Sump capacity

[Lonnie]

Would increasing sump capacity be useful (if you could figure out how to do it) change to make an engine last longer, and help to extend the oci?

There is a trucking operation in the Imperial Valley that hauls sugar beats and these stake bed trucks live a hard life. The one mod they do to these GM V8 engines is changing the oil pan to one that holds and extra 6.5 quarts of oil. The other mods they do is a Frantz on the oil and gasoline and a big baffled air filter with a K&N like outer filter and a paper innner element. They claim the last mod they figured out, the hugh oil pan was a big improvement. Oh, and they use Delo 400 15w40 oil and Napa/Wix oil filters. These trucks have two conditions they operate in loaded going from the fields to the processing plan and empty, returning. They operate at two speeds, full speed ahead and parked for the off-season. With the larger pan they don't get temp spikes when the trucks are waiting with the engine idling, to be loaded or unloaded after a fast run.

 

[427Z06]

What about short trippers or those engines that are never heavily loaded over an extended period of time? I would contend that a thermostatically controlled oil cooler would be the best compromise.

 

[BrianWC]

In SAAB's the oil cooler serves no real useful purpose on short trips...other than having a relatively high setting so it doesn't open readily. SAAB locates the cat very close to the oil pan to speed up the process. And that's with a 4 qt sump!

 

[CBODY67]

In prior times, there were about three different oil pan capacities for GM small block Chevy engines. One was for cars (5 quarts with filter change), then there was a 6 quart pan for medium-duty trucks, and also a 7 quart pan for the larger medium-duty trucks. All were rear-sump pans, but the difference was in the "step" between the rear sump and the front of the pan, with the larger capacity pans having more distance to the oil pan rail farther forward from the rear of the pan.

You might suspect the larger pans would result in lower oil temperatures (when oil temps were not an issue), but these are regular oil pans and have no additional "fins" on them for cooling, so any additional cooling from the larger capacity issues would be very minimal. These engines also came factory equipped, in many cases, with external oil coolers mounted near the radiator (even on some of the higher GVW 3/4 and 1-ton light duty trucks). These cooler mechanisms generally added about 1 quart to the system.

On those truck chassis, which I suspect are medium-duty chassis vehicles, there is lots of room to add "wings" (as many circle-track race oil pans have) and added depth, but basically doubling the oil capacity would take a lot of additional metal in an oil pan.

One issue not mentioned would be oil consumption and the decreased need for checking engine motor oil levels with the larger capacity oil pans. IF those trucks start running and don't stop for many miles during harvest season, a simple oil level check might not be as important as getting the goods to market on time. Even with an oil pressure gauge, the oil level can be below "Add" and still act normal.

Just some thoughts,
CBODY67

 

[harrydog]

Quote:

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Would increasing sump capacity be useful (if you could figure out how to do it) change to make an engine last longer, and help to extend the oci?

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I think the answer regarding extending the OCI is a definite yes. The answer to making the engine last longer is more of a probably.

 

[Lonnie]

You're right, checking oil levels was another problem that the larger pan solved. I think the pans now hold 13.5 quarts of oil and the Frantz adds about one more. They put the same large sumps on a couple of trucks that see only short stop and go driving and don't carry heavy loads and never get really warmed up. These stop and go no load trucks have only been running like that for two years and only have 10-15k miles, but the sludging from not warming up is not happening. They have pulled off the valve covers on three or four of them and they are not sludged up at all. It's really too soon to tell, but it appears that larger sump capacity is useful. Yard trucks like these are usually run for ten or more years. The heavy haul trucks never make it past three years, and most go in two years. A typical season is 100 working days and 200 miles a day. During a season a truck will miss part of all of 10 days for service. In the cold part of the season the temps will drop down into double digits but much of it is triple digit weather.

I looked through the records and their time with synthetic oil showed no operational advantages. They were unable to extend oci's because of wear particles and falling tbn's. They have arrived at a good running solution with the Delo 400 and their current maintenance and truck setups.

 

[427Z06]

Given the operational conditions and maintenance program, it looks like this organization came up with a good solution particularly if they're incapable of checking fluid levels while the truck is being fueled. I thought your question was of a more general nature.

 

[Lonnie]

I thought it was interesting that they think that increased sump capacity was the most important part of their plan. They equate the sump capacity with increased engine life and also extending their oci's 5k miles to 10k.

 

[Syntec-Man]

That is a damm good idea! Add a engine oil cooler aswell and there will never be problems

 

[TallPaul]

IMO, an oil like Redline can "increase sump capacity" in that the higher heat tollerance of Redline and the lower friction will more or less produce the same results as running a larger load of conventional or even Group III synthetic.

 

[Lonnie]

I asked a friend that manages a fleet of truck in S.America on a big construction project. He considers increasing the sump capacity as the single most important thing they have done to their trucks and tractors, beyond the obvious good oil and filters along with services driven by lab results. They have a bunch of Ford pickups and they went to a lot of trouble engineering hugh sumps that almost doubled the capacity. He said coolers are great but are expensive and troublesome and to stick with a big sump. The company that fabricated the sumps was give a truck to experiment with and it's a two piece affair. One part bolts on and the other is attached by a large flange. They now have more oil and an easy way to look inside. They use a local 15w40 oil and change it based on gallons of gasoline consumed, I think I remember 500 gallons. He said gas consumed was far more important that miles driven and they have been doing it that way for a long time.