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PostPosted: Tue Jun 04, 2013 4:14 pm 
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Spends Too Much Time Under The Hood
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Location: Evansville, IN
What are good oil pressure for a 4g61t at:
Cold Start 1600rpm:
Cold aka not fully warm 300orpm:
Warm Idle 800rpm:
Warm 3000rpm:
Max Oil Pressure:

What are good oil pressure for a 4g63t at:
Cold Start 1600rpm:
Cold aka not fully warm 300orpm:
Warm Idle 800rpm:
Warm 3000rpm:
Max Oil Pressure:

I assume there is a difference do to the engines having a different head design
If answering Please give details, if reporting what you read that is fine, but please state if you have balance shafts, oil squirters, and or ported oil pressure relief valve. I know what I have ran, but looking for more of a technical side. Yes there are things like balance shaft delete and oil squirter deletes also that complete change what people see as a result. There are also things to correct too high or too low.

_________________
92 Colt GT 4G63t
92 Summit TSI AWD 4G63t Auto
92 Eagle Talon TSI AWD Auto DRag CaR
5 X 90 Talon TSI
90 GSX
99 GSX..........31 Dodge 4dr Rat Rod, 67 Catalina, 92 3kgt vr4, 83 Civic,4 00 F-350, 01 Chevy 2500HD
3 KIDS, FUTURE FIANCE, AND CAR ADDICTION


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PostPosted: Tue Jun 04, 2013 7:02 pm 
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The Silent Administrator
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Too many variables from what you have asked.
What oil viscosity are you running, what outside ambient temp is the oil at when at cold start, on throttle or decel for higher rpms, oil coolers inline, ported cylinder head oil mods, stock head oil pressure regulator, etc, etc.

Good rule of thumb is 10psi per 1000 RPM.
Most unmodified balance shaft motor 4g63's will likely see 25-50 psi cold idle spring/summer, with light oils. My 4g63t (91 w/oil cooler, balance shafts, no oil port relief, 10w40 Brad Penn Racing synthetic oil (no detergents) gets these figures and my 4g61t (no coolers, 5w30 Mobil 1 synthetic oil, no balance shafts, squirters intact) also got these figures at those temperatures. Idle speed and lopy cams will affect idle pressures due to surge.

All 4G61/63/67/64 DOHC heads from 1987 (overseas) to 1994 are identical in terms of oiling, NA or turbo motor blocks they are bolted to, from what I know. Oil pressure reliefs across the different oil filter housings are considerably different in terms of length I the spring and piston combinations and the relief hole in the housing. Jafromobile does an excellent video with graphs to illustrate that on YouTube. But I digress, if your oil pressure are at any point below say 20 psi at idle, not anywhere near (10psi x per 1000 rpm) when the oil is warmed up to operating temp, then suspect a problem or a situation created by modifications that needs to rectified. These are my thought, and I'm sure many experience very high oil pressures with cold 20w50 oil, external coolers, balance shaft (4g61 block off parts), plugged squirters holes, etc.


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PostPosted: Wed Jun 05, 2013 4:05 pm 
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Spends Too Much Time Under The Hood
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Location: Evansville, IN
Flying Eagle thank you to stepping this conversation up to the next level.
Did mitsubishi ever release a oil pressure reading and at different temperature and or rpm?
I worked at Caterpillar for years and we had documents like this.

For the point of this conversation 10w30, 40degree cold start, constant throttle at 3k rpm, oil cooler included, stock head, stock head oil pressure regulator. I am mainly looking for stock info. I mean that oil pressue at the head and different locations were designed with pressure limits or standards.

Or could be cut all this out and say at warm what is the lowest and highest acceptable pressures.

Sorry I am really disappointed by this reply and would like add more but I currently am out of time and need to go home.

_________________
92 Colt GT 4G63t
92 Summit TSI AWD 4G63t Auto
92 Eagle Talon TSI AWD Auto DRag CaR
5 X 90 Talon TSI
90 GSX
99 GSX..........31 Dodge 4dr Rat Rod, 67 Catalina, 92 3kgt vr4, 83 Civic,4 00 F-350, 01 Chevy 2500HD
3 KIDS, FUTURE FIANCE, AND CAR ADDICTION


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PostPosted: Thu Jun 06, 2013 7:36 pm 
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The Silent Administrator
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Location: Ottawa, ON, Canada
Well, here is what the 1989 FSM is saying about oil pressure for a 4G15 or 4G61(t), or 4G63(t) (in fact all 4gXX motors have this spec listed from 89-92 that I saw, likely more):

Oil pressure at curb idle speed - kPa (PSI) 80 (11.4) or more - NOTE found an entry in the 4G63 Overhaul Manual - but it only shows a "-" indicating max pressure, no spec.
Oil temperature is 75-90 degrees Celcius (167-194 degrees Fehrenheit)

Opened up the 90 DSM Technical Manual and it had this little bit of information about the squirters:

When the pressure of oil from the main gallery exceeds 200 kPa (28 psi), the oil pushes open the check valve, spurting over the inside of the piston, thus cooling it.
(Turbo engines only)

90 DSM relief valve opening pressure = 78 PSI <- likely most others are close if not identical within the 4GXX series of motors, 4G15 or 4G6X.
Oil pressure switch on at 4.3 PSI or less
Oil cooler bypass valve hole closing temperature = 97-103 degrees C (207-217 degrees F)


I think it best not to over think some of what is presented.

Stick to the rule of thumb for oil pressures climbing as RPM does.
Too much oil pressure whether at idle and as RPM climbs, will at a point become dangerous to bearing materials, just as would overheating a thin weight oil.
Use good oil designed for your design goals ie Factory output, 2X factory output etc.
If you aren't at the race track doing severe autocross competition or track racing (with corners, and laps), then a 20w50 might not be for your engine setup.
How tight are your bearings/crank tolerances in your motor and oil pump?
All you can go by, is a gauge right (?) and also factoring in temperatures for engine starting and racing temps.

There are guys here that can tell you what pressures their motor is running at, but it is very subjective. I would take to heart what everyone has to say, because if the motors setup the way they have them are lasting a long time, and their intended usage, then likely there must be something right about their pressures staying in the sweet spot.


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PostPosted: Thu Jun 06, 2013 7:40 pm 
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I've always lived by the "if there's oil pressure, that's great!" rule, lol.

_________________
Early 2000's: 1992 Summit sedan - 14.1 @ 100.9mph w/ 155/80 13s
2012: 1989 Dodge Colt GT Turbo - 14.9 @ 100mph, 10psi/s16G


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PostPosted: Thu Jun 06, 2013 7:52 pm 
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The Silent Administrator
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Location: Ottawa, ON, Canada
Yes, biggest hurdle is low pressure threshold, and oil pressures cold and at cold/hot at high RPM.

Oil starvation or lack of the lubrication barrier created by a low volume of oil, filters blowing gaskets from over-pressure, and too much pressure when the motor is cold and or at high RPM causing a galling of the bearing material (Babbitt), are at the far end of the spectrums.

What are the goals of your motor DSMERwCOLT ? Mods ? Motor size ?


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PostPosted: Fri Jun 07, 2013 7:36 am 
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Location: Evansville, IN
viewtopic.php?f=64&t=37816&p=303173#p303173
is my build.
Each one of my cars have a different purpose. Evo date night, 1g tsi fwd go fast autocross/drag, colt turbo toy, 67 pontiac happy car puts a smile on my face everytime I drive it, 2g gsx daily, 1g gsx autocross, 1g tsi awd going back to original, 89 colt is for laughs, parts getting, and dog hauler.
I was just asking for general use and there is so many hear say I just wanted something official.

You wrote exactly what I was wanting. Great response.

_________________
92 Colt GT 4G63t
92 Summit TSI AWD 4G63t Auto
92 Eagle Talon TSI AWD Auto DRag CaR
5 X 90 Talon TSI
90 GSX
99 GSX..........31 Dodge 4dr Rat Rod, 67 Catalina, 92 3kgt vr4, 83 Civic,4 00 F-350, 01 Chevy 2500HD
3 KIDS, FUTURE FIANCE, AND CAR ADDICTION


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PostPosted: Tue Jun 18, 2013 8:15 pm 
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The Silent Administrator
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Location: Ottawa, ON, Canada
Well, happy to hear it was informative. Every once in a while I dig into the manuals much like I used to here, for many members when I first joined.
My knowledge pales in comparison to many guys here. :rock:


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PostPosted: Wed Jul 31, 2013 2:37 pm 
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Location: Duluth, MN
I am wondering if the relief valve springs are different from the 4g15 to the 4g63t? Length, width, tension? I have really high oil pressure on my 63t and didnt port the OFH, but am wondering if i could swap out the springs, or cut a coil or two off of the old 4g15 spring and use that to see if it helps. Thanks!


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PostPosted: Wed Jul 31, 2013 7:23 pm 
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On my 6 bolt I both ported the relieve hole and cut 1/3 of a spring. I didn't want to port too much but it was still a little high so I ground the spring down a bit.

[edit] just don't ground too much of the spring. Do a little and then test.

_________________
05 wrx wagon
99 Benz ML 320
91 eagle summit swapped - 6/4 bolt combo
94 Audi s4 - sold
88 Eagle Vista Turbo LX sedan, RIP


Last edited by j2dapo on Thu Aug 01, 2013 9:26 am, edited 1 time in total.

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PostPosted: Thu Aug 01, 2013 2:24 am 
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thanks! good to know. I was really hoping that i wouldnt have to take off the OFH, but I got it half apart tonight to put in a different turbo so might as well. Thanks for the help!


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