low oil psi

[rd.stick]

Looking for a little help, I am rebuilding a 73 240 had the eng. totally rebuilt everything seems fine runs great. I had a after market cam put in and the cam lobes have oil holes in them but I also have a cam oil tube spray bar and was told that having both will make the oil psi low. when the eng warms up the oil psi is to low at idle. Now I'm just trying to decide on the fix. I was thinking that since the cam itself has oil ports that I could just cap off the spray bra. But was told by a friend of a friend that using just the cam lube ports would increase the psi but would not supply enough oil to the rockers. He suggested upgrading the oil pump to a turbo oil pump Just looking for some feed back. He suggested a 81 model but I wanted to be sure of compatibility. Any help would be greatlly appreciated.

Rick

[SteveJ]

Are you getting your oil pressure off of the dash gauge or with a mechanical meter at the engine? If you're not using a mechanical gauge at the engine, you might want to try that before spending the money & sweat to make changes.

[5thhorsemann]

I saw a pretty trick setup on a car at a show last summer, as I recall it was made by Moroso, but don't quote me. It was an adjustable auxiliary pump that was fitted to the oil filter port. it had dual remote filters and an integrated oil cooler with a pressure gauge on the output. It looked really slick and would mount nicely in an old Z. The pressure adjustment was a simple regulated bypass circut which makes for constant output pressure regardless of oil temp. The mechanical pump in the pan acts as a stuffer pump.

[rd.stick]

I installed a "T" fitting so I could run both a Mech. and Elec. Guages they both read the same

[5thhorsemann]

So what kind of pressure are you seeing?

[rd.stick]

The manual says 14-17psi at idle is minimum at operating temp and 40psi at 2000rpm. I am right at minimum in both ranges about right at 15-17psi at idle and 38-40psi at 2000rpm. Psi is perfect on start-up. I know its low I'm just trying to find the right fix.

[Zforce]

I have been using both methods of cam oiling with the turbo oil pump and I get between 10 and 20 psi at idle. What weight oil are you using ? Ambiant temp is also a factor.

[rd.stick]

I'm using Valvoline VR1 racing oil 20w50 its supposed to have the highest content of zink of any oil out there. Also I'm in the deep south HOT as hell. I get between 10-20 psi also but my manual says it shouldn't drop below 14-17. I'm just worried about long term damage. I'm trying to find out which high volume oil pump will supply enough oil for both methods of oiling

[Zforce]

20/50 is thick as molasses,but your oil pressure is fine. Cams don't really need all that much oil, most of the oil is going to the bottom end. Just look at how tiny the oil passage is going to the head, its like 2mm, don't worry about it.

[ezzzzzzz]

Pull the valve cover, pull the spray bar, tap the holes in the cam towers (3 each) with a 6mm tap about 1/4" deep using bearing grease on the tap to catch the shavings, install 6mm set screws until nice and snug (don't get heavy handed), replace the valve cover. The internal oiling of the cam is fine. Swap out the stock pump to a Melling 111 (about $100) if you want a bit more pressure. I run Rotella T 15w40 and a bottle of GM EOS. My pressure is about 11psi at a hot idle.

[chaztg]

if you want to block the cam tower oil ports, tapping & plugging them is best. An easier method is to buy the block off plates from Motorsport Auto, same effect but quicker to install. They are held in place with the stock oil spray bar's 10mm bolts.

[Bruce Palmer]

My only thought would be that with what you have going on you could be piling too much oil up on top of the head. I had that problem and went back to the non turbo pump and everything was fine.

I think your pressures are fine just the way they are. Even at 5pounds at idle you are still moving lubricant through the engine. You aren't trying to blow the bearings out of the block just keeping things slicked up.