Hey guys, I removed the carbs and have been checking on the linkage. Underneath the carbs in front of the linkage, I have this weird looking... valve/switch sort of thing? Image Unavailable, Please Login It does not appear to be hooked up to anything. Could someone help me understand the function? I think the screw that was to actuate it was backed out to the point it wasn't even touching. Any advice is appreciated! Thank you! E
It's a pneumatic "dashpot" (a small damper) that prevents the throttle plates from closing too quickly (even if you release the acc. pedal cable quickly). 112638 (item 53 on TAV 16 of the 161/78 SPC)
Hey Steve, as always thanks for the lightning-fast reply!! So given the function, I don't believe it was adjusted correctly. I assume I want the linkage screw to depress the damper when closed to prevent the slap? Thanks, E
Yes, the screw should engage the dashpot for the last portion of linkage travel (but it shouldn't "bottom" the dashpot so maybe something like ~1/2 the stroke of the dashpot might be a reasonable initial adjustment to try -- and then adjust from there, if necessary). The dashpot should not affect the final position of the throttle plates (it should only "slow" the RPM decrease as it goes down to 1000).
Hey Steve and all, I have the linkage back together and I'm positive it was the way I found it. I reviewed my earlier pictures and I'm just not sure there's any way that this thing has ever been working under my ownership. When I reinstalled, I figure I'm a good 1.5" away from actually engaging the dampener at all: Image Unavailable, Please Login What's odd, is that there is another device on the top side that looks like it might serve a similar purpose? Could someone let me know how this top side piece works? Image Unavailable, Please Login It appears to be connected to the coolant tower and is in adjustment. It has a spring on it as well. Finally, here's a shot of the linkage entirely, just in case I'm completely backwards or something. Image Unavailable, Please Login Thank you for all your pointers, tips and help! I really appreciate it!! E
Agree -- that seems very strange (like the pivoting arm with the setscrew was rewelded at the wrong angle). I don't have an example to look at anymore for comparison, but maybe you can find some pics of other carb car linkages to compare. Or maybe the tie rods have enough adjustment to bring it into use (but your acc cable is the wrong length) -- something weird like that. I will say that your cold fast idle device is way, way out from touching its cam even thought its adjustment screw is protruding a fair bit so that seems odd, too (IIRC) -- again like the acc cable is too short. That's the cold fast idle device that (when adjusted as intended) holds the throttle linkage more open when the coolant is cold to raise the cold start RPM, but it requires using the choke, too. Very common for that one to be adjusted not touching, and the Driver uses the acc pedal to keep things running at cold start-up (so can avoid using the choke).
