39 Plymouth was running rich

[Briann]

Drove the car around town this summer ran not bad for sitting for years 

was not able to get the idle down rebuilt carb mixture screw did not c do much and was worse when hot plus plugs were on  the hot side 

 

this week I took the head off    

when i took the intake off the middle horn broke off so was sucking air all this time so thats why was running rich and the exhaust had a couple of cracks and as i thought the heat riser was jammed on heating up the intake and not letting out the exhaust out much on 3 cylinders.

that made for harder starting when hot 

the valves are lap in now should be up and running again soon 

 

the spare engine i had will come in handy for the manifolds 

 

 

 

Edited December 4, 2022 by Briann (see edit history)

[61polara]

A crack in the intake manifold pulling in air will cause an engine to run lean not rich.

[Briann]

I got my word mixed up 

it started well and idal was a little hi but after a dive it went up a bit the crack i guess opened up 

plus the gaskets were very old they were most likely never taken off the engine 

 I check for air leaks never found any and vacuum was around 20 

it will be fine now with  the new intake and exhaust 

 

the compression was low on 2 cylinders there was not much gap on the 2 valves in these cylinders and these valves needed to be dressed a bit on my B&D valve grinder the rest lapped in by hand quick