Newbie Tip #2
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Joined: Sep 2016
Posts: 720
Likes: 205
From: Michigan
Newbie Tip #2
Hi Folks,
Ran across my second "aha moment" this week, which I contributed as a quick post on an on-going thread, so I thought I'd post it here as a stand-alone in case it helps others like me!
If you have any question or doubts about your wide-open-throttle range, and whether your carb/throttle are reaching its full open position, I want you to go out to your C3 (mine's a '69), and check the tightness of the clamp bolt on the joint between the gas pedal pivot rod and the stamped metal vertical arm that levers the cable through the firewall. (it's the right-most bolt/nut in the photo that feeds front to rear through the U-bend of the bracket. it tightens a clevis around the rod to prevent free play)
I discovered mine to be loose, which allowed excess play between the rod and the bracket hole, which both have flats. When loose, the pedal experienced over a full inch of free play before it would start to pull on the cable and actuate the throttle linkage.
What this resulted was, a tight cable at idle, but:
At full-down, mashed-to-the-floor pedal, the throttle was only open about 2/3.
I had my son stomp on the pedal and hold it (engine off), and I grabbed onto the throttle linkage and held it there. Had him release the pedal while I was still holding the linkage steady. Then I was able to turn another ~1/3 travel to get to WOT.
I had been suspicious that my secondaries were not kicking in as designed, and was going through some of the recommended diagnostics for that, and was about the dis-assemble the secondary vacuum actuator when I decided to get back to basics and check the cable adjustments. That's when we discovered the throttle travel being short.
I thought it was a cable length/adjustment issue at the linkage, but my son caught sight of the loose bolt/nut at the clamping joint.
After snugging up the joint, I had him again floor the pedal, and, viola! the throttle opened to full WOT.
I then took it out for a quick ride, and I was gushing at the new-found extra power at the top end.
Even though this is "just" a 350/300 small block, it really makes a big difference when you open all four barrels the way they're supposed to! (duh)
I'd say it went from being pretty quick to scary quick (at least for me).
Free Power!!
Is it worth a quick duck of your head under the dash to check the tightness of that one bolt?? I'd say so!!
Ran across my second "aha moment" this week, which I contributed as a quick post on an on-going thread, so I thought I'd post it here as a stand-alone in case it helps others like me!
If you have any question or doubts about your wide-open-throttle range, and whether your carb/throttle are reaching its full open position, I want you to go out to your C3 (mine's a '69), and check the tightness of the clamp bolt on the joint between the gas pedal pivot rod and the stamped metal vertical arm that levers the cable through the firewall. (it's the right-most bolt/nut in the photo that feeds front to rear through the U-bend of the bracket. it tightens a clevis around the rod to prevent free play)
I discovered mine to be loose, which allowed excess play between the rod and the bracket hole, which both have flats. When loose, the pedal experienced over a full inch of free play before it would start to pull on the cable and actuate the throttle linkage.
What this resulted was, a tight cable at idle, but:
At full-down, mashed-to-the-floor pedal, the throttle was only open about 2/3.
I had my son stomp on the pedal and hold it (engine off), and I grabbed onto the throttle linkage and held it there. Had him release the pedal while I was still holding the linkage steady. Then I was able to turn another ~1/3 travel to get to WOT.
I had been suspicious that my secondaries were not kicking in as designed, and was going through some of the recommended diagnostics for that, and was about the dis-assemble the secondary vacuum actuator when I decided to get back to basics and check the cable adjustments. That's when we discovered the throttle travel being short.
I thought it was a cable length/adjustment issue at the linkage, but my son caught sight of the loose bolt/nut at the clamping joint.
After snugging up the joint, I had him again floor the pedal, and, viola! the throttle opened to full WOT.
I then took it out for a quick ride, and I was gushing at the new-found extra power at the top end.
Even though this is "just" a 350/300 small block, it really makes a big difference when you open all four barrels the way they're supposed to! (duh)
I'd say it went from being pretty quick to scary quick (at least for me).
Free Power!!
Is it worth a quick duck of your head under the dash to check the tightness of that one bolt?? I'd say so!!
Last edited by Bergerboy; May 17, 2017 at 06:43 AM.
Thread Starter
Pro
Joined: Sep 2016
Posts: 720
Likes: 205
From: Michigan
Well - I don't have a good feel for horsepower, but based on the throttle positions, I'd say I went from 200 to 300 for free! And that's not even accounting for the extra boost from the secondaries that might not have been kicking in much (if at all) before the fix!
