SoCal Jet Boats
Tech Talk => Engine Mechanical / Electrical => Topic started by: el mojado on April 23, 2017, 06:40:49 PM
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What are the benefits of a larger capacity pan. Is 10 qts enough for a 496? I have a 12 qt. pan (might be more) which I would like to trade for a 10. I dont want to have to fill with more oil. Is there any good reason that i should just run the larger capacity pan?
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One argument is cooler oil temperatures (which I call bs).
The major benefit is keeping the oil pump bathed in a constant supply of oil, the heads and lifter valley can hold large amounts of oil, especially without good windage and ventilation control in the crankcase.
99 times out of 100, a ten quart pan is enough. Something I always say is that a ten quart pan does not really hold ten quarts. Same can be said about a 12, a 14' and so on.
The other things to take into consideration is the room they take up and service access.
We ran a 14 quart pan and an Oberg filter on the race boat with a bypass system to filter the oil down real tight. The system worked perfect, but it was a ton of money in oil capacity.
We could have easily gotten away with a ten quart pan, but we would have had to change the oil more often (the added oil stays very clean, much longer). This was a marathon engine that ran 80-120 miles a day for two or three days. Absolutely wide open.
So to each their own, if you are only talking a couple quarts, it's not a really huge debate. Just make sure the trap doors open extremely easy and the pan is stupid clean when you install it.
You can use a measuring cup and water to see what the capacity is....... Should be just below the tray when full.
GT
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Engine angle plays a roll in how much oil should be in the pan.
A Berkeley pump and its clones have a 4-degree intake. Low-profile intakes are typically 5-degrees. That means that the pump shaft will be anywhere from 4 to 5.5-degrees relative to keel. Carburetors don't like to work at such extreme angle, so the front of the engine is rocked down to set the engine at a better approximation of level. I haven't directly compared stringer angle to keel angle, but I will venture to say, it is always different. The majority of my engine installs fall in the range of 2.5 to 3.0-degrees relative to the stringers. Now, combine that with the attitude of the hull while underway. Now factor in different speeds (and their different attitudes).
I'm sure that you can see the difficulty in determining the actual operating angle of the engine.
So, how much oil does any given pan actually hold? Unfortunately, I believe that the answer to this question is dependent on the uniqueness of the individual rigging of your boat.
My philosophy is, only enough oil so that it remains under the windage tray. If the oil slashes back, particularly under acceleration, it will be picked up by the rotating assembly and oil pressure will drop. Some experimentation is required to arrive at the proper oil level.
So, which pan? Deeper is better from a windage standpoint. I believe that you have a 3-point mount system. That will limit your pan depth to about 8" in the rear before you run into interference issues with the front intake bolts and/or through-bolted loader fasteners. Therefore a higher capacity pan needs to be wider and not deeper.
A wider pan, however has some disadvantages. The oil level, for the same volume of oil, will be lower than in a narrower pan. It is possible that, during spirited driving, the oil sloshing sideways/forwards could potentially uncover the oil pump pickup. I don't see that as an issue in your case.
I would run the 12-quart pan. Start with 8-9 quarts and monitor your oil pressure. Adjust accordingly.
Cheers,
Joe
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Inquiring minds want to know; and one test is worth 1,000 theories.
I have this oil pan of unknown origin that I decided to run some tests with. This is off of my boat and it's probably what will go back on, after some minor modifications. Anyway, it's chrome, so it must be good, right?
I also measured the stringers on a 19' CP. I zeroed a digital level on the keel, just in front of the intake. This is the location where all of our measurements are basselined from. The suction surface of the intake is 4-degrees up towards the bow. The back cut of the shoe is 3-degrees down towards the transom. The ride plate will initially be set 4-degrees up towards the diverter. The nozzle will initially have 7-degrees up and 4-degrees down nozzle. These are just starting points and may change as the combination is fine tuned. I am including these numbers to reinforce this location as baseline for all other measurements.
So, here are my findings:
The stringers angle up 0.6-degrees towards the bow (Picture 1).
The engine angles up 2.5-degrees towards the bow, relative to the stringers. That places the engine (in this boat) at 3.1-degrees angled up towards the bow, relative to the keel.
The oil pan:
I started by rigging the pan at 4-degrees up (Picture 2). Filled with 10 quarts of water, the level is 1/8" below the top edge of the rear baffle (Picture 3).
Dropping the front of the pan down to 2-degrees, the level is 1/2" below the baffle (Picture 4).
Filling the pan with a total of 11 quarts, while at 2-degrees, the level returned to 1/8" below the rear baffle.
With the pan level, 12 quarts brings the level within 1/8" of the bottom of the windage tray (Picture 5).
Conclusion:
I still have no idea what the relationship between the engine and the surface of the water is, while on plane. A guesstimation, the engine could be over 8-degrees angling up towards the bow, while on plane (in calm water).
With just 4-degrees of angularity, 10 quarts comes dangerously close to the rotating assembly. Any more angularity or quarts and the crank is beating the oil into froth. Picture 6 illustrates what 12 quarts @ 8-degrees looks like, putting the oil level just 3/4" from the oil pan gasket and well into the 4th crank throw.
This should also illustrate, just how important a rear pan baffle is. Granted, the oil pump takes up a lot of space where the windage tray is cut away, the pump does not seal to the pan, nor does it prevent hot oil from flowing around it, into the spinning crankshaft, and up into the 7 and 8 cylinders.
Lastly, deeper is better because the oil level is further away from the rotating assembly. Unfortunately, 8" deep is what we are limited to. Picture 7 shows damage from the intake bolts. Moving the engine forward can allow a slightly deeper pan. Raising the engine is not worth the increase in center of gravity.
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Wow guys. This is great info. Thank you.
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What are the benefits of a larger capacity pan...I have a 12 qt. pan...which I would like to trade for a 10...Is there any good reason that i should just run the larger capacity pan?
Given a choice between a 10-qt pan & 12-qt pan, I would opt to run the pan that will provide the best oil control for the engine. The difference in capacity in this case probably doesn't matter at all