<VV> oi pressure revisited

[Daniel Monasterio]

By your results with STP, I should add small washers or spacers that fit easily in the piston, instead of stretching the spring. Think that about 1/32" to 1/16" will raise the overall oil pressure. It worked for me. Stretching the spring can work but, you can easily strectch it too much. Washers can be put between spring and cap, instead.

Daniel Monasterio

> Date: Tue, 20 Sep 2011 13:34:13 -0700
> From: kovacsmj at sbcglobal.net
> To: virtualvairs at corvair.org
> Subject: <VV> oi pressure revisited
> 
> Just to see the result, I added a can of old STP I had on the shelf. The idle 
> pressure now at hot cruise sits at about 22-25 PSI, Cruise still starts out cold 
> at 35 (factory recommendation). Hot idle is about 20 PSI. All as I expected with 
> the STP in there. Next is to put mechanical gage on and compare with electrical. 
> Got new standard pump and will eventually get around to pulling parts off engine 
> to replace the old pump. 
> 
> 
>  What effect is there by stretching the spring?  Just curious. I think higher 
> pressure as the spring acts like a pressure relief valve.
> 
>  MIKE KOVACS
> ................................................................................................................................................................................
> 
> 
>  1966 140 pg very well rebuilt engine by me. Balanced, bored, Steadman  heads, 
> mild cam etc.  Clark .010-.010 crank run out almost .000 and  plasti guaged 
> carefully. 10,000 miles, runs very smoothly with strong  acceleration. 20-23 
> MPG.
> 
>   Starts cold at 850 RPM at 35 PSI oil  pressure. After a 20 mile drive with 
> engine now at operating temp, Tach  at about 2900 RPM = 60-65 mph, the oil 
> pressure now has dropped to about  20 PSI. 
> 
> 
>  It will stay there unless the engine is idled back to 750 RPM = 13-15 PSI and 
> is still running smooth and no lifter clatter.
> 
>  Using fresh NAPA 10-40 oil. Clark filter. I forget if I did the oil pump, but 
> probably looked it over and reinstalled. 
> 
> 
>  I  assume the pressure relief valve is the reason for the 35 PSI cold. The  oil 
> press  gage is electrical and I assume it is accurate due to the steady 35 PSI  
> when cold even at cruising speeds. As oil heats, up just a steady  decline in 
> pressure.
> 
>  Suggestions? Should I check oil pump for clearence? Change filters? Check with 
> mechanical gage too?
> 
> By the way I use the same NAPA oil in all four operating Corvairs and they hold 
> about 35 PSi when hot. 
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