The Ford Barn

tubman · 10-12-2015, 06:58 AM

Quote:

Originally Posted by Diavolo

Just a thought but what if all the oil drained out of the pump and it can't prime? Could pull the cover off and cram some grease in the pump, also check for engagement into the idler gear to the cam.

I had flow out of the pump (it made quite a mess on the shop floor when I removed the line to the filter to check it), but no pressure; I could hold the pressure in with my finger. The pump's coming out today.

Bluebell · 10-12-2015, 02:17 PM

My guess is that flatheadmurre is onto it. A rusted spring or oil pressure has pushed the relief open and it stuck there.
If it's the cam gear, then it has to be caused by by something like the pump not turning.
Moisture or acids in the oil, plus time, have done something.

tubman · 10-21-2015, 10:37 AM

I pulled the oil pump out a couple of days ago and took it apart. It was clean as a whistle inside, and the relief valve and spring looked great. There was some gunk in the pickup screen, but I don't think it would be enough to make a difference. I "Plasti-gaged" the clearance between the bottom plate and the gears and got .003" (factory specs are .0015" to .006"). I had ordered a new pump for the 258" I am building and it feels about the same as the existing pump; about the same effort to turn and the same "slack" in the gears. I'm going to put the new pump in the Merc and mount it back on the engine stand and try it that way. I also have another oil pressure gauge to try and have a new pickup screen. I pulled the plate off the back of the engine and all the gears and everything look fine. The only thing I haven't done is pull the timing cover and cam gear to check to see if there is a problem with the gallery plug. I didn't want to take too much apart on this engine if I could help it, as the front of the engine has obviously never been apart. If I don't get any pressure with the new pump, I guess that would be next.

Wish me luck and stay tuned.

scooder · 10-21-2015, 02:29 PM

Got me fingers crossed for you tub.
It's a bugger that you didn't find a good reason for the lack of pressure.
Martin.

tubman · 10-21-2015, 04:50 PM

Thanks Martin, I'm hoping it's 6 volts and a bad gauge. Or as others have said, maybe I'm overthinking it. With the good compression and the condition of the bearings and crank surfaces, I just don't want to take any chances.

10-12-2015, 02:17 PM	#22
Bluebell Senior Member Join Date: Nov 2012 Location: Tauranga, New Zealand Posts: 726	Re: Engine builders - a little advice please My guess is that flatheadmurre is onto it. A rusted spring or oil pressure has pushed the relief open and it stuck there. If it's the cam gear, then it has to be caused by by something like the pump not turning. Moisture or acids in the oil, plus time, have done something.

10-21-2015, 10:37 AM	#23
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 11,638	Re: Engine builders - a little advice please I pulled the oil pump out a couple of days ago and took it apart. It was clean as a whistle inside, and the relief valve and spring looked great. There was some gunk in the pickup screen, but I don't think it would be enough to make a difference. I "Plasti-gaged" the clearance between the bottom plate and the gears and got .003" (factory specs are .0015" to .006"). I had ordered a new pump for the 258" I am building and it feels about the same as the existing pump; about the same effort to turn and the same "slack" in the gears. I'm going to put the new pump in the Merc and mount it back on the engine stand and try it that way. I also have another oil pressure gauge to try and have a new pickup screen. I pulled the plate off the back of the engine and all the gears and everything look fine. The only thing I haven't done is pull the timing cover and cam gear to check to see if there is a problem with the gallery plug. I didn't want to take too much apart on this engine if I could help it, as the front of the engine has obviously never been apart. If I don't get any pressure with the new pump, I guess that would be next. Wish me luck and stay tuned.

10-21-2015, 02:29 PM	#24
scooder Senior Member Join Date: Jul 2010 Posts: 2,595	Re: Engine builders - a little advice please Got me fingers crossed for you tub. It's a bugger that you didn't find a good reason for the lack of pressure. Martin.

10-21-2015, 04:50 PM	#25
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 11,638	Re: Engine builders - a little advice please Thanks Martin, I'm hoping it's 6 volts and a bad gauge. Or as others have said, maybe I'm overthinking it. With the good compression and the condition of the bearings and crank surfaces, I just don't want to take any chances. Last edited by tubman; 10-21-2015 at 08:59 PM.