dry sump update and question

[roadracer55]

I just moved my dry symp oil tank and placed my water header tank and catch cans for both. Took a lot of thought to position them in the best spot and plan the bulkhead (which I'll make out of aluminum later), but I'm happy now.

To be honest, this is the second attempt, I had to cut the brackets off the chassis and move them after my first attempt where I didn't remember the rocker covers were on studs and needed some room to remove..
:ssst:

https://static1.pt-content.com/images/pt/2008/01/2220986133_373cd358e8-1.jpg

So, my question is regarding the problem where the dry sump tank will potentially drain down into the engine overnight and you can hydraulic the engine. I planned to add a valve in the return line and use a cable in the dash to shut it off. An ignition cut-off switch would be next to the valve so that I couldnt start the engine when the oil is shut-off.

That was the plan, but I heard the other day that some motorbikes had dry sumps and to prevent drain-down they had a spring-loaded inline valve that opened when run (presumably closed until the pump generates 5psi or whatever) ..anyone heard of an automatic solution like this?

[roadracer55]

ttt - anyone?

[parsonsj]

Sure. I've seen spring-loaded oil accumulators, but they were for failure modes rather than startup. Once the oil pump is shut down, the accumulator shoots it wad, and it takes a running motor to re-arm the accumulator.

For startup, you'd need some sort of electronic sensor, or an electric oil pump or the like.

jp

[roadracer55]

thanks john, but as you say accumulators solve a different problem. I guess dry sumps aren't common even on here?

i found a few people who use them and they did the same as me, installing a shutoff valve to stop the huge amount of oil in the tank from draining into the engine overnight.

but there was this one guy who said "My '52 Indian has a spring loaded ball check valve on the oil pump outlet to prevent the sump from filling when the engine is not running."

it's that "spring-loaded ball check valve" that intrigues me.

although, my system is at least simple which is a good thing. the only downside to a manual valve is if you forget to close it.

(thinking out loud..) Perhaps I'll hook the kill switch to the valve so the only way to turn off the engine is to start turning the valve..

[parsonsj]

t's that "spring-loaded ball check valve" that intrigues me. Ah. Have you looked at what Aeroquip, Goodridge, and the like offer? I know they have check valves, and probably up to 12AN.

jp

[parsonsj]

Here ya go. Look up Moroso pn 23875.

This link at Summit Racing might work:

http://store.summitracing.com/partdetail.asp?autofilter=1&part=MOR%2D23875&N=700+%2D126442+115&autoview=sku

[wendell]

I've never heard of a motor hydrolocking from oil drain back. I can't even vissualize how it can happen. In the dry sump motor I work on a bunch, the oil will drain into the pan over time but..

Even on the first revolution of the pump (I prime the motor every morning during a race weekend) the scavange stages remove a TON of oil from the pan. If you think about the volume and efficiency of the scavange side (effiecent enough to pull 10# of vacuum at 5Krpm) it wouldn't take long to empty a full pan. I wouldn't worry about it.

To put your mind at easy, have some one crank the motor with the ign off while you watch the tank level. The scagenace side moves a TON of oil.

[roadracer55]

I've never heard of a motor hydrolocking from oil drain back. I can't even vissualize how it can happen. In the dry sump motor I work on a bunch, the oil will drain into the pan over time but..

Even on the first revolution of the pump (I prime the motor every morning during a race weekend) the scavange stages remove a TON of oil from the pan. If you think about the volume and efficiency of the scavange side (effiecent enough to pull 10# of vacuum at 5Krpm) it wouldn't take long to empty a full pan. I wouldn't worry about it.

To put your mind at easy, have some one crank the motor with the ign off while you watch the tank level. The scagenace side moves a TON of oil.

wendell, that's awesome, thanks! trying to find people who run dry sumps was harder than i thought.

great news to hear that i can (worst case) simply turn over the engine to get it primed, then flick the ignition on to start.

as for "hydraulicing", yeah, i don't know where that idea came from - perhaps I should have just ignored them. I thought it was almost plausible at the time, but you'd have to fill a fair way up the cyllinders from the bottom to have that sort of effect. :rolleyes:

so much happier now. :yeah:

[fiorano]

an accusump will work as it hold engine oil at pressure, and when opened will load the engine with oil at engine oil pressure long enough to start the car, than no worries... remeber to close the accusump valve before shutting off the car though so it has oil at pressure

[wendell]

The crank case has a static volume. As the pistins go up and down the volume of the crank case doesn't change. IF you somehow filled the crank case to the brim with oil and started the motor the oil would just pump around from one bore to another.

As for priming, I wouldn't worry about it. The motor I'm reffering to is about as gnarly as it gets and runs on zero WT synthetic. Basically light brown water. Priming in MAYBE gives it another hour of run time between freshening. In most any other aplication, there's no need to prime.

Good luck with your project.

[rocketman]

a dry sump doesnt drain back in the motor, if the pump isn't spinning it wont let anything drain, there is less than a acouple quarts in the pan.

Now its best to mount the tank on the pump side the lines are all on one side.

[HsvToolFool]

I always thought one advantage of a dry sump was that it circulates oil before the engine is started. In other words, the sump is drained and oil pressure is good before ignition. Is that right?

[rocketman]

No a dry sump does not, You have to crank the motor(prime it) before starting to build oil pressure if you don't you could spin a bearing in those split seconds it take to pump the oil in there.

[wendell]

Diito what Rocket said. I take the belt off the pump and spin it with a cordless drill for a minute or so before starting the motor the first time in a day. Gets the oil up to the top end. Prior to starting the rest of the day the engine is cranked a few seconds before the ignition is turned on.

[Tiger]

there is a electric valve to be used with the Moroso accusmp, it could be connectet in such a way to shut when you turn of the ignition preventing oil drainback.

[rocketman]

Diito what Rocket said. I take the belt off the pump and spin it with a cordless drill for a minute or so before starting the motor the first time in a day. Gets the oil up to the top end. Prior to starting the rest of the day the engine is cranked a few seconds before the ignition is turned on.


Yep thats how do it.