First run on the STREET! Oil pressure drops LOWat idle?

Posted By: Plum440

First run on the STREET! Oil pressure drops LOWat idle? - 06/10/11 02:23 PM

I just got back from running the Challenger for the FIRST TIME

. The oil PSI while running is b/w 45 - 55. At idle it drops to 15 - 20

. Is this NORMAL??? In the garage it ran at idle b/w 40 - 50 but it's never been driven.

It's is a FRESH stock built 440 with a 268* Comp cam with 0 miles. A crusier built car - no mods....Running 10W-30.

Thanks

Posted By: Plum440

Re: First run on the STREET! Oil pressure drops LOWat idle? - 06/10/11 02:28 PM

IS the rule of thumb 10 per 1,000 in relation to RPMs? Just found that on an on-line search

Posted By: JohnRR

Re: First run on the STREET! Oil pressure drops LOWat idle? - 06/10/11 02:32 PM

Quote:

IS the rule of thumb 10 per 1,000 in relation to RPMs? Just found that on an on-line search

Yes it is , though that is a little low for a fresh build , what pump do you have ?

Posted By: Challenger 1

Re: First run on the STREET! Oil pressure drops LOWat idle? - 06/10/11 02:33 PM

Should be OK, keep an eye on it and if it don't go down anymore, it'll be fine. Good luck with it and enjoy!

Posted By: Diplomat360

Re: First run on the STREET! Oil pressure drops LOWat idle? - 06/10/11 02:33 PM

YES, you are looking for 10PSI/1K RPM typically....I think you are fine with 15-20 at idle...some setups might show more, etc....but this should be fine.

Can you tell regarding your engine what the bearing clearances were like? Loose or tight side?

Posted By: Plum440

Re: First run on the STREET! Oil pressure drops LOWat idle? - 06/10/11 02:39 PM

Quote:

YES, you are looking for 10PSI/1K RPM typically....I think you are fine with 15-20 at idle...some setups might show more, etc....but this should be fine.

Can you tell regarding your engine what the bearing clearances were like? Loose or tight side?

Not sure about the bearing clearances. I do know the builder and the shop have a GREAT reputation! Thank!

Posted By: Plum440

Re: First run on the STREET! Oil pressure drops LOWat idle? - 06/10/11 02:40 PM

Quote:

Quote:

IS the rule of thumb 10 per 1,000 in relation to RPMs? Just found that on an on-line search

Yes it is , though that is a little low for a fresh build , what pump do you have ?

Melling high performance - OEM type.

Posted By: scratchnfotraction

Re: First run on the STREET! Oil pressure drops LOWat idle? - 06/10/11 02:41 PM

gauges can vary also

i have one thats 10lbs off from any others i have used.

my 440 does about the same thing and its well used with 75,000 miles on it.

may bump up to a thicker oil when you change it.

i run the napa fleet 15/40 in all of mine,10/30 drops pressure way down on mine

you did break the cam in with a oil additive with high zink correct?

on a fresh engine I change the oil 2-3 times in short order and cut the filter open to look for junk/shavings..ect

after that i lets it rip and change it when it gets black

Posted By: Plum440

Re: First run on the STREET! Oil pressure drops LOWat idle? - 06/10/11 02:42 PM

Quote:

Should be OK, keep an eye on it and if it don't go down anymore, it'll be fine. Good luck with it and enjoy!

Thanks!

I'm sure you remember that first time feeling of rowing through the gears of your FIRST BIG BLOCK!

Posted By: Mr.Yuck

Re: First run on the STREET! Oil pressure drops LOWat idle? - 06/10/11 02:45 PM

I'd like a little more than that but that is thin oil. Should be ok but I wouldn't want it to go too much lower.

Posted By: 70Cuda383

Re: First run on the STREET! Oil pressure drops LOWat idle? - 06/10/11 03:38 PM

my big block used full groove main bearings (full time oiling vs half with stock bearings) and an High Volume oil pump, and it had the following numbers:

with 15w40 oil:

PSI at cold engine start up 75 psi

hot idle 30 psi

hot cruise 45-50 psi below 2000 rpm, and 60-65 above 2000 rpm.

switched to 10w30:
cold start up 75 psi

hot idle 20-25
hot cruise below 2000 rpm was 40 or so, and 55-ish above 2000 rpm.

knowing if you have full groove main bearings or not would help, as well as whether or not it's a stock pump or HV pump. (you said "high performance OEM type)

Posted By: jbc426

Re: First run on the STREET! Oil pressure drops LOWat idle? - 06/10/11 05:39 PM

What RPM is it idling at? Like mentioned above, the pressures you gave are close to the minimums. I would run a bit thicker oil....15-40 or something.

I just bolted on the billet Milidon pump and their low-profile, baffled roadrace pan. I'm sure my hot idle pressures will be up now.

Posted By: ademon

Re: First run on the STREET! Oil pressure drops LOWat idle? - 06/10/11 05:44 PM

what kind of 10w/30? high zinc "racing" ? or just regular oil?

Posted By: Plum440

Re: First run on the STREET! Oil pressure drops LOWat idle? - 06/10/11 07:15 PM

I'm just running Pennzoil 10W-30 with a break-in additive for the cam.

The oil pump is a high volume oil pump.

I think I'll switch to a thicker oil after I drain this first round.

Thanks!!

Posted By: BSB67

Re: First run on the STREET! Oil pressure drops LOWat idle? - 06/11/11 12:16 AM

Quote:

Quote:

IS the rule of thumb 10 per 1,000 in relation to RPMs? Just found that on an on-line search

Yes it is , though that is a little low for a fresh build , what pump do you have ?

. Its not too low, but is low for a new motor and it would be nice to know why.

Posted By: 70Cuda383

Re: First run on the STREET! Oil pressure drops LOWat idle? - 06/11/11 01:08 AM

Quote:

. Its not too low, but is low for a new motor and it would be nice to know why.

That's why I asked about full vs half groove main bearings.

Posted By: ahy

Re: First run on the STREET! Oil pressure drops LOWat idle? - 06/11/11 03:01 AM

With performance bearing clearance on the rods and mains - around .0025" vs OE at about .0015 - and/or full groove main bearings your oil pressure would be typical. I'd bump up to 15W40 diesel engine oil and call it good. 15 psi shouldn't hurt the engine but I'd be happier with 20 at hot idle.

With OE bearings/clearances, I'd call that a bit low. Suggest you get the info from your shop as mentioned above on bearing setup.

Posted By: Dodgem

Re: First run on the STREET! Oil pressure drops LOWat idle? - 06/11/11 03:17 AM

I would go to a 15/40 min maybe a 20/50 oil

Posted By: Dads426

Re: First run on the STREET! Oil pressure drops LOWat idle? - 06/11/11 03:46 AM

Quote:

I would go to a 15/40 min maybe a 20/50 oil

And if that doesn't work it is so easy to shim the relief spring on the big block pump. The relief spring plug faces the back of the engine on the pump.

Posted By: DartGTS

Re: First run on the STREET! Oil pressure drops LOWat idle? - 06/11/11 04:52 AM

Hello:
Thats not excessively low as long as it comes up as you rev engine. Mopars are famous for low idle oil pressure. Just keep an eye on it as mentioned above. If it is a constant concern to you switch to a heavier weight or go to an adjustable pressure set up on your oil pump. I've ran Mopars with your pressure readings for many many years with no problems.

Maynard

Posted By: Rug_Trucker

Re: First run on the STREET! Oil pressure drops LOWat idle? - 06/11/11 07:20 PM

I do a 20min break in and drain oil and change filter. I had low pressure when idling and pitched the Fram. Problem fixed!

Posted By: terzmo

Re: First run on the STREET! Oil pressure drops LOWat idle? - 06/11/11 09:38 PM

Quote:

Quote:

IS the rule of thumb 10 per 1,000 in relation to RPMs? Just found that on an on-line search

Yes it is , though that is a little low for a fresh build , what pump do you have ?

then why have a tach ? does Your oil pressure gauge leap around like a tach ? Mine stays at 80 when cold....goes to 65 to 70 when warm....40 at idle....and if I juice the motor it doesn't react to a 10 psi increase for every 1000 rpm.....My

is this pressure per rpm is rubbish

Posted By: DennisH

Re: First run on the STREET! Oil pressure drops LOWat idle? - 06/11/11 09:50 PM

My 440 likes Amsoil 10-40. Slight drop off of peg after extended high speed driving.