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Old 04-27-2010, 12:18 PM
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Can I safely try another start...low oil pressure.

I made my first attempt to start the sedan/delivery this morning (newly rebuilt 302 Ford). It ran, but so poorly I had to keep feathering the throttle and couldn't even jump out of the cockpit to start tweaking the timing and carb. I tried to keep the revs up (for cam break in) but (due to a latter discover fuel leak) the thing sputtered and coughed so much I was never able to really hold it much over 1500 rpm...and then only erradically.

The oil pump was primed a couple weeks ago and I had oil out all the pushrods and I primed it again for 2-3 minutes before my attempts this morning to get it running.

However, once the engine actually fired, I only had about 25 lbs of oil pressure (granted, it was barely running on its own) and then on my last start attempt, it appeared there was no oil pressure at all. So I immediately shut it down.

I then pulled the distributor and the valve covers and ran the oil pump with my 1/2" drill. I once again got oil coming out all the push rods. However, since I'm the only one around the place at the moment, I can't see into the cockpit to check the actual pressure on the gauge while I'm running the drill, so I don't know exactly what kind of pressure the engine has. But I'm assuming if I can pump oil to the rockers that I have some decent pressure.

The question is, am I running a risk trying to fire the car again? I certainly don't want to flatten a cam. Is there another test (or two) I can do to insure I am producing enough oil pressure to get the thing running again or is running the pump with a drill adequate to safely move forward?

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Old 04-27-2010, 01:35 PM
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I think your safe. If you have oil coming out of the pushrods your in good shape. The drill should also lug down as it`s turning the oil pump which also indicates you have good oil pressure. You could maybe use the trick I`ve used in the past to check the pressure while using a primer, I would wedge a mirror in the cockpit so I could get a view on it if I didn`t have anyone else there to assist. 25 psi for 1500 rpm is fine, that`s 10 psi over the given RPM.
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Old 04-27-2010, 01:46 PM
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I agree with DV, can't do this on a sbf but on my sbc I lock the drill motor switch and let it rest up against the distributor so it can run and I can check the gauge. You could rig a bungy cord around the drill handle for a few minutes....sounds hank I know or also install a temporary gauge on the engine if you have a fitting. Working by yourself....you have to adapt and over come.
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Old 04-27-2010, 01:52 PM
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If it were mine?
I'd tee in another MANUAL oil pressure guage, and mount it out in the engine bay.

Better yet, have a complete set of guages (including a tach) and an ignition switch out there to monitor ALL of the vital signs. It doesn't need to be pretty either. I mounted mine in a small cake pan and screwed it down to the rad support. "Betty Crocker meets Stewart Warner"

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Old 04-27-2010, 03:20 PM
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Wow. You can bake your cake...and drive it too!!
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Old 04-27-2010, 04:10 PM
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Well, I'm not liking the looks of this but I'd like a few more opinions.

After reading the first couple response to my question, I once again fired the engine. It ran slightly better due to a bit of tweaking but it was still pretty ragged and I had virtually no oil pressure. So I shut it down fairly quickly.

I then installed another oil pressure gauge and mounted it right on the engine so I can see it. Then I pulled the distributor and ran the oil pump with my drill and could only muster 12.5 - 15 lbs. of pressure. I tried it with both my 1/2" drill (600 rpm) and my 3/8" drill (1200 rpm) and they both produced the same results. By my calculation, running the drill at 1200 rpm is the equivalent of the engine running 2400 rpm...so I should have twice the pressure I am producing. Is that correct thinking?

Might this possibly be a loose...but not yet completely dislodged, plug in the front oil galley (behind water pump)? I'm not sure what the symptoms would be for that. I would think if the plug was totally gone, there would be zero oil pressure, correct?

When I primed the oil pump a couple weeks ago, I had very decent pressure using the drill. As I recall, something in the neighborhood of 35-40 lbs. So something has clearly happened as a result of starting and running the motor.

Any thoughts on how to diagnose the situation without starting the tear the entire motor apart?
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Old 04-27-2010, 04:21 PM
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Quote:
Originally Posted by cboy



Might this possibly be a loose...but not yet completely dislodged, plug in the front oil galley (behind water pump)? I'm not sure what the symptoms would be for that. I would think if the plug was totally gone, there would be zero oil pressure, correct?

When I primed the oil pump a couple weeks ago, I had very decent pressure using the drill. As I recall, something in the neighborhood of 35-40 lbs. So something has clearly happened as a result of starting and running the motor.

Any thoughts on how to diagnose the situation without starting the tear the entire motor apart?
Had a friend who had this exact scenario happen to him when he rebuilt his 302 5.0 Mustang GT engine in his college class years ago(1990-ish). He neglected to stake the edges of the plugs behind the timing chain and as soon as the engine was fired it pushed one out. Pressure was good with a drill the weekend before, low just like you describe when engine was fired a week later. Roller cam engine so he didn't hurt anything, but pulling a EFI engine at home is a pain in the butt, lots of stuff to unhook.

You may be right as to what you are thinking.
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Old 04-27-2010, 06:32 PM
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The cam turns at 1/2 the RPM of the crank, right?
So if your engine idles at 600 RPM (crank speed), the cam -- and consequently the oil pump will be turning at 300 RPM.

Most engines seem to make full oil pressure by what -- 1200 RPM? After the desired oil pressure is obtained, the relief spring in the oil pump begins to bypass.

So your 600 RPM drill speed is equivalent to 1200 RPM engine speed, and is likely turning the oil pump at a rate that achieves the desired pressure.

When you use your 1200 RPM drill, you're at the equivalent to 2400 RPM crank speed ... and a have likely entered the by-pass zone.
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Old 04-27-2010, 06:54 PM
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Another couple of quick thoughts ...
Oil pump pickup and hexagonal drive shaft.
Are both items new?

These items are the cause of more engine / oil pump failures than many people seem to realize.

The worst thing you can do is to rinse a used pickup screen assy in varsol, as it simply dissolves the sludge and allows chunks of it to enter the oil pump. Once there, it begins to gall the rotor and reduce pressure until it eventually seizes. I've seen this happen, and the driveshaft comes out spiralled ... or it sometimes takes out the shear pin on the dist drive gear. This usually results in the dist not turning at all and the engine dies completely, which is a good thing at that point.

Many Fords have a gasket between the (bolt-on?) pickup tube and the oil pump body. If it isn't there ... perhaps you're sucking a little air? Some engines have another gasket between the oil pump body and the block as well. I've been away from Fords too long to remember how a 302 is configured, though ...
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Old 04-27-2010, 07:03 PM
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Quote:
Originally Posted by ericnova72
He neglected to stake the edges of the plugs behind the timing chain and as soon as the engine was fired it pushed one out. Pressure was good with a drill the weekend before, low just like you describe when engine was fired a week later.
Thanks for that info. Sounds very similar. Any way to diagnose whether this might be the galley plug vs. a more major problem like improper bearing installation or bearing failure?
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Old 04-27-2010, 07:12 PM
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Quote:
Originally Posted by 66GMC
"Betty Crocker meets Stewart Warner"
That's eff'n HILARIOUS!
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Old 04-27-2010, 07:13 PM
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Originally Posted by 66GMC
"Betty Crocker meets Stewart Warner"
That's eff'n HILARIOUS!
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Old 04-27-2010, 07:15 PM
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Quote:
Originally Posted by 66GMC
Oil pump pickup and hexagonal drive shaft.
Are both items new?
Yes, new distributor (and shaft), new oil pump & pickup, and new intermediate shaft (from pump to dizzy). I've pulled the distributor and there does not appear to be any wear or markings on shaft or the hex drive on the end.

Quote:
Originally Posted by 66GMC
Many Fords have a gasket between the (bolt-on?) pickup tube and the oil pump body....Some engines have another gasket between the oil pump body and the block as well.
Yes on both counts. And I specifically remember installing those gaskets.

And thanks for verifying the drill rpm comparison to engine rpm in your prior post.
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Old 04-27-2010, 07:28 PM
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Well those are a couple of good things to have ruled out, at least.

The oil pump pickup that you installed is the correct one to match your pan, too, right?

Seems to me that pickup trucks had a larger capacity pan than a passenger car, and therefore used a deeper pickup screen. Once you've moved some of that (cold, thick) oil up to the top of the engine ... could it be starving at the bottom?
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Old 04-27-2010, 07:40 PM
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Quote:
Originally Posted by cboy
Thanks for that info. Sounds very similar. Any way to diagnose whether this might be the galley plug vs. a more major problem like improper bearing installation or bearing failure?
Not that I can think of, looks as if you wil have to tear into it. I would just pull the engine and open it up, I don't think it will be anything you can fix in the car. The more you run it now the worse any damage will get if there is any.

Any chance there is a filter problem?, might look there first and try a different filter. Don't know what you are using but we have had the dreaded "Fram collapse" you hear about on various boards happen to us on a SBC but caught it before the engine got hurt.

On the Ford story I posted above, we didn't know what the problem was, just knew something wasn't right. When we tore into it looking at the oil path and oil system the loose plug was soon evident.
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