rejetted my new carbs today, from 045 to 042. and installed a new holley f/reg. set it at 2 1/2 to 3lbs.. dialed the carbs in with a vacume guage. i have a new unisyn, but vaige directions. has anyone dialed thiers in with a unisyn?
Dear Jan, you can take this anyway you want to but going to a smaller jet size is the wrong way to go with a Stromberg carb. With multiple carb setups I prefer to increase the jet size for two reasons. The first is to richen up the mixture on the upper or cruising end of the scale. With mulitple carbs the air flow increases and therefore twin carbs has a tendency to lean out the mixture as the rpm increases, this raises the cylinder operating temperature, which cause the water temp to creep up. While this may make it run a little fat on the idle side, the running performace is a liitle better. Secondly the new fuels being forced upon us have about 10 % ethanol which is requires a larger jet to accomodate the larger volume of the fuel vs just plain un altered gasoline. This will be worse with the 15% stuff coming. You are using present day ideas with technology from 70 years ago so some things become a compromise. My suggestion would be first increase your jetting from 45's to at least 48's. Also a recheck check of the timing dosent hurt either make sure that it is not on the retarded side. You unisync is good for setting the idle balance.
As far as using it, open the adjusting cone screw fully, stand the vial straight up, then put it over the choke horn on either carb and close the adjusting screw until the bubble is centered in the vial. Then check the other carb. You'll adjust both idle speed screws until both carbs are reading the same on the vial, and your idle speed is where you want it.
alot of guys on here are saying to go with 042 jetting. ilistened becaused my car was puffing black, and the plugs were black sootie, you could really smell it in the air how rich it was. it even had a low and mid range miss. that was with 045 jets now it doesn't have any of above.
I might have you mixed up with another hamber, but I thought it was you who had one of the carbs flooding over? If so, you would get the black smoke at idle too, and the main jets are not even working at an idle.
If the unisyn won't fit due to something sticking up above the air cleaner flange, just cut both ends out of a tin can & put a foam gasket on both can ends. Use the can for a spacer to get the unisyn above the obstruction.
i did the f/pump was pushing thru the f/press. reg.. i changed the press/reg. and installed a p/guage in each line. no more leaking. running 2 1/2 to 3 lbs.
Yes, but after you got the pressure down and the carb stopped leaking over, did you try the old jets first? to see if it was still running black? ...or did you swap to smaller jets at the same time that you fixed the pressure?
no, went right to 042 i can always check the plugs to see how its burning. so we all know these are the speedway carbs.
I think you're close with the 42 jets. if it leans out at higher revs,step up to 63 power valves from the stock 65 and try that.
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