[Steve V]

I spoke to a man at TA Performance. I told him my mians were .0018-.002 and wondered did I need a HV pump and could I run 20w-50(it's in there now). He said I could run a HV and not to be too concerned about the clearence being on the high side. He also said to run the 40lb spring. He assured me this would not affect idle oil PSI. swapped the spring and no difference at the guage.His reasoning was the stiff spring makes the pump work hard and create a lot of back pressure. The 40lb spring would take care of that and my cam bearings and sensor drive would be okay. So since I get about the same oil PSI as MPH in 3rd and 4th gear I will be mostly running with the bypass open???Does this make sence??To me it doesn't. Let get some opinions. eek!

 

[CallMeMud]

I have had almost .003" on the mains and never had a problem. In fact it is still running to this day. And the oil pressure was 18 PSI or so at idle hot! I have always used a 60 PSI spring in the pump at the minimum. What do you get cold for oil pressure when you start it? That is where my concern with the spring would be.

 

[Steve V]

At idle 60 psi 700-800 RPM going down the road it'll go above 80 psi until warm after it's warm 70 when I am on it.

 

[CallMeMud]

Sounds fine then....rock on headbang

 

[Steve V]

I was hoping for some other opinions,not say anything against Mud I am getting my new front cover together and want it to be correct the 1st time.

 

[Steve Wood]

We always fall back to the old magic number of 10# per thousand. Therefore, I would use the 60# spring. This is the high pressure bypass spring and has no affect on your idle pressure as you were told.

Clear as Mud?

 

[Steve V]

Okay Steve,now iy your motor had the main clearences that mine has would you use the HV or stock pump.I am going to switch to Mobil 1 15w-50 when I install the new cover,with properly clearenced gears!!! powersix

 

[Steve V]

iy should be "if"

 

[Steve Wood]

I would use the hv pump kit, but, not the high volume cover.

I don't believe in large clearances for street engines that don't turn high rpm, but, I am probably in the minority.

I have never figured out why the factory can send engines out with clearances of less than .001 and they run 200,000 miles with no problems and then we rebuild them with .0025" and they don't last all that long.

Now, the Power Manual suggests large clearances on Stage engines and everyone follows that, I think. However, those engines were turning 8500 rpm and the bearing speed was high which heated up the oil. We ain't got that problem. I also think some of the restriction of the oil to the top that is suggested is due to the high rpm that was anticipated. Lots of difference in 5500 rpm and 8500 rpm.

I have seen lots of engines with .002" tolerances, and more, that had great oil pressure so I would not be concerned about oil pressure as long as the pressure jumps up with rpm. Also remember that there is no load on the engine at idle so idle oil pressure is not much concern as long as it jumps up with rpm when a load is on the engine.

The factory does not turn the light on until 4# as I recall.

 

[Steve V]

Thanks Steve great info,I remeber reading something about #4 also. cheers powersix