The Ford Barn

Flathead · 03-13-2016, 11:58 PM

I hear a lot about running an oil line to the center main, and it sounds like it could be a good idea. I even have a new line and fittings I bought at Hershey to do it with. But (there's always a but) I have questions. Would you put a loop in the line to allow for vibration since the pump is only anchored by a spring? Looking at the oil grooves it seems to me that the oil would just go back UP the oil tube in the block and not have any pressure at all, plugging the tube makes me nervous. Maybe I'm over thinking it but I want to get this right. I have never heard any explanation besides "run a line to the center main" I am leaning towards leaving it stock like Henry made it.

Mike V. Florida · 03-14-2016, 01:36 AM

http://www.fordbarn.com/forum/showthread.php?t=19234

Tom Wesenberg · 03-14-2016, 06:34 AM

The best way to save the center main babbit (and the front and rear) is to install counterweights on the crankshaft.

Synchro909 · 03-14-2016, 07:14 AM

I run inserts and a counterweighted crank AND I have pressure fed the middle main. I didn't put a loop in the line - I put a 1/4" bolt into the block to hold the oil pump in place and ran the line from the oil pump body just below the block directly to a tee fitting in the bearing cap. The line is about 3" long at most, flared at both ends and can be a bit of a fiddle to get in place as you slide the oil pump in. Things have to line up just right but after about 16,000 miles, it is going just fine. In fact, I'm so happy with the motor, I'm currently building another just like it. I made a pressure relief valve that hangs immediately below the bearing cap from that tee fitting which is designed to open at 25 psi. I run a modified V8 Oil pump for volume and pressure.
I have seen diagrams where the oil line is screwed into the block along side the pump thus:
http://www.modelaparts.net/special.h...entermain.html
To prevent oil going straight through to the valve chamber, I plugged the passage but in the case of inserts, some sets have half of them with no oil holes in them. Put that one in the block side of the bearing and oil will not go "upstairs". The plug need not be permanent. If you tap the top of the oil passage and screw in a plug, it can be removed later if you like. Just make sure you remove all cuttings before you assemble.

George Miller · 03-14-2016, 07:34 AM

IMHOP it will do no good. There is only a pound or two of pressure, plus you are putting it on the bottom of the bearing, which is loaded. No engines that I have worked on do that. It works from the top, the crankshaft rolls the oil between the crank and the bearing. It is called hyd wedge.
The other thing bad is most people use copper line. After time it will work harden and break.

I have run many miles in Model A's with stock oiling with out problems. Both with inserts and with babbitt.

tbirdtbird · 03-14-2016, 08:43 AM

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larrys40 · 03-14-2016, 08:57 AM

X3 . My since past away mentor and friend terry Oberer for a time in the 80's did some center main pressurizing setups and did them well, silver soldered lines and all. I disassembled one if the engines years later and the center main line had cracked and actually was dumping the oil in the pan and even though the oil pump has good volume the damage was starving the mains. Leave it stock.. It's a model A engine and they run for many years with their original design.
The find of the failure convinced me there was more risk of destruction of the mid failing than good from it
Larry Shepard

PC/SR · 03-14-2016, 10:39 AM

Do not attach the line to the oil pump or put a loop in it. Tap into the block. Dennis Pirano makes a kit for 10-$15 that has everything, including drills and taps, steel tubing, all fittings. An easy installation with that kit. All you need is a drill.
http://www.modelaparts.net/ Some oil may go back up to the valve chamber, but it first has to go through the bearing and that is the point. It flows into the grooves and completely oils the bearing.

MikeK · 03-14-2016, 10:58 AM

George Miller's explanation is spot on.

Tom Wesenberg · 03-14-2016, 11:32 AM

Quote:

Originally Posted by George Miller

IMHOP it will do no good. There is only a pound or two of pressure, plus you are putting it on the bottom of the bearing, which is loaded. No engines that I have worked on do that. It works from the top, the crankshaft rolls the oil between the crank and the bearing. It is called hyd wedge.
The other thing bad is most people use copper line. After time it will work harden and break.

I have run many miles in Model A's with stock oiling with out problems. Both with inserts and with babbitt.

Exactly, and that's why I've always installed cam bearings with the oil hole on top, on the engines where the block has a full circle oil groove to feed the bearing insert. If the block doesn't have the groove, of course then you must line up the oil hole.

Lawrie · 03-14-2016, 03:44 PM

Basic hydraulics.OIL will take the path of least resistance, oil will go to the valve chamber first,its easier.
Lawrie

Synchro909 · 03-14-2016, 06:56 PM

George, Tbird and Larry, (posts 6,7&8).
While I can't argue against what you have said in your posts for an engine running a standard oil pump I suspect you may have missed me saying in my post that I feed the bearing at at least 25 psi, not the 2 or 3 pounds a standard oil pump is limited to. A bearing's biggest enemy is heat. A good flow of oil through it will keep it cool as well as lubricated. The middle main bearing is the weak link in these and most other 4 cylinder motors of the era and can do with a little help.

jfreddie · 03-14-2016, 07:48 PM

My only objection to the line is that it uses unfiltered oil. If you have the full flow filter unit on the valve cover, the bypass line would send unfiltered oil up into the filtered valve chamber oil.

Flathead · 03-14-2016, 08:01 PM

Thanks to everyone for all the responses! I now have some good info to use. Since it is a basically stock motor, except for inserts and a Burlington crank, I think I will leave well enough alone this time.

Dave in MN · 03-15-2016, 09:55 AM

The question was asked: "I hear a lot about running an oil line to the center main, and it sounds like it could be a good idea."
Most of the guys commenting replied to your question before you revealed that you had just installed a Burlington crankshaft and insert bearings. I think they were framing their answers with the thought of Babbitt bearings and the standard oil delivery grooves present with Babbitt bearing material.

Most said it has no benefit because the oil needs to be delivered to the top of the bearing, away from the area of the bearing under extreme pressures. When using insert bearings, I do not agree with their comments and the following is why:
Typically, inserts have a radial groove in their design or installation. (See picture of AER insert main bearings and the Federal Mogul bearings placed in position as typically installed.) In both bearings sets, the only delivery of oil to the bearing surface is from the radial gap or groove. Note that there are no wells at the bearing parting lines to spread the oil across the width of the bearing. With the radial groove, I think/know the oil delivery will be greater to the bearing under pressure from the pump rather than gravity from the valve chamber. Resistance in the oil passage creates some line pressure as many have discovered when installing an oil pressure gauge. Supplying oil to the dynamic areas of a bearing, center main, where it can be drawn into the bearing at 3-10 pounds from the pump is better than about .5 pounds from the well. Without the radial groove, top oiling from the valve chamber is better for all the reasons George and Mike state above.
The problem, as I see it, with an inserted engine, the oil should be as clean as possible. Delivering unfiltered oil directly to the bearing without passing through the valve chamber will result in dirtier oil in the bearing. The valve chamber with its three wells, two dams creating 3 wells, actually acts as a settling area for heavy particles in the oil. If you study the floor of the wells, you will discover that the inlet holes for the oil to the mains are slightly raised. The heavy particles, metal, would need to rise up from the floor to get into the feed holes. Rarely will this happen.
With inserts, I think after market oil filters are best but unfiltered also works well if you keep your oil clean. If you change your oil often, or add an oil filter, the pressure feed to the center main will help prolong the life of your bearings. All I have stated is just my opinion and I strongly believe I am correct but...I also believe in the content of Red Green's "Men's Prayer": I'm a man, but I can change, If I have to, I guess. So to, can my opinions
Good Day!

ps: I have an inserted engine with Federal Mogul inserts in my Phaeton. It has a valve cover mounted oil filter that filters about 95% of the oil each time it is pumped to the valve chamber. We have over 80,000 miles on this engine. I have never had the pan off this engine since it was rebuilt. If I make it to 100,000 miles, and I think I will, I will open it up just to see what's going on inside. It has oil delivered to the center main, with the same system you describe, at 8-10 psi when running at road speed from a tap near the oil pump...so technically at that point, it is unfiltered oil. The filter system creates the pressure in the delivery system to the center main from the internal restriction to flow from the filter element. When the car is started, the oil is delivered immediately to the center main. I change my oil at intervals of between 2,000 and 2,500 miles. If you are willing to invest in an oil filter (see photo below) for your inserted engine, I think the pressure to the center main will be a good investment of your efforts. You already have the center main kit...JMO.

Jim Brierley · 03-15-2016, 10:40 AM

I like the idea of the bearing getting oil quickly instead of having to fill the valve chamber first.

George Miller · 03-15-2016, 11:11 AM

On my hill climb engines I do run 45 lbs pressure also. It goes through a filter then to the top of the mains. I use to drill the crank for pressure to the rods also. But after a couple of broken cranks at number 4 rod journal I quit that. It seems to do fine for that short run time up the hill.

03-13-2016, 11:58 PM	#1
Flathead Senior Member Join Date: May 2010 Location: Southern Maine Posts: 1,497	oil line to center main I hear a lot about running an oil line to the center main, and it sounds like it could be a good idea. I even have a new line and fittings I bought at Hershey to do it with. But (there's always a but) I have questions. Would you put a loop in the line to allow for vibration since the pump is only anchored by a spring? Looking at the oil grooves it seems to me that the oil would just go back UP the oil tube in the block and not have any pressure at all, plugging the tube makes me nervous. Maybe I'm over thinking it but I want to get this right. I have never heard any explanation besides "run a line to the center main" I am leaning towards leaving it stock like Henry made it.

03-14-2016, 01:36 AM	#2
Mike V. Florida Senior Member Join Date: May 2010 Location: South Florida Posts: 14,054	Re: oil line to center main http://www.fordbarn.com/forum/showthread.php?t=19234 __________________ What's right about America is that although we have a mess of problems, we have great capacity - intellect and resources - to do some thing about them. - Henry Ford II

03-14-2016, 06:34 AM	#3
Tom Wesenberg Senior Member Join Date: May 2010 Location: Mpls, MN Posts: 27,582	Re: oil line to center main The best way to save the center main babbit (and the front and rear) is to install counterweights on the crankshaft.

03-14-2016, 07:14 AM	#4
Synchro909 Senior Member Join Date: Jun 2014 Location: Melbourne, Australia Posts: 7,496	Re: oil line to center main I run inserts and a counterweighted crank AND I have pressure fed the middle main. I didn't put a loop in the line - I put a 1/4" bolt into the block to hold the oil pump in place and ran the line from the oil pump body just below the block directly to a tee fitting in the bearing cap. The line is about 3" long at most, flared at both ends and can be a bit of a fiddle to get in place as you slide the oil pump in. Things have to line up just right but after about 16,000 miles, it is going just fine. In fact, I'm so happy with the motor, I'm currently building another just like it. I made a pressure relief valve that hangs immediately below the bearing cap from that tee fitting which is designed to open at 25 psi. I run a modified V8 Oil pump for volume and pressure. I have seen diagrams where the oil line is screwed into the block along side the pump thus: http://www.modelaparts.net/special.h...entermain.html To prevent oil going straight through to the valve chamber, I plugged the passage but in the case of inserts, some sets have half of them with no oil holes in them. Put that one in the block side of the bearing and oil will not go "upstairs". The plug need not be permanent. If you tap the top of the oil passage and screw in a plug, it can be removed later if you like. Just make sure you remove all cuttings before you assemble. __________________ I'm part of the only ever generation with an analogue childhood and a digital adulthood.

03-14-2016, 07:34 AM	#5
George Miller Senior Member Join Date: May 2010 Location: NC Posts: 2,975	Re: oil line to center main IMHOP it will do no good. There is only a pound or two of pressure, plus you are putting it on the bottom of the bearing, which is loaded. No engines that I have worked on do that. It works from the top, the crankshaft rolls the oil between the crank and the bearing. It is called hyd wedge. The other thing bad is most people use copper line. After time it will work harden and break. I have run many miles in Model A's with stock oiling with out problems. Both with inserts and with babbitt.

03-14-2016, 08:43 AM	#6
tbirdtbird BANNED Join Date: May 2012 Location: inside your RAM Posts: 3,134	Re: oil line to center main Sponsored Links (Register now to hide all advertisements) X 2 __________________ '31 180A

03-14-2016, 08:57 AM	#7
larrys40 Senior Member Join Date: May 2010 Location: St Charles , Missouri Posts: 1,998	Re: oil line to center main X3 . My since past away mentor and friend terry Oberer for a time in the 80's did some center main pressurizing setups and did them well, silver soldered lines and all. I disassembled one if the engines years later and the center main line had cracked and actually was dumping the oil in the pan and even though the oil pump has good volume the damage was starving the mains. Leave it stock.. It's a model A engine and they run for many years with their original design. The find of the failure convinced me there was more risk of destruction of the mid failing than good from it Larry Shepard

03-14-2016, 10:39 AM	#8
PC/SR Senior Member Join Date: May 2010 Location: Santa Rosa, CA Posts: 1,278	Re: oil line to center main Do not attach the line to the oil pump or put a loop in it. Tap into the block. Dennis Pirano makes a kit for 10-$15 that has everything, including drills and taps, steel tubing, all fittings. An easy installation with that kit. All you need is a drill. http://www.modelaparts.net/ Some oil may go back up to the valve chamber, but it first has to go through the bearing and that is the point. It flows into the grooves and completely oils the bearing.

03-14-2016, 10:58 AM	#9
MikeK Senior Member Join Date: May 2010 Location: Windy City Posts: 2,919	Re: oil line to center main George Miller's explanation is spot on.

03-14-2016, 03:44 PM	#11
Lawrie Senior Member Join Date: May 2010 Location: Qld, Australia Posts: 4,212	Re: oil line to center main Basic hydraulics.OIL will take the path of least resistance, oil will go to the valve chamber first,its easier. Lawrie

03-14-2016, 06:56 PM	#12
Synchro909 Senior Member Join Date: Jun 2014 Location: Melbourne, Australia Posts: 7,496	Re: oil line to center main George, Tbird and Larry, (posts 6,7&8). While I can't argue against what you have said in your posts for an engine running a standard oil pump I suspect you may have missed me saying in my post that I feed the bearing at at least 25 psi, not the 2 or 3 pounds a standard oil pump is limited to. A bearing's biggest enemy is heat. A good flow of oil through it will keep it cool as well as lubricated. The middle main bearing is the weak link in these and most other 4 cylinder motors of the era and can do with a little help. __________________ I'm part of the only ever generation with an analogue childhood and a digital adulthood.

03-14-2016, 07:48 PM	#13
jfreddie Senior Member Join Date: Jan 2015 Location: anchorage, alaska Posts: 117	Re: oil line to center main My only objection to the line is that it uses unfiltered oil. If you have the full flow filter unit on the valve cover, the bypass line would send unfiltered oil up into the filtered valve chamber oil.

03-14-2016, 08:01 PM	#14
Flathead Senior Member Join Date: May 2010 Location: Southern Maine Posts: 1,497	Re: oil line to center main Thanks to everyone for all the responses! I now have some good info to use. Since it is a basically stock motor, except for inserts and a Burlington crank, I think I will leave well enough alone this time.

03-15-2016, 10:40 AM	#16
Jim Brierley Senior Member Join Date: Jun 2010 Location: Temecula, CA Posts: 4,085	Re: oil line to center main I like the idea of the bearing getting oil quickly instead of having to fill the valve chamber first.

03-15-2016, 11:11 AM	#17
George Miller Senior Member Join Date: May 2010 Location: NC Posts: 2,975	Re: oil line to center main On my hill climb engines I do run 45 lbs pressure also. It goes through a filter then to the top of the mains. I use to drill the crank for pressure to the rods also. But after a couple of broken cranks at number 4 rod journal I quit that. It seems to do fine for that short run time up the hill.