FE Engine Oil

[1795]

Originally Posted by Large Arbor

Gents,

I am not critiquing anyone's choice, I was just curios with what others are running. I like the higher pressure and it can get hot and muggy here in Columbus in the summer.
The Rotella Synthetic works well and I never hear lifter noise. I do have small leaks around the valve cover and rear intake seal. No crank seal leaks. I know that from having the flywheel ring gear replaced last year.

Would it be accurate to state at running higher pressures you would have greater leaks? It seams like a double edged sword. If you run a lighter oil it would thin out when warmer. That would seem to make it more prone to leaking. If a heavier oil is used, it seems that pressures would be higher. Is it just me or wouldn't you want something in the middle? Not trying to start a conflict here. As a novice on this subject, I just trying to think if its worth trying something different.

Phil

Phil,

I had asked that question of my mechanic last year, wondering if running a heavier oil at higher pressures could lead to gasket failure and his take was that our engines do not produce enough pressure to blow a gasket out that was properly sealed. He runs 1200 hp in his drag race car and has not had an issue with too much oil pressure. I imagine there are downsides, as everything tends to be double edged.

Run what works in you engine and only consider a change if problems start.

[blykins]

Well, there should be no gasket in an engine that's in front of oil pressure. Every gasket and seal should only be exposed to splash and fluid level only.

[RICK LAKE]

Guys there are a couple different types of oil leaks
Lets start with the rearmain seal on an FE motor. If it's a rope seal, they are designed to seep or leak at the crankshaft. This helps keep the rope from drying out and from heat and really leaking. Most of the builders here now have a 2 piece Rubber/Plastic seal for the crankshaft. Most FE's don't mark their ground any more. Installing the seal in a clean and correct way and allowing the RTV 24 hours to cure, with the rotation of the seal being 10 to 20 degrees off the flat of the block should product no leak. Rope seal will seep over time.
Blowing out a gasket, I have done this on a gm product but not on an FE motor, if you call an Shelby block a true FE motor. This was from running a 10-40 oil. I have had cork gaskets break out over time. Had an oil fire at the last R&G. No damage just the oil hitting the headers. I run a PCV valve and breathers on the motor and have little pressure inside the motor. It just cracked out from age. Mechanic got cheap and reused 1 too many times.
If you blow out a gasket in a low pressure area, your motor is failing or your pcv or valve cover breathers are not working. Some guys are running vacuum pump systems the will not allow pressure to build up in a motor. Dry sump systems work the same way with less vacuum building up in the motor. A gasket that is weak to seal could get sucked in.
Bottom line is proper assembly, clean area, and I use HI-tac on all my motors and the basic cheap old Fel-pro master gasket set. The gray RTV for all sealing corners. Last note is warning up a motor before driving it on the street or track hard. If I took out my motor with running about 130 psi oil pressure it could do some damage, blow a gasket, or break the oil pump drive or distibutor gear.
I run rolleta 15-40. I do get a leak at the rear main seal because I run 1.5 quarts over fill and it leaks out when the motor is not running. level drops with motor turning and leak stops. I go a season before changing oil. My whole system with lines, accusump, oil pan hold just under 13 quarts. Run a Fram oil filter. That's it. Rick L.

[sea2jet]

If I'm understanding this correctly, bearing clearances dictate the weight of oil you should run. But what if you don't know what those clearances are? Joe Lapine built the motor in my Cobra. I'll give him a call sometime to see what he recommends, but what if you don't know the builder? Is there a certain pressure hot and cold that will be a tell tale sign?