thisismatt Posted September 9, 2019 Report Share Posted September 9, 2019 Personally, I would do this at the carb, right on the butterfly pivot. I would put some kind of slack in that ball linkage so the solenoid only has to work against that single spring. Quote Link to comment
Crashtd420 Posted September 9, 2019 Author Report Share Posted September 9, 2019 1 hour ago, thisismatt said: Personally, I would do this at the carb, right on the butterfly pivot. I would put some kind of slack in that ball linkage so the solenoid only has to work against that single spring. I understand what your saying but the springs you see on the carb are the only ones I have on my throttle setup.... one of the reasons I bought that throttle setup was because my pedal doesnt have it's own return spring in the cab..... that one was broken and lost years ago, even before I got the truck.... So I dont believe there would be any difference in effort that the solenoid would see if I did it at the pedal or at the carburetor it would still be pushing against the same number of springs.. I have read about others with the issue I believe you think would occur. Which is it's not strong enough to increase the idle... most say you have to hit the throttle once when the solenoid is activated then it would stay out.... 1 Quote Link to comment
wayno Posted September 9, 2019 Report Share Posted September 9, 2019 That firewall area is not a place I like working around, it is tight and I have dual SUs on all my L blocks, plus putting something there makes it hard to get to that transmission bolt when one has to remove the transmission. OK, see the photo below, see the bolt that holds the air filter housing on, does that threaded hole go all the way thru, if it does you could put a longer bolt thru that hole that sticks out far enough to hold a bracket and the nut holding the bracket on, then point the bracket with the solenoid pointed right at the lock nut or an "L" bracket that the lock nut holds on to that linkage, I would just use the lock nut myself. 1 Quote Link to comment
Crashtd420 Posted September 9, 2019 Author Report Share Posted September 9, 2019 I see your point about the fire wall but I feel it's the strongest location to support the solenoid... I do have the room and it would be easily removable if necessary..... With stroffgrens idea about a welded nut on a riveted on plate opens up the possibility of what solenoids I can use.. But wayno I also like your idea about the air cleaner bolts, they are through holes so longer screws and nuts on the backside is possible.... But I'm not sure which lock nuts you are referring too.. I would probably do it on the back side of the carburetor.... there is a lever back there also and 2 empty locations for the idle screw and something else.... not strong enough to hold the whole unit but should be ok to stabilize a bracket mounted to the air cleaner bolts.... Looks like I'll get one that could suit both ideas and see what will work best... 1 Quote Link to comment
thisismatt Posted September 10, 2019 Report Share Posted September 10, 2019 5 hours ago, Crashtd420 said: I understand what your saying but the springs you see on the carb are the only ones I have on my throttle setup.... one of the reasons I bought that throttle setup was because my pedal doesnt have it's own return spring in the cab..... that one was broken and lost years ago, even before I got the truck.... So I dont believe there would be any difference in effort that the solenoid would see if I did it at the pedal or at the carburetor it would still be pushing against the same number of springs.. I have read about others with the issue I believe you think would occur. Which is it's not strong enough to increase the idle... most say you have to hit the throttle once when the solenoid is activated then it would stay out.... Nah, that's not what I'm saying. I'm suggesting you need to bypass the springs for the solenoid to function. I highly doubt it's going to be strong enough to counteract the 3 springs, plus the cable and pedal fulcrum friction. What I'm talking about is probably too complex for you to want to bother, but it would be something like this... 1 Quote Link to comment
wayno Posted September 10, 2019 Report Share Posted September 10, 2019 I guess I wasn't looking at it close enough, the lock nut is the pivot point of that arm and that will not work. OK a bracket coming off the back side of that air filter housing bolt tilted the same angle as the throttle arm in the photo with the solenoid aimed right at the center of the arm just below where the cable connects to the arm, once the air conditioning is on it will set a new idle speed, it doesn't have to force the arm forward as you already are driving it, but when the air turns off the idle may drop if idling, but I don't think a solenoid of such a small size would work against the spring at an idle by itself, but if you tapped the pedal it would find the new idle position. The same thing would happen the way Matt suggested, it likely could not force the idle up at an idle against the springs, but your driving the truck so it only has to hold the new idle position and it would not need to have slop in the linkage. It's all about if the solenoid can hold the new idle position against the spring, also if the arm is too narrow you can put a flat plate on the end of the solenoid, and it would be so much easier to adjust/fiddle with out in the open. 1 Quote Link to comment
thisismatt Posted September 10, 2019 Report Share Posted September 10, 2019 Having to blip the throttle is going to grow tiresome reeeal quick. The solenoid should act on the idle setting regardless. AC compressor isn't always going to be engaged when you take your foot off the gas... 1 Quote Link to comment
wayno Posted September 10, 2019 Report Share Posted September 10, 2019 Your only going to have to tap the throttle if the air conditioning comes on at an idle, I rarely sit in any of my vehicles while it is idling, when I am in them I am driving them. Quote Link to comment
mainer311 Posted September 10, 2019 Report Share Posted September 10, 2019 I know you're going for something automatic here, but a hand throttle cable from a roadster would work awesome. Some people use them for cruise control, but they were originally meant to hold a high-idle while the car warmed up. Roadster SU's don't have a true choke, they have an "enrichener" which pulls the nozzles downwards to open the orifices a bit more. A hand throttle was needed when it was cold to hold the RPM's up until the car was warm, and then you could just push the knob back in. I'm actually searching for one for my car. When I bought it, it was missing. 1 Quote Link to comment
thisismatt Posted September 10, 2019 Report Share Posted September 10, 2019 8 hours ago, wayno said: Your only going to have to tap the throttle if the air conditioning comes on at an idle, I rarely sit in any of my vehicles while it is idling, when I am in them I am driving them. I guess there are no stop lights, stop signs, drive-throughs, busy parking lots, or a million other instances one would still be considered "driving" while idling. 2 1 Quote Link to comment
Charlie69 Posted September 10, 2019 Report Share Posted September 10, 2019 Make it easy on yourself and raise your idle 100 rpms problem solved! Quote Link to comment
Crashtd420 Posted September 10, 2019 Author Report Share Posted September 10, 2019 38 minutes ago, thisismatt said: I guess there are no stop lights, stop signs, drive-throughs, busy parking lots, or a million other instances one would still be considered "driving" while idling. I could always put the solenoid on it's own on/off switch so it doesnt cycle with the compressor.... And matt I now understand what you were suggesting earlier but I dont think the linkage would do what your thinking.... that arm you were talking about is to adjust the cable to achieve wot .... I think I just need to buy a solenoid, hope for the best and try it.. I still have till next week to decide what to buy.... play money all spent, waiting for next paycheck... 1 Quote Link to comment
Crashtd420 Posted September 10, 2019 Author Report Share Posted September 10, 2019 Just now, Charlie69 said: Make it easy on yourself and raise your idle 100 rpms problem solved! I did that and it wants to diesel on me... 1 Quote Link to comment
Crashtd420 Posted September 10, 2019 Author Report Share Posted September 10, 2019 And mainer311 I though about a pull cable but was worried about the cables slacking and getting caught or something since both would have to be attached to the throttle.... 1 Quote Link to comment
mainer311 Posted September 10, 2019 Report Share Posted September 10, 2019 32 minutes ago, Crashtd420 said: And mainer311 I though about a pull cable but was worried about the cables slacking and getting caught or something since both would have to be attached to the throttle.... Yeah, roadsters are a little different in that the pedal cable and hand cable both work the same linkage, and then one cable goes to the carbs, but in theory, it's the same idea. 1 Quote Link to comment
Stoffregen Motorsports Posted September 10, 2019 Report Share Posted September 10, 2019 The reason Chevys can use the solenoid on the carb is because they have a sort of passive linkage. The solenoid can push on the carb lever without affecting the pedal. I'm sure you could design something for the Weber, but I'd give it a try on the pedal first. You never know until you try. I do like the idea of using a vacuum switch, but as we discussed earlier, there are lots of variables. 1 Quote Link to comment
Crashtd420 Posted September 10, 2019 Author Report Share Posted September 10, 2019 29 minutes ago, Stoffregen Motorsports said: The reason Chevys can use the solenoid on the carb is because they have a sort of passive linkage. The solenoid can push on the carb lever without affecting the pedal. I'm sure you could design something for the Weber, but I'd give it a try on the pedal first. You never know until you try. I do like the idea of using a vacuum switch, but as we discussed earlier, there are lots of variables. I get what you were saying before about the vacuum switch idea but I dont really like the idea of a vacuum leak per say.... As far as the solenoid I just need to try one and see what works or doesnt work.... just trying not to waste money.... 2 Quote Link to comment
thisismatt Posted September 10, 2019 Report Share Posted September 10, 2019 1 hour ago, Stoffregen Motorsports said: The reason Chevys can use the solenoid on the carb is because they have a sort of passive linkage. The solenoid can push on the carb lever without affecting the pedal. I'm sure you could design something for the Weber, but I'd give it a try on the pedal first. You never know until you try. I do like the idea of using a vacuum switch, but as we discussed earlier, there are lots of variables. This is what my idea would do. Other cars do this with a kind of double cable, like when using cruise control. The throttle plate has two spring loaded pulls, one for each cable... 2 Quote Link to comment
Crashtd420 Posted September 10, 2019 Author Report Share Posted September 10, 2019 30 minutes ago, thisismatt said: This is what my idea would do. Other cars do this with a kind of double cable, like when using cruise control. The throttle plate has two spring loaded pulls, one for each cable... I'll look into it more but I still dont think my set is capable of doing that.... 1 Quote Link to comment
wayno Posted September 10, 2019 Report Share Posted September 10, 2019 This is how I shut my engine down, I am slowing down to park in front of my house, it is in first because I just made a right turn onto my street, I am the second house on the right, I pull up next to the curb, push the clutch in and hit the brakes and stop, I turn the key off and let out the clutch at the same time and it dies, I have been doing this for 25 years, I don't even notice I do it anymore, if I where to put my truck in neutral and shut it down it will diesel terribly, and it could in theory roll away down a hill after I get out even though the e-brake is on, no I will never leave my truck in neutral and shut it down as one day I would forget to put it in gear and it would rill down the hill and hit a tree if I was lucky and hit someine if I and they were unlucky. There are folks on Ratsun that have had this happen because they left their 521 truck in neutral, and they were lucky, it hit a tree. 1 Quote Link to comment
mainer311 Posted September 10, 2019 Report Share Posted September 10, 2019 Who the fuck leaves a parked vehicle in neutral? 2 Quote Link to comment
wayno Posted September 11, 2019 Report Share Posted September 11, 2019 People that shut the engine off while it is in neutral like it is a modern car that was put in park and then forget to put it in gear. This dieseling thing is not going to go away, even Nissan couldn't do it so they put a cutoff valve in the carb, but these side drafts do not have such a thing so they diesel unless one turns it off and lets out the clutch at the same time while it is in gear. I personally don't like my idle so low as I don't want to go thru all the hassle of getting the carbs set so perfect that they will idle that low smoothly(that day), I just want to get in it and drive to where I want to go without worrying about if it is going to drive like it did yesterday, mine drive great every day but they diesel if I shut the engine down any other way than the way I described, when I am working on the engine in the driveway is when I notice the dieseling, as it is in neutral when I shut it off as I am not in the drivers seat when I turn it off, most the time it is either in the air on my air jacks, or is has a block behind the tire to keep it from rolling away. 1 Quote Link to comment
thisismatt Posted September 11, 2019 Report Share Posted September 11, 2019 My downdraft doesn't diesel at all with idle <700rpm 1 Quote Link to comment
thisismatt Posted September 11, 2019 Report Share Posted September 11, 2019 9 hours ago, Crashtd420 said: I'll look into it more but I still dont think my set is capable of doing that.... I'm talking quite a bit of one-off modification... 2 Quote Link to comment
wayno Posted September 11, 2019 Report Share Posted September 11, 2019 I have dual SU side drafts on all my L blocks, they do not idle smoothly at 700rpms, and I don't want to deal with getting them set up to idle that smooth that day to just have them act different a week later after the weather changes, I can live with 900rpms and letting the clutch out when I turn the key off. Quote Link to comment
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