Smog pump...

#1
Anybody ever tried a smogpump supercharger? I have a few of old smog pumps laying around and dont really have a use for them..... I was wondering if you can do it with any gain? I found one on ebay that is just like the one I have but the bad parts is what do the 2 outlets go to? I know the one is for you to pump air out of but whats the other one for? :confused: anyway I just thought I would ask and see if any one has tried...

TRN
 
#6
MDB, I am going to try but I dont know when, I need some parts made on a lathe and mill for me to get it to run properly... Pulleys and such... I wil keep everyone updated on this subject of when I get it going....

TRN
 
#7
I have a lathe...have access to a complete machine shop...willing to help for fun/no money involved...should be interesting...never done it, but heard it works...
 
#8
Hey yellowhand that sounds great!!! I will get back to you around the end of the week? Leaving for a few days and will be back friday to get with you on the mater....

TRN
 
#9
Hey anyone know whats the best way to run the smog pump? Should I route a air filet to the inlet and then run a hose to the carb from the outlet?
Or should I run a hose to a carb to the inlet that sucks in the gas and air~~ then run a hose to a custom manifold to the port? Any pros and cons to these setups?

TRN
 

Oldsalt

Well-Known Member
#10
The one rule I know to be true when putting forced air to a carb is that the metering system in the device is then badly confused. Carbs [commonly] work by using the normal air pressure [outside the carb] to do the proper metering of air/fuel. Putting pressure [above atmospheric] to the carb will not work above about 4 PSI. The whole carb will have to be pressureized by your puffer if you want it to work first time. Of course you can put the carb on the intake of the puffer and there will not be a problem. But you can run into some other problems. I heard that this smog pump thing has been done. Always wanted to learn how it was done.
 

Oldsalt

Well-Known Member
#12
That would be a pull through system. You may need a bigger carb than was used on the stock engine. In fact it is almost a sure thing. Have you decided on the RPM increase [over crank RPM] that you will use?
 

65ShelbyClone

Well-Known Member
#13
A couple things to be aware of are that smog pumps were not designed to move air at much pressure and they are not positive displacement pumps like Rootes blowers. That means that with enough boost and rpm, the vanes can become a weak point. It will also be a matter of experimentation regarding what drive ratio will produce what amount of boost.

If you put the carb on the blower inlet in a drawthrough setup, you won't really need to modify the fuel system. If you feed boost into the carb in a blowthrough configuration, then a fuel pump, pressure regulator, and more fabrication is necessary.
 
#14
That would be a pull through system. You may need a bigger carb than was used on the stock engine. In fact it is almost a sure thing. Have you decided on the RPM increase [over crank RPM] that you will use?
Oldsalt im not sure what you mean? Do you mean how many rpm will the motor spin?
 
#15
A couple things to be aware of are that smog pumps were not designed to move air at much pressure and they are not positive displacement pumps like Rootes blowers. That means that with enough boost and rpm, the vanes can become a weak point. It will also be a matter of experimentation regarding what drive ratio will produce what amount of boost.

If you put the carb on the blower inlet in a drawthrough setup, you won't really need to modify the fuel system. If you feed boost into the carb in a blowthrough configuration, then a fuel pump, pressure regulator, and more fabrication is necessary.
65shelby, I was thinking on drive ratio, and woudnt 1:1 be the best to get the most boost? Any ideas on what size sprockets I should run like 10 on the motor and 5 on the pump for example? Also what size carb should I run? I am going maybe to get a mikuni off of ebay... Should I use a electric fuel Pump? Like low pressure fuel pump from pep-boys?



Its the middle pump--
So basically I am going to run a pull threw style pump and see what happens...

TRN
 

65ShelbyClone

Well-Known Member
#16
65shelby, I was thinking on drive ratio, and woudnt 1:1 be the best to get the most boost? Any ideas on what size sprockets I should run like 10 on the motor and 5 on the pump for example? Also what size carb should I run? I am going maybe to get a mikuni off of ebay... Should I use a electric fuel Pump? Like low pressure fuel pump from pep-boys?
The amount of boost a blower makes is all in relation to the blower RPM versus crank RPM. Overdrive, underdrive, or 1:1 doesn't matter in the end, but I would recommend spinning the blower slower than the crankshaft until you know what it's going to do.

A bike-type carb like a Mikuni should work fine. Same for the electric fuel pump.
 
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