I just finished installing my Edelbrock carb on my 425 nailhead. I left the dashpot on along with a simple kickdown bracket I made. If I fire it up with the dashpot on, the idle is high and it feels like it slowly creeps up the rpm's in fast idle. Please note that I've adjusted the dashpot all the way down on the bracket and the throttle is allowed to come to a full rest while still pushed up against the dashpot. I removed the dashpot and it's running fine again. I blip the throttle and the fast idle is disengaged and it drops to a lower idle. So my question is, does the car need a dashpot if I'm running an aftermarket carburetor? Does the Edelbrock performer series design take the quick throttle release scenario into account and actively prevent it from stalling? Maybe my dashpot is broken? When I release the throttle it hits the dashpot and slows the throttle down. There is play on the rod but it still seems to function properly. Thank you Chris
If the Carb is made for the application, then the linkage is set up for the dash pot and probbily needs to be used. The thing is a dash pot in its original intent was only to keep the Carbs secondary from opening up while the motor was running on the choke / cold. I think you may just need to consult a manual to see how to adjust things right.
Stevem, Thank you for the response. I've added an image and you can see the linkage. It's custom because there is no aftermarket linkage that works with our engines. It's a simple L-Bracket (Home Depot or I can provide dimensions) that hits the kickdown at WOT. It will also hit the dashpot (not in picture). I think i'll try it one more time after I adjust the idle mixture screws and see what happens. Picture below is for reference for future modders! Chris
You would probably get more replies if in you told us what model and year car you're working on, does it have A/C....etc. o No: Derek
The dashpot's function is to cushion the deceleration when the throttle is suddenly closed. That is all. It keeps the car from stalling out. I've run several cars without them. And most of the cars that have them installed do not work, or are broken.
Derek, Sorry, you might be right. I figured the engine size would be enough. It's a 1964 Riviera w/ AC. It has an Edelbrock 1411 (750CFM with e-choke). There is probably a simple solution to this. I just need time to trial and error my way through it. Chris
I'm probably going to end up running without one. I am going to try to put it on one more time and adjust per the service manual. If it works, GREAT! If not, I ain't gonna lose sleep over it. Chris
Its either going to work or it ain't. I think one of the functions of that gizmo is to increase RPM when the A/C is switched on because of the extra load of the compressor as well. If the car stalls when the A/C is turned on at idle you'll know why, but like Steve said most cars can function without one. GL Derek
Adam, Does the rod on that dashpot come up as slowly as it goes in? My dashpot goes in slowly but because of the spring it comes up much quicker. I think the way mine operates is correct. Chris
You answered your own question, my friend. I've never had the need to run a dashpot on any engine with an aftermarket carb (Holley, Edelbrock, Carter, or otherwise). Since it works properly without it, get rid of it. No harm, no foul.
Thank you Lucas. I agree...I never did try it again. I figure there is some design improvement made by Edelbrock that allows for the dashpot removal. Thank you for letting me know you've actually used aftermarket carbs with no dashpot. That is more than enough for me to comfortably remove it. Chris
The dashpot is essentially there to keep the engine running in case of a panic stop, or when ever you come off the gas and let's say have to brake hard, or during emergency maneuvers. When the throttle slams shut like that, the fuel requirements to keep the engine alive while in the transition from the power circuit back down to the idle circuit are such that the engine could stall; the dashpot just allows a quick bounce into the off-idle circuit and therefore a quick shot of fuel. In the 70s they used an idle solenoid on A/C equipped cars that would click in on idle when ever the compressor kicked on, ostensibly to do the same thing. Do you need it? No, probably not. Did Edelbrock improve the design? If so very marginally. The last one I took apart looked just like an AFB. There isn't much you can do to the basic architecture if the design is sound; and the AFB was a pretty solid and easy to service design. The point here is the manufacturer put these parts on for a reason; not to just clutter up an otherwise pretty engine design with useless crap. So before dismissing it totally, try it with and without, see if there's honestly any difference. But just remember, if you get into a situation where you have to come hard off the gas and onto the brakes, and then back on the gas again, it may have stalled. And this can happen in a simple move like doing a left-hand turn off a green light.
Your Edelbrock carb will be fine without it. If for some reason your car dies because of lack of fuel for any reason, your carb is improperly tuned. I autocross race with one of these carbs, which is cramming the brakes, flooring it, hard left, hard right, easy left, easy right, easing on the throttle, easing off it, etc., in any hundreds of variances of order, and it never stalls. Then I drive it home. If you set your float height and idle mixture screws properly, there is nothing to worry about. There are hundreds of thousands of these carbs running around the world with no issues or dashpots. Next time you go to a car show, look at the carbs on the custom cars. Is there a dashpot? 99.9% of the time, I'm going with "no". On the old factory carb, I'm sure it was necessary probably due to lean tuning. Not trying to start an argument, just my real world experience with your exact carb.
One more thing.....Carter and Edelbrock AFBs are both made by Weber. Same carb, some differences in metering rods and Edelbrock uses a few more plastic pieces than Carter does. All parts are completely interchangeable.
