As anyone who has actually seen the insides of a 472/500 inch motor the size of the rod and main crank journals are very generous. They should be capable of much more horsepower than the Engineers ever intended and they are. The oiling system likewise is sufficient to keep these motors (if the oil is up to capacity) running for several hundred thousand miles without failure.
The oil pump too is more than sufficient.
When, however modifications to the motor are made for high performance that allow higher motor speeds (this motor was designed to run at a maximum of about 4600 RPM) over 5000 RPM the seemingly singular pitfall becomes apparent. Due to the oil circuitry where oil is fed first to the passenger side gallery which serves the lifters, cam shaft, rods and mains and then fed (via the crossover passage) to the drivers side gallery, the "end of the line" where the oil pressure sensor is is also where the rear main and crank throw bearings reside.
The short version is that it is not uncommon for #7 and/or#8 rod bearings to be destroyed with an extended 6000 RPM "jaunt".
Folks in the esoteric Cadillac high performance arena have tried several remedies without much success but have found that by running an auxiliary oil lone from the factory plugged high pressure port just above the pump around to the back of the motor and tapping into the galleries through existing plugged gallery plugs oil is distributed equally and the inherent short fall is overcome. You ask how I found the short fall? 6200 RPM.
Anyhow my motor is going back together and I have included a couple of shots of the oil system plumbing.
I know this is purely academic for most of you but some might find it interesting. I wonder what Robert Templin would think?
Greg Surfas
Greg, thanks for the info...First question is why you went with rigid tubing instead of flex lines?
Are the lines steel or aluminum?
Jim,
The lines are Steel. Flexible lines are intended when there might be relative movement between the two ends of said line. There should be VERY LITTLE movement between the front and the rear of the block.
Greg Surfas
very interesting! On my engine the #8 connecting rod bearing failed (spun), however I certainly never drove the car with rpms over 4500. During the rebuild I have not found the reason for the failure.
Nicholas,
#8 is "at the end of the line" in the oiling system, so anything that effects oil delivery such as a weak pump, plugged filter, excessive leakage elsewhere (excessive lifter/bore clearances), or debris in the oil galeries will get to #8 first.
Greg Surfas
Quote from: "Cadillac Kid" Greg Surfas 15364 on December 25, 2018, 03:12:56 PM
Nicholas,
#8 is "at the end of the line" in the oiling system, so anything that effects oil delivery such as a weak pump, plugged filter, excessive leakage elsewhere (excessive lifter/bore clearances), or debris in the oil galeries will get to #8 first.
Greg Surfas
Ok, maybe there was left over debris from a previous rebuild. However, I was not sure how much debris was from the recent bearing failure. The bearing where already oversized.
I understand that the pressure sensor / gauge is also at the end, so could one check the pressure readings?
Would you need move the location of your pressure sensor because it is not at the end of the oiling system anymore?
Doesn't show in the picture but the blue fitting in the rear that is shown going into the oil pressure sensor tap has a female pipe thread on the side here pressure sensor and gage wll go.
Greg Surfas
Quote from: DeVille68 on December 26, 2018, 03:42:04 PM
Would you need move the location of your pressure sensor because it is not at the end of the oiling system anymore?
You always want your pressure sensor at the end simply because it will show any pressure loss throughout the system.
Having it at the pump will only indicate a pump failure.
BUT, the big thing is to actually monitor the gauges and not simply forget about them.
The best thing is to include a warning buzzer to immediately alert the operator that something is not right. Lights are good, but the buzzer is instantaneous. As long as it is louder that the rest of the noises within the car, or without the car.
Bruce. >:D
Bruce,
Simply put there are 3 actual "end of the circuitry" points in the 500 inch motor's oiling system. The location of the pressure sensor on the stock motor is a compromise and it is possible to have low oil pressure at several points without it activating the sensor at (I believe it is) 8 psig. You are correct also in a "Warning system", and that consists of a big b right red light just opposite the shift light on my dash. Buzzer? You have to be kidding. Ambient sound at 6000 RPM with open headers and 110 MPH is something approaching 120db.
Remember this is not a modification necessary for a 500 until you get somewhere into the 500 HP and 6000+ RPM.
Greg Surfas
Most of the classic American engines have pretty similar oil paths and systems don't they? What was the setup on the V-12 WW2 aircraft engines? Those had some pretty big pistons to throw around and I assume ran at a pretty high rpm especially considering their size.
What is the question in there TJ?
Greg Surfas
I was just wondering how someone would design the oiling system of a big engine that you planned on spinning fast and I was assuming the WW2 V12 plane engines would qualify as big and fast so I wondered how they did it.
Also wondered if any of the car makers ever did anything significantly different oil path wise or if they were all more or less the same? I assume some of the other 'big blocks' from the 500 era were expected and rated to spin pretty fast how did they more or less survive?
TJ,
Engines such as the Allison 1600 and the RR Merlin as well as the high output radial engines were dry sump oil systems. That means that the designers could introduce oil through external lines to the points that they thought most needy. That said, 3000 RPM was the "war emergency" red line for these motors and they were only expected to last something like 300-500 hours before replacement. Most of these motors were extremely complex and so were there oil circuitry.
Regarding other (than Cadillac) manufacturer's V-8 oiling systems, many feed the crankshaft directly (first in line) from the pump or have multiple parallel oil galleries. That means they feed the cam/crank directly off of a gallery and the lifters/valve trains off their own supply gallery.
The galleries in the Cadillac depend upon a cross-over between the two galleries which is just aft of the second cam bearing to feed the drivers side valve train and the rear main and rear crank throw.
This oiling system is more than adequate for all "Normal" expected operations of this motor, but when pushed into the 500+ HP and 6000+ RPM the shortfall is the last main/crank throw.
Greg Surfas
Thanks for the info. I didn't know that 3k was redline for those aircraft engines but it does make sense. Its got to be some of those pesky laws of physics that make it difficult to make a big mass reciprocate really quickly and survive.
If you have the answers and don't mind more questions.....
When you put an engine under more stress like in this case are you just trying to get more oil to the bearings? What happens to the oil that is there when its under stress? I assume its multiple issues. Does the increased pressure on the bearings from compression stroke and the force of changing directions just mash the oil out so to speak? Or the extra heat break it down? Getting more oil there helps both cool things and replace what was go squished or thrown out?
Interesting! I kinda had the same thoughts but you outlined them nicely!
Lubrication and rotating bearing lubrication is quite a complex combination of viscosity, temperature, clearances, relative rotating speeds, unit area loading, metallurgy, and a myriad other factors. Aircraft engine speed as the WW II motors were designed is limited by propeller speed or rather propeller tip speeds. They worked backwards with motor design to maximize output at the propeller speed they were intending to use.
Greg Surfas
I have resisted looking at this thread since it's been up, but finally did so. I know just about enough to be like Penny on Big Bang. I could follow what you guys were talking about and understand it pretty well. I don't have a car with one of these engines, so my interest is moot, but I certainly appreciate having people at hand that can explain (and work out the fix) in such an interesting way. Good job! I've learned something new today.
(My dad worked on the V1710 engine at Allison plant three during WWII and kept some of his manuals, but I never knew that War Emergency Power turned relatively slowly.)
Barry,
"war emergency" power settings increase the blower boost, add a few hundred RPM to the engine speed and engage the "water" (water/methanol) injection.
Greg Surfa
Quote from: "Cadillac Kid" Greg Surfas 15364 on December 28, 2018, 08:06:52 PM
Barry,
"war emergency" power settings increase the blower boost, add a few hundred RPM to the engine speed and engage the "water" (water/methanol) injection.
Greg Surfa
And probably saved many pilots when they really needed the extra grunt to escape.
Bruce. >:D
Did a mock up and the oil line seemed a bit close to the header. Re routed the line and put it in an insulated jacket. Might wrap the headers also.
Greg Surfas
Greg,
DO NOT wrap your headers as this will draw moisture when cooling and hold the moisture until the engine is started and cooks the moisture back out. I would strongly recommend having the headers coated both inside and out. This yields multiple benefits.
1. Ceramic coatings will help with a reduction in understood temperatures.
2. Your headers will last a very very long time.
3. Improved appearance. Today's coatings can also be tinted to some degree.
4. Most importantly by having g the inside coated the heat stays out of the metal and is reflected which causes a low pressure area in the primary tube that can help exhaust evacuation from the exhaust port . This can mean a slight improvement in power.
One side note, a friend of mine had a set of nickel coated headers that he wrapped with Thermotec header wrap. The headers retained so much heat that they formed a sag. This was for a 170 cid straight 6 Ford engine where the header is below the intake manifold.
I use a place in Joliet Illinois for my header coatings and my headers look as new today as when I installed them. Contact your header manufacturer for verification or recommdations.
Hope this helps,
Terry
P.S. These coatings can also be applied to exhaust manifolds for the same benefits and CAN be tinted to mimic the look of new cast iron.
I know this is an old thread. But I'm new to building one of these engines and new to this site. What oil pump are you using? CadCo or self modified?
Started out with an MTS modified pump and went a bit further.
Greg Surfas
Despite low rpm, those engines running on up to 150 octane
gas and some water injection, were developed with outrageous
boost to manage 1 hp per cubic inch. The engine speed is not
the prop speed, they were geared, and the prop (up to 13 feet
dia and with an increasing number of blades) had to be
variable pitch (toward constant engine rpm) to be competitive.
Bruce Roe
Thanks for all the input. Have read similar oil articles on GM 455 engines too. Today I drove my 472 powered Cadillac and kept it around 70 mph, never going past 2,800 rpms. Good to know nonetheless.
Is the Cad Co pump comparable to the MTS pump? And what mods did you ad? MTS, which is now CHP has pending court action in I think three states. So I won't deal with them.
Quote from: manicmechanic on February 10, 2022, 09:40:41 PM
Is the Cad Co pump comparable to the MTS pump? And what mods did you ad? MTS, which is now CHP has pending court action in I think three states. So I won't deal with them.
Do you have a link to the story?
That would be an interesting read. I have never been done wrong by MTS in any way. I haven't dealt with them since the passing of Marty. I've honestly had no reason to.
After Marty died company changed names three times. From MTS to another company and to Cadillac High Performance. Went from CA to FL to IL. or IL. to FL. I know the IL. Was an article in an IL. newspaper. BBB went after them for non delivery of parts and services. Was on the H.A.M.B., Cadillac Magazine forum and I think another Cad forum.
https://cadillacmagazine.com/forums/attachments/7db85153-02b4-49d4-aa93-06d876be956c-jpeg.25544/
Link to Cadillac Magazine. https://cadillacmagazine.com/forums/threads/cadillac-high-performance-chp-at-it-once-again.19196/
I recall about 93 buying a trans support from, I think, the original
MTS in Gardner, MA. He was bought out by Max in Delavan WI.
This was not far, by a long time friend, and I was over there a few
times, bought smaller parts, fixed some ECUs, and even fixed his
trailer wiring on an IL trip. Saw his 69 Eldo drive train in a Corvair
race car. He had a big customer party with some interesting vehicles
showing up, then MTS was sold to Marty. I did buy some EFI temp
sensors, but those sold out, and our Scott Kent has redesigned them.
Have not had MTS contact since then. Bruce Roe
It's a real shame to see a quality supplier of parts and services to take such a nose dive.
Yeah
Marty is quite unhappy about it himself.
Greg Surfas
If you are talking with him Greg, you're better than I thought. ;)
Greg. Do you have better pix of the oil lines and an explanation on where you are drilling the block?
Here are a couple of shots
Greg Surfas
and a couple more.
The only hole is through the bellhousing as shown.
Greg Surfas
Max in Delavan? I remember dealing with an Al there just before it went to Marty. Marty was obviously what gave the company its drive and direction because they sure got lost after they lost him.
Amen.
Quote from: TJ Hopland
Max in Delavan? I remember dealing with an Al
Both names seemed to apply, do not ask me to understand. Bruce Roe
Greg, there is a guy on another site that has some interesting ideas on Cad oiling systems also. I haven't seen you there in a while.