Any interest on a deep dive into Cat C12 oil systems? Specifically into Oil Pressure?

[IridiumRed]

Is there any interest in a deep dive into Cat C12 oil systems, specifically oil flow / oil pressure?

I got an MTVR about 8 months ago, and its oil pressure seemed a bit low to me, and also a bit "odd"... i work w commercial trucks everyday (mostly garbage trucks in the 30-40k GVWR size range), and the oil pressure readings on the C12 didnt quite make sense to me (seemed low overall, but also didnt behave the way im used to seeing when it comes to oil press vs rpm, and also with changing engine temps)

This MTVR is my own personal truck, and is mostly a playtoy for me (am working on making it essentially a huge pickup for myself, not driven everyday but probably 2 or 3 times a week, often to commute)

Anyways, i took a pretty deep dive into how the oil systems work on these trucks, to either fix the oil pressure on my truck OR understand how it works and one way or another get comfortable w the oil system. This stuff is still pretty fresh in my head, i could write out a fairly detailed report on it, including what all the oil bypass valves are & how they work (there are 4 valves in the oil filter base, each w its own function... each of which can be their own problem)

Is there any interest out there in reading that? I wouldnt be surprisef if this turn into 10 to 20 pages. With me, there is no "short story", i tend to get very detailed (possibly excessively so).

I wouldnt say im an "expert" on these systems, but i think ive put together more of an explanation on how/why these systems work then ive seen anywhere else, at least gathered together in one place. Currently its just in my head, so i need to do this soon before it starts getting stale / forgotten. It would be a little work to do, but be kinda enjoyable for me to work on when i need a break from other stuff. If i knew that a few of you would read it, enjoy it, that would prob be the motivation needed for me to start working on it.... so let me know

 

[IridiumRed]

Wanted to add that I'm particularly interested in hearing from those of you who have youtube channels / otherwise post a lot of content RE MTVRs... since i've watched / utilized a lot of that myself, been very handy for me, I'd like to give back as i can

 

[Mullaney]

Is there any interest in a deep dive into Cat C12 oil systems, specifically oil flow / oil pressure?

I got an MTVR about 8 months ago, and its oil pressure seemed a bit low to me, and also a bit "odd"... i work w commercial trucks everyday (mostly garbage trucks in the 30-40k GVWR size range), and the oil pressure readings on the C12 didnt quite make sense to me (seemed low overall, but also didnt behave the way im used to seeing when it comes to oil press vs rpm, and also with changing engine temps)

This MTVR is my own personal truck, and is mostly a playtoy for me (am working on making it essentially a huge pickup for myself, not driven everyday but probably 2 or 3 times a week, often to commute)

Anyways, i took a pretty deep dive into how the oil systems work on these trucks, to either fix the oil pressure on my truck OR understand how it works and one way or another get comfortable w the oil system. This stuff is still pretty fresh in my head, i could write out a fairly detailed report on it, including what all the oil bypass valves are & how they work (there are 4 valves in the oil filter base, each w its own function... each of which can be their own problem)

Is there any interest out there in reading that? I wouldnt be surprisef if this turn into 10 to 20 pages. With me, there is no "short story", i tend to get very detailed (possibly excessively so).

I wouldnt say im an "expert" on these systems, but i think ive put together more of an explanation on how/why these systems work then ive seen anywhere else, at least gathered together in one place. Currently its just in my head, so i need to do this soon before it starts getting stale / forgotten. It would be a little work to do, but be kinda enjoyable for me to work on when i need a break from other stuff. If i knew that a few of you would read it, enjoy it, that would prob be the motivation needed for me to start working on it.... so let me know

.
I would like to see what you have to share.
I have a MK23 and it sure can't hurt to learn more about it...

.

 

[IridiumRed]

Ill probably put something together. Partly for mysrlf, in case i have issues down the road and have to revisit this subject, be nice to have summary document. Prob 70 to 80% of what ill present wlll be info from cat's factory documentation, but condensed into one place. The cat onfo itself is spread across 3 or 4 sources and multiple pages, which makes it hard to see the big picture sometimes.

Anyways, ill prob do.something soon, since things are still fresh in my mind.

A lot of people might say i over analyze things sometimes, and maybe thats true... sometimes. But i get a lot of pleasure out of digging into something and really understanding it, and then i get comfort out of fixing something to the point where i dont worry about it anymore and just kinda forget about it... which is why i need to do this soon... before i forget

 

[MightyMiteDiesel]

interested

 

[IridiumRed]

I havent forgotten about this. Its still in mind, ill be doing something on it. Gotten distracted by some work trucks breaking down, having to scrsmble to get them fixed (all good now).

Also, i have been working on some things that are related to this (oil prsssure, flow), should be done soon. This stuff will give me some interesting data and just be cool to share.

What ive been setting up is -
Putting in another oil pressure gauge (this time a full sweep electrical gauge, reading from the oil filter base area, dont know if the pickup will be any more accurate then the stock oil pressure pickup, but the gauge at least probably will be vs its stock counterpart, and will be essier to resd/give more precise reading).

Bypass oil filter. Cat C12s can run a bypass filter (mounted to the oil filter base, right next to the primary oil filter). On the MTVRs tho, packaging is tight, the main oil filter is mounted remotely, and theres not enough room for the bypass filter, and dven if there was room it would be difficult to get to.

So, ive figured out way to run a bypass filter (same filter as what cat would normally run) but mounted remotely. Took a while but figured out reasonably priced remote mount that is good quality (fleetguard unit, that is spec'd by cummind for various OE applications i think), and how to hook it into system.

Also, and for me as a motor geek, the coolest thing - im setting up a couple of oil accumulators to act as prelubers. The basics of an accumulator - have a tube with a sealed piston in it, on one side of piston you have sealed air, the other side has oil in it. Have a line from that oil side to the engines oil supply system, with shutoff valve in between accumulator and engine. Air side is adjustable for pressure. If the pressure in the accumulator is grester than oil system presdure, and accumulator is full of oil, then oil will flow to the engine if valve is opened (this is the core of the "preluber" concept... can open valve right before engine is started, which gives quick dhot of pressurized oil to oil system, eliminating dry starts.

While engine is running, if oil system pressure is greater than the air pressure, the oil will flow back into the accumulator, refilling it. And vice versa... can use accumulator to send a few seconds of oil flow/pressure to engine if it has momentary losses in oil pressure. This is a common thing w race cars that have oil system issues, where maybe the oil pickup is on one side of engine and they have long turns on a track that pulls oil away from pickup. Or maybe its a front to back issue, maybr have oil pickup at the back, and hard braking runs all the oil forward. Bottom line if there are places where for 5, 10 seconds an engine is running low/no oil presdure, an accumulator can fill in that gap, provide flow/pressure for that narrow window until system recovers normal operations...

Anyways, am in process of setting up the above on my truck. Hopefully be done soon... and ill be sharing details on it when i do. Its giving me some good info / ideas on the oil system as i do it / use it.

Running a preluber is just something ive wanted to do for a long time, this just gives me an excuse/opportunity to do it. Its more in the realm of "want" than "need"... but this truck is my toy, so perfect time to do it. And eliminating dry starts is a good thing. Esp on this nice and expensive of an engine. Having bypass filter will be nice too, that keeps oil a lit cleaner, reduces wear particles and hence wear. Keeps oil good for a lot longer too. Again, just stuff i want to do ill share about that setup + oil system info on c12s in general when ive got it figuref out a bit more. Am getting close

 

[flyfishtrailer]

I don't have a truck that big (M1078 with CAT 3116), but it is always good to learn more. Even if there is not a ton of folks asking questions now, preserving your knowledge on a thread may help folks down the road as more of these trucks hit the civilian market.

 

[BKubu]

I am interested in reading this information. Thanks!

 

[msgjd]

I got an MTVR about 8 months ago, and its oil pressure seemed a bit low to me, and also a bit "odd"... i work w commercial trucks everyday (mostly garbage trucks in the 30-40k GVWR size range), and the oil pressure readings on the C12 didnt quite make sense to me (seemed low overall, but also didnt behave the way im used to seeing when it comes to oil press vs rpm, and also with changing engine temps)

you didn't say what your oil pressure readings are in relation to rpm and engine temp .. perhaps you could document them over a period of operational days and see if there's a consistent pattern or not ..

i don't have any military trucks newer than 1970's but i have heavy-hauled commercial 800+ miles daily before i retired with 550-600hp Cat C15's up front and on those particular 2007-up tractor trucks their oil pressures ranged from 15psi to 20psi hot , no more than 30psi cold start ..

To compare with something similar but different, my 2000 FLD with Series-60 475hp detroit runs 70psi cold start and 35-50psi hot , doing the same jobs as the C15's

 

[fuzzytoaster]

Of the 3 MTVRs I have, all idle around 10-15 psi. One truck has a freshly rebuilt engine with 3000 miles on it and it only idles at about 17 psi cold. I too was concerned about oil pressure but that is in spec says Cat. Now my Big Cam 400 loves oil pressure and will have 80 psi cold and idle hot around 20-25 psi. Different technology from a different era.

 

[msgjd]

my Big Cam 400 loves oil pressure and will have 80 psi cold

the 400's were the monster of their day .. drove a 1990 western star for a couple days with a NTC400 turned up to 425 horse, ya couldn't load it enough to kill it on hills.. But then again, the gearing had it maxed out at 55mph .. Rode so rough i was glad when I got my regular truck back

 

[dlynes]

IridiumRed any updates? did you complete your additional remote bipass?

 

[IridiumRed]

I'll write up something one of these days. Been busy with other projects, been kinda swamped with other stuff.

Instead of making it a really long formal post, I may break the whole thing up into shorter sections... be easier for me to do (and its the sort of things I could spend a ton of time trying to make it look really good, which would be nice, but isn't essential).
I spent years as a financial analyst doing managerial reporting, so basically my work product was making charts, graphs, for the execs to read, share with each other, so my natural instinct is to go a bit overkill on presentation.

I will say one thing, these engines (C12s) do run a lot lower pressures on the dash gauges then a lot of other trucks, and its just a part of the design. "normal" oil pressure on a hot C12 idle would be pretty scary on a lot of other engines.

Anyways, i'll get some stuff put down on this soon, just to do something, share some info. I can get 80% of the benefit in the first 20% of the work...

 

[DeMilitarized]

I'll write up something one of these days. Been busy with other projects, been kinda swamped with other stuff.

Instead of making it a really long formal post, I may break the whole thing up into shorter sections... be easier for me to do (and its the sort of things I could spend a ton of time trying to make it look really good, which would be nice, but isn't essential).
I spent years as a financial analyst doing managerial reporting, so basically my work product was making charts, graphs, for the execs to read, share with each other, so my natural instinct is to go a bit overkill on presentation.

I will say one thing, these engines (C12s) do run a lot lower pressures on the dash gauges then a lot of other trucks, and its just a part of the design. "normal" oil pressure on a hot C12 idle would be pretty scary on a lot of other engines.

Anyways, i'll get some stuff put down on this soon, just to do something, share some info. I can get 80% of the benefit in the first 20% of the work...

Another note. I have found with Cat ET an almost 50% difference in oil pressure reading between the gauge and ET. It will sometimes at idle on the gauge say 15-18psi and Et says 35-40

 

[biscuitwhistler37]

I'm interested, don't have one yet but I will some day, probably the last/only computer controlled vehicle I'll buy .

 

[aw113sgte]

Just ran across this in the CAT troubleshooting manual.

 

[IridiumRed]

Theres actually TWO graphs, based on what "personality" is loaded into ECM, see chart below, out of same manual. The graphs are WAY different (1st chart, the one you show, for oct 99 and up personality module, has way lower pressures). This is something i've wondered about, why the difference.

I'm not sure they changed any hard parts that would change oil pressure between the two versions. Personality modules, (as I understand it, and its something i'm still fuzzy on) are mainly just software loaded into the ecm. It might require certain hardware to work along with it, but the personality module is just software. I'd like to know if i'm wrong on that.

I THINK they might have just redefined what they considered to be low / very low oil pressure for the system to react to, whether that be throwing warnings, derating, etc.

EITHER WAY, BOTH charts show that cat is comfortable with oil pressures that would be CRAZY low for most engines. Hot idle pressure in the single digits would, for many engines, be a big red flag. But Cat is showing that 5 psi hot idle (and a bit of RPM above that too), is acceptable / not cause for concern.

Finding those charts is one of the things that made me a lot more comfortable with the oil pressure on my Mk25 (it was in the teens hot idle on the dash gauge, from memory right now). I did some things to improve that (which I'll get into sometime), i'd say its more like 20 on the dash now hot idle (I added about 40-50% to hot idle pressure), but overall after doing a bunch of research on the topic, I got to where i just wasn't so concerned about it anymore. IE, if my hot idle was in teens, or even down to high single digits I think i wouldn't be too worried about it. Now as the engine speeds up you need more pressure of course

Also, with the way these systems are built, they bleed off excess pressure above 40psi (its a pretty good system, i like the design philosophy) so the COLD oil pressures can be misleading / concerning. Took me a while to figure out why it seemed like the cold pressures and hot pressures weren't that different. Compared to a lot of other engines, the oil pressure readings act different. But I think the cat system is a good one, I like it quite a bit actually. I'm a gearhead, sometimes i really get into the how / why something works, and I've got a real appreciation for good designs, esp ones that seem to tackle old issues with new solutions... that actually work.

When they say that the C12 is a HIGH VOLUME, LOW PRESSURE oil system, they really mean it, thats not just "advertising fluff". Also, there are lots of newer engines now that are doing a bunch of stuff to manage oil pressure (for lower parasitic drag, therefore better fuel economy / emissions), some of which are running really low oil pressure at hot idle... and I think a bunch of THOSE systems are dangerous in terms of engine longevity, because the oil pressures get really low, the rest of the engine really isn't setup to work well with that (they added a low pressure system onto an engine which was designed to have regular system... or at least didn't do enough design change to accomodate the oiling changes). And i think also those systems might be malfunctioning some too. Example, I hear the 7.3 Godzilla engines often have oiling issues, often have components failing due to insufficient oil flow/pressure (I think valvetrains / lifters are a particular sore spot with them).

But the way Cat designed their system, its very different, I think it avoids issues plaguing other engines. Just a different mindset all around. I dont know exactly how the godzilla system works, but I've got good idea on the C12 system, and i LIKE it. Its not some system that was put in to meet arbritrary / insane fuel economy / emissions rules... I think the C12 system stands alone as being a good idea itself, it probably helps reduce fuel consumption, but I think it should oil things better too, esp over the life of an engine. Feels like a win to me, not taking a loss because regulations / legislation demands it...

Anyways! blah blah blah. I'll do a writeup on the C12 system soon, promise At least a basic overview of it, you'll get the overall idea pretty quickly