are there any ways to increase the oil pressure in a 400? other than a higher weight oil?

 

High volume oil pump, theres an increase in 25%

 

Modify your oil pump discharge circuit.

 

We could help you a lot more if you would elaborate. Are you building an engine and want to improve the lubrication system, or are you talking about an older engine with low oil pressure?

 

its an older engine and am just trying to improve the oil pressure any way i can im using 10w-40 right now and when i get off the highway oil pressure drops below normal operating pressure i wish i could tell you the exact pressure but all i have to go off of is my dash gauge ive already replaced my oil pump and sending unit however i havent gotten a hgih volume pump i will try that

 

Oh, here we go...depending on 30 years old factory gauge.

It's nothing more than a variable idiot light!

Get a mechanical gauge on it before you throw any green on it!

 

if its above 15 psi... i wouldn't worry about it on a stock 400.

 

Ive heard around here the general rule is 10 psi for every 1000 rpms, so in iddle (600 rpms - 800rpms) 6 or 8 psi would be enough....

 

you should've tried the high volume oil pump and instead of a standard but that was then. sounds like it's time for main and rod bearings. if the crank is original and still standard size you can get +.001" mains. the front cam bearing also plays a role in oil pressure. if it's worn out maybe you can get by with just replacing the front cam bearing but it important that it gets installed right, .003" back from the edge of the block.

as mentioned you can get by for some time with marginal pressure and thicker oil. i had a car i'd mix oil to get 'medium heavy', like 3 quarts 10-40 and 2 quarts 20-50

 

alright i installed a mechanical gauge and at idle it gets to about 5 psi and there is a knocking noise also i have dual exhaust and there is white smoke coming out the ride exhaust pipe i bought a new oil pump new rod and main bearings and a rear oil seal all will be installed tommorow the bearings i bought are just stock size atm should i plan on .001 bearings instead?

 

forgot to mention that on cold start psi is at 45

 

sounds like it's time for head gaskets too. technically the crank should be measured before throwing +.001" bearings at it, it's your call...

standard or high volume pump?

 

high volume and its got a brand new head gasket already as i was working on the heads before this happened

 

clark is right, .001 under bearings on a worn crank is NOT a good plan. Crank pins almost always wear flat, or egg shaped. They don't wear the same all the way around.

Yes, with white smoke you need to do some more analysis on this engine. A quick and easy place to start would be to pressure check the cooling system.

 

also when i got the new head gaskets there was a coolant hole that the new gasket didnt have a hole for but i didnt think it would be a problem since the old gasket was the same way should i go back in there and cut out the holes and reseal the heads?