Ignition shielding clips

[Tracy C.]

Late 63 L76 340 hp 327.

Questions regarding the placement of side ignition shield retaining clips that are held in place by the exhaust manifold bolts:

Do these clips go under or over the exhaust bolt washers used at cylinders #1, #7, #2, & #8 ?

Also, were they in place during engine painting or installed in St Louis?

One more...Might anyone have pictures of the clips installed prior to mounting the side shielding. This would help me so I don't need to determine location of each clip by trial and error...

thanks,
tc

[John H.]

Re: Ignition shielding clips

Late 63 L76 340 hp 327.

Questions regarding the placement of side ignition shield retaining clips that are held in place by the exhaust manifold bolts:

Do these clips go under or over the exhaust bolt washers used at cylinders #1, #7, #2, & #8 ?

Also, were they in place during engine painting or installed in St Louis?

One more...Might anyone have pictures of the clips installed prior to mounting the side shielding. This would help me so I don't need to determine location of each clip by trial and error...

thanks,
tc

Tracy -

The spacer washers go between the clips (supports) and the exhaust manifold, and the french locks go between the clips (supports) and the bolt heads. The illustration was clarified in later AIM's. They were installed at St. Louis. Photo below isn't 100% NCRS-correct, but it shows the supports installed after being aligned with the holes in the shields; note that the bends are parallel to the ground as a reference for positioning.

The plant used a bar fixture with four pins in it to pre-align and hold the supports in position while tightening the exhaust manifold bolts so they didn't have to fiddle with bending the supports to get the shield wing bolts installed.

[Tracy C.]

Re: Ignition shielding clips

Bingo !! Thanks John.

tc

[Jerome P.]

Re: Ignition shielding clips

Tracy -

The spacer washers go between the clips (supports) and the exhaust manifold, and the french locks go between the clips (supports) and the bolt heads. The illustration was clarified in later AIM's. They were installed at St. Louis. Photo below isn't 100% NCRS-correct, but it shows the supports installed after being aligned with the holes in the shields; note that the bends are parallel to the ground as a reference for positioning.

The plant used a bar fixture with four pins in it to pre-align and hold the supports in position while tightening the exhaust manifold bolts so they didn't have to fiddle with bending the supports to get the shield wing bolts installed.

John,

Great picture.

Do you have a picture of the left side that you could share?

What year is the engine? It sure looks correct What's not?

[David L.]

Re: Ignition shielding clips

Tracy -

Photo below isn't 100% NCRS-correct, but

John,

Do you need some engine mounts that look very close to the original GM mounts?

Dave

[John H.]

Re: Ignition shielding clips

John,

Great picture.

Do you have a picture of the left side that you could share?

What year is the engine? It sure looks correct What's not?

Jerome -

Photo below of the left side. It's a '64 300hp from my files (not my engine). It has aftermarket poly engine mounts, exhaust manifold-to-head gaskets, the manifolds should show orange paint, the fuel pump mounting plate shouldn't be painted, it has a spin-on oil filter conversion, and the clutch cross-shaft pivot stud shouldn't have that thick felt washer on it.

[John H.]

Re: Ignition shielding clips

John,

Do you need some engine mounts that look very close to the original GM mounts?

Dave

Dave -

Thanks for the offer, but it's not my engine - it's from my files.

[Dan D.]

Re: Ignition shielding clips

I take it there are no spark plug wire clips on the oil pan bolts either?
-Dan-

[Tracy C.]

Re: Ignition shielding clips

Dan,

There should be one clip each side on the oil pan bolt under the center of the lower boomerang shields.

tc

[Dan D.]

Re: Ignition shielding clips

Thanks Tracy,

Will do. I have the clips. -Dan-

[Scott S.]

Re: Ignition shielding clips

Dan,

There should be one clip each side on the oil pan bolt under the center of the lower boomerang shields.

tc

Tracy,

When the pictures above were posted a while back, I was wondering how the clip worked with the V-shields. Today I was looking for something else and stumbled across some information about these clips. According to Adams' book, those clips were only used on cars WITHOUT radios:

"The engine compartment of a non-radio Corvette contained many components that differed from those found in radio-equipped cars. For example, the two front spark plug wires were held against the block in all Corvettes to prevent them from being roasted by the exhaust manifold.Nonradio cars used two metal clips, part number 3744409, mounted under the pan bolts and bent to encircle the wires. On radio-equipped cars, a V-shaped shield covered the two front spark plug wires." p. 162, bold-face underline emphasis mine

Is this correct?

The clips are pictured in the '67 AIM, on UPC 6-B3 (see Section 6, Sheet C7 in the 1963 AIM), but are not called out by part number. The Section 6 drawing is for the "base" model though, which would not include the radio option in section U69.

So, should a car with radio (and therefore the lower "V" ignition shields) have these oil pan clips, or not?

[Michael H.]

Re: Ignition shielding clips

Tracy,

When the pictures above were posted a while back, I was wondering how the clip worked with the V-shields. Today I was looking for something else and stumbled across some information about these clips. According to Adams' book, those clips were only used on cars WITHOUT radios:

"The engine compartment of a non-radio Corvette contained many components that differed from those found in radio-equipped cars. For example, the two front spark plug wires were held against the block in all Corvettes to prevent them from being roasted by the exhaust manifold.Nonradio cars used two metal clips, part number 3744409, mounted under the pan bolts and bent to encircle the wires. On radio-equipped cars, a V-shaped shield covered the two front spark plug wires." p. 162, bold-face underline emphasis mine

Is this correct?

The clips are pictured in the '67 AIM, on UPC 6-B3 (see Section 6, Sheet C7 in the 1963 AIM), but are not called out by part number. The Section 6 drawing is for the "base" model though, which would not include the radio option in section U69.

So, should a car with radio (and therefore the lower "V" ignition shields) have these oil pan clips, or not?

I think all 63-67 small block engines had the clips, no matter if radio equipped or not. Weren't the clips installed at Flint, not St Louis?

[Scott S.]

Re: Ignition shielding clips

I think all 63-67 small block engines had the clips, no matter if radio equipped or not. Weren't the clips installed at Flint, not St Louis?

Michael,

That's a good question, I don't know if they were installed at Flint or not. But, even if they were, the assembly line workers at St. Louis probably wouldn't hesitate to remove them during the ignition shield installation, if they were not needed.

John Amgwert’s article on Ignition Shielding (Restorer Magazine, Spring 1986) mentions the rubber coated wire supports (GM #3744408) attached to the side of the engine block and the two wire retaining clips we're discussing here (GM #3744409) attached to an oil pan bolt on each side. In the next paragraph, he says “While the preceding supports were used on all Corvette 327 engines, those used to attach the left and right horizontal spark plug shields were only used on radio equipped models.”

The paragraph in Adams seems to say these clips are specifically for a radio-delete application, and it would make sense that something was needed to hold the plug wires to the block. But with the radio option, and associated lower "V" shields covering the front spark plug wires, where would the clips go and why would they still be needed?

On the other hand, John's article says the oil pan clips were used on ALL small blocks, which would necessarily include those with radios and ignition shielding.

[Scott S.]

[Michael H.]

Re: Ignition shielding clips

Michael,

That's a good question, I don't know if they were installed at Flint or not. But, even if they were, the assembly line workers at St. Louis probably wouldn't hesitate to remove them during the ignition shield installation, if they were not needed.

While the preceding supports were used on all Corvette 327 engines, those used to attach the left and right horizontal spark plug shields were only used on radio equipped models

The paragraph in Adams seems to say these clips are specifically for a radio-delete application, and it would make sense that something was needed to hold the plug wires to the block. But with the radio option, and associated lower "V" shields covering the front spark plug wires, where would the clips go and why would they still be needed?

On the other hand, John's article says the oil pan clips were used on ALL small blocks, which would necessarily include those with radios and ignition shielding.

I haven't looked at the assembly manual yet but I'm pretty sure the clips are not shown by part number. If the part number isn't there, that means the clips weren't items to be installed by St Louis. It means the engines came from Flint with the clips installed and probably painted orange along with the rest of the engine.

If the clips weren't needed with radio, they would probably still be left in place. It would be easier to do that than it would be to remove them for radio equipped cars. But that's not how it happened. These clips were probably about $0.01 each so it wouldn't have been cost effective to remove them at the St Louis assy plant.

The plug wires still need a clip to hold them in place, even if the car was equipped with a radio and had the "V" shields.

I think the two 3744408 retainers at the motor mount position are installed at the St Louis plant, not the Flint engine plant. These items are shown in the AIM which means "installed at St Louis".

I'm pretty sure all of the other spark plug wire retainers and clips were St Louis installed items.

The pic below shows both the upper wire retainer at the motor mount and the lower retainer on the oil pan rail.

Don't believe everything you read in the Noland Adams book!!