oil pressure for 427 aluminum block

[patrickt]

It wouldn't be as much of a nuisance if the engine wasn't already delivered, installed, and running in his car. It's not like a case of "my horn won't blow." Considering how much dough we drop on these POS FE engines, you would think they would all be burned in on the dyno, run in nice and hot, and pressures and leaks checked and double checked. But NOOOOO.... But wtf, I'm not even sure were it came from.

[Bernica]

Patrick,
Take a breath and don't stroke out on us. We need you!
It is what it is, and he needs any help and/or advice we can provide. Yes, it may suck in the end, or maybe not. I think we all owe it to a fellow member to chase every corner. That's why we are here, right?

[ERA Chas]

And the OP?

[brettco]

Put some 10/40 in it and check the gauge.

[flipscobra]

I have a Shelby block it holds about 75 lbs at start an runs about 60 lbs when hot an idles at about 45 to 50 lbs been holding this for 7 years. I run 20W50 racing oil. Great motor Flip

[Al G]

Coach Mike - Since Keith built your engine have you asked him what your oil pressure should be?

[COACH MIKE]

Thanks for info. I will contact builder. Mike

[olddog]

It may have a thin break in oil, in the engine, and we still do not know if the gauge is accurate. To early to tell if there is a real problem.

Warm idle oil pressure will drop off the most if there is a lot of clearance someplace, but it is not necessarily a good indicator of the likely hood of an engine failure. I have had people claim that the oil pressure at higher rpm is more indicative of will the engine fail.

I had an old junk truck I used to haul firewood. It idled at 5 psi and only carried 30 psi at high rpm. I ran the crap out of it for 7 years. It was drove to the junk yard under its own power. I realize this does not compare to a $12+K FE. Just saying people may put more focus on oil pressure than it deserves.

[patrickt]

Originally Posted by olddog

It idled at 5 psi and only carried 30 psi at high rpm...

FEs were absolutely notorious for low hot idle pressures. For the most part, it meant nothing. Just like the "commercially acceptable" amount of oil that would leak from them.

[Bernica]

Originally Posted by patrickt

FEs were absolutely notorious for low hot idle pressures. For the most part, it meant nothing. Just like the "commercially acceptable" amount of oil that would leak from them.

Yep, I've had 390's, 406's, and 427's back then. That's when we all ran plain old 30-weight and the tolerances were pretty loose, compared to these days. Oil pressures were 30 psi at best, and sometimes much less. Oh, and they all leaked oil from somewhere. That's why we all had those sheet metal drip-pans under our cars.

[Cobra #3170]

FE's and old Harleys have a lot in common.

[Eljaro]

A few months ago I received my new KC482 Pons Sideoiler block with the new forged crankshaft.
After assembling the engine and installing it in the car I was surprised at the low oil pressure I was getting.
I drove the car for about 30 minutes do do the break in and when hot at idle oil pressure would come down to less than 20 PSI with 20-50 Oil. This being a new engine I knew something was wrong.

I drained the oil , removed the oil pan and found one bolt from the oil pump cover laying in the oil pan and the other 3 bolts of the Melling HV oilpump could be undone just with the fingers.
Luckily the oil pump is submerged in oil, so it did not take in air, but some pressure was seeping out of the cover.
I took the oil pump cover to have it shaved flat and installed it with the bolts tightened at 19 ft/lb torque using red locktite .
Pressure is now 40 PSI at idle and very stable across the rpm band, between 40 and 60 psi hot.
The bolts on the Melling pumps as they come from the factory may not be tightened as should so I would check that.I also removed the aluminum tag with the model code.

[ERA Chas]

Originally Posted by patrickt

FEs were absolutely notorious for low hot idle pressures. For the most part, it meant nothing. Just like the "commercially acceptable" amount of oil that would leak from them.

Pal-Please stop dragging out the ancient history lessons. That stuff doesn't apply to the 1.2 to 1.5HP engines we (well most of us ) have today.
We use small journals, bearings, better rings and much tighter clearances. Plus oil is 1000 times better.
Only the newbs are impressed with you archival skills...
that's not helpful info anymore.

[patrickt]

Originally Posted by ERA Chas

Pal-Please stop dragging out the ancient history lessons.

But one must have an appreciation for whence forth one has been in order to appreciate the journey. Much less what lies over the horizon.... And besides, Bernica likes it.

[ERA Chas]

Originally Posted by patrickt

But one must have an appreciation for whence forth one has been in order to appreciate the journey. Much less what lies over the horizon.... And besides, Bernica likes it.

[Bernica]

Thanks Chas. I am out. Good luck Mike.

[COACH MIKE]

I took the cobra out again and warmed to operating temperature. Oil pressure was around 20 lbs at 1100 rpms and responded quickly to rpim increases. 40 to 50 lbs between 2,000 and 2,500 rpm, up to 60 quickly at 3,000+. 60 lbs plus at anything approaching 4 to 4500 rpm. Spoke with Keith Craft and he assures me this is the tendency with the aluminum blocks he builds. If there are any problems he will take care of it. I have every confidence in Keith since I have had two other engines from him and they have performed flawlessly. Also, have two other friends with engines built by Keith and have had no issues with those engines either.
I appreciate everyone's input. Always intersting to see the wide variety of knowledge available on club cobra.
Coach Mike

[COACH MIKE]

Took the cobra out again yesterday and warmed to operating temp. Oil pressure response quickly with any increase in rpm's. 35 to 40 lbs at 2,000 rpm, 45 to 50 quickly at 3,000 + and 60 lbs to 70 at 4500 and up.
Keith Craft explained this was typical for his aluminum block builds. If there are any issues he will take care of it. I have every confidence in Keith. I have had two other engines he built with no problems and very good performance.
Also, two friends he has built engines for with the same good reviews.
Thanks for all the information. Very impressive the wide variety of advice available on club cobra. Much appreciated.
Coach Mike

[COACH MIKE]

Sorry for the double reply. Thought the first one got kicked off and tried to remember exactly what I posted. Again, Thanks much. Will see how it runs down the road.
Mike

[Bernica]

Congrats Coach Mike. Sending you a PM.