so i have been working on this m*****f***** for some time now and im stumped. im installing oil pressure gauges and water temp gauges and i am having problems with oil pressure. then i find out about all the different oil pan sizes. i dont know if this is original pan and dipstick. but i dont seem to have and pressure according to gauge. (autometer electronic gauges) first what gauge of wire should be used. second how many quarts of oil do the pans hold. heard 5 , 6, and all the way up to 8. motor has new cam, lifters, intake, seals in the heads, new oil pump new everything but crank and block and heads--all other parts edelbrock performer package. first i blew oil out of dipstick and around oil cap, took oil cap off and no oil squirts out. gauges just dont read and oil at idle but 30 or so when i gas on it. any tips etc would be great thank robert

 

come on now somebody has to have an idea

 

All that new stuff...was the block hot tanked and the oil passages rodded out? Is it a 'high volume' pump?

Was the pan installed compatible with the oil pickup tube?

Was the tube properly secured to the pump and possibly one of the main caps?

New bearings? Clearances checked?

Wire? I can't imagine 18 or 20 ga wouldn't be enough. Capacity? Cars 5 qts with filter, not sure on trucks but then we don't know what pan it is.

Front or rear sump?

 

rear sump and i had a high volume pump and i took it off and put a stock one back on. im sure its on tight and rite but then again i cant tell without lifting motor again. should i add oil and see if it helps or u think its
a bad idea

 

Could be something clogging one of the passages in the block....I know I swapped pans and engines and used the same exact oil pressure gauge and it's always worked just fine....never needed to fine tune or adjust it for changes in the engine.....

 

First:
Are you saying that when you start the engine, you get zero oil pressure at idle, and then it goes up to 30psi if you rev the engine up? But it never gets above 30?

Did you do anything with the main and rod bearings? Did you replace them, or disassemble them, or check the clearances? Or did you just leave the short block alone?

Those symptoms (that zero-30psi thing) generally mean that you've got some worn out bearings in the engine. It could be mains, rods or even cam bearings. Something has too much clearance and the pressure can't build up. So, if you don't already know for sure that the bearings are all good, you may have to pull apart the whole engine and go through it all.

However, there are a couple of things which are less serious, which can also cause that low pressure reading:

You could have a clogged oil pressure sensor. Pull out the sensor and make sure that the little hole in the end of it isn't clogged up. That can give you a funny reading. If you're suspicious of the sensor or the gauge, hook a pressure hose and a 200 psi mechanical gauge up to the same port and get a second opinion. That's an easy way to tell for sure if you really have an oil pressure problem. Make sure the hose is rated for 200psi or you'll have a mess!

Or, your oil pump may be worn out. If it has too much clearance internally, it won't develop full pressure. Did I understand that you had a high performance one on there, and then swapped the old one back on? The old one may be worn out. It also could have a bad internal pressure relief spring.

About the size of the oil pan: As long as you have 5 quarts in there, you shouldn't have any problem picking up oil, even if it's actually a 6 or 8 quart pan. The pickup tube and screen should fit down to about 1/2" from the bottom of the pan. Unless the tube and pan are mismatched, there shouldn't be any problem with oil pickup. Did they look okay when it was apart?

The problem with blowing oil out the dipstick tube is a different thing. That's caused by blowby; cylinder pressure leaking past the rings and causing high air pressure inside the crankcase. It's often caused by rings sticking in the piston grooves from oil varnish buildup. A common problem in an older engine being restarted after a while. It'll often clear up after the engine gets warmed up. That's less of a worry....get your low oil pressure problem fixed first.

 

No FE engine came with a 8 quart oil pan.

1965/66 F100/250 2WD's used a truck specific oil pan (C5TZ6675E): 6 quarts w/a filter change.

1965/66 F100/250 4WD's used a truck specific oil pan C5TZ6675F): 6 quarts w/a filter change.

1967/72 F100/250 2WD's & F350's used the same pan (C7AZ6675AA) as 1967/71 passenger cars: 5 quarts with a filter change.

1967/72 F100/250 4WD's used a specific truck oil pan (C7TZ6675E) AFAIK: 6 quarts with a filter change.

 

i swapped in a new stock oil pump. i replaced the main bearings but i did nothing to the crank.(it seemed liked it was in great condition) had the local machine shop replace the cam bearings and install a new cam. also honed the cylinder walls out, cleaned the pistons and put new rings on.
I was told that because i had a oil fill cap that had no breather on it that is why the oil shot out of the dipstick and blew front main seal. took motor out and replaced seal (again) and put back together and left oil cap off for now.(this is the same time i replaced oil pump with a new stock one)
when i first start motor i have around 30psi (according to this gauge) when i push on the gas(in nuetral(4 speed)) it goes up to 50ish then after the motor warms up it slowly drops to 5 psi and 25-40 when i gas on it. the motor doesnt change in sound doesnt do anything differen except on the gauge.
water temp gauge reads 200 - 210 in my garage when im doing all this a little cooler when driving.
I will take sending unit off tonite a see if clogged 6-9-2010