<VV> oi pressure revisited

[Daniel Monasterio]

If hot idle (600-700 rpm) is 20 psi and hot cruise (2500-3000 rpm) at 22-25 psi, I vote for increasing regulated presure by adding shims or changing the spring as there is no significant change on oil pressure when the oil pump gears increase speed by 4 times. 

Daniel Monasterio

> From: hyarnell1 at earthlink.net
> To: kovacsmj at sbcglobal.net; virtualvairs at corvair.org
> Date: Tue, 20 Sep 2011 17:51:26 -0400
> Subject: Re: <VV> oi pressure revisited
> 
> Stretching the spring will do nothing for the lower pressure you're seeing
> when hot. The relief will be out of the circuit at that point.
> Actually your pressures arn't out of line.
> 
> 
> 
> -----Original Message-----
> From: virtualvairs-bounces at corvair.org
> [mailto:virtualvairs-bounces at corvair.org] On Behalf Of Michael Kovacs
> Sent: Tuesday, September 20, 2011 4:34 PM
> To: VV
> 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. 
>  _______________________________________________
> This message was sent by the VirtualVairs mailing list, all copyrights are
> the property
> of the writer, please attribute properly. For help,
> mailto:vv-help at corvair.org
> This list sponsored by the Corvair Society of America,
> http://www.corvair.org/
> Post messages to: VirtualVairs at corvair.org
> Change your options: http://www.vv.corvair.org/mailman/options/virtualvairs 
>  _______________________________________________
> 
>  _______________________________________________
> This message was sent by the VirtualVairs mailing list, all copyrights are the property
> of the writer, please attribute properly. For help, mailto:vv-help at corvair.org
> This list sponsored by the Corvair Society of America, http://www.corvair.org/
> Post messages to: VirtualVairs at corvair.org
> Change your options: http://www.vv.corvair.org/mailman/options/virtualvairs 
>  _______________________________________________