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Dry Sump Oil Tank mounting question... 40Ford??????

Posted By: DemonDust

Dry Sump Oil Tank mounting question... 40Ford?????? - 03/06/09 05:59 PM

I was talking to one of the local circle track guys here and he told me the return line has to empty into the tank higher than the engine He didn't know why thats just what he was told. Can anyone explain this to me.
Posted By: boatracer572

Re: Dry Sump Oil Tank mounting question... 40Ford?????? - 03/06/09 09:43 PM

I have never heard that! I would just make sure Its higher than the pump!

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Posted By: DemonDust

Re: Dry Sump Oil Tank mounting question... 40Ford?????? - 03/06/09 10:42 PM

Quote:

I have never heard that! I would just make sure Its higher than the pump!



Thats what I thought too.. Being higher than the engine makes no sense to me
Posted By: 40ford

Re: Dry Sump Oil Tank mounting question... 40Ford?????? - 03/07/09 03:58 AM

Don't worry about getting the tank higher than the engine---just worry about the oil level in the tank being higher than the pump!

A pump can(and does) lose its "prime"! So to keep the pump primed all the time, you mount the tank so the oil level is always above the pump.

Now for a true story---A friend had a nice dry sump installation----worked fine! This is until he put the car on an inclined trailer and pulled about 200 miles. Fried the engine on startup! Why? The pump was above the tank for the 200 mile trip and the pump would not suck oil on startup!

Opps!
Posted By: DemonDust

Re: Dry Sump Oil Tank mounting question... 40Ford?????? - 03/07/09 01:59 PM

The bottom of the tank will be will easily be above the pump.

Thanks for the info. If I had to mount it the other way I have no idea where I'd mount it.
Posted By: silverfish

Re: Dry Sump Oil Tank mounting question... 40Ford?????? - 03/07/09 02:45 PM

I'm new to this dry sump thing too. I was told that you have to prime the pump any time the motor sits for a 12 hour or more time period. They told me the reason for this is because gravity drains all the oil out of the tank while it sits. Peterson told me you have to be able to slip the belt off the pulley and spin it with a drill or something until you see oil pressure start to build. They say after that you're good for that day. Like I said I'm new to this and haven't even fired the engine up yet so I'm just relaying what I was told. Anyway, here is a pic of how I mounted mine...

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Posted By: 40ford

Re: Dry Sump Oil Tank mounting question... 40Ford?????? - 03/07/09 03:27 PM

Under normal conditions---you do not need to reprime the pump before startup. If we haven't started the engine for a week, we might spin the engine over for 15 seconds before turning on the ignition. If we haven't started the engine for 1 month, we probably would reprime.

Think about a dry sump system as two separate systems, the pressure system and the scavenge system. The scavenge system goes from the oil pan to the pump and into the top of the tank. There is no way for the oil to get from the tank back into the oil pan if it is plumbed correctly. The tank keeps the pressure section always primed---and there is no way that gravity can drain a tank UNLESS the tank is mounted well above the engine.
Posted By: silverfish

Re: Dry Sump Oil Tank mounting question... 40Ford?????? - 03/07/09 03:41 PM

Quote:

Under normal conditions---you do not need to reprime the pump before startup. If we haven't started the engine for a week, we might spin the engine over for 15 seconds before turning on the ignition. If we haven't started the engine for 1 month, we probably would reprime.

Think about a dry sump system as two separate systems, the pressure system and the scavenge system. The scavenge system goes from the oil pan to the pump and into the top of the tank. There is no way for the oil to get from the tank back into the oil pan if it is plumbed correctly. The tank keeps the pressure section always primed---and there is no way that gravity can drain a tank UNLESS the tank is mounted well above the engine.




Thanks! I was wondering about just spinning the engine over like you say. Thats basically the same as spinning it over with a drill. Also, I'm glad you confirmed the drain back thing too. I thought the exact same thing when I was told the oil would run back into the pan. The only line coming out of the bottom of the tank is the suction line that goes to the pump. Thanks for the clarification.
Posted By: DemonDust

Re: Dry Sump Oil Tank mounting question... 40Ford?????? - 03/07/09 03:58 PM

Great! Thanks for the all the info. I didn't want to burn anything up either. Pretty simple.

I was wondering about turning the engine over with the ign off to prime it, if it sits for a while.

Thanks again
Posted By: boatracer572

Re: Dry Sump Oil Tank mounting question... 40Ford?????? - 03/07/09 03:59 PM

Peterson Fluid systems make nice drive nuts for the pump pulley to prime!I can remove the belt
on the pump,and spin the pump by "hand" and see 40 psi!!

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Posted By: DemonDust

Re: Dry Sump Oil Tank mounting question... 40Ford?????? - 03/07/09 04:04 PM

One more dumb question, can these pumps cavitate and lose their prime if there isn't any oil for them to pickup for a short time? Say on accel or decel?

Just curious, cause my block has a scavenge in the rear of the cam tunnel, but the cam tunnel has some holes drilled in it to drain to the oil pan. Should I run the pickup in the rear or just cap it off? Cause it may be just sucking air %80 of the time
Posted By: 40ford

Re: Dry Sump Oil Tank mounting question... 40Ford?????? - 03/07/09 07:50 PM

Without knowing your block exactly, I would say run the rear pickup. All the scavenge sections run dry some---think about it, one pressure section, three or four scavenge sections. They actually suck air most of the time---that's what builds the great vacuum in the engine!
Posted By: MR_P_BODY

Re: Dry Sump Oil Tank mounting question... 40Ford?????? - 03/07/09 11:27 PM

Quote:

One more dumb question, can these pumps cavitate and lose their prime if there isn't any oil for them to pickup for a short time? Say on accel or decel?

Just curious, cause my block has a scavenge in the rear of the cam tunnel, but the cam tunnel has some holes drilled in it to drain to the oil pan. Should I run the pickup in the rear or just cap it off? Cause it may be just sucking air %80 of the time



As 40 said they do run some oil all the time but you
have 2,3, or even 4 times the scavenge rate of the
supply side... also this is the reason the dry sump
creates a vac in the engine. With just the dry sump
on my engine it creates 12" of hg in the higher revs
Posted By: DemonDust

Re: Dry Sump Oil Tank mounting question... 40Ford?????? - 03/08/09 06:09 AM

Wow that's more vaccum than some street engines. Sorry for the dumb questions I just want to cover all my bases. So I don't screw anything up.

Thanks for taking the time to explain this to me. I've always stuck to my stock SB oil systems so the whole dry sump is new to me.
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