Low CFM carb

#21
It’s about 48 cc. 1 1/2 HP "Z" Engine CC Calculation:
To estimate the CC rating of a 1 1/2 hp "Z" engine, you would multiply the horsepower (1.5) by the approximate cc per horsepower (32.5). This results in roughly 48.75 cc. Carb is rated down to 50 cc.
 
#22
48cc? maybe 4.8 CID?
I do think this is a hit and miss engine, even though the OP states it is "throttle governed"
Yes I am a member at Smokstak.com.
This is a flywheel engine and I am not aware of a flywheel type engine with a motorcycle carburetor installed on it.
I really would like to help to get this project moving along, but I do not think a motorcycle carb is the solution on an antique cast iron hit and miss engine.
I did see video of this engine running with the Flo-Jet carb installed. Let's backtrack to the point when it was still running, and go from there, OK?
 
#23
I believe what he is saying is the carb for this engine is supposed to be similar in size to what a 48cc engine would run, found through the formula he posted earlier.
It is throttle governed, like a hit and miss but the governor is connected to the throttle plate rather than the exhaust valve. watch video for difference:

I never heard of one either until now.
 
#24
That is a great video. Thank you for adding it to the discussion!
But it still does not equate "throttle governed" engines to "variable throttle" engines.
Those seem to be able to adjust their governed speeds via the throttle opening and mixture adjustment, not by simply opening a throttle valve.
I have observed the OP not answering questions and seeming to misunderstand some of the questions being asked.
Those antique engines were not "throttle" they were basically, single speed.
 
#25
I agree, it is a constant speed engine and the locomotive the OP is working on would need throttle control to operate correctly.

I also don't quite get the formula that this engine only needs the carburetor equivalent to a 50cc engine. at 1000 RPM (or whatever speed it is run at) it will draw the same air/fuel mixture in that any other 4 stroke engine of it's size will use.
 
#27
48cc? maybe 4.8 CID?
I do think this is a hit and miss engine, even though the OP states it is "throttle governed"
Yes I am a member at Smokstak.com.
This is a flywheel engine and I am not aware of a flywheel type engine with a motorcycle carburetor installed on it.
I really would like to help to get this project moving along, but I do not think a motorcycle carb is the solution on an antique cast iron hit and miss engine.
I did see video of this engine running with the Flo-Jet carb installed. Let's backtrack to the point when it was still running, and go from there, OK?
 
#32
Carburetor airflow is measured at a certain vacuum level.
I have to think your engine is somewhere around the 18 to 20 Cubic Inch range, and I also think your carb needs a shaft and a throttle plate, like the video above, so the governor can "govern the throttle". I do not think it ever be happy with a small motorcycle slide type carburetor on it.

Where are you located, roughly? Maybe a member or two could have a look at it and try some ideas.
Do you still have the Flo Jet carb?
 
#34
It is difficult to find anything accurate, I found this after doing some searching. What is the CC rating of this engine.
To estimate the CC rating of a 1 1/2 hp "Z" engine, you would multiply the horsepower (1.5) by the approximate cc per horsepower (32.5). This results in roughly 48.75 cc. Carb is rated down to 50 cc.
Best I can do.
 
#35
It would be much easier to help you if you gave the bore and stroke of the engine.

Again, the dribbling of gas out of the carburetor while you are attempting to start the engine cold is likely from gas condensing on the walls of the cold intake path. it will do this no matter how big or small of a carb you attach to it. it likely did this when first constructed and the builder understood that once the engine was running it would no longer dribble. This is made much worse by choking (or covering the carb intake) while attempting to start.
 
#37
The Flo Jet is long gone, I have the throttle linkage all set with the new carb, and in fact when I was trying to start it this AM it popped over about 5 rev’s, seems to be on the right track, who knows.
P/S for the above post. bore 4” stroke is 4”
 
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