Hi people my father just bought a Dodge 1941 business coupe. It has a 1948 230 flathead engine (d24). The problem is that it dosen´t run smoth on low rpm, like it miss in the ignition.. You can here a "tjoff" sound under hood and behind the car at the exhaust.. when come upp at 50mph its get better.. this what is done with the car: New carburator new coil new sparkplugs new ignition cables new cylinderhead gasket can it be a burnd valve? we running out of ideas.. thanks for you time Fredrik
After the machine shop finished all of the machining on my block I mounted it on the engine stand. Then installed all of the valves with out the cam and rotated the block so that the valves were down then filled the ports with paint thinner, marked the ones that leaked then hand lapped the valves until I had a good seal on all of them. The valves will leak if not lapped real good, you may have a valve leaking under pressure that isn't burned yet. You would have to inspect the bottom of the valve head and the seat to see if any are not sealing good.
Hi! we have now adjust the valves with engine running.. they were to tight.. but the problem wasent solved so we took a compression test, there were low compression on cylinder two and six.. But the sparkplugs looks ok, they are not full of oil.. probably the valves or what do you guys think??
If the car had been sitting might have a stuck valve or two but if they all adjusted right that shouldn't be a problem. Chack for a vacuum leak between the carb and the ports. what were the results of the compression check. Are you sure your firing order is correct? Also check the wire in teh dist that conects the coil terminal to the points. Sometimes they wear and will ground out against the dist body. Try pulling plug wires at the plugs with the engie running ( insulated pliesr recommended) and see if you can isolate the offendig cylinder/s.
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