304 oil pressure problem?? Help please

[Immortality]

Good to hear it's sorted.

I think your problem was the fact you let it sit after doing an oil change. On the 304/308's I like to get the filter off and back on quick and don't do it when the sump is empty as it allows the oil to drain back out the pick up as well as out of the front of the oil pump introducing air into the system. I like to start it as quick as possible after an oil change.

I made that mistake years ago and lost oil pressure after an oil change. Tried everything including a new pump, priming the pump with vaso etc but nothing worked. Found nothing when stripping it down. Some fresh bearings/gaskets and it fired up with pressure no problem.

 

[Deuce]

Good to hear it's sorted.

I think your problem was the fact you let it sit after doing an oil change. On the 304/308's I like to get the filter off and back on quick and don't do it when the sump is empty as it allows the oil to drain back out the pick up as well as out of the front of the oil pump introducing air into the system. I like to start it as quick as possible after an oil change.

I made that mistake years ago and lost oil pressure after an oil change. Tried everything including a new pump, priming the pump with vaso etc but nothing worked. Found nothing when stripping it down. Some fresh bearings/gaskets and it fired up with pressure no problem.

Yeah, I think not starting it straight away may have been my first mistake, and I was thinking yesterday that from now on I would empty/fill sump and change filter as 2 separate task's not at the same time.

 

[mr j-man]

Lucky man! Good to hear no major issues.
Ive gone through 3 filters and 3 oil changes since my 355 run in, in approximately 5000km if that and im still getting traces of that black assembly lube as I drowned my lifters and cam in the sh1t.

Ps get a oil psi gauge onto it mate...just a little piece of mind helps to calm the nerves.

 

[Deuce]

Lucky man! Good to hear no major issues.
Ive gone through 3 filters and 3 oil changes since my 355 run in, in approximately 5000km if that and im still getting traces of that black assembly lube as I drowned my lifters and cam in the sh1t.

Ps get a oil psi gauge onto it mate...just a little piece of mind helps to calm the nerves.

Thanks for the feedback on your experience, I also went super cautious with assembly lube, Coated the lifter bases with a couple of mm thick of the special cam lube, and squirted the rest over what was still visible of the cam (just to be sure).

I have run the wiring for oil gauge, I just need to get hydraulic lines and mount my remote filter (as that has the take-off for the sender). Maybe I will move it up my priority list a little, LOL.

 

[Vs hsv manta]

Oil pressure gauge is the only must for a built holden motor, you need to know your pressure at idle while hot!!

Less then 20 at psi hot running temp will eventually present problems, I know lots of factory 5L have the 12-20 psi but a properly built 355 should have 20 psi running temp and on the other site I asked what people had in there worked 355 and all said 20 psi when hot and closer to 30psi cold, one with a mad external oil set up had 25 psi hot and 60psi cold and he is on the high end of the scale making 600+rwhp in a N/A e85 383 and has a heavly modified oil circuit

all used around the 20-50 oil of various brands, most liked good mineral oil over synthetics

Couple people with 5L said they had 15psi hot in a 130-200k near factory motors

Personally I'm using joe gibbs HR1 oil from now on

Get that oil pressure gauge on there ASAP

 

[Not_An_Abba_Fan]

The one I built had about 50psi cold and 25psi hot. Until the block cracked, then it had 20psi hot....