I've ran the Pony Express ORR at speed 130 - 150 MPH using the Canton RR pan + the Canton HV blueprinted oil pump that uses the Canton pan specific 3/4" DIA oil pickup. Went with the HV pump due to the increased volume inside the -10 AN oil lines running to an external Mocal oil cooler and remote mount filter. Ran a sustained RPM of 4800-5500 for 83 miles, pumped all of the oil into the top end and heat scored the rod & main bearings.

After the fact I found a good description of how this happens in my 5th edition GM "Chevy Power Manual" page 3-29 directly from the manual....

"The final most difficult basic requirement is a steady oil pressure supply. The majority of engine bearing failures are a direct result of oil pressure loss due to the oil pump picking up air while negotiating turns at racing speeds. This occurs at a time when the driver is busiest and may go unreported, or be reported as a slight drop in oil pressure in the turns.

Oil pressure loss in turns is aggravated by three things:
1) Insufficient oil level or capacity
2) High engine oil flow rates due to excessive bearing clearances, or higher than necessary oil pressure.
3) Improper oil pan baffling, usually over-baffling which prevents the engine oil from properly draining back into the oil pan while the car is in a turn."

I had planned to install an oil accumulator but didn’t get it completed in time for the event, believe #3 above was part of the cause; the sustained RPM over such a long period allowed the HV pump to fill the upper end W/ oil and the extra baffling in the Canton RR pan slowed the oil return rate to the sump. During one of the long 120 MPH + sweepers the G loading caused the oil in the sump to move away from the pickup for a split second.
My bad should have had an accumulator installed, knew better...

 

superlund, the setup which caused your failure is where i am now (240T pan with "pressure balanced" HV pump and 3/4" inlet), and i'm positive it's not running the pan dry. yet i am having some oil pressure issues at high rpm. i really think it's a pump cavitation issue, and it might be due to how the larger inlet interacts with the pump and bypass. (the irony.)

keep in mind, the bypass means you don't see more than 70psi, ever. so if there's no increased pressure, just how is all the extra oil going to the top of the engine? and why does a HV only fill the top without more flow also going past the crank/rods and back into the pan.

also, your excerpt doesn't say a HV pump will suck a pan dry.

i don't deny some problems exist with certain combinations, but the sucking dry theory just doesn't fly with me. for one, i overfilled mine by 2 quarts and it behaves identically. no lag in the pressure drop at all. it's purely a function of rpm. i can sit still in the driveway and keep it at 4900rpm for hours, but as soon as i go past 5k rpm, the pressure drops 20psi.

i am sorry to hear of what happened. is it back together now? if so, what pump/pickup/pan combination are you running?

-michael

 

great info! :cheers:

 

Headed to work so this will be relatively short,

I agree, it did not suck the "pan dry" but IMHO it puts too much oil into the top end.
The gold nugget of Info was #3 in that list for me. The extra baffling is great for keeping oil at the sump provided there is enough oil in the sump to begin with. After that the baffling slows the oil return to the sump.

I believe my sump got low enough during the sustained RPM W/ slower than normal oil return. G forces placed the remainder of oil in the sump away from the pickup for a split second. The car was fine & still made plenty of power for months afterwards. Found the issue on tear down / inspection.

FWIW, I ran Mobil-1 15-50 and had the rod & main bearing clearance set at .0023 -.0025

Just a theory Mike, I'll address the balance of your question later...

-Jim

 

Hi Mike,

I just spoke to Dan at Melling and he said that you can use the same pickup for the M155HV (20-079) as you can for the 10552. He told me the 10552 looks different but you can press on, or bolt on using a flanged bolt. he said the measurements are .739 at the start and .735 at the press, which he thinks is 19mm.

We'll see if John can get it together this weekend.

Mike

 

Poeple using the Melling 10552.....make sure you check your mating surface at the main maining cap. The first pump i bought didn't seal. I accidently found this out when i matched a baffle to the pump and then layed it on the cap. I could see right thru at one of the corners. After spending some time on the phone with melling, they decided the pump was miscast. I sent it back and ordered another one, which just barely sealed in the same spot. Not sure if the main cap on the 400 block was at fault or the pump, but they didn't match very well.

 

mike, perhaps i wasn't persistent enough, but i really thought the 20-079 was the wrong diameter to fit the 10552. given the numbers from dan at melling, that's smaller than 19mm. (it's 18.7mm.)

maybe it would have gone in if i forced the issue. on the other hand, the pickup went it with just some tapping into the 155 pump.

i still have the parts, i'll check them out when i get time. or update us on what john finds.

thanks.

ralph, thanks for the info. i always check for that, fwiw.

-michael

 

Mike, I'll try to answer your questions directly. Keep in mind I'm not arguing a point just sharing what I believe happened in my case for everyones benefit.

Probably not running the pan dry but based on my experience I would highly recommend an oil accumulator, heck everybody with sticky tires and a wet sump oil system should have one as insurance.


I agree the design / shape of an oil pickup will affect pump cavitation; I relied on the Canton engineering group to get the shape correct, as it's not my area of expertise. There is an entire fluid dynamics discipline happening in and near the oil pickup & the only way to ever get it right would be thru development & testing. I'm assuming based on Cantons good reputation they got it right.

Yep, never did see over 70-75 PSI ever. Only one way to the rocker area and that is thru the pushrod orifice. IMHO, the HV pump simply keeps the volume a constant so that the extra volume in the larger -10 oil lines / oil cooler remote large oil filter Etc are always full of fluid & thus the oil pressure does not drop while attempting to fill those large extra capacity volumes. It stands to reason extra oil is passing thru the rod & main bearings, but that would be based on specific bearing clearances. At sustained high RPM I believe the large gears in the HV pump and near 3/4" DIA pickup are removing oil from the pan at or near the oil return rate. It's my opinion (based on what I have read & experienced) the baffling slows the return to the actual sump area further.

It shouldn't never did on mine, but it "may" remove more oil from the sump area of the pan & allow the oil pickup to uncover during high G cornering & suck air then cavitate


Agreed correct combinations are critical, the exact reason I went with all Canton products and even spoke with the Tech rep when I ordered / purchased directly from Canton. Never overfilled mine, didn't want to raise the oil level above the windage tray / screen. Certainly sounds like yours could be cavitating at 5K + RPM. Mine never dropped pressure over 5K RPM, ran it to 6500 RPM quite a bit and never noticed a pressure drop. I would call Canton or even Peterson Fluid Systems and talk about the issue.

Not back together yet, decided to upgrade a few things and ended up upgrading everything, kind of a life long problem I've had. Hand built Coilovers, Rod end rear suspension links everywhere, trick heads with top notch parts, more cam, lighter tool steel piston pins, Etc, Etc.
Last winter I went thru an exercise on installing a 4 stage dry sump system, believe I have it figured out but spring is here and that will have to wait until next winter. I plan to reuse this Canton pan or possibly sell it and purchase one of Merle's new pans out at Exotic Muscle, probably toss the Canton HV pump and get a standard volume pump & blueprint it W/ cavitation grooves Etc. My only concern is low oil pressure with the added oil cooler / filter and large -10 plumbing. And the car won't even be fired up until a 3 QT oil accumulator is in place.

Here is a shot of the pump; I wasn't using the oil filter adaptor in the pic. I had a large block off that went to a remote unit






[Modified by superlund, 6:45 PM 4/14/2004]

 

I did that. It wasent apparent untill the engine was running.

 

ditto! this is a good discussion.

i'm beginning to think canton isn't doing such a bangup job with their pans, and they know it, which is why they push the accumulator. for example, on my stock LT4 with the stock oil pan and windage tray, i never had oil pressure problems even in extended cornering on 315 victoracers.

the baffles preventing quick return is an idea i had as well. part of the reason this occurred to me is because my oil level sending unit often claims the oil level is low, when i know it's not. i replaced the sending unit, no change. so something funky is going on.

were you using the sending unit for oil level? if so, did it work properly?

i made the same assumption. but, i have to admit, i'm not sure where canton's "good reputation" comes from. seems to me like a high percentage of people on this forum who roadraced with a canton oil pan has had problems.

well, sounds like something is different/wrong with my setup, then. since the pressure behaves as a stepped function, this almost mandates that it's a pickup/pump problem, rather than a problem in the engine (where pressure would be low all the time or have a linear dropoff).

who is peterson fluid systems?

thanks.

-michael

 

Does anyone have a part number on the oil accumulator, and where to purchase? Since I have the motor torn apart right now, this would be a good time to add it. John (CorvetteZ51Racer) had mentioned to me that this was the way to go.

Mike

 

Mike it's just a 3qt. Accusump. (I'm not entirely sure that the don't make it for Moroso also) If you don't want it inside the cabin, you may want to locate it perpendicular to the rear frame rails back where the spare "was". ;)
You should use both the manual and electric valves. (The manual is a back up in case the electric valve pukes, which I understand is not uncommon.) Just make sure that you place the mounting band clamps at the outermost ends of the sump. (on the endcaps is good.)

 

Where's the oil getting "hung up"?
Since it's a closed system, it has to be stacked someplace.. :confused:
heads?
under the intake?
I've heard of oil stacking in the heads on some high camber road courses.

Have you guys tried "porting" the oil returns? polishing etc.

How about running extra return lines from the valve covers?

 

i think superlund was suggesting the baffled pans are slowing the drain back into the pocket where the pickup is.

in my engine it's not in the heads. i can leave the oil cap off and not see an appreciable puddling of oil in the head at any rpm. all of the lifters seemed to have tight tolerances into the lifter bores, so i don't think oil is puddling under the intake.

if there were debris in the oil drainback holes from the lifter valley, that would be a problem. (but it would also be a problem with a SV pump.)

something else, if flow is increased through the rods (and i maintain there's no flow increase unless you're seeing higher oil pressure), there's more potential for windage to mist the oil. now this is something i might be experiencing, since oil does pool into the hose connecting crankcase and TB. my engine does not consume oil, nor does it have blowby, so such an accumulation is likely due to condensing mist.

if i'm having this problem, it would have to be due to the rod clearances and rod side clearances being too large, since i'm never seeing higher than stock oil pressures.

there's a lot going on here. but that's always the case when something is really analyzed closely. i've always been a proponent of SV pumps, but for different reasons. these problems just solidify my initial stance.

-michael

 

I went to great lengths accurately measuring how much oil the "pan" would hold prior to installing it, also tested the capacity of each piece in the oiling system. Accurately marked the dipstick while the engine was on the stand, and double checked my work by removing the pan Etc. Did all this so I could keep the oil level as full as possible but remain below the windage tray / screen. Checked the oil every time the car was fired off and the dipstick would show full but sometimes the low oil sender would trigger and set off the low oil light. Mine acted "funky" as well, if it came on at start up I could drive a few blocks, turn the key to off, kill the engine then back on and the light would go out when the engine restarted. My thought now is that cold / thick oil was not returning to the pan sump as quickly as it was being removed by the HV pump

Peterson Fluid Systems makes high quality oiling systems, their focus is the dry sump market, but they specialize in oiling systems. Often it helps to get a third or even fourth perspective. The dry sump guys get to hear all about wet sump problems everyday.

Here's a couple links.... http://www.petersonfluidsys.com/index.html http://www.rehermorrison.com/techTalk/36.htm

Brian C,

Yes I ported the oil return passages to a degree, when I initially built the engine I worked on the oil return passages in the heads with a die grinder. In reality the LT4 heads have very large rectangular shaped oil returns at each end, much better / larger than the old "round" 3/8" - 1/2" SBC oil returns.

I've got to admit; when I was diagnosing my problem I found a post where H Rocks described the problem almost exactly. I believe it was in the Auto-X Road Race section, he spoke of how his oil light would illuminate for a split second at high G load cornering. I think the large light is key as most of us are way to busy at speed in high g cornering to ever notice the drop on a gauge...
-Jim





[Modified by superlund, 7:17 PM 4/15/2004]

 

Well Michael, you were right... the Canton 20-079 pickup is not a direct fit with the Melling 10552 pump, but John was able to get it to work by doing the following 3 things:

1. Open up the inlet tube on the pump by .0015 (I think that is right)
2. Put a notch in the pump so the bolt flange on the pickup could slide in.
3. Increase the size of the bolt hole (horizontally) on the pickup so it would line up with the pump hole.

Here is a shot of Jim's motor with the 20-079 pickup and what I believe to be the M155HV pump:



This will give you a better idea of what John had to do to mate them up. We were also lucky there was a kid working on a tube frame chasis car at the engine lab who tack-welded it for us.

Next comes the notch for the sensor on the passenger side of the pan, and checking the dipstick. We now have the bottom end together (no clearance issues) but are waiting on a new timing set and rear main seal from Superior Chevy.

BTW, Nathan, sorry about us somewhat hi-jacking your thread. I do think there is some pretty good information here though if anybody plans on going with this Pan.

Mike


[Modified by luvmy92, 11:28 AM 4/18/2004]

 

Don't worry about that! There's great information in this thread. It will be very valuable if / when I decide to upgrade the pan.

 

mike, thanks for the update. i'm glad i wasn't spreading misinformation!

how did john open the pump inlet?

i think i'm probably going to try a stock pump next.

-michael

 

Michael, sorry I haven't been in touch with you about the pump progress. I'm right in the middle of writing my master's thesis, and got the pump sorted out during a "break" in writing :lol:

Anyway, the OD of the pickup tube is 0.749", and the ID of the pump housing is 0.735". I took a 0.750" 4 flute end mill, turned it down to a 0.745" diameter, and built a small jig so that I could clamp the bottom piece of the pump housing in a mill. I literally just plunged the end mill into the hole once I centered the spindle on the hole's centerline. I will be up at the engine shop for a few minutes tomorrow, and will try to take some pictures of the notch I made in the pump housing and the mods I made to the pickup's flange to make it fit.

 

Im under the impression a 'high volume' pump is the same as a high pressure pump. that true? my builder said he has a high pressure pump with my canton setup...

:confused: