Air intake system parts compatibility
Posted: Fri Mar 04, 2011 4:16 pm
Our efforts to get my M38 drivable again so that it can be handed down to my son have 1) turned into a bigger (aka "more expensive") project than we expected it to be (surprise, surprise, huh?), and 2) turned into a bit more of a restoration project than originally intended.
Part of the project is getting a functional air intake system on it. When I bought it many, many years ago, it had none of the original air and fuel system. Mechanical pump had been replaced with an electric pump which did, and still does, work just fine. Carb is a WO. Upstream of that, though, is worse: a hole had been cut into the hood above the carb and a sheetmetal box welded on to clear and cover a dome over the carb. Under the dome was just a screen for a filter. I found a 4" Mr. Gasket aftermarket paper filter to replace the screen, then later found a lower-profile 6" Mr. Gasket filter that allowed me to patch in the hole in the hood and get rid of the ugly box.
But nowadays that thin 6" filter isn't available, so we're on Plan C (or is it D?). We bought an original oil bath air cleaner from a forum member, and I found brackets for it on ebay. A correct YS carburetor is out of our budget at the moment unless we get lucky, so the WO will have to suffice. So, finally, the compatibility questions:
1. If we use an MB-style air horn elbow on the WO carb, is the inlet diameter of the elbow the same as the outlet of the M38 air cleaner, allowing us to connect the two with a hose or duct?
2. If we add an M38 crossover tube in the path, is there any problem connecting it to an MB carb elbow? Would the MB rubber hose work? Length issue, maybe?
3. If we do score a YS carb, do we need a M38 fuel/vacuum pump to make it work correctly? I'm thinking vac-operated accelerator pump, for example?
Any answers and other insights would be appreciated.
-Jim
Part of the project is getting a functional air intake system on it. When I bought it many, many years ago, it had none of the original air and fuel system. Mechanical pump had been replaced with an electric pump which did, and still does, work just fine. Carb is a WO. Upstream of that, though, is worse: a hole had been cut into the hood above the carb and a sheetmetal box welded on to clear and cover a dome over the carb. Under the dome was just a screen for a filter. I found a 4" Mr. Gasket aftermarket paper filter to replace the screen, then later found a lower-profile 6" Mr. Gasket filter that allowed me to patch in the hole in the hood and get rid of the ugly box.
But nowadays that thin 6" filter isn't available, so we're on Plan C (or is it D?). We bought an original oil bath air cleaner from a forum member, and I found brackets for it on ebay. A correct YS carburetor is out of our budget at the moment unless we get lucky, so the WO will have to suffice. So, finally, the compatibility questions:
1. If we use an MB-style air horn elbow on the WO carb, is the inlet diameter of the elbow the same as the outlet of the M38 air cleaner, allowing us to connect the two with a hose or duct?
2. If we add an M38 crossover tube in the path, is there any problem connecting it to an MB carb elbow? Would the MB rubber hose work? Length issue, maybe?
3. If we do score a YS carb, do we need a M38 fuel/vacuum pump to make it work correctly? I'm thinking vac-operated accelerator pump, for example?
Any answers and other insights would be appreciated.
-Jim
