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Re: Oil Pressure at Start up [Re: emarine01] #310738
05/07/09 03:07 PM
05/07/09 03:07 PM
Joined: Feb 2007
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U.S.
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moparniac Offline OP
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So 66lbs is okay


Mopar Performance
Re: Oil Pressure at Start up [Re: moparniac] #310739
05/07/09 03:26 PM
05/07/09 03:26 PM
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yes plenty at idle

Re: Oil Pressure at Start up [Re: HemiDart68] #310740
05/07/09 03:39 PM
05/07/09 03:39 PM
Joined: Oct 2005
Posts: 46
Macomb Michigan
65 Belv A990 Offline
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Macomb Michigan
Quote:

I don't really see the benefit of cranking an engine with the ignition off to build oil pressure. It’s still going to move around the same number of dry revolutions to build oil pressure. My use a preoiler if your concerned, or just start it. I don't see how 30 seconds of cranking to build pressure is any better then starting it for a second to build it.




I agree plus the residual oil that is sitting on the bearings after an ignition off cranking session is not what protects them or the journals from damage. It is the crank getting up off the bearings on its oil wedge that protects these parts, and that is a function of oil feed pressure AND sufficient continuous rpm to sustain the wedge. Now if you are trying to suck up some heavy viscosity oil out of the pan in the dead of winter, or an engine that sits for extended periods of time, then a pre-oiling accumulator system like Matt suggested would be a smart idea. I also agree that pre oiling a new motor with an oil pump priming shaft is mandatory. My motor has an instantaneous 80-85 psi cold at fire up at a 1400 rpm idle with 20w 50 synthetic oil, and settles down to about 45-50 psi once it warms up.

Ed.

Re: Oil Pressure at Start up [Re: moparniac] #310741
05/07/09 03:40 PM
05/07/09 03:40 PM
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More than enough for the garage Sorry Wedgie, couldent stop myself

Re: Oil Pressure at Start up [Re: 65 Belv A990] #310742
05/07/09 04:06 PM
05/07/09 04:06 PM
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emarine01 Offline
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When I crank to preoil I crank for 15 sec @ 65 psi then fire the engine , I dont stop after cranking and restart , I find that cranking then hitting the ign the engine wont kick back also

Re: Oil Pressure at Start up [Re: emarine01] #310743
05/09/09 01:02 AM
05/09/09 01:02 AM
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Bend,OR USA
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Bend,OR USA
Quote:

Hey Cab , How come you dont like to crank to build press?


Sorry for not responding sooner, I've been out of town for two days. I don't like cranking the motor over for any longer than it takes to get the motor started because most BB Mopars take to long on the starter to make oil pressure with the spark plugs in I have seen SB Chevys get oil pressure in two revolutions on the starter but not any Mopars I have ever owned As already mentioned several times, the crank and rod bearings and crankshaft surfaces have residual (SP?)oil on them, no matter how long the motor sits unless the oil was real hot, above 260 F and the motor sits for several months between starts, like in the winter months I have had drag race motors sit for several months in the Mojave desert where the outside air temps reach 100+F and the rods and main bearings oil look like I had just shut the motor off right before pulling the oil pan and rod and main caps off


Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
Post deleted by Defbob [Re: Cab_Burge] #310744
05/09/09 04:22 AM
05/09/09 04:22 AM

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Re: Oil Pressure at Start up #310745
05/09/09 07:33 AM
05/09/09 07:33 AM
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Quote:

Accusump





X2

Re: Oil Pressure at Start up #310746
05/09/09 07:39 AM
05/09/09 07:39 AM
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emarine01 Offline
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Thanx guys, All good points, We have over 2 seasons on our short block , My mains and rods show no ware, still have the gray film solid all the way around on all the bearings , only the thrust points show any signs of ware,I dont know if a light piston and alu rod has anything to do with it or maybe preoiling on the starter helps? We start making pressure on around the 5th turn and then it jumps to 65 fast, I run 16vdc to the starter so it turns kinda fast?

Re: Oil Pressure at Start up [Re: emarine01] #310747
05/09/09 08:08 AM
05/09/09 08:08 AM
Joined: Jun 2003
Posts: 52,972
Romeo MI
MR_P_BODY Offline
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Romeo MI
To me its just a matter of X revolutions to get the pressure
up no matter if its on the starter or if it fires, but
in my opinion its easier on the engine if its cranking
without the ignition(less pressure on the bearings).
Of course the Accusump would be the best way

Last edited by MR_P_BODY; 05/09/09 08:10 AM.
Re: Oil Pressure at Start up [Re: MR_P_BODY] #310748
05/09/09 05:33 PM
05/09/09 05:33 PM
Joined: Dec 2006
Posts: 4,647
aotearoa
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i must be lucky or something because when we do mid week servicing during race season, just winding the engine over with the long ratchet to check tappet clearences, we get oil dripping off the rockers before we finish. thats only maybe 3 complete turns & we've taken to draping rags across the back header tubes so they don't get smeared in oil. this is with -1 heads.

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