C1 Generator Brace ID

[William B.]

Does anyone know if the generator adjusting brace has the part number 3704884 casted into it, for a dual 4BC and/or the F.I engine ? Or, is it blank ? What are the correct dimensions for the brace on the dual 4BC and the FI engines? And, are the mid year 57 braces painted semi-gloss black ? Seen many variations and am so confused ... Thanks, Bill

[Troy P.]

Re: C1 Generator Brace ID

On the generator bracket, my info says all 56-57 except 57 with the hi-lift cam is part number 3728514 (6.6"). The one for the 57 hi-lift is 3746267 (7.1").

For the 3704884 brace I see the AIM does not show installation of the brace. Just installation of the generator and attachement thereof to the brace. This implies that the brace was on the engine when delivered to the assembly plant floor. Thus it would have been painted along with the engine - orange. Of course there could be variations I'm not aware of.

Now if you had an air box car the story would be much different.

[William B.]

Re: C1 Generator Brace ID

Did "all" the generator braces have the part number 3704884 casted into them ? If not, what did the FI 283 HP non air-box cars come with ? My 283 FI came with a brace that has the 3704884 casted (not stamped) into it and I'm wondering if that's original or not. Thanks, Bill

[David L.]

Re: C1 Generator Brace ID

Bill,

My 1957 Chev. Parts Catalog (Mar. 1957) lists GM # 3704884 in Gr. 2.317 for the following:
55-56 ALL, CORV. (8 cyl.)(exc. 40 amp. low cut-in)
57 ALL, CORV. (exc. dual 4BC, 40 amp. low cut-in)

I have 3 of these braces in my "collection",two are stamped "3704884" and one is unstamped, all are original.

GM # 3704884 was discontinued in Dec. 1959 and replaced with GM # 3760364. I have five 3760364 braces in my "collection".

The generator braces are made of steel so obviously can not have a casting number. Can you provide a photo of your 3704883 brace that is "casted (not stamped)"? What do you mean by "casted"?

I have many generator & alternator brackets, most are steel but a few are cast iron.

Dave

[Troy P.]

Re: C1 Generator Brace ID

Attached factory photo shows brace painted engine color.
57Neg3000.jpg

[John H.]

Re: C1 Generator Brace ID

Attached factory photo shows brace painted engine color.
[ATTACH=CONFIG]49028[/ATTACH]

Troy -

That photo was taken in the Design Check room, and the color of the brace is incorrect. The assembly of the 3704884 generator brace to the engine was re-allocated from Flint V-8 to St. Louis in late March or early April of 1955. All "FG" '55 Corvette engines after April, and all "GR" '55 Corvette engines should have the 3704884 generator brace painted semi-gloss black. This change remained in effect through 1962, although the generator brace part number changed later on. The assembly allocation change was made due to severe damage to the brace during engine shipping, and is reflected in the 1955 Chevrolet V-8 Engine Engineering Bill of Material for Flint V-8. St. Louis assembly of the brace is shown clearly in the '56-'57 A.I.M in UPC 6, sheet 9.00.

[Joe L.]

Re: C1 Generator Brace ID

Troy -

That photo was taken in the Design Check room, and the color of the brace is incorrect. The assembly of the 3704884 generator brace to the engine was re-allocated from Flint V-8 to St. Louis in late March or early April of 1955. All "FG" '55 Corvette engines after April, and all "GR" '55 Corvette engines should have the 3704884 generator brace painted semi-gloss black. This change remained in effect through 1962, although the generator brace part number changed later on. The assembly allocation change was made due to severe damage to the brace during engine shipping, and is reflected in the 1955 Chevrolet V-8 Engine Engineering Bill of Material for Flint V-8. St. Louis assembly of the brace is shown clearly in the '56-'57 A.I.M in UPC 6, sheet 9.00.

John------


I never could figure out why anyone would ever have thought that it was a good idea to build the engines with the brace installed. To me, that was just asking for trouble. I suppose at the time the idea was that someone "calling the shots" just couldn't accept the concept that the folks at the vehicle assembly plant would have to remove something (i.e. a bolt) to install the brace.

[John H.]

Re: C1 Generator Brace ID

John------


I never could figure out why anyone would ever have thought that it was a good idea to build the engines with the brace installed. To me, that was just asking for trouble. I suppose at the time the idea was that someone "calling the shots" just couldn't accept the concept that the folks at the vehicle assembly plant would have to remove something (i.e. a bolt) to install the brace.

Joe -

The generator brace on pass. car and truck V-8's was simply pivoted over to the passenger side of the engine for shipping, and the assembly plants pivoted it back to the driver's side when they installed the generator. What messed up the soup on the Corvette engine was the front motormount bracket - it had a slot for the brace which fixed the brace in its final position (it couldn't be pivoted out of the way to clear the shipping rack), so it stuck up in the air and got damaged.

Photo below, taken on the Flint V-8 shipping dock in 1955 (note no oil filter provision), shows the passenger/truck V-8 with the generator brace pivoted out of the way; couldn't do that with the Corvette engines.


55V8Shipping1024.jpg

[Troy P.]

Re: C1 Generator Brace ID

John, Your logic and info is always respected and valuable. But I do note in my edition of the AIM it shows the brace already installed. Sheet 9.00 shows the generator being installed and attached to the brace. Last revision of the drawings is 6-4-56.

[William B.]

Re: C1 Generator Brace ID

Thanks for all the photos and information in regards to the generator brace for a 57 FI Corvette, but still alittle confused as to, was it painted the same color as the engine or semi-gloss black? Thanks to all, Bill

[Troy P.]

Re: C1 Generator Brace ID

I never doubt what John says. So it sould be black.

I'm just explaining why I and perhaps others have been fooled into thinking engine color - the photo of the 57 FI engine and the AIM not showing a step to install the arm.

[Bruce B.]

Re: C1 Generator Brace ID

Attached factory photo shows brace painted engine color.
[ATTACH=CONFIG]49028[/ATTACH]

Interesting engine.
Looks to have front passenger car front motor mounts and also the corvette type saddle mount.
Is the engine for use , either or?

[Troy P.]

Re: C1 Generator Brace ID

Beats me. John says its a test engine.

[Joseph T.]

Re: C1 Generator Brace ID

On the generator bracket, my info says all 56-57 except 57 with the hi-lift cam is part number 3728514 (6.6"). The one for the 57 hi-lift is 3746267 (7.1").

For the 3704884 brace I see the AIM does not show installation of the brace. Just installation of the generator and attachement thereof to the brace. This implies that the brace was on the engine when delivered to the assembly plant floor. Thus it would have been painted along with the engine - orange. Of course there could be variations I'm not aware of.

Now if you had an air box car the story would be much different.

My Nassau car early in life..

Joe

nassau[1].jpg

[Troy P.]

Re: C1 Generator Brace ID

Since the engine is "special engineering" perhaps is was assembled by the same folks that pieced together the one in my factory photo. Or perhaps it is the same one and those that came via the normal engine assembly and shipping route were those that got the black brace added at Saint Louis.