My 60 Parisienne has a straight six in it and I'm assuming it is the 261 Starto six.
The engine number is WR190152.
Can you guys please give me some info. till I find my self a shop manual... also let me know where I could buy a shop manual from.
Spark plug type (NGK if possible) and gap
Points gap
Ignition timing
Valve lash and correct method of adjusting
I have read that this engine should have hydraulic tappets... there are varied opinions on how to adjust the valve lash... I have read on the web different amounts to turn the adjuster after zero clerance. The settings given on different sites differ from 1/4 turn after zero lash, to 1 and a half turns !!
If your 235/261 is equipped with hydraulic lifters, the adjustment procedure is the same, except you carefully adjust each valve to zero lash when it is in position, then give the adjusting screw 1/4 turn more and lock the nut. After all are done you must run the engine and whilst it is idling, adjust any valve that clatters only just enough to make it stop clattering.
Some folks will tell you to set zero lash then 1-1/2 turns more on the adjusting screw; this is wrong, and will result in misfiring and burned valves.
Be aware that the 235/261 engine design isn't good for installation of hydraulic lifters, and once the engine is fully broken in, the oil pressure at idle will not be sufficient to keep the lifters pumped up at idle, leading to clattering valves again. Later blocks have larger oil galleries in the lifter areas to provide the increased oil flow required by hydraulic lifters but normal hot idle oil pressure in these engines is under 20#; this isn't sufficient to keep the lifters pumped up.
I don't have 1960 specs, however I do have complete 1956 specs and I suspect they did not change too much (although one of the guys here with 1960 vintage 261 would be more knowledgeable than me, for sure).
Send me a 'private message' with your email message and I will send you the complete 1956 specs, shows all that you want and more. No NGK plugs though, only AC but you maybe can find a crosslisting.
Dave
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1956 Pontiac Pathfinder 2dr sedan, 496 - dyno'd 545 hp, stick shift, 4.11 posi - Hot Rod