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Home » Public Forums » GMCnet » Add 30hp to your 455 for $2
Add 30hp to your 455 for $2 [message #333194] Thu, 07 June 2018 17:58 Go to next message
rgogan is currently offline  rgogan   United States
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Parameters in the title are very approximate but I will share my discovery and see how much more power you get out of your 455:
I found my secondary throttle leaflets were not opening completely. When I went about trouble shooting this,among other issues, I found that the rubber grommet that connects the accelerator cable to the throttle carb linkage was worn through completely. This loss of an 1/8" space prevents the secondary leaflets from opening completely. I was able to get a replacement from Aplied GMC and now I have full opening of my secondaries and more power. Pretty cheap project with big hp gain.
Re: Add 30hp to your 455 for $2 [message #333244 is a reply to message #333194] Fri, 08 June 2018 18:41 Go to previous messageGo to next message
Matt Colie is currently offline  Matt Colie   United States
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rgogan wrote on Thu, 07 June 2018 18:58
Parameters in the title are very approximate but I will share my discovery and see how much more power you get out of your 455:
I found my secondary throttle leaflets were not opening completely. When I went about trouble shooting this,among other issues, I found that the rubber grommet that connects the accelerator cable to the throttle carb linkage was worn through completely. This loss of an 1/8" space prevents the secondary leaflets from opening completely. I was able to get a replacement from Aplied GMC and now I have full opening of my secondaries and more power. Pretty cheap project with big hp gain.

Robert,

Your observations are accurate, but the "Leaflets" are called "Butterflies" in the technical world.
Yes, the secondaries are essential when climbing things like though things like the Buckhorn.

The only thing I will caution you about is that opening the secondaries is oft referred to as "flushing" a Quadrajet.
Be cautious of imploding the fuel tanks if you do it too often.

Did you know that, under the correct driving conditions, a TZE can burn fuel at the rate of 1/5 of a gallon per mile?

Matt


Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
Re: Add 30hp to your 455 for $2 [message #333254 is a reply to message #333194] Sat, 09 June 2018 07:32 Go to previous message
thesmith is currently offline  thesmith   United States
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Registered: February 2015
Location: Cary, NC
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Got a picture of these "grommets" in situ?

Cary, NC 1978 Center Kitchen Royale.
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