390 engine

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390 engine

Post by AEP »

Why would a newly rebuilt 390 engine pump all the oil to the top of the heads, over flowing the valve cover gaskets and therefore starving the bottom end and causing a bearing to fail? :doh:
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Re: 390 engine

Post by fordman »

just some guesses. to much oil pressure. blocked oil passages. bearings on wrong?
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Re: 390 engine

Post by DuckRyder »

Because someone put a high volume oil pump in it without restricting the rocker shaft oiling feeds in the head.

Pull the rocker shafts and drop a #90 Holley jet in the oil feeds in each head (it is the hole in the head next to the longer bolt with the reduced shank).

Make sure the oil return holes at each end of the head are clear.

Over fill it one quart...
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Re: 390 engine

Post by bmerkley58 »

One common cause is the rocker shafts upside down. The oil holes in the rocker shafts need to be down toward the head. Another thing to check is the drain back holes, they may be plugged up from broken pieces of valve stem seals.

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Re: 390 engine

Post by 390F100 »

When I replaced my valve stem seals I made sure to check the oil passages and even pulled the oil pan and cleaned the pickup as well. It helped that I was resealing the engine but the pickup was plugged solid with broken seals and the passages were plugged solid as well. If the motor was recently rebuilt then my guess would not be the valve stem seals but a mistake in reassembly of the engine. :2cents:

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Re: 390 engine

Post by AEP »

I have read your responses carefully, I have several FE motors. I have noticed the bolt that holds the rocker shafts down that has the oiling port has a reduced shank. And some have a standard bolt. Would using a standard bolt slow the oil down enough to fix the problem as opposed to using a reduced shank bolt? The mechanic that installed the motor did install the driver side shaft upside down. Which we corrected. He also claims he partially pulled the engine enough to remove oil pan and replace what may have been a high volume pump with a stock one. The problem still exists and now the motor is knocking, probably from a starved bearing. Also this was a freshly rebuilt motor with a brand new pick up screen. :?


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Re: 390 engine

Post by DuckRyder »

Hmm...

So, it is both heads (sides)?

Are the drain pans (for lack of a better term) installed below the rocker stands?

How stock (or not) is this engine?

For OEM rocker assemblies #90 jets are the most often reccomended to reduce flow, with roller rockers people go as low as #70, and no I don't think that non-reduced shank bolts will work.
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Re: 390 engine

Post by BobbyFord »

bmerkley58 wrote:One common cause is the rocker shafts upside down. The oil holes in the rocker shafts need to be down toward the head. Another thing to check is the drain back holes, they may be plugged up from broken pieces of valve stem seals.

Bob
Also, rocker shafts upside-down will result in a serious smoker...
Watched a buddy of mine make that mistake.
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Re: 390 engine

Post by AEP »

could someone put the wrong head gaskets on a motor? Or put them on upside down? Which could possibly restrict the oil flow back to the oil pan. This motor was professionally rebuilt by motor master in High Point, North Carolina, and installed by Bruce Dillon in Jamestown North carolina. both have great reputations. But I believe as a carpenter, that i could have done a better job.
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Re: 390 engine

Post by 70shortwide »

how new is this motor? head gasket idea seems possible although i havent personally heard of that happening with these motors. i dont think that there are any that are close enough for someone toi think that theyd be ok, if they were wrong. depending on how new the motor is id be raisin hell with the builder. if it has lasted any length of time they will probly try to find a way that its your fault :2cents:
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Re: 390 engine

Post by AEP »

It lasted about 100 miles before it started knockin. It smoked from the beginning, the mechanic blamed my carburator, we changed the oil and he added a quart of STP oil treatment. I drove it for another 100 miles, It started knockin again. And still smoked. So this time i payed to have it towed to him because i was afraid to drive it any longer. he still thought it was my carburator, so i came by on my lunch break one day, and removed the valve covers. And made him watch the motor run as we stood there. and within thirty or forty seconds, the motor had pumped all the oil to the top and was over flowing the heads. At this point he agreed that the carburator was not the problem. The rocker arm on the driver side was upside down, which they flipped back over. And as i said before, the "supposedly" put in a stock oil pump. I drove it for another 100 miles, and again it started knocking. The mechanic said the motor was not assembled correctly. And the machine shop says the mechanic screwed the motor up. All I know, is that my truck is broke, and so am I. So at this point im in the process of pullin the motor to take it to a third party to diagnos what went wrong. Thanks for all of your responses :)
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Re: 390 engine

Post by BobbyFord »

Rocker shaft installed upside-down = rebuilder is at fault.
Clearly, someone that installs an FE rocker shaft incorrectly has little knowledge of Ford engine assembly. Question is, what other mistake did the rebuilder make during machining/assembly? Sounds like it's time to take your mechanic and your findings and let a judge decide. I would first tell the rebuilder that you intend to sue; maybe that will persuade him to honor his warranty.
Also, a high volume pump, with or without the top-end oil restrictor in place will not flood the top to the point of starving the bottem-end.
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Re: 390 engine

Post by 70shortwide »

he at least owes you bearings! maybe a crank. running an engine with no oil in the bottom end will wip[e them out fast. the machine shop should be building you another motor imo. if it was me i would tell them that. its obvious that the machine shop assembled it wrong, he already admitted it. id tell them that i expect them to get started on another motor and that you want everything replaced. that or go to another machine shop and send the bill to the old machine shop. sounds to me like theyre hoping to burn you.
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Re: 390 engine

Post by 70shortwide »

BobbyFord wrote:Rocker shaft installed upside-down = rebuilder is at fault.
Clearly, someone that installs an FE rocker shaft incorrectly has little knowledge of Ford engine assembly. Question is, what other mistake did the rebuilder make during machining/assembly? Sounds like it's time to take your mechanic and your findings and let a judge decide. I would first tell the rebuilder that you intend to sue; maybe that will persuade him to honor his warranty.
Also, a high volume pump, with or without the top-end oil restrictor in place will not flood the top to the point of starving the bottem-end.
+1 on all that
i know that i had the rockers off mine and back on with 0 difficulty. i am no professional, definately not marketing my skills. however, even good people have bad days. if he is not willing to stand behind this, i would only go back to drop off the bill from another machine shop. tell everyone you knwo not to go there. its is important for someone to stand behind these things. you have a lot of money into a motor that is no good. if he wont stand behind a simple mistake where will he be when your next motor he builds for you isnt right?
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Re: 390 engine

Post by My427stang »

An FE unless severely resticted ALWAYS looks like its pumping all the oil to the top

Are you sure that was really the problem?

Sounds to me like there may have been another issue. I have run unrestricted rockers to 6500 rpm with a stock pan in a 427, and although stupid :) , it lived just fine

Sounds to me like you had a bottom end problem
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