ECR in the AIM

[Kurt B.]

Recently I was told that the AIM contains notes called ECR with numbers, such as ECR91788.
One suggestion I received was that ECR might mean Engineering Change Revision.
Does anyone know how to determine what ECR91788 refers to or where to find such information?
I'm told this ECR91788 has something to do with Carburetor Idle Solenoids and I am trying to determine exactly what it means.
Thank you,
Kurt #26406

[Duke W.]

Re: ECR in the AIM

The names vary, but the basic process is the same across most manufacturing industies. The responsible engineer writes an Engineering Change Request (ECR), which can be something as simple as adding a note to a drawing to a complete redesign of a major system. So the ECR can be one page or many volumes.

The ECR is presented at a meeting often called the Change Control Board, which typically meets weekly. Most of the engineering executives attend up to and including the Chief Engineer. Manufacturing and Purchasing are also represented.

The ECR is presented at the meeting and discussion ensues. It may be approved as presented, or it may be sent back for rework. Some are routine. Sometimes a lot of blood gets spilled. If approved the formal name usually becomes "Engineering Change Order", but the number remains the same and the wheels start turning to implement it.

I forget what Chevrolet's "ECR" stands for, but Engineering Change Revision is redundant, so it's probably something slightly different, but the equivalent to the ECO as described above.

One of the items in any change request affecting production would be new AIM sheets, and that's why the AIM references the ECR number. That package, whether one page or multiple volumes of data is the authority for the change.

Unfortunately I think all the Corvette ECR records were scrapped, so your chance of finding any original documents that were part of that ECR are low.

But, at least the AIM references the fact that changes occurred due to ECRs, so you know that parts, torques, or whatever changed during the model year, and old part numbers or a summary of the change like "note added" are often listed in the change record reference. Whenever refering to an AIM sheet always check the ECR record to see if a change occurred and take that into account if you can with whatever you are trying to accomplish.

However, AIM sheets that were "redrawn and revised" lost the ECR record of the superseded sheet, so no change history prior to the redrawn and revised sheet is available.

Duke

[Chuck S.]

Re: ECR in the AIM

Recently, Art Armstrong explained some AIM processes, and indicated the name for Chevy's ECR was the same...Engineering Change Request. I presume the five digit number shown on the AIM sheet revision block under "AUTH" is the Engineering Change Order that resulted from the ECR...Is this correct, Duke?

Kurt, if my assumption is correct, you may be able to find some evidence of the idle solenoid being eliminated on the carburetor installation sheet...look for the five digit number under "AUTH" and read the written text on the revision lines; you might get lucky. If it's an optional engine, the carb installation sheet may be in the options section under the engine option code.

[Art A.]

Re: ECR in the AIM

Actually the acronym ECR at Chevrolet Engineering had three different meanings over the years, engineering change recommendation, engineering change request, and engineering change requirement. All three did basically the same thing, released parts and changes for various vehicles and vehicle lines. While some ECRs did release parts just for Corvettes, most ECRs released parts and changes for many car and truck lines. Chevy Eng. did not use the term ECO. We did used another releasing document called an ECA, Engineering Change Authorization, but that's a story for another time.

With that said, an ECR for releasing a Carburetor Idle Solenoids, BTW I wouldn't know a Carburetor Idle Solenoids if I tripped over it, sounds to me like it would be part of the carburetor it self. And IF that is the case, it is unlikely that it would get an ECR written against it. Something like a carb or a starter or a voltage regular was received as a single part, or unit as we called them, and it was very unlikely that we would issue an ECR on the INTERNAL portion of such a unit. Yes, a ECR could/would/was written for the attachment, connecting, location, etc of such a unit, but not generally for the innards. Their were ECRs written for internals of such units, BUT they would have been directed at the supplier and wouldn't have show up in the AIMs.

To my knowledge GM still has the ECR files going way back...................getting your hands on them is another story..............slim to none.

Art

[Kurt B.]

Re: ECR in the AIM

Art,
This particular solenoid was attached on the outside of the carburetor allegedly for all Air Conditioned Corvettes in 1968 and 1968 if I am reading (and believing) the NCRS Judging Guide. I am reading your reply to mean that sine this past was attached on the outside of the carb, and not part of the innards, it would be subject to an ECR. Is that a correct assumption on my part.
Also, I have not been able to find anyoen else with a 68 Corvette smallblock with A/C who has this solenoid on their carb so I am wondering if perhaps the Judging Guide is in error for this solenoid.
Kurt

[Art A.]

Re: ECR in the AIM

Kurt,

I did a little more research in this subject and low and behold I found the answer to your question in my files. Yes, the solenoid in question did have ECR 91788 written against it, it is mentioned on NPC # C68-309 which covers a multitude of changes and is too complex to discuss here. This NPC is a very long, as far as NPCs go, and covers many issues related to the engine area. I don't have a copy of the ECR, but I found it referenced on this NPC (Notice of Production Change) which I do have copies of. I would copy and post it, but I'm not very good at posting pictures. PLUS, it's so complex with lots of GM abbreviations it would take me about a week to analyze it.

The last page of this NPC, there are a total of 11 pages, does indicate that this item was cancelled as C60 was cancelled for the 427 option, dated 3-26-68.

Hope this helps.

Art

[Kurt B.]

Re: ECR in the AIM

Art,
Since it was cancelled for big blocks with A/C, can I deduce that it was not cancelled for small blocks with C-60 A/C option and therefore I should have such a solenoid on my 68 small block L79 with A/C ?
Kurt

[Art A.]

Re: ECR in the AIM

NO, It was cancelled....................because A/C was cancelled for the 427 engine. I did not see any mention of any other engine size, but then again, I did not do an in-depth search of the NPC, but that is the bottom line.

Art