I wouldn't seal a pan with just silicon. It takes too much and invariably some will spoodge out on the inside and end up in the oil pump screen. You have my sympathy to have to lay under a truck and do this job. I have been a mechanic all my life and I can't think of anything on a Ford pickup I would rather not do.
A quick word on oil. Multi weight oils start out as the lighter weight in the rating and then a viscosity enhancer is added to keep the oil from thinning down when it gets hot. 10w40 oil is 10 weight with a viscosity enhancer so it is supposed to act the same as 40w does at a certain high temp. Well it actually doesn't plus the fact that the visc. enhancer is the first thing to break down in oil. A healthy engine and especially newer ones are quite happy with the thinner oils and actually find a few horse power from running it. I think many of the Winston cup cars now run 10w30 so that tells you something. Tired FEs still like straight weight and I have even ran straight 50w in some. I have hadf a few tired 351m-400s and 460s too that the oil light would flicker when idling. I would put in 40w and tweak the idle up just a little so I could sell it without someone freaking out about it later.

 

Yeah I was feeling kind of bad for him down there and with no gasket, that's why I suggested to goob it and go.

Barry

 

Also a couple of tips to ease the pain of this nasty job. Getting the pan wrestled back up in there with the gasket intact can be a problem. Here's how I put many gaskets on. Clean the part to be bolted on. In this case the oil pan. Then glue the gasket on with gorilla snot (3M weatherstrip adhesive). Let it dry good and the gasket will not move. I also apply a thin film of good silicon to the side of the gasket that goes to the engine. This makes a nice seal and if you ever have to take it apart again the gasket comes off with the part you unbolted and you dont have to chisel a petrified gasket off your block, water pump housing or whatever.

 

my 360 was rebuilt 2 years ago. i get 50+ when cold, once warmed up i get 30 and at a stop light i will show 7-12. i read from someone else that a low pressure is a sign that the engine is warmed up. i used to worry about mine, did oil change after oil change using different weight oils and filters, now i just let it run. change my oil when it needs it and quit worrying about it

 

I've got the opposite problem.
I just picked up a 74 High Boy with a '70 390 in it. The pressure gauge reads high anytime it's under a load, even when hot. I suspect it's just the sending unit or the dash guage isn't all that accurate, but still it bothers me.

This motor had the heads and lower end reworked a few thousand miles ago, so I'm hoping it just means the guy did a good job on the bottom end.

Bugs me, though, cause it coughs out a nice puff of oil smoke when I step on it after I've been engine braking. I.e., When I let off the gas for a bit and then step on it I blow a smoke ring in the face of the Chevy I just passed. Does this sound like rings or perhaps valve stem seals? The truck had been parked in a barn for awhile when I found it and I'm hoping it just needs to have the oil circulated a bit... (not holding my breath till the smoke clears, though).

Could the high pressure indication and the smoke rings be related?

 

Well, it sounds more like valve guides or seals but if the high pressure is real then I suspect you're flooding the top of the heads with oil. Maybe pull off a valve cover and take a look.

Barry

 

hey ....one of my 390 thats bored out...well runs like a top no tic or tocs just the sounds of good running 390...at an idle the oil pressure bout 25 sence its been bored think i should get diffrent oil pump stead of stocker.....just wondering either that or the line broke again...what you think?

 

25 at idle? What's the problem and what line do you mean?

 

guage line you think thats cool...25 at idle?

 

An FE with 25 at idle, you're lucky.

I had a gauge line blow out of my Falcon once, what a mess!

Barry

 

yea me to cept was your in the car mine was the half in the cab my buddy tighted it to much and it pushed to hard and blew all under the dash and pedal and i was driving so all over my boot and pants lol

 

Yep, right out of the gauge that was hanging below the dash. I went electric after that incident and a new carpet.

 

Hey BB, What would cause it to run high pressure and flood the heads... clogged return passageways? Is that something I can blow out with compressed air or maybe clear out by poking at it with some bailing wire?

I just had the covers off a few days ago (fixing up some leaks) and the heads looked sparkling clean. The covers themselves were a bit crusty. The heads were just redone, ergo the discrepency. This motor blows oil out at the timing cover, as well... a couple quarts in 70 miles! No drips when it's parked, just oil squirting out at the seams under power. Plugs look good and no smoke, other than the aforementioned puffs when coming off the downhill side and starting up another hill. It was doing this when I bought it and since it had been sitting unused for some time in a barn I thought it might seal back up when it had the oil circulated for awhile. I rinsed it out with some seafoam and changed the oil and it came out relatively clean (ran it a few minutes with some seafoam, drained the oil and then poured a bit of seafoam through it with the drainplug out to wash any crud off the bottom of the pan... it ran through pretty clear and no gritty junk in the bucket.)

There was a big mouse nest in the heater, complete with a mummified field mouse. I hope I don't have another one in an oil passage somewhere. 8^0

Whaddya think? Plugged artery or has my oil pump been smoking crack?

 

The high pressure is bugging me. It's possible the pressure relief valve in the pump is stuck. You'd have to pull off the pump to fix that, don't know if seafoam would get it. Is there a lot of blow-by too? That would be your rings or the intake manifold is leaking underneath where the exhaust crossover is. If there is, that would also explain the timing cover or they forgot to put the slinger back on.

Barry

 

I don't think there's a *lot* of blow-by. I pulled the oil filler cap off and revved it and didn't feel any breeze coming out. Hmm... I suppose I should check this on the pcv side...? If it's building pressure under the covers from blow-by, wouldn't that get equalized by the vacuum through the pcv?

Anyway, whatever's causing the high pressure, it doesn't seem to be *immediately* destructive. I made four 70 mile trips in the past two days (at the expense of 30 gallons of premium and 6 quarts of 10-40!) and it hasn't started to clatter or knock.

Could be that the pressure guage is just a bit sensitive. It starts out cold just on the safe side of "H" and when hot, at idle, will settle just above halfway. But, even when hot, under load it will get pretty close to "H"... about 7/8 of the way there.

The leak around the timing cover doesn't literally spray out... it just leaks really well. Let's just say the front of my heads and rocker covers are well protected from corrosion... I'm thinking that I could look at this as an advantage. No oil changes.. just swap out the filter now and then... Damn shame those timing cover bolts can't be gotten to without pulling that water pump. So close and yet so far.... I'm sure that if I could give 'em just a half a twist I could cut my oil bill by 75%.

I'm thinking of renting this oil sieve out to folks around here with unpaved roads for dust control. "Fill the crankcase and make a few passes through the neighborhood and you'll be lookin' good."