oil pressure fe 390

[Carnut427]

Originally Posted by BigAl

...If this makes you feel any better check out Chevrolet's minimum oil pressure specs. for new truck.

1000 RPM-6PSI min.
2000 RPM-18PSI min.
4000 RPM-24PSI min.

Don't compare bearing clearances or oil pressure needs between the FE and other engines...the FE, with it's large connectiong rod bearings, requires special attention.

MaSnaka, a look under the intake to check for an internal oil leak might be wise. You can spin the oil pump shaft (I use a bare distributor shaft) once the intake is removed. If you do decide to "just run it", I personally wouldn't do much spirited driving; you're likely to end up with a pile of rubble. As mentioned before, all any of us can do is give advice based on our own experiences; the final call is yours.

[SCOBRAC]

Put in a high pressure pump if it makes you feel better...

[tpiini]

I guess I should have been more clear. I too would suspect that things are just worn. ie, excessive bearing clearance. BUT... I'd sure check the galley plugs. Just in case. If they HAVE been left/popped out, your fix is simple. If they are there, well, I agree that you should just drive it & plan a rebuild sometime in the next 10k miles or so.

[Jerry Clayton]

While you had the pan down to replace the pump, didn't you check the bearings? If the engine had any amount of miles or I wasn't sure of its history I would have checked the bearings---we used to do that between rounds at the drag races and back then we only had 45 minutes not 75 like these days

Jerry

[Carnut427]

Originally Posted by Jerry Clayton

...If the engine had any amount of miles or I wasn't sure of its history I would have checked the bearings...Jerry

While I don't disagree with your thinking, the reason I haven't jumped on the "worn bearing" bandwagon is because motors in Cobras don't usually have enough miles on them to justify the thought. Improper assembly is another matter.

Dan

[Jerry Clayton]

The man said he purchased a used cobra with a rebuilt 390--who rebuilt it , when, how thoroughly, and how much use after that????

IF I HAVE AN ENGINE WITH LOW OIL PRESSURE AND I TAKE THE PAN OFF I WILL CHECK THE BEARINGS!!!!!

The FE engine family have the same needs as all other engines--too much side clearance is not a problem unless the rod bearing has too much clearance--the rod bearing clearance controls the oil flow, not the side clearance--if the mains have too much clearance the rods won't get the oil to begin with and if they are too big the problem gets bigger
Cam bearings more of the same--

There is no need for high volume/high pressure pumps in the fe engine--if things aren't right they ain't right--fix the problem not the symthom

Jerry

[Carnut427]

Chill, Dude...reread my post and you'll see I only mentioned that most Cobra motors don't have enough miles to have worn bearings, I didn't disagree with your line of thinking. It appears we do disagree with some of the special needs of FE engines, and I can live with that. Perhaps you could try to do the same?

Dan

[MaSnaka]

Jerry,
I will be taking the pan off again. How do I check the bearings? As I mentioned in my first post I am somewhat novice in the knowledge and experience dept. Doesn't mean I'm stupid just that this is my first project car and I had a limited budget to work with. I'm learning. I could tear your house down and rebuild it with my eyes shut if you need some help in that area. I could help. That goes for all of you helping me with your engine advice. When I had the pan off and laid under my engine I was in awe that I could see the internal parts, crank, rods, pistons. It was beautiful. I know...ROOKIE! Unless something was blatantly wrong or fell off in my face I don't think I would have recognised a problem. After I replaced the pan, and yes I used a gasket and ample sealer, I have a bit of an oil leak dripping out the rear end of the pan and bottom of the bell housing. I was thinking my rear main seal is the culpret. Is it possible that removing the pan upset the rear main seal? I also noticed a leak on the backside of my intake manifold. I am planning to remove the intake manifold to replace/seal the gasket there and will check the plugs in the lifter valley as tipiini suggested. All you guys chiming in here have certainly given me much to think about. Thanks a bunch. I mean that!! It's great to have this forum.

John

Classic Roadster
Silver no stripes

[Jerry Clayton]

Dan and John

First I wish both of you would put where you live in your profile--maybe your just down the street from me or each other--
Dan - I did reread your post several times-and mine-I was in a rush to go to a neighbor hood meeting about all our wells and being anexxed--
And you said twice that you didn't disagree with my thinking but that we did disagree--which is it? I don't know how experienced you are about finding reasons for something being the way it is--but the FACTS in this case are low oil pressure--Bad Guage? or really low oil pressure?/
John had the pan off the engine--he replaced the pump--if he had any experience he would have checked the bearings--now he has still got low oil pressure, and he has to take the pan off again--if we knew where he lived, maybe someone could go help him out-
And I am totally a chilled out dude--thanks for the concern
And further, maybe you could enlighten me on the need for all this high volume/high pressure in a FE engine--didn't need it in 58,still don't need it now--

John- you will need to remove the bearing caps to check the bearings-you can mike the rod journals to see there size and check the back of the bearing shell to see if they have the proper size insert installed--check the appearance for shiny spots, dull areas, scratches,etc--if your rear main is worn the rear seal will never stop leaking until you get control of the clearance--it takes some experience or beginners luck to change a rear main seal--don't forget to torque the bolts to spec

Need more help PM me

Jerry

[MaSnaka]

Thanks Jerry, I'm in Thousand Oaks, Northeast of Los Angeles California by about 30 minutes...10 minutes Cobra time. If there wasn't any traffic that is. Thanks for your input.

John

Classic Roadster
Silver no stripes

[kbisconti]

John, Don't let this FE Stuff get you down. We're all like practicing Doctors and Lawers. We're just practing FE's. Cobra's are a on going project. Everyone has there two cents worth of advice. Listen to everyone and learn. Just drive your Fe and have fun with it. If you don't run it at high RPM's for to long periods of time. It will probably run fine for a long time. I have had friends even with 427's with low oil pressure and they just lived with it until they wanted to rebuild and upgrade the whole engine. Like one guy said, there just rough tough truck motors. They are work horses. If you not pushing much over 400HP they are pretty tough. Good luck and enjoy! Ken

[Carnut427]

Originally Posted by Jerry Clayton

Dan...I did reread your post several times...Jerry

It appears a course in reading comprehension would be of help to you.

[Excaliber]

I would NOT suggest a guy new to motors attempt to read and interpret the results of a micrometer reading on crankshaft journals. This assumes he even HAS a micrometer!

Wipe the oil off the crank journal, bearings, rod surface etc. so it's clean and dry as possible and use PLASTI GAUGE to take a reading.

Low pressure could be a HUGE number of things, like bad\worn cam bearings, which you CAN'T check. I'd PLASTI GAUGE the main bearings, as they are more suspect than the rods actually. I would NOT check the rear main bearing for fear of upsetting the rear main seal. Which may not be leaking at all. Oil on the bottom of the pan, rear, could be valve cover or as mentioned, rear of the intake manifold.

And don't get me started on PLASTI GAUGE, if your not using it I wouldn't let you near MY motor! DO take your mic readings, do the math, calculate the clearance and CONFIRM the readings using Plasti Gauge. What? Your SO good there is NO WAY you could possibly make a mistake doing the math on your Mic readings? And pigs fly! I won't take chances, I'll double check, only way to be sure.

[Jerry Clayton]

Carnut427
I not only reread your posts on this thread but read most of your posts on the forum and the impression that I got was---well, maybe I shouldn't go there--I believe if my reading comprehension is in need of a tuneup--that quite possibly you should be in the writing class across the hall.
Still I would like to see the location of all posters listed--I still don't know where your located.

Slick--modern engine work is done with micrometers, dial bore guages, etc. not plastigauge--I haven't had a piece of plastic guage around anything I've worked on in over 30 years--however,I have had people come to me with cranks, blocks and rods that they had checked with plastic guage and thought their clearances were off(generally tight) where we took mics to check the crank size and setting fixtures to set dial bore guages to verify the bearing clearances.The plastic guage is at the very best, extremely inaccurate. If you wanted to double check my work, I would not be upset, but it would elevate my opinion of you as wanting to have it right.( I'd do the same)

John--If I wasn't so busy, I'd come out there to give you a hand, but My son Corey has jury duty for a few weeks on a murder trial and I can't get away-maybe we can find someone near you to help--What is the capability of the shop that told you about your low pressure-can they help?

Jerry

[Excaliber]

MsSnaka is hardly at your level Jerry, give the guy a break.

Recent example of why you should use it. Experienced engine builder in our local 'race shop'. Sends the crank out for grinding, gets it back on a Friday, race day Saturday morning. He HAS the mics AND the experience to measure the clearance, he thinks he doesn't have the time (foolish eh?). He drops in the crank to my FRIENDS race engine with NO measuring. I let him have it with both barrels, at the very LEAST use Plasti Gauge to see if it's in the 'ball park', which he did, and it was. He was trusting the machine shop to get it right, (I trust no one)! If I was doing the engine I would have mic'd it AND used the Plasti.

As fate would have it, the used crank he selected for the build was wrong anyway and would not accept the flywheel. Race day didn't happen, other stuff happens when you don't pay close attention.

Richard Hudgins (JBL Cobras) uses Plasti Gauge and MANY other top notch race teams use it as well, as the FINAL step. It IS as accurate as the guy using it, which is also true with micrometers! EASY to make a mistake in either case.

[MaSnaka]

Thanks for the pep talk Ken. I will probably keep driving while I iron out some of my car's wrinkles here. Damm if I will park it...it's California legal. I have a pile of reciepts I will look through to see what clues I can find.

Jerry believe it or not I do have a Micrometer. Inherited several from my Grandfather. He never showed me how to use them though. Never heard of a plasti-gauge until today.

Excaliber, Thanks for the support. I'm trying to figure out where you put your surfboard racks on a Cobra? Just kidding.

About all I can do now is some homework and report back what I find. You all have given me a pretty good idea what direction I should go and where to look.

John
Classic Roadster
Silver no stripes

[kbisconti]

John, Hope you can make it to "Westerns States Cobra Bash" in Sparks ,NV. in May. Over 100 Cobras's and some venders. Tom Lucas from FE Specialties will be there to show some engines and answer questions. Ken

[Barry_R]

Fun to listen/read about FEs needing special treatment and tons of oil pressure. Sadly its just not true. FEs have their quirks, but they behave and react exactly like every other engine. And they dont need very high oil pressure to live.

I have made thousands of passes with mine over the years, and never see anything beyond 60-70 psi hot at any RPM. My Engine Masters FE made 752HP on 91 octane, survived 3 consecutive pulls on the dyno, and had only 50 pounds +/- a few all the way to 6500RPM. I suppose if I had 10 at idle my teeth would be chattering too, but 30 is plenty. If you open it up I'd check the bearings - - its too easy - - and I might cut the oil filter open to see if anything metallic is getting caught in there...

[rblong]

Also be careful what filter you use. I used a Fram that was a stage II or something like that. Great to remove very small paticulate, but at a hell of a pressure drop. I went back to standard oil filter and pressure raise 15 PSI across the board. I know this isn't too techy of an answer, but I believe in treating the easy stuff first.

[Carnut427]

Originally Posted by Barry_R

Fun to listen/read about FEs needing special treatment and tons of oil pressure. Sadly its just not true. FEs have their quirks, but they behave and react exactly like every other engine. And they dont need very high oil pressure to live...

Some clarification is needed on this issue. We’re comparing apples, oranges and grapes.
The “top oilers” all Fes except 427 side oilers with standard FE-sized rod bearings of 2.438”,
“Top oilers” using cranks with BB Chevy-sized rod bearings of 2.200” and a bit wider than the FE bearing.
427 side oilers with standard FE-sized rod bearings
427+ side oilers with BB Chevy-sized rod bearings of 2.200” and a bit wider than the FE bearing.

I’ll give in to your oil pressure requirements on side-oiler blocks when using cranks with BB Chevy rod bearings. However, the others are a different animal, and IMO especially the top oilers.
Most machine shops, where a lot of engines are built, build more Chevies than anything else, so they know what clearances work on them. Along comes a top-oiler FE, which oils the cam first, then the mains, and finally the rods get their oil from the oil pressure surrounding the main bearing. Add to this their larger diameter rod bearing. Using the rule of thumb of .001 clearance per inch of diameter, the standard FE naturally needs more clearance than the Chevies most shops are used to. Also, with a larger bearing size comes more surface feet per minute, meaning there is more friction on any given spot on the rod bearing because of the larger diameter of the rod throw. If you’re building a stock or mild top-oiler, everything will be fine. However, modify your heads, put on a good intake and add a cam so that you’re pushing 6000 rpm or more with it’s higher hp, and you’d better make some changes to the stock oiling system if you want the motor to live. If Ford thought it wise to increase the oil pressure to over 100 psi on the side oilers, doesn’t it make sense to make the same modification to a high performance top oiler? I certainly think so, and IMO high volume pumps are a given in anything except your standard grocery getter. They’re cheap insurance.
Obviously, everyone isn’t going to agree with me, and there’s nothing wrong with that. The better oils available today help considerably, especially the synthetic and diesel oils that still contain zinc.

Dan