AlanC

What's considered the ideal oil pressure range for an LSx motor?

The stock gauge seems to tolerate a very wide range before the needle is actually "in the red".

I've got a dry sump system on my LS2 based 406 so I have some range of adjustment available.

When my motor is cold I can see around 90 psi. After it is warmed up I see as low as 20 psi when is idling.

What pressure range should I be targeting? At what point is it too low or too high?

I'm currently running 10w-30 Joe Gibbs oil. I'm considering blending in some thicker oil to try to bring the hot idle pressure up a bit, then using the bypass adjustment to lower the cold psi down if necessary.

Thanks,

Alan

Sales4@Texas-Speed

iTrader: (4)

The stock oil pressure gauges are pretty bad and have been known to read wrong on many occasions. A lot of times we will just run a mechanical gauge right off the oil pan. On a stroker motor like yours we usually look for 30-40 psi at idle, and 50-60 psi when running around. For it to see 90psi when cold and then 20 once warm it leads me to think there might be a problem with the oil pump o-ring. We see that issue a lot because they are very sensitive, the smallest nick or pinch can cause those things to leak once the oil is warm.

AlanC

John,

Thanks for the reply!

I'm pretty sure my car doesn't have a stock oil pump (it has a dry sump pump), so I don't think the o-ring could explain the problem (could it?).

I have a mechanical gauge that it attached to the output side of the pump at the filter/regulator. This reading is quite a ways before the motor inlet however.

I'm running AN12 lines on the pressure side and my thought is just that as the oil gets hot it thins out and that accounts for the pressure drop. Another thought is that the bypass valve just isn't working well when the oil is cold and it can't bypass the pressure.

I had a (radiator integral) oil cooler plumbed in when we first fired it up and the pressure drop was worse. We removed the cooler and gained about 20 psi or so.

Also, prior to removing the oil cooler from the system, we swapped a smaller pulley onto the oil pump which seemed to help a little bit.

The low pressure is only at idle. If I give it any RPM the pressure jumps up to the 40-60 psi range almost immediately.

Thanks for your thoughts and suggestions!

Alan