So I took the car on another drive today with the new motor (408ci sb)to monitor everything, and now I have new worries...I gave the car full throttle tonite for the first time ever (I have been giving it quarter or half throttle, just because I am not used to the power and have not really layed into it since it was still fast otherwise lol), shifting through all 3 gears off the light set at 6600rpms...I am running a remote oil filter (wix 51515) with -10AN lines, a kevko pan, a HV pump (standard pressure spring) and about 7-8 quarts of Brad Penn 10W40 oil. Upon jazzing the throttle I hit 60psi, then the oil pressure drops to between 55-60psi....This has me worried since I feel like it should be going up, or atleast staying the same. I am wondering if the pump is not able to keep up with the remote filter and added volume? Last year I ran a stock pump in my 365 with a high pressure spring and running it to 6500rpms I would get a rock solid 70psi throughout a pass (no remote filter though)

Do you think the addition of the high pressure spring would help this issue? At all other speeds, the oil pressure holds steady. I get 60psi cold when I fire it up (used to get 70-80 last year with the high pressure spring), cruising at 40mph all warmed up I am around 45psi steady, idle is around 18-20 heated up. Just looking for some input on this since I think this is a pretty serious issue and I don't want to go eating up bearings. If the remote filter is the problem, I could easily remove the lines and just run a super dinky filter on there...not my first choice (which is why I ran the remote in the first place as I can't even get the short version of the 51515 to fit) but if it will help cure this pressure problem then I will definitely try it...Or would it have to be pump related and need the high pressure spring?

Thanks
Matthew

It your spring on the by-pass... you have 60 psi cold
so thats the pressure its blowing of at... and when
it gets warm it could be even going a bit lower..
what weight oil is in it

Change the filter and see what happens.

my 408 has the same pressures as yours. 18-20 hot at idle,going down the track 55psi,cold idle is about 65-70. been this way for 7 yrs now.

If you are worried about the health of your fresh motor, cut open your oil filter.

Remember the bypass spring is the pressure regulator for the system, like Mike said if it opens at 60psi that will be max.

Oh and thanks for the on the Dart pic thread.

Mine is 40# at cold idle and 18-20 hot,down the track it's sbout 55,been this way for the last 4 years. with no issues.

what bearings in mains? groove??d 1/2 or 3/4? what clearances are mains? rule of thumb is 10psi/1000 rpm.

hey guys,

im running Brad Penn 10W40 weight oil, .0025" on the rods and .003" on the mains (full groove bearings).

It has been suggested to me that I may be running too much oil in the pan as this is just a Kevko pan that only holds 5 quarts I believe...However, to get the full reading on the dipstick with the remote filter, I needed to add more (I believe 7 bottles instead of 5).

What I am most concerned with is the drop in pressure instead of it holding steady at 60, especially at higher rpms, which is when it seems to be happening

I think you are seeing a spike in pressure till it cracks the spring then it's holds steady a little lower. I would run it, I have a little (65psi)more but I spin mine a lot harder then you do.(8000)

IMO, nothing to really worry about, but I would monitor it for any changes - a good thing to do under any circumstances. A slight drop in pressure at rpm is probably nothing more than the bypass spring opening. A good rule of is 10 psi for every 1000 rpm and you are right there. You could try running it a quart lower to see if that makes any pressure changes if you are concerned about airation. Assume you know exactly how much your remote system holds ( hoses and all )? -10 lines can hold a lot of fluid. Hot oil pressure at idle is a little lower than I would like to see with 10/40 and a new motor, but still acceptable and there can be a big difference in pressure between 180 and , say, 240 degrees oil temp. Valve train can also have a big effect on idle oil pressure also. Some leak a lot more than others.

I'd run it, cut the filter open for the first few weeks if you're worried about it.

Are you using the same oil pressure gauge on both motors? If not maybe your seeing a difference between gauges I know a lot of the Mopar SB drag race guru in SO CA do NOT recommend using the high volume or high pressue oil pumps in those motors as already sia on whipping the oil by being over full I always calibrate the oil dip stick to the pan, not vise a versa

I've been running 20w50 Napa oil with a zinc additive the last couple years in my BB. This spring I went to 15w50 Mobil 1. With the Napa oil the gauge would sometimes spike to 80-90 and idle hot at 20-25. With the Mobil the thing will not go above 75 and it hot idles at 40-45. Just something I thought I'd add in here from my experiences.

Can someone explain to me what is meant by the bypass spring opening up? When would it open, why does it open, and when it does why does the pressure drop? I thought under load the pressure is supposed to always go UP, not down some.

Also, I think I am going to try taking away a quart and see what happens. It is a different gauge from last year (Using an auto meter pro comp oil pressure gauge, but im losing faith in auto meter products as I have now had two brand new faulty gauges from them that I have had to send back) but the oil weight is the same as the motor I ran last year, although last year I ran stock volume with high pressure spring. Brian at IMM suggested I run the HV pump in this build, which is why I did

Just think if your gauge is reading high and not low. 18-20 could really be 10-15. Scary thought.

There is nothing wrong with the oil pressure Cut the oil to 6qts total and see what happens. The worst thing you can do is foam the oil with too much in pan. I raced a 340 engine with 40-45 psi total pressure period hot or cold and never had a issue, for years. Just stay away from HV pumps. I prefer to modify the stock pumps

The bypass spring is set to open at a certain pressure, when that pressure is met the pressure overcomes the spring and the valve opens and the oil bypasses back into the pump and more or less recirculates.

The spring is there to pop the by-pass valve open at
a certain pressure... yours is right around 60 psi
and if the spring heats up some it CAN loose a little
pressure... but if it didnt open up you would be stalling
the pump... something has to give or you have breakage..
if you want a bit more pressure you can put a washer
in the end of the spring to stiffen it up some