Author Topic: Heat Riser - Purpose of Spring?  (Read 5444 times)

sdkar

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Heat Riser - Purpose of Spring?
« on: June 04, 2012, 10:54:30 PM »
I just got a new heat riser for my 69 Camaro and I see that there is a spring on it that seems to have no purpose.  Not the copper coil spring, as I can see the purpose of that.  There is however, another spring that simply pinches between the small bar and the shaft.  It doesn't hook onto the shaft or cause it to return or anything.  It is just there with apparently no purpose.  What is it there for?  Is it supposed to hook onto the shaft or act as a return spring?  Because iif it is supposed to do this...the one I got doesn't. 

Here is the one I got.

http://www.amazon.com/ATP-105019-Heat-Riser/dp/B000C8NTQW/ref=sr_1_21?ie=UTF8&qid=1338850457&sr=8-21

Thanks,

Steve


Mike S

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Re: Heat Riser - Purpose of Spring?
« Reply #1 on: June 04, 2012, 11:04:20 PM »
 It is supposed to keep pressure on the shaft so it doesn't chatter from the exhaust pulses. It doesn't hook into the shaft, it just presses against it.
I see yours doesn't have the small barrel spring on the shaft the weight pushes up against when fully open.


Mike
67 04B LOS SS/RS L35 Hardtop - Original w/UOIT
67 05B NOR SS/RS L35 Convertible - Restored

sdkar

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Re: Heat Riser - Purpose of Spring?
« Reply #2 on: June 04, 2012, 11:20:18 PM »
Barrel spring?  What is this?  Is there a third spring?  What am I missing?

Thanks,

Steve

Mike S

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Re: Heat Riser - Purpose of Spring?
« Reply #3 on: June 04, 2012, 11:48:41 PM »
Hi Steve,

  See the image from my restored L35 for the location. I checked my survivor L35 and it has the same spring too.

Mike
67 04B LOS SS/RS L35 Hardtop - Original w/UOIT
67 05B NOR SS/RS L35 Convertible - Restored

sdkar

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Re: Heat Riser - Purpose of Spring?
« Reply #4 on: June 05, 2012, 01:11:59 AM »
The limit bar on your photo is between the coil and the weight whereas the setup I received is below both of them toward the bottom.  So what I received may not be correct.  Also, what does that spring that I am missing do?

Thanks,

Steve

Mike S

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Re: Heat Riser - Purpose of Spring?
« Reply #5 on: June 05, 2012, 01:31:48 AM »
Now mine is a BB if that matters compared to your application. That spring prevents the weight from chattering against the shaft.
The small coil spring (not copper) prevents the shaft from chattering in the housing. If you put your hand on the weight when you first start the engine you will feel the weight oscillates quite a bit with the exhaust pressure pulses so you can see the potential for mechanical chatter.

Mike
67 04B LOS SS/RS L35 Hardtop - Original w/UOIT
67 05B NOR SS/RS L35 Convertible - Restored

Boston14

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Re: Heat Riser - Purpose of Spring?
« Reply #6 on: June 05, 2012, 01:56:10 AM »
I don't know, my L48 doesnt have a "barrel" spring. My car was built November (11D) 1968. Maybe it is a later date or a big block thing????

boston14
boston14

1969 SS/RS 350 Convertible
Dover White with Black Top and D90 stripe, Red Standard Interior

sdkar

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Re: Heat Riser - Purpose of Spring?
« Reply #7 on: June 05, 2012, 11:42:37 PM »
Boston14,

What is the positioning of your counter weight when the car is not running and in a cool down mode?  Is it up or down?  Could you post a pic or maybe send me one if you have it?

Thanks,

Steve
sdkar@bellsouth.net


Boston14

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Re: Heat Riser - Purpose of Spring?
« Reply #8 on: June 07, 2012, 02:31:55 AM »
http://www.camaros.org/forum/index.php?action=dlattach;topic=7928.0;attach=6453;image     Here is a picture of JohnZ's heat riser on his 69 Z from a post on this Forum. My L48 is the same. I don't have any pictures of mine at this time, it is wrapped up on an engine stand right now. However,  it is pictured in the assembly manual under UPC 6  C6, and on page 13 of Jerry M's 1969 book.  Hope this helps.
boston14

1969 SS/RS 350 Convertible
Dover White with Black Top and D90 stripe, Red Standard Interior

sdkar

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Re: Heat Riser - Purpose of Spring?
« Reply #9 on: June 08, 2012, 02:58:05 AM »
So, it is at the bottom of the "Triangle" with the weight going side to side?  I have had mine installed all these years with it being installed on the left side going up and down.  I installed it this way as it was how I saw one installed somewhere, but don't remember exactly where.  Is the photo above correct?

sdkar

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Re: Heat Riser - Purpose of Spring?
« Reply #10 on: June 08, 2012, 03:11:15 AM »
I looked at both sources and sure enough, the counter weight is at the bottom and goes side to side.  It is a little hard to see in Jerry's book as the heater hose is kinda blocking it, but the fact you can't see it on the side is enough.  The assembly manual shows it well enough.  I was sure I saw it installed with the weight on the left side.  I suppose that person had it wrong and I perpetuated it.  I wonder how many guys now have this part installed incorrectly after using my car as a reference.  Finally, why didn't anyone ever say something to me.  I have attended dozens of car shows and have even entered (and won) some serious competitions with supposedly very knowledgeable judges and not one bothered to mention this.  They took off points for a grease smudge on my intake and for the wrong color black tape on a wiring pigtail, but not a single mention of this.  I feel so stupid.  I wonder if it even worked properly with it being installed incorrectly.  Was the coil strong enough to lift the weight upward as opposed to just moving it side to side.

Anyway, I now have a new one and will finally get it right. 

I suppose now someone is going to tell me that the tapered end of a lug nut is supposed to go toward the wheel as opposed to facing outward.  Wouldn't that be funny.  I'm sure I have them installed correctly.  Now if I could just figure out that shimmy problem I have had high speeds and the loud clunking when I brake suddenly.

Thanks,

Steve