How should I determine sump oil level after a customised sump?

[rcx194]

I don't want to mess up a good engine so I thought I best ask for advice on determining oil level.

My buggy uses the chassis and running gear from a Suzuki SJ413 / Samurai, which is a solid axle based car. But I've fitted the engine from a Suzuki Vitara / Sidekick. It's same engine family so it bolted straight on (almost). I had to use the sump from the original engine though, as the Vitara engine is originally a front sump to get around the independent suspension, whereas the buggy needs a rear sump.

So now, what do I do to determine the correct oil level?

 

[TugboatEng]

When you use a dipstick you're measuring the sump level relative to the engine block. Changing the pan/sump doesn't change this measurement.

 

[BrianPetersen]

Did you swap out the oil pump pick-up tube and screen as well? (did that swap over from the old engine?) It should be pulling oil out from very close to the bottom of the sump. (I like the shape of that sump, by the way.)

 

[rcx194]

Hi Brian, I had to modify the oil pick up to get it into the wrong place. I didn't want to swap the pickups as the SJ has a much smaller diameter pickup which would have caused a restriction.

 

[EdStainless]

So what matters is the volume of oil above the pickup.
You need to figure out how much oil it takes to cover the pickup, and then add the required volume for the engine.
And then adjust the dipstick or tube so that you can measure it.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[gruntguru]

Or put the same quantity of oil you used to put in that sump. Its shape hasn't changed so that quantity should fill it to the same level.

je suis charlie

 

[TugboatEng]

It's common on the old American V8 engines to install oil pans with extra capacity in the sump. They're wider, taller, deeper. The oil level remains the same on the dipstick. You want it to be as full as possible without the crankshaft whipping it up. Use your existing dipstick to set the correct oil level.

 

[waross]

Two important measurements.
Minimum head of oil above the oil pickup.
Minimum clearance from the oil surface to the bottom of the crank.
With that in mind, the distance from the bottom of the block to the relocated oil pickup is important.

--------------------
Ohm's law
Not just a good idea;
It's the LAW!

 

[romke]

Apart from the suggested measurements (head of oil above the oil pickup,clearance from the oil surface to the bottom of the crank)there might be a few other things to consider. If the vehicle is to be used in rough terrain and sometimes short steep slopes, the shape of the oil pan may need attention, to prevent that under some instances the oil pump sucks in air in stead of oil. Another thing to consider is the total amount of oil available. What you want is so much oil that when the engine is thoroughly warmed up, it still has sufficient viscosity to lubricate all the moving parts. Since oil is very temperature sensitive, oil will be far to viscous when warming up. That means that the total amount of oil should not be excessive, the amount should be chosen on the basis of "thick enough at the maximum expected operating temperature". Anything more will extend the warm up time, anything less could endanger the parts to be lubricated. It may well take some time to find out the optimum quantity that is both sufficient and not too high.