The Ford Barn

hotcoupe · 07-27-2019, 01:08 PM

I have a 239 c.i.,full floating rods with 10 k onthe clock. Changed oil today, bearing material in the oil (small, thin flakes), so the motor is coming out. My question is, i have a new Melling M-19 pump, can i use this pump without any adverse effects? I didn't mention, the motor will be completely disassembled,cleaned,new bearings, crank polished or ground, big end on rods checked for round.
Thanx,
Tom

hotcoupe · 07-27-2019, 01:12 PM

One more thing, why are there two oil pressure relief valves? One on the pump and one at the front of the engine in the valve chest.tom

flatheadmurre · 07-27-2019, 01:50 PM

The one in the block was the only one from start...the early pumps didn´t have a relief valve in them.
And you can´t take the relief valve in the block away or block it out even if newer pumps have a relief valve since it is lubricating the camdrive.

hotcoupe · 07-28-2019, 10:30 AM

Flatheadmurre, thanx for that info, i was unaware that the early pumps didn't have a pressure relief. I guess i should have been more direct when i asked about the M-19 pump. So . . . Am i going to create a problem using an 80# pump in an application that calls for a 50# pump? Thanx in advance for your response.
Tom

Ol' Ron · 07-28-2019, 11:00 AM

The right place for the relief valve is at the end of the system, as in the early blocks. Not sure why Ford changed. Back in the 60's we were having bearin problems, so I added a gauge at the front of the oil manifold, bu drilling a small 1/8 hole in through the front of the block (8ba). THere was a 10/15 lb drop between the two gauges. After you take apart as many blocks as i have, you'll see the front bearings are warn more and fail sooner.

flatheadmurre · 07-28-2019, 11:51 AM

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The pressure is set by the weakest relief valve in the system so your 80# pump will only reach 50# before the block relief valve opens.
The only thing the shortbody pump changes is that it has a higher displacement so you get some more flow.

tubman · 07-28-2019, 12:05 PM

Do not buy an after market pump from Speedway. I put one in a new build (8BA) and it produced marginal oil pressure. I replaced it with a known good used pump and the oil pressure came back to normal.

07-27-2019, 01:08 PM	#1
hotcoupe Senior Member Join Date: May 2010 Location: imperial,mo Posts: 694	Oil pump questions I have a 239 c.i.,full floating rods with 10 k onthe clock. Changed oil today, bearing material in the oil (small, thin flakes), so the motor is coming out. My question is, i have a new Melling M-19 pump, can i use this pump without any adverse effects? I didn't mention, the motor will be completely disassembled,cleaned,new bearings, crank polished or ground, big end on rods checked for round. Thanx, Tom

07-27-2019, 01:12 PM	#2
hotcoupe Senior Member Join Date: May 2010 Location: imperial,mo Posts: 694	Re: Oil pump questions One more thing, why are there two oil pressure relief valves? One on the pump and one at the front of the engine in the valve chest.tom

07-27-2019, 01:50 PM	#3
flatheadmurre Senior Member Join Date: Apr 2015 Location: Sweden Posts: 3,045	Re: Oil pump questions The one in the block was the only one from start...the early pumps didn´t have a relief valve in them. And you can´t take the relief valve in the block away or block it out even if newer pumps have a relief valve since it is lubricating the camdrive.

07-28-2019, 10:30 AM	#4
hotcoupe Senior Member Join Date: May 2010 Location: imperial,mo Posts: 694	Re: Oil pump questions Flatheadmurre, thanx for that info, i was unaware that the early pumps didn't have a pressure relief. I guess i should have been more direct when i asked about the M-19 pump. So . . . Am i going to create a problem using an 80# pump in an application that calls for a 50# pump? Thanx in advance for your response. Tom

07-28-2019, 11:00 AM	#5
Ol' Ron Senior Member Join Date: May 2010 Location: Chester Vt Posts: 8,855	Re: Oil pump questions The right place for the relief valve is at the end of the system, as in the early blocks. Not sure why Ford changed. Back in the 60's we were having bearin problems, so I added a gauge at the front of the oil manifold, bu drilling a small 1/8 hole in through the front of the block (8ba). THere was a 10/15 lb drop between the two gauges. After you take apart as many blocks as i have, you'll see the front bearings are warn more and fail sooner.

07-28-2019, 11:51 AM	#6
flatheadmurre Senior Member Join Date: Apr 2015 Location: Sweden Posts: 3,045	Re: Oil pump questions Sponsored Links (Register now to hide all advertisements) The pressure is set by the weakest relief valve in the system so your 80# pump will only reach 50# before the block relief valve opens. The only thing the shortbody pump changes is that it has a higher displacement so you get some more flow.

07-28-2019, 12:05 PM	#7
tubman Senior Member Join Date: Dec 2013 Location: Minnesota, Florida Keys Posts: 10,302	Re: Oil pump questions Do not buy an after market pump from Speedway. I put one in a new build (8BA) and it produced marginal oil pressure. I replaced it with a known good used pump and the oil pressure came back to normal.

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