1937 Dictator Cylinder Compression

[Studebaker1965]

Hi All,

 

What should cylinder compression be on a 1937 dictator with the six cylinder in it.  I believe these are 218.8 ci engines.  I checked mine today by pulling one plug at a time.  I didn’t have throttle or choke open.  I got between 85 and 90 psi with one cylinder at 80 psi.  The car runs rich but my carb is likely out of adjustment.  It runs good, but at idle has a miss occasionally.  I didn’t check timing yet.  I am trying to decide if my original 72000 mile engine is tired enough for a rebuild.  Should a leak down test be done next?

 

Nate

Edited November 27, 2020 by Studebaker1965 (see edit history)

[hchris]

Could I suggest that you take all of the plugs out, disconnect the high tension lead, keep the throttle wide open, then carry out your compression test; this way you'll get a meaningful result. Typically a variation of about 10% between pressure readings is considered satisfactory. 

 

Based on your other info, pulling the engine would be way down my priority list, a miss at idle could well be ignition or fuel related and I would be working my way through them beforehand. 

 

If you find a significant drop in compression on a cylinder, perhaps move on to checking valve clearances as the next step; I'm sure others will chime in with wet and dry compression checks plus leakdowns etc. All well and good and appropriate in due course, but,  do the simple stuff first. 

[nvonada]

+1 on the simple stuff.  Even with a couple of weak cylinders the car should idle and run well, you will just not get as much power.  And yours look pretty good.  Check your ignition, then check ignition again, then maybe start messing with the carb after you check ignition.  

[Studebaker1965]

Got it. So I’ll check ignition first.  I will replace the points.  It has the original coil and I don’t know where to get a replacement.  Thanks.

 

nate

[nvonada]

Coils tend to be OK.  Mine is at least 35 years old and could be 80 and still works fine.  Wires, points, caps, rotors, and plugs are the big ones and you can get those.  If the coil is bad any 6-V coil should work but if you have that armored cable from the key going to the coil it may have no place to attach to.  Here is a screenshot from a scanned 1939 AutoLite catalog I have, might help in the parts search.