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wjoef
Samba Member
Joined: August 29, 2009
Posts: 58
Location: Vancouver, no, not that one, the original one
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 Posted: Thu Nov 19, 2009 1:15 pm Post subject: |
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OK, I've reread this thread about 4 times now...
Motor oil is an incompressible fluid, yes?
Temperature affects the viscosity of motor oil; single weight motor oil has a "narrow" temperature band in which it maintains it's lubricating qualities, meaning that if it gets to cold, it doesn't flow, and if to hot, it flows too quickly (doesn't stick around to lubricate).
It appears that the only item resembling a thermostat in the engine oiling system is the two "relief" springs. Are they actually temperature sensitive (more so than regular springs)?
The oil pump is suction feed, yes? If the oil is not flowing properly (too thick, too thin, or in short supply), the oil pump will have trouble picking up (suctioning up) oil out of the sump, yes? It seems that if the oil pump is receiving the right amount of oil from the sump and then pumping the right amount of oil into the oil galleries, the pressure developed would be constant for a given pump speed (pressure would vary with pump speed). The springs would then only reroute the oil to the short route (not through the cooler) based on the volume of oil (volume affects pressure, yes?) that the pump could suction up from the sump, yes?
My point/question: It appears that it is not the temperature of the oil that determines the path it takes, but whether there is a sufficient supply of oil in the sump for the oil pump to produce the required pressure to overcome the force of the first bypass spring/valve and allow the oil to proceed to the cooler, instead of bypassing the cooler and taking the "short route" back to the sump, yes?
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Jimmy111
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Joined: October 05, 2006
Posts: 2643
Location: Wyoming
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| Posted: Thu Nov 19, 2009 5:20 pm Post subject: |
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No.
Just think of it this way. Oil is stickey when cold. The viscosity is high and resistant to flow.
As you heat the oil it becomes less stickey (less viscosity) so it flows eaisier and will flow faster. This results in lower oil pressures because the oil moves faster thru the system and will flow faster thru small cracks. |
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tmbryhn
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Joined: March 18, 2010
Posts: 3
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| Posted: Thu Mar 18, 2010 12:57 pm Post subject: |
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Hi everyone. Greetings from Norway! A great subject, Jimmy.
I have a couple of questions regarding this.
For the time beeing, I'm putting together a 1915-engine. I won't have oil pressure issues with too low oil pressure as I have experienced earlier. Since a 30mm oil pump will bypass the cooler with stock spring pressure in the control valve, I have decided to actually plugg off this gallery from the inside.
Thus giving the oil no other possibility than to flow 100% through the cooler.
Of course I have drilled the releif gallery (8,8mm actually) so that this gallery actually can cope witht he high pressure.
What do you guys think about this sollutiuon? Will I only be blowing coolers, or do you think this can work?
The reason I'm, doing this is because I don't want an external cooler, and I still want as high oil pressure in my bearings as possible because I feel that the pressure provides the real protection buffer between the metal surfaces. |
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Glenn 
Mr. 010
Joined: December 25, 2001
Posts: 76897
Location: Sneaking up behind you
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| Posted: Thu Mar 18, 2010 1:03 pm Post subject: |
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| tmbryhn wrote: |
30mm oil pump will bypass the cooler with stock spring pressure in the control valve, I have decided to actually plugg off this gallery from the inside.
Thus giving the oil no other possibility than to flow 100% through the cooler. |
There's a good chance that you'll blow the oil cooler seals on a cold morning.
The bypass it to protect the oil cooler.
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miniman82
Samba Swamp Donkey
Joined: March 22, 2005
Posts: 9515
Location: Southern Maryland
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| Posted: Thu Mar 18, 2010 2:02 pm Post subject: |
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PLus you'll be over cooling the oil most of the time, and warm up will take forever.
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| Glenn wrote: |
| satterley_sr wrote: |
I just wanted to bitch but I'm getting no sympathy. |
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nsracing
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Joined: November 16, 2003
Posts: 9459
Location: NOVA
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| Posted: Thu Mar 18, 2010 2:55 pm Post subject: |
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Just think of this way, the oil leaks better when it is heated...so will reflect lower pressures on the gauge.
Cold oil is like pushing grease or lard. Heat the lard and you got oil!  |
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[email protected]
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Joined: August 03, 2002
Posts: 12785
Location: Salt Lake City, Utah
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| Posted: Thu Mar 18, 2010 3:37 pm Post subject: |
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the cooler bypass only keeps the oil at the proper temperature. When closed the cooler is still exposed to full oil pressure from the bearing side of the galley.
The pressure relief is what protects the cooler, but even that isn't enough if you have thick oil and a 30mm pump, the bypass orifice is too small.
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miniman82
Samba Swamp Donkey
Joined: March 22, 2005
Posts: 9515
Location: Southern Maryland
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| Posted: Thu Mar 18, 2010 4:15 pm Post subject: |
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I keep waiting for some genius to install a 32mm pump, throw in some 50wt oil, then post about not knowing why his block cracked through the main galley. 
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| Glenn wrote: |
| satterley_sr wrote: |
I just wanted to bitch but I'm getting no sympathy. |
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bugninva
Samba Member
Joined: December 14, 2004
Posts: 8858
Location: sound it out.
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| Posted: Thu Mar 18, 2010 7:32 pm Post subject: |
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| [email protected] wrote: |
the cooler bypass only keeps the oil at the proper temperature. When closed the cooler is still exposed to full oil pressure from the bearing side of the galley.
. |
been trying to tell folks that it only "bypasses" flow through the cooler, for years... but since they've been *told* the cooler "bypass" protects the cooler from high pressure, they ain't buying it...
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WhirledTraveller
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Joined: January 09, 2008
Posts: 1399
Location: Cambridge, MA
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| Posted: Fri Mar 19, 2010 7:29 am Post subject: |
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| tmbryhn wrote: |
Hi everyone. Greetings from Norway! A great subject, Jimmy.
I have a couple of questions regarding this.
For the time beeing, I'm putting together a 1915-engine. I won't have oil pressure issues with too low oil pressure as I have experienced earlier. Since a 30mm oil pump will bypass the cooler with stock spring pressure in the control valve, I have decided to actually plugg off this gallery from the inside.
Thus giving the oil no other possibility than to flow 100% through the cooler.
Of course I have drilled the releif gallery (8,8mm actually) so that this gallery actually can cope witht he high pressure.
What do you guys think about this sollutiuon? Will I only be blowing coolers, or do you think this can work?
The reason I'm, doing this is because I don't want an external cooler, and I still want as high oil pressure in my bearings as possible because I feel that the pressure provides the real protection buffer between the metal surfaces. |
I forsee two main problems. First, you are incorrect in your feeling that pressure provides the buffer in the bearings. This is a common misconception. Pressure does nothing but provide the force which moves the oil through the system. The pressure itself does not float the bearing. If it did, it would force the bearing to one side because the oil hole is only in one place. What provides the separation is a hydrodynamic wedge which is a function of the thickness and other properties of the oil, the bearing clearance, and the speed of rotation. It depends upon an adequate *flow* of oil, which is related to pressure but it's not a direct correlation. There is a correct amount of flow required to maintain the wedge. Too little flow will kill your motor, but too much will not help. Seeking maximum pressure is foolish.
Second problem: Living in Norway, I'd imagine it gets a bit chilly sometimes. The oil cooler bypass is designed to quickly bring the oil up to operating temperature. Your oil will take a long time or never get up to proper temperature, which will result in *reduced* oil flow from the thicker oil, and condensation in in the engine since the water will never get driven out of the oil.
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Hippie
Samba Tinner
Joined: August 16, 2004
Posts: 1781
Location: Iowa: The Mud State
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| Posted: Sat Aug 14, 2010 1:57 pm Post subject: |
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Bump
| Jimmy111 wrote: |
Its fine. It is called MAXIPump 3 from CB performance. It is about $40 dollars or so. It bolted right on my bug. I have heard of complications with some busses . Check and see how much room you have between your pump cover and fan. Also remember that you do need to pull all of it apart to install a oil pump.. 
If you do it post some photos here for others. |
'69 Bus worked out fine for clearance. NAPA made the hydraulic lines for me.
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bsairhead
Samba Member
Joined: October 08, 2008
Posts: 3560
Location: viroqua wi.
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| Posted: Sat Aug 14, 2010 2:49 pm Post subject: |
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| Hippie wrote: |
Bump
| Jimmy111 wrote: |
Its fine. It is called MAXIPump 3 from CB performance. It is about $40 dollars or so. It bolted right on my bug. I have heard of complications with some busses . Check and see how much room you have between your pump cover and fan. Also remember that you do need to pull all of it apart to install a oil pump..
If you do it post some photos here for others. |
'69 Bus worked out fine for clearance. NAPA made the hydraulic lines for me.
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Is it just me or do you have a ton of clearance between your pump gears and body. |
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Hippie
Samba Tinner
Joined: August 16, 2004
Posts: 1781
Location: Iowa: The Mud State
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| Posted: Sat Aug 14, 2010 3:44 pm Post subject: |
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| bsairhead wrote: |
| Is it just me or do you have a ton of clearance between your pump gears and body. |
Optical illusion. It's the light playing on the beveled tips of the gear faces.
Last edited by Hippie on Sat Aug 14, 2010 6:49 pm; edited 1 time in total |
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mark tucker
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Joined: April 08, 2009
Posts: 23937
Location: SHALIMAR ,FLORIDA
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| Posted: Sat Aug 14, 2010 6:49 pm Post subject: |
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| bugninva wrote: |
| [email protected] wrote: |
the cooler bypass only keeps the oil at the proper temperature. When closed the cooler is still exposed to full oil pressure from the bearing side of the galley.
. |
been trying to tell folks that it only "bypasses" flow through the cooler, for years... but since they've been *told* the cooler "bypass" protects the cooler from high pressure, they ain't buying it... |
well kinda sort of yes but no. when the oil only goe's throught the cooler it sees all the presure. but when the oil go's the other way through the "bypass" then to all of the gallerys it does drot pressure to the cooler. not a lot but some due to the presure bleading off through the bearings& lifters.the more wore out your motor is the more drop in pressure, but not much because the thing is still wore out but dosent have two paths to go. what it does do is create a place for a surge to go and have time to equalize.and when it warms up the oil is thinner, and the clearances are what they are .yes it's kinda like a thermostat. I use the strong on the relief(fly wheel end) and a stock one on the cooler, I have a 72 plate with fan external cooler mounted .I see no need to raise the presure to the cooler. in reality I dont see any need for putting a stronger spring there at all. but yes it should be used at the fly wheel valve. one other word on this. big pump,thick oil, external cooler, more restrictive fittings = a hard life for the oil pump drive that dont fit worth a shit it the cams any way. so be easy on rpm till your oil is warmed up good. thats part of the reason I use synthetic oil, it is thin when you pour it in. but there is a down side to it other than the leaks. it drains back fast.so if your bearings are a little loose( and loose is always better than tight) you may hear some noise till it gets full presure .( usualy only after it sits for more than 24 hours. ( I add a little stp because it is sticky & synthetic isant) hope this fuels the fire some. but yess the cooler always sees pressure when the engine is running and has oil in it.( thats if the oil pump is worken) |
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tundrawolf
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Joined: February 24, 2009
Posts: 1384
Location: RIP Mishomi my friend. I will always love you.
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| Posted: Tue Aug 31, 2010 11:39 pm Post subject: |
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| I am installing a bypass filter pump with 33mm gears. If I drill out the relief passages as detailed on the drawing to 7 or 8 mm, will I be OK? |
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RockCrusher
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Joined: August 03, 2010
Posts: 4596
Location: Parkesburg, PA
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| Posted: Wed Sep 01, 2010 3:10 am Post subject: |
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| tundrawolf wrote: |
| I am installing a bypass filter pump with 33mm gears. If I drill out the relief passages as detailed on the drawing to 7 or 8 mm, will I be OK? |
Where did you find a 33?
It has kind of been said in this thread but just to be 100% clear.....oil goes thru the cooler 100% of the time the engine is running. The key is what percentage of the oil flow volume goes thru the cooler? That is where the 1st relief valve spring pressure comes into issue. If the spring is too light for the system pressure then too much volume goes to the main galley and not enough goes thru the cooler.
I'm glad someone pulled this thread out of the archives since engine heat and viscosity vs spring pressure was just in a recent thread. This has certainly made the 30mm pump issues much clearer in my tiny little way overcrowded mind. Being a Berg Tech fan, I just took the advice to not run more than a blueprinted 26mm as gospel without much further thought. Occasionally we get good used 30's and just put them on the smaller "budget" motors when a customer is money tight. Now I can see that was in error without a couple mods.
Well, as much as I know, there is always room for more knowledge.
RC
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tundrawolf
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Joined: February 24, 2009
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Location: RIP Mishomi my friend. I will always love you.
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| Posted: Wed Sep 01, 2010 8:48 am Post subject: |
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| Jimmy111 wrote: |
Here is a photo of the inside of the oil side of the case I took ar RIMCO.
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I have a question about drilling the 7-8mm hole through the relief. How deep do I need to go in that hole, it looks like it goes all the way through the case! You said we should go through the bellhousing side, but that doesn't look like the right relief cylinder, I could be seeing it wrong though. |
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RockCrusher
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Joined: August 03, 2010
Posts: 4596
Location: Parkesburg, PA
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| Posted: Wed Sep 01, 2010 10:26 am Post subject: |
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That picture doesn't really show every thing. The hole is BELOW that long passage that travels the length of the block and it exits into the sump area down in the region of the lifter bores.
RC
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jesus_chrysler
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Joined: March 04, 2009
Posts: 425
Location: Wisconsin
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| Posted: Thu Sep 02, 2010 3:48 am Post subject: |
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| So I would just like to know how the Auto Linea case fits into all these mods for use with a 30mm. Anyone gone through one before? |
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RockCrusher
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Joined: August 03, 2010
Posts: 4596
Location: Parkesburg, PA
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| Posted: Fri Sep 03, 2010 1:12 am Post subject: |
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| jesus_chrysler wrote: |
| So I would just like to know how the Auto Linea case fits into all these mods for use with a 30mm. Anyone gone through one before? |
Funny you asked.....just today I took a look at the Auto Linea Bubble top case in the shop now. Two things of note.
1. The small orifice plug for the #4 main bearing is not there, just a simple plug. Glad I added the extra slinger drain passage.
2. The pressure relief port at the flywheel end is about 6mm (maybe 6.5 coz the caliper was at a slight angle). Definitely not 7-8mm.
RC
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