1963 4 Note Horn Installation Question

[Jim Cannon]

2 hours ago, Chasander said:

 

 

Correct!  Once you add one ground wire, you have grounded the entire hood.  The other horn gets its ground through the hood.

 

 

[1965rivgs]

Bill,

  If you refer to post #35 fig. 11-202 the engineers are grounding the left horn and in the diagram it says "to the right side" for the ground wire. I realize this is an early arrangement but if they grounded both horns in that arrangement it makes sense that the grounding needs in the later arrangement did not change. Horns pull quite a few amps and demand a good solid ground to sound properly. "Clean, bright and tight"! A hinge is not a solid connection by its nature and although it is likely a ground will be obtained one way or another (thru the hinges or latch when the hood is closed) such a ground may not be consistent.

I sent you a diagram with measurements for installation...what is the wiring arrangement on that diagram?

  Tom

[Riviera63]

7 hours ago, 1965rivgs said:

Bill,

  If you refer to post #35 fig. 11-202 the engineers are grounding the left horn and in the diagram it says "to the right side" for the ground wire. I realize this is an early arrangement but if they grounded both horns in that arrangement it makes sense that the grounding needs in the later arrangement did not change. Horns pull quite a few amps and demand a good solid ground to sound properly. "Clean, bright and tight"! A hinge is not a solid connection by its nature and although it is likely a ground will be obtained one way or another (thru the hinges or latch when the hood is closed) such a ground may not be consistent.

I sent you a diagram with measurements for installation...what is the wiring arrangement on that diagram?

  Tom

 

Tom,

 

I have a copy of the 64 Service Manual page and the 65 page that you sent me. Both seem to show a ground wire going just from the small horn lower bracket to the firewall. Neither seems to show a wire from the large horn to the smaller horn as the 63 Service Manual shows. It is hard to tell though as the 64 & 65 copies I have are fairly small and slightly blurry. 

 

I do have the horns mounted and the hood seems to close with no problems. I had a ground wire made and have it attached. I ran it from the lower bracket on the small horn to the firewall. There was a phillips screw in my firewall that served no apparent purpose and it seemed to be in a good location so I did not even have to drill a hole. Jim Cannon suggested using star washers on the ground wire connections and also to put one on one of the the bolts for the larger horn to get a good bite on the metal through the paint. I did as Jim suggested with the star washers. I did install the main wiring yet as I am having a couple of the connector connections redone as they seemed a bit iffy. I tested each horn separately by using a jumper wire to the battery. Both horns worked to perfection. The horn tone had been adjusted by the vendor before he sent them to me. The sound seemed good to me. We'll see how things work when I get the main harness installed. 

 

Thanks to Chuck for the ground wire picture and thanks to Jim for all of his advice that he sent my way in this thread and via a PM. 

 

Bill

 

[RivNut]

On 6/8/2017 at 10:09 PM, RivNut said:

Grounding takes place through bolting the horns to the body.  One 12V source is all the wiring that is necessary.  

I guess I got lucky when I replaced the horns on my car (they had been stolen from the car before I bought it) Because I didn't run a ground wire. I'm guessing that there was sufficient ground through the hinges so that they'd work.  When I get back to this car, I'll add the ground strap just for good measure.

[1965rivgs]

5 hours ago, Riviera63 said:

 

Tom,

 

I have a copy of the 64 Service Manual page and the 65 page that you sent me. Both seem to show a ground wire going just from the small horn lower bracket to the firewall. Neither seems to show a wire from the large horn to the smaller horn as the 63 Service Manual shows. It is hard to tell though as the 64 & 65 copies I have are fairly small and slightly blurry. 

 

I do have the horns mounted and the hood seems to close with no problems. I had a ground wire made and have it attached. I ran it from the lower bracket on the small horn to the firewall. There was a phillips screw in my firewall that served no apparent purpose and it seemed to be in a good location so I did not even have to drill a hole. Jim Cannon suggested using star washers on the ground wire connections and also to put one on one of the the bolts for the larger horn to get a good bite on the metal through the paint. I did as Jim suggested with the star washers. I did install the main wiring yet as I am having a couple of the connector connections redone as they seemed a bit iffy. I tested each horn separately by using a jumper wire to the battery. Both horns worked to perfection. The horn tone had been adjusted by the vendor before he sent them to me. The sound seemed good to me. We'll see how things work when I get the main harness installed. 

 

Thanks to Chuck for the ground wire picture and thanks to Jim for all of his advice that he sent my way in this thread and via a PM. 

 

Bill

 

Yes, one ground wire should work as it grounds the inner structure of the hood which both horns are mounted to. I checked the late `63 thru `65 illustration and the factory only used one ground wire to the small horn on the Riviera. Looking thru the shop manual I realized I had seen each horn grounded by an individual ground wire on the full size cars...because the small horn is piggyback mounted to the large horn via an insulated clamp a dedicated ground for each horn is necessary.

I also recall a service bulletin regarding the rear most screw for the small horn interfering with the top of the cowl. I suspect it is a `65 bulletin,

  Tom

[Jim Cannon]

12 minutes ago, 1965rivgs said:

I also recall a service bulletin regarding the rear most screw for the small horn interfering with the top of the cowl. I suspect it is a `65 bulletin,

  Tom

 

You are correct, Tom.  A service Bulletin was issued on February 22, 1963 listing several possible interferences of the 4-note horns with things under the hood on the driver's side.  They are in Bulletin number 63-48, in Group 11, sequence number 11-10.

 

Some of them came up when they moved both horns to that side.  Others were intended to be dealt with on the assembly line but were missed.

 

</begin shameless plug>

 

I sell the Service Bulletins on CD for all 3 years of the First Gen. Rivs.  Email me if you would like to buy any or all of them.. Cheap.  Really.

 

</end shameless plug>

 

I'm glad to hear that the horns sound good with the ground wire added.

 

 

[Turbinator]

On 6/9/2017 at 7:27 AM, telriv said:

Jim Cannon knows the correct wiring as I gave him the info directly from my car yrs. ago.

 

 

Tom T.

Surprisingly, I wired my 4 note horns today and they worked the first time. Disconnecting the battery when I do electric work is a good habit for me.

Turbinator

[Jim Cannon]

19 hours ago, Turbinator said:

Surprisingly, I wired my 4 note horns today and they worked the first time. Disconnecting the battery when I do electric work is a good habit for me.

Turbinator

Great!

 

You can adjust each horn individually (disconnect the wires to the others) to get the best tone for it. Then they will blend together beautifully.

 

😎

[Turbinator]

14 hours ago, Jim Cannon said:

Great!

 

You can adjust each horn individually (disconnect the wires to the others) to get the best tone for it. Then they will blend together beautifully.

 

😎

Jim, I noticed a a small nurled knob on the back of the horns. The tip on disconnecting the other horns makes perfect sense so you can hear the pitch of the sound. Depends on my horns, but I’m going to try to tune the horns to a certain quality four not chord. Depending on how the horns can be adjusted , if mine can be adjusted, will tell if a chord tone quality can be achieved. I must admit the cool factor would be very high should horns be tuned to chord tone quality.

T

[RivNut]

The horns are tuned to a specific note from the factory.  On the ROA website, open the "other interesting links" link and find the 63-65 Tech Tips.  One of the tips is on Trumpet Horn Repair. In it is a chart of the tone of each separate horn for each year, as well as the different lengths. It also tells the stamped number and where to find the number for each year.

[1965rivgs]

2 hours ago, Turbinator said:

Jim, I noticed a a small nurled knob on the back of the horns. The tip on disconnecting the other horns makes perfect sense so you can hear the pitch of the sound. Depends on my horns, but I’m going to try to tune the horns to a certain quality four not chord. Depending on how the horns can be adjusted , if mine can be adjusted, will tell if a chord tone quality can be achieved. I must admit the cool factor would be very high should horns be tuned to chord tone quality.

T

Hi Bob,

 

  I was told years ago by someone I considered to be a horn expert, ie, he had a rebuilding business specifically for automotive horns, that the tone of a Delco Remy horn is determined by the coil, thickness of the diapghram, and the "air column" or shape of the horn. The adjustment screw is basically a point adjustment and controls the amp draw of the horns which relates to volume and not tone. Perhaps there is some cross over. My personal experience is that adjusting the screw varies the volume but not the basic tone or note. This can change at the extreme ends of the adjustment range but when in the normal operating range this applies. Try it and see what you find. As a musician, you are able to discern tone from a change in volume which commonly misleads folks to assume a change in tone.

  There is info in the shop manual which reinforces the connection between amp draw and volume and also an amp range. The shop manual states 4.5 to 5.5 amps and I have found this specification in the Delco Remy horn bulletins which are in my literature collection. Make sure you have the appropriately sized wire and good connections. Also, be careful how long you allow the horns to operate because by their design they are intended for intermittent operation. It is possible to overheat and damage the horns if you operate them for a period of time beyond which they were intended to operate. I`ve never encountered a specification for this. This warning is all over the Delco literature and is reinforced by my personal experience. This is one of the reasons for amp draw adjustment, ie, to enable the horns to sound without overheating and self distructing.

  The typical two horn setup, NOT NECESSARILY OUR RIVIERAS BUT IN GENERAL, is a low and hi tone. The notes cited by Delco Remy are E flat and G whose frequencies are 313 and 390 vibrations per second. Another common pair are F and A notes whose vibrations per second are 360 and 447 per second respectively. There are also D and C tones at 300 and 525 vibrations per second. When the Delco Remy engineers added a 3rd and 4th tone the intent was to produce a chord effect which is the reason certain notes were chosen and blended together....so they have already done your work for you!

  Just a word about the tones which are listed in the parts books.....when I researched the Riviera horns decades ago I found contradictions in the tone description listed in varying sources for the same horn and part number, so take those listings with a grain of salt.

  Not related to tone but just general info....there is most often no correlation between the part number listed in the GM parts books and the actual partial part numbers stamped on the horns. The first gen Rivieras are a not often seen exception to this but most of the time the numbers dont correlate. The reason for this is because most of the service replacement horns are generic horns provided with multiple styles of horn brackets for universal installation which are attached to the horns with a very large stamped steel nut. The original horns have a welded mounting bracket to properly index the horns and hence are model and year specific. So the same GM service part number was intended to cover many years and models and their part number most often doesnt match the partial stamp in the original horns. I have found the only reliable source for horn stamping info is the year specific assembly manuals and accumulation of data from actually inspecting the cars.

  Sorry for the long post, probably too much information,

 

Tom Mooney

[Turbinator]

1 hour ago, 1965rivgs said:

Hi Bob,

 

  I was told years ago by someone I considered to be a horn expert, ie, he had a rebuilding business specifically for automotive horns, that the tone of a Delco Remy horn is determined by the coil, thickness of the diapghram, and the "air column" or shape of the horn. The adjustment screw is basically a point adjustment and controls the amp draw of the horns which relates to volume and not tone. Perhaps there is some cross over. My personal experience is that adjusting the screw varies the volume but not the basic tone or note. This can change at the extreme ends of the adjustment range but when in the normal operating range this applies. Try it and see what you find. As a musician, you are able to discern tone from a change in volume which commonly misleads folks to assume a change in tone.

  There is info in the shop manual which reinforces the connection between amp draw and volume and also an amp range. The shop manual states 4.5 to 5.5 amps and I have found this specification in the Delco Remy horn bulletins which are in my literature collection. Make sure you have the appropriately sized wire and good connections. Also, be careful how long you allow the horns to operate because by their design they are intended for intermittent operation. It is possible to overheat and damage the horns if you operate them for a period of time beyond which they were intended to operate. I`ve never encountered a specification for this. This warning is all over the Delco literature and is reinforced by my personal experience. This is one of the reasons for amp draw adjustment, ie, to enable the horns to sound without overheating and self distructing.

  The typical two horn setup, NOT NECESSARILY OUR RIVIERAS BUT IN GENERAL, is a low and hi tone. The notes cited by Delco Remy are E flat and G whose frequencies are 313 and 390 vibrations per second. Another common pair are F and A notes whose vibrations per second are 360 and 447 per second respectively. There are also D and C tones at 300 and 525 vibrations per second. When the Delco Remy engineers added a 3rd and 4th tone the intent was to produce a chord effect which is the reason certain notes were chosen and blended together....so they have already done your work for you!

  Just a word about the tones which are listed in the parts books.....when I researched the Riviera horns decades ago I found contradictions in the tone description listed in varying sources for the same horn and part number, so take those listings with a grain of salt.

  Not related to tone but just general info....there is most often no correlation between the part number listed in the GM parts books and the actual partial part numbers stamped on the horns. The first gen Rivieras are a not often seen exception to this but most of the time the numbers dont correlate. The reason for this is because most of the service replacement horns are generic horns provided with multiple styles of horn brackets for universal installation which are attached to the horns with a very large stamped steel nut. The original horns have a welded mounting bracket to properly index the horns and hence are model and year specific. So the same GM service part number was intended to cover many years and models and their part number most often doesnt match the partial stamp in the original horns. I have found the only reliable source for horn stamping info is the year specific assembly manuals and accumulation of data from actually inspecting the cars.

  Sorry for the long post, probably too much information,

 

Tom Mooney

Tom, not too much information at all. Juicy substance I did not know is now helpful. True the volume of air through the bell of a horn/saxophone only makes what is voiced louder. I actually thought changing the amps would alter the pitch because of change in the parts Vibrating of the horn that makes the sound.
I don’t know much about what goes on in the horn, but I have clues about changing sound by changing how the notes are voiced. ( voicing is the order the notes are played) And there are enharmonic chords that have different names, but sound exactly the same with the notes the voicing.
I don’t think I’ll have much luck “tuning” the horns with my knowledge and tools available. I will say four notes arranged properly can give you some really cool sounds. I think it would be neat to find those four notes, but it might be like trying to rope in a goat. I appreciate your thoughtful insights and consideration to devote the time to write a good posting.
Turbinator

[1965rivgs]

3 hours ago, Turbinator said:

Tom, not too much information at all. Juicy substance I did not know is now helpful. True the volume of air through the bell of a horn/saxophone only makes what is voiced louder. I actually thought changing the amps would alter the pitch because of change in the parts Vibrating of the horn that makes the sound.
I don’t know much about what goes on in the horn, but I have clues about changing sound by changing how the notes are voiced. ( voicing is the order the notes are played) And there are enharmonic chords that have different names, but sound exactly the same with the notes the voicing.
I don’t think I’ll have much luck “tuning” the horns with my knowledge and tools available. I will say four notes arranged properly can give you some really cool sounds. I think it would be neat to find those four notes, but it might be like trying to rope in a goat. I appreciate your thoughtful insights and consideration to devote the time to write a good posting.
Turbinator

Hi Bob,

  I am recalling the details as explained to me many years ago. Perhaps the "air column" relates to volume and not tone and I mixed those up. Is a tuba "louder" than a trumpet? Or is the character of the note being played changed by their shape or "air column"? Or is their difference a function of lower vesus higher octaves? I dont know. its been a very long time since I took music theory. The only reference I could find in Delco literature which pertains to air column, which Im assuming relates to the shape of the horn housing whether sea shell type or trumpet, says " The air columns are designed to produce a trumpetlike sound from the diaphram vibrations".

  I also always assumed adjusting the screw would change the number of vibrations and hence pitch but as it was explained to me the diaphram is operating in a fixed space and its the gauge or thickness of the diaphram that determines the number of vibrations per second. The adjusting screw is like an adjustable stop for the points. If the stop is adjusted so the points barely close (held open most of the time) the horn will "sputter". If the stop is adjusted so the points spend too much time closed the amp draw will go up and the horns are more likely to overheat and the coil windings melt down and permanently open. I was told the pitch may vary at the extreme ends of the adjustment range but once the point adjustment is in the typical operating range it is the gauge of the diaphram that controls the frequency of vibration. Understanding how the diaphram is energized and returned to its original shape this makes sense.

  Try it and see what you think. Id be very interested in feedback from a music man!

 

Tom

[Jim Cannon]

Guys-

I did not say you could tune the horn, I said you could adjust it. You are not tuning the tone. That is set by the dimensions of the horn.

 

You are adjusting the point gap internally for the best sound tone and volume. If the points are too close together, the sound is weak. If the gap is too large, the sound is rough and harsh. Tom is right, you can also adjust for target current draw, too. I have found that clarity and sharpness of horn sound, one horn at a time, works best.

 

Tom is correct, don't operate any horn for too long at a time. Adjust, blow, adjust blow. Small changes. OR, if you like how each one sounds individually on a test, leave them alone!

 

😎

[RivNut]

Sometimes you have to disassemble the horns to clean points, get rid of rust etc.  That means that you have to drill out the rivets.  for the same look as a rivet, which is used to attach braces to a bicycle fender, use a rivet screw.  The head that you see will look just like a rivet but the back side uses a nut and lock washer to attach.  Much easier to disassemble if you need to get into the horn again.  They come in all sizes.

 

[1965rivgs]

4 hours ago, Jim Cannon said:

Guys-

I did not say you could tune the horn, I said you could adjust it. You are not tuning the tone. That is set by the dimensions of the horn.

 

You are adjusting the point gap internally for the best sound tone and volume. If the points are too close together, the sound is weak. If the gap is too large, the sound is rough and harsh. Tom is right, you can also adjust for target current draw, too. I have found that clarity and sharpness of horn sound, one horn at a time, works best.

 

Tom is correct, don't operate any horn for too long at a time. Adjust, blow, adjust blow. Small changes. OR, if you like how each one sounds individually on a test, leave them alone!

 

😎

Hi Jim,

 

  Just to set the record straight my response was prompted by Bobs post about creating a chord, nothing to do with your post.

 

Tom

[Jim Cannon]

4 minutes ago, 1965rivgs said:

Hi Jim,

 

  Just to set the record straight my response was prompted by Bobs post about creating a chord, nothing to do with your post.

 

Tom

 

I knew that!  

😀

[Jim Cannon]

12 minutes ago, RivNut said:

Sometimes you have to disassemble the horns to clean points, get rid of rust etc.  That means that you have to drill out the rivets.  for the same look as a rivet, which is used to attach braces to a bicycle fender, use a rivet screw.  The head that you see will look just like a rivet but the back side uses a nut and lock washer to attach.  Much easier to disassemble if you need to get into the horn again.  They come in all sizes.

 

 

Yes, this is what I did. And then I sprayed them all black to match the horn. You don't even notice that they're there.

 

😎

[WQ59B]

Great info!
Is there any difference in the horn relay between 2-note and 4-note set-ups?
I'm going to combine '72 Riviera trumpet & mid-note horns with '59 H/L seashells. After adjusting them, I've direct-wired them and did a quick test and they sounded great... but my car's original harness is gone, and I need to pick up a relay (I believe). Any advice greatly appreciated.

[RivNut]

On the first generation cars, the four note horns get 12V from a harness that splices into the two horn harness which come from the same horn relay.  I don’t know about the 3rd generation Rivs but I would think the thinking would be the same.