Oil Pressure /woes question....

[castone001]

Hey folks,
78 charger berkely 12jc after 8hours on my new rebuilt 460 .030 over basic build high rise tunnel ram, Demon 750, mallory dist and coil. Driving up from topaq, still in break moide, i.e. nothing over 4,000rpm. Ran the boat for two consecutive days when I watched my brand new autometer elec gauge drop to 0lbs oil. I immed shut off engine. got towed back in.
tried a couple things to verify pressure, ultimately put a mechanical gauge on the block on got 20lbs. welp went ahead and pulled the engine and dropped the pan, found that the oil pump had broken in half just below the flange that bolts to the block. It was being held on only by the pickup tube. Amazin and damn glad I shut the motor off.
OK so put in new high volume oil pump started it up and now get 15 - 20 lbs at idle and 50 -60 at 2000rpm and above with elec gauge, 20 lbs at idle and 65 - 70 with the mechanical gauge.
Now my elec gauge had always read 75lbs at startup for hte first 8 hours of the engine life. Waht gives here? Anyone have any ideas?
thanks much,
Chris
the following scenario occurred.

[centerhill condor]

I'm thinkin' that whatever caused the pump to energetcially disassemble also caused a crack around the oil gallery (not galley). and you're losing the oil at a crack somewhere maybe the pump failure affected the mating surface?. checked the bearings and what not? Did the pump ingest some piece of the engine? why the pump failure? also, today would be a good day for you to buy a lottery ticket Mr. Lucky!

[castone001]

Thanks for the lotto advice I guess I should go get at least one. :)
The break was a nice clean break, no missing ares when you mate the two pieces back together. Didn't check the gallery but the everything looked in order on the visual.
Were thinking that a) the pump was dropped thus weakinging it or b) I got the one in a million with a casting defect.
I talked to the guy that built the motor who told me that 20 lbs at idle then jump up to 60lbs + for a high volume pump is normal? I just never saw that before?

[centerhill condor]

also, what about debris being forced into the gallery? just a thought. As a second guesser I'd try to get the oil to run backwards while the motor is apart..or run a pencil magnet into the passage.. or vacuum..or compressed air from a "higher point" in the oiling looop...but not too much pressure wear the goggles.
You've got it in and running.. the other option is to drive the heck out of it. My BBC, 20 years old as it is, hasn't had less than 40 psig indicated at any time... the thing is you have oil pressure! how 'bout some lucky numbers?
(run it)

[LakesOnly]

Castone,
Two things may have happened:
1) You changed oil pumps. They are not all the same and one pump to the next will vary in oil pressure. This assumes that you did immediately shut down the engine upon seeing low oil pressure.
2) If you did not shut the motor down but instead ran the engine at an upper rpm for some time, then your reduced oil pressure could be a result of greater bearing clearances due to lack of lubrication during some extended run time.
Being that you shut the motor down immediately, I'd say it is likely that you simply have a different pump in your engine. If you have reservations about this, you can always inspect a few bearings while your pan is off and that pump is changed. That would've been a good idea while you were in there. Also, you can increase the oil pump's output pressure with a shim kit. We sell 'em on our website.
LO

[LakesOnly]

I'm thinkin' that whatever caused the pump to energetcially disassemble also caused a crack around the oil gallery...also, what about debris being forced into the gallery?
The first suggestion is highly, highly unlikely (never enven heard of an oil pump breaking at the "neck" and taking a block with it). The second suggestion is not very likely because the oil gallery goes from the pump directly to the filter, three inches downstream, where the debris would be caught. But it still would be a good idea to check that short gallery for any blockage. Good thing you found all the parts of the oil pump.
LO

[castone001]

LakesOnly,
thanks for your replies and insight. Any chance I can call and talk with you directly?
If so what time works best for ya? #?

[LakesOnly]

LakesOnly,
thanks for your replies and insight. Any chance I can call and talk with you directly?
If so what time works best for ya? #?Under "Contact Us" on the website (link in my signature line). 310-435-1900
LO

['78 gt boat]

This sounds like something we may have run into. What do you think?

[LakesOnly]

78GT,
It's possible, but too soon to jump to conclusions. Remember that castone has already pulled his motor and seen the problem.
The 429/460 oil pump has a very large pump "head," and it hangs from the cylinder block by a rather thin "neck." I have occassionally heard of these pumps breaking at the neck (or the mounting flange at the block), but I regularly dismissed this and belive it to be an uncommon problem because hundreds upon hundreds of thousands of these pumps have been manufactured and functioned without fail. Of course, this is not to argue that it doesn't happen.
Further, ususally if this does happen, it happens on a front sump engine and consider that the front sump pump's pickup screen bolts to the oil pump and then drops straight to the pan. In other words, there is no effective "oil pump brace" like in a rear sump setup, where the long rear sump pickup also attaches to a main cap and thereby provides some added structural integrity/bracing of the head-heavy pump.
This is one of the reasons that we inspect and hand file our oil pump flanges flat; they usually come out of the box with some warpage or concavity to them, but we want them to mount flush with the cylinder block so that the flange is not stressed when tightened down. Unfortunately, short of adding a pump brace there is not much that can be done about the structural integrity of the pump neck from one oil pump casting to the next. And so that's the nice thing about the rear sump pickups: they double as a support brace. In castone's experience, his pickup likely kept the oil pump from colliding with the rotating assembly and doing greater damage.
The 429/460 internal oil pumps have handled hard launches from tube chassis drag cars with huge slicks and not swung back and broke at the neck; sometimes there is a bad casting in the bunch such as in castone's case and even lighter duty may cause it to fail. Others will last 500,000 miles.
LO

[Moneypitt]

Just curious, how long were you suppose to be "in break in mode"? Running for 2 days and still not ready to hammer? A profesionally built engine should be ready to be used almost from the first time it's fired.......I could see maybe 10 minutes under 4K, but 2 days? As far as the oil pump breaking, who installed the distributor? Is it the right oil pump drive shaft, and is it twisted? MP

[rerfert]

As far as the oil pump breaking, who installed the distributor? Is it the right oil pump drive shaft, and is it twisted? MP
pound on the distributor shaft with a hammer to get it to set into the block
I had a ford motor apart years ago that a guy had put a new oil pump in, test run and found no oil presure...he couldn't believe all the problems he was having with putting the motor back together and after the no oil presure was not happy....I looked at it in the car,turned it over by hand and the distributor turned so I had him pull the motor out again and drop the pan.
He found a broken oil pump at the neck.....cause was possibly the pounding on the distributor shaft with a hammer to get it to set into the block. :rolleyes:

[castone001]

Thanks all for the replies thus far.
The drive from the distributor looks great and seats in the bottom of the Distrib and then into the new pump. good solid fit. The guy who built the motor put it all together the first time around.
As far as "Break-In" You are correct he told me it was buil;t as a race motor so go run it as one. Me, however and most of buddies, believe that if we take our time and care for em, i.e. nice smooth and long (around 8 hours) break in then oil change the motors will last forever. I guess we'll. I can tell you that had I been jumping on it and this pump problem still happened, I would be catching crap from my buds for years to come. Now at least all they say is good thing you stayed out of it :) Too funny.
I am still curious about the low oil pressure at idle though. At least it jumps up soon as you hit the gas. I guess thats a good thing.
Ok heres another question that has probably been posted already.......What weight oil should you run in a motor when new and when as mine is, 8 hours old :) 10/40, 10/30 ? Less more?

[SmokinLowriderSS]

I've been running 10W-50 Syntech synthetic on my 454 for the last 2 yrs, both before and after a rebuild. Broke it in on the syntech too, cam included.
Cold, she idles 53 psi. Hot, she idles 23PSI. Hot at anything over about 2,500 RPM, 53psi, stock pump, 5 qt pan. Hot pressure is even after a 3 or 4 mile WFO run.
The oil pump is a fixed volume pump, the faster you spin it, the more it puts out. At idle it's only spinning 1/2 engine speed, 450 RPM, and doesn't put out much oil which bleeds out the bearing spaces like it is supposed to. At 3,000 RPM, it is putting out 3x the oil volume, into the same size bearing spaces, which increases the pressure. Arround 10psi per 1,000 rpm is a good, safe, ammount of pressure to have.
My "break in" was 2.5 hrs, as advised by several sources.
half-hr on the cam, reduced springs. Changed the oil/filter.
Hr under 3,000 RPM, drive it and enjoy.
Hr under 4,000 RPM, drive it harder, and enjoy. Tube, Ski, whatever.
Hr under 5,000 RPM, No long WFO runs. Since I couldn't pull 5K, I was done. just enjoy it and enjoy a few short blasts all over the loud-pedal.
I put the full springs in about 8 hrs run time, and been running great ever since.
Your oil pressure is fine, go run the dog snot out of it! :boxed: