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Harmful to run oil 1 qt low?


Thumper

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I have heard some solo II drivers run their oil about 1 qt low to get less resistance. My question is if the oil pressure is good even under extreme cornering is there any side effects to running the oil low. I am probably not going to do this. I was just wondering if there were any side effects since my car burns a alittle oil and does get low if I don't check it every 1000 miles or so. Thanks

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Stock pan holds 5 quarts... probably no harm in normal driving or in abnormal driving with sudden stops and sharp turns with a baffled pan..Some cars may blow off a 1/2 quart from full 5 qt capacity oil level from the turbulance inside the engine and run great on 4 1/2 quarts without blowing off more. A full quart low tends to worry me

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Guest bastaad525

Thumper - this question is totally out of left field, but I'm just curious, because I have a little problem with a small oil leak + my engine seems to burn a small bit of oil.

 

So my question is, how quickly does your motor use oil, say, how much do you have to add per 1000 or 3000 miles?

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In response to a 240 Z running one quart low I would have to say the danger is with respect to the cornering forces. A friend and I traded race cars for a Sears Point race and I smoked a bearing to his car during qualifying (second track session). There was nothing noticeable from the gauges. I was doing faster lap times than he was and he said he always ran a quart low. My goof for not checking before belting in. Dave Rebello was quite amused when we brought the engine back to him...Baffles are great if the rules allow, pressure tank (accusump) systems are an easy fix too. IMO one quart less oil is not going to gain you anything but the chance to lighten your wallet.

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If I am running 1 quart low on the street in my '83 turbo I DO NOTICE!

The guage reads a lower pressure and won't jump to 90 like normal. This is only on heavy street use. I would say it could be potentaily dangerous. I'm not real sure the exact reason my car does that. It might be that my oil filter is clogged. The other 2 cars won't make a difference 1 or even a bit more low.

In any case do what ever with that info.

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I stumbled across an old post from Norm (of the 12 sec SU fame) the other day and he let one of his speed secrets slip out by suggesting you gain some power by running a quart low. I know if you run about two quarts high it'll start puking out the breathers - and I mean like coat the engine bay in a nice coat of oil puking - at about 6 grand:)

 

Cameron

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It really depends on what kind of driving you're doing. Running a quart low on a drag car isn't going to cause any problems, but running a quart low on a road racer isn't the best idea.

 

PeterZ has it right. When my buddy lost a main bearing in his 510 it gave no signs other than starting to lose power. After a couple turns the lack of oil pressure showed on the gauge, but by then it was too late. This was on a stock L18 pan and slicks, FWIW. We both got baffled pans after that incident.

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With a Nissam Comp pan you can run a quart low without any danger to the engine. With any other pan on an L6 it would be foolish to run 1 qt. low to gain some small increment of horsepower. Long duration, high G right turns cause oil starvation in the stock L6 oil pan.

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The guy who re-build my motor was telling me he (and a number of his racing boddys) ussually runs 3/4 quart low for drag racing. He actually did an experiment once and a 'test and tune day' . He build an 88 Chrysler sudance, well stripped basicaly.. and ran a slightly worked 2.2 turbo engine. I think he said his first two runs were almost identical. For the third run, he dropped some oil out and shaved off 3 tenths! He said he didn't even believe it himself, so he checked that evrything else was set up the same, and made another run; 4th pass was nearly identical to the 3rd! I agree though, for auto-x or road racing, it could be awefull...

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But we are agreed it does free up so hp. So do it at your own risk.

 

 

No, but running a lighter weight oil will. 10-30 comparred to 20-50. Running low will just risk wiping out your rods and mains. I guess the added clearance from wiped bearings would loosen the motor up some and drop the pressure, that might get you 1 or 2 hp though.

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Guest norm[T12SDSUD]

Wrong Clifton, it DOES free up HP.I know from personal experience that it works.

However,if you doubt this please read September's CAR CRAFT magazine.Page 50 and 51.

In test 2 they picked up 13 HP by running 9 QTS in a 10 QT sump.

In test 3 they only picked up one additional 1 HP by running 7.5 QTS.

 

Later,Norm

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Guest norm[T12SDSUD]

With just one quart low they picked up 13 HP.

 

I agree though that it would be DUMB to run it a quart low on a high speed race course.

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