Dribbler

Does anybody have a schematic on how to set up a dribbler system to help low speed idle?
I found we'll need a T, a check valve, nozzle, some check valve injectors and such, but nothing really on a full setup and a baseline setting.
Does anybody even run this sort of thing?

 

Thanks Will,
What we'd like to do is to get a clean idle with decent temperature distribution over all cylinders. We now have a choice of high (lean) idle with hot cylinders or low (rich) idle with cylinders dropping due to too much (or too little?) fuel. Some people seem to have the art under control to get a clean low idle and I was thinking to use a dribbler setup to arrive at just that.
I heard there should be a pill in the line to the dribblers and then of course the question what size of nozzle to use on the ports.
If I'm correct you're suggesting an idle circuit on the ports with low check pressure with a higher check pressure for the top nozzles? That doesn't sound good for the blower or am I misinterpreting here?

 

Are you talking a screw blown motor? If you are, there are actually three circuits. One is to lube the blower and idle the engine and is on all the time. That is what is dumped in at the hat or above blower level. The second would be the dribblers and as Will has said, it will be open at 5 or above pounds which is barely any throttle opening. The third would be the main and normally would be above 25 pounds which is a throttle setting higher than idle or the dribbler setting. The barrel valve setting needs to also be considered as that will control the fuel (and temps) at idle and just off idle. It along with the constant on nozzles will control you EGT settings. In my experience, the idle EGT's are not that important but what should be focused on is the rise off idle and through the rest of the run and try to get them equalized while adhering to the plug readings of all the cylinders.

PSI has a manual to set up the fuel system that explains most of this. It's a good baseline,

 

boost at stage. you can change spools and every thing else but x amount of hp requires x amount of boost more load more power needed to get there 1.7 to 2+ works as an agressive start 5 + is dropping cylenders higher presure (Idle return )retards spool to acvhieve desired stage lower psi advances it works with roots, psi ,or
whipple just ask norm

 

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Thanks,
It's actually a roots setup, but that probably doesn't make much of a difference at idle. I'm first going to check fuel setup to see if check valves are maybe set a bit high . I think we're close to the 5 psi at idle, but we can back it off a bit to see what happens. At least that will be easier than adding the dribbler setup. Note that we are using top (hat) nozzles with a low pressure checkvalve and then port nozzles with a higher pressure checkvalve. This is pretty straightforward. The dribblers I mentioned would be additional to feed some of the ports at idle using fuel from the low pressure (hat) distribution block to separate port nozzles. That requires more complex plumbing than I'm used to. I will try to dig up the old stuff I once found on this sot of thing and try to upload it.
It also was discussed years ago on ITA, but without clear suggestions on setup unfortunately. Notice the response by Creech on Jan. 14

http://www.insidetopalcohol.com/threads/jets-in-hat.21873/