AIM then it happened at the St.Louis factory". That's my guideline for determining what happened where. Regards, Gary....

Maybe the closer reality " was meant to happen at the St.Louis Factory " but I get the meaning.

Joe

[Tom P.]

Re: 1957 RPO 684 big brakes

Gentlemen, John Hickley always reminds me; "if it's in the AIM then it happened at the St.Louis factory". That's my guideline for determining what happened where. Regards, Gary....

AH HA!
But let's take a prime RECENT EXAMPLE----------------Florida Regional.
What if it isn't in the AIM, but it did IN FACT get done during assembly at St. Louis????
Whenever drawing/assembly changes occured, instructions were given to REMOVE pages from the AIM, destroy them and replace them with NEW updated pages.
Thus, the 56-7 AIM has ZERO pages related to the parts/assembly of the 56 SR1 cars!
Why?
Because those pages were removed, trashed and replaced with updated pages. OR, with so few cars built (6? SR1s at St. Louis) did those pages ever even get put into the AIM to begin with back in 56?
Consequently, through the years, numerous OTHER people, as well as John Neas, have been deprived of deserved judging/points in the past, even though documentation was provided!

[Art A.]

Re: 1957 RPO 684 big brakes

Were the 1957 RPO 684 big brake inner fenders supplied with air tube holes from the supplier or were they template cut in St.Louis?

What about he unusual shape air entry cut to the airbox..when and where was that done?

Who was the supplier of the air box?

Who was the supplier of the elephant ears?

Who was the supplier of the metal rear dust covers and air scoops?

Who made the handfull of metal 37 1/2 gallon Sebring tanks?

Joe

Some of these items are mentioned in the Chevrolet Engineering Build Work Order #17792 and Design WO 17969.

[Joseph T.]

Re: 1957 RPO 684 big brakes

Some of these items are mentioned in the Chevrolet Engineering Build Work Order #17792 and Design WO 17969.

Art

The Sebring gas tanks, I would imagine.

Bartush once suggested to me that the tanks were made in Detroit as I recall either in special fabrication or something to that effect.

The blueprints that Frank Burrell had would probably answer most of these questions...in terms of detail and timing.

I came across a copy of the big challenge and it includes a brief shot of the Bill Mitchell SR2 in the hanger at Sebring 1957 with an engineer literally working inside the engine compartment. I wonder if that is when the repaired previously blown engine was reinstalled.

Joe