MadDart - what do you suggest to remedy this ?
should i change to a different weight oil ? will synthetic help ?
hi volume pump or hi pressure pump ?
416 low oil pressure at idle
- Thread starter 340kid
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MadDart - what do you suggest to remedy this ?
should i change to a different weight oil ? will synthetic help ?
hi volume pump or hi pressure pump ?
Snake
Mopar Nut
throw a bomb at it
Mad Dart
Nothing to see Here!
You can do what you want but I would run the bageebers out of it the way it is. There is nothing wrong with it. I ran the dog snot out of mine and never had an issue. Did it bug me? Yeah but it is not going to hurt it.
Before you start blaming it on parts, look at your oil.
You are running 20w/50 VRI.
Look at the viscosity index of that oil.
At 212 degrees F/ 100C it's at 20.5
At 104 defrees F/ 40C it's at 181.8
http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1496497
20w/50 is going to act like that. It's going to jump up in thickness/viscosity at low temp/ cold start and go down to around 10psi per 1000rpm at running temp, because it's engineered to protect parts under heavy use and this is consequential.
Listen to your engine builder. Every engine is different. If you were running 10w/30 or something lighter, you may have some concern on good seal on moving parts with tolerances, but the numbers you are seeing in oil pressure drop are normal for an eccentric viscosity index oil like that.
Dave - would running straight 30 make the hot idle pressure better or worse ? based on the chart Im thinking worse ???
MRL Performance
Well-Known Member
Its the Lunati bar bell lifters that are the cause. With the high lift cam the oil band is dropping out the bottom of the lifter bore. I just went thru this on the 600hp 408 I posted a few days ago. I caught it during mock-up. This will cause the low oil pressure issue. I have call Lunati and pleaded to them to change the lifters of put in their description that they are not for high lift applications.
Its not the bearings or the filter, Its the Lifters. If you want to solve it, change them out for the Howards EDM's and it will not have low oil pressure any more.
Its not the bearings or the filter, Its the Lifters. If you want to solve it, change them out for the Howards EDM's and it will not have low oil pressure any more.
DaveBonds
Garage Trash
The oil reference will only show you if the pressure is higher and lower due to viscosity, when the engine is cold.
If you swapped the oil, pressure will be closer between cold and hot, but you may need 20w/50 oil if that is how your builder set spring pressure and clearances up.
If your lifters are showing groove out of the bore on high lift, that's where all of your pressure is going. When that oil warms up and drops viscosity, it will creep even more out of those grooves, because it flows faster.
Remember, pressure is the opposite of flow. You need pressure to create motion/flow, but they are equal opposites in forms of measurement.
If what MRL is saying is happening with your engine, it's likely ok at high viscosity/ cold, because the oil is not thin enough to find it's way out of the lifter bore fast enough to drop pressure significantly.
Your crank is likely getting hosed by the lifter bores from above, too, which is not helping balance or performance.
If the sides of the lifters are exiting the bore to the point of any ridge showing, it could potentially broach the bore or create odd tension in the lifter bore, due to the lifter bore no longer supporting the area of the lifter, below that groove/ void area, and when it goes back up into the bore, the edge can potentially contact the bore untrue and broach it or even break a lifter, under high load.
If you swapped the oil, pressure will be closer between cold and hot, but you may need 20w/50 oil if that is how your builder set spring pressure and clearances up.
If your lifters are showing groove out of the bore on high lift, that's where all of your pressure is going. When that oil warms up and drops viscosity, it will creep even more out of those grooves, because it flows faster.
Remember, pressure is the opposite of flow. You need pressure to create motion/flow, but they are equal opposites in forms of measurement.
If what MRL is saying is happening with your engine, it's likely ok at high viscosity/ cold, because the oil is not thin enough to find it's way out of the lifter bore fast enough to drop pressure significantly.
Your crank is likely getting hosed by the lifter bores from above, too, which is not helping balance or performance.
If the sides of the lifters are exiting the bore to the point of any ridge showing, it could potentially broach the bore or create odd tension in the lifter bore, due to the lifter bore no longer supporting the area of the lifter, below that groove/ void area, and when it goes back up into the bore, the edge can potentially contact the bore untrue and broach it or even break a lifter, under high load.
moper
Well-Known Member
I've seen that on other engines too. This is not a problem that can be ignored. It won't "go away" with anything other than stopping that exposure.
kt340sport
Well-Known Member
I had plenty of 340,s 360,s over the last 25 plus years , and every small block at idle hot ran around 12, 13 psi .My father was aChrysler mechanic for over 20 years and he always told me it only takes 6 psi to put the light out .And right now my 340 Dart Sport runs about 10 to 13 hot , never had a problem .
big shout out to mike @MRL I had a lengthy conversation with him on the issue, its definitely the lunati Lifter, their EDM style lifter is not a good fit for a higher lift cam. We went thru specs on the howard EDM's but my pushrods will not work since the howards sit a little taller. I just replaced the rocker adjusters and pushrods with custom length smith bros pushrods 2 weeks ago, I wish I addressed this sooner, for now I may just deal with issue until the end of the season then tear it down and replace the lifters, I will check with smith bros maybe I can send them back and have them shortened if I go with the Howards or look at alternative lifters.
I really wish Mike from MRL was closer to me and built our stroker!!
I really wish Mike from MRL was closer to me and built our stroker!!
Mad Dart
Nothing to see Here!
It is usually just as expensive or close to have them shortened then buying new ones.
racerhog
RacerHog likes his Mopars
Mike would be more than happy to create one up and send it to you. :burnout:
I am also using the canton billet oil filter plate on my smallblock with TTI headers and I use a Wix 1068 with zero issues. fits and clears fine.
highflyer
Well-Known Member
Did you get this cleared UP..try a different oil.CHEAPEST REMEDIE TRY FIRST..IV NEVER HAD GOOD LUCK WITH VALVOLINE..
MRL Performance
Well-Known Member
Nothing wrong with Valvoline, its a great oil.
1320duster
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Hate to bring up old post couldn't find anything else close ,
I have run 3 different oil grades , replace bearing ,rods and mains twice, I am having same issues with low oil pressure(10-20) at Idle (oil pressure gauge looks like a tach) and goes to 60 psi above 3000 ,I have tried big and small wix and napa gold oil filters, I really cant afford to keep tearing down engine , I am a average working man, I do have solid roller cam bullet but no idea what brand lifters , any and all Help would be helpfull
I have run 3 different oil grades , replace bearing ,rods and mains twice, I am having same issues with low oil pressure(10-20) at Idle (oil pressure gauge looks like a tach) and goes to 60 psi above 3000 ,I have tried big and small wix and napa gold oil filters, I really cant afford to keep tearing down engine , I am a average working man, I do have solid roller cam bullet but no idea what brand lifters , any and all Help would be helpfull
Rodzilla
Well-Known Member
I have 15-20psi at 1000rpm hot in my stroker. 65-70psi cold. 55psi hot at 3000rpm. 60-65psi wound out hot. My motor has the oiling mods done in the sticky in this section. I've got 850miles on it now, half of those are bagging on it. I'm not worried at all.
Edit - forgot to mention thats with 10-30
Edit - forgot to mention thats with 10-30
1320duster
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yea I hope it would be ok , just scary and it doesn't help I have a 20 psi low pressure warning light so it stays on mostly,,??/
How can anybody say what's wrong with it or even if anything IS wrong? Up to this point, unless I missed it, I don't see where he's said what kinda oil pump he's runnin.
Rodzilla
Well-Known Member
What kind of numbers are you putting up now for psi? Hot, cold or otherwise? Thanks
340sFastback
Well-Known Member
When I mocked up my stroker I ran the oil pump with a drill and turned the engine by hand with the intake off. Oil squirted 8 feet in the air out of lifter bore at max lift. Had to have a custom ground small base circle cam to correct the problem (special thanks to Brian at Indio Motor Machine). This was with a hydraulic retrofit roller cam and Crane roller lifters.
My point is mock the engine up and run oil pump with drill and check for leaks both under and above the lifter. Factory blocks are very sloppy so this is a problem on some blocks and not others.
Glad to hear original poster corrected the problem instead of ignoring it.
My point is mock the engine up and run oil pump with drill and check for leaks both under and above the lifter. Factory blocks are very sloppy so this is a problem on some blocks and not others.
Glad to hear original poster corrected the problem instead of ignoring it.
Mine does this same thing. With the throttle blipped open the psi goes to 70+ psi. At idle it hovers around 15-20 and bouces around there with the lope of the motor. That's with 20/50 oil in it. It has MRL roller lifters , oiling mods done, HV oil pump, etc. Engine builder was not concerned with that pressure at all and he's a picky dude. As long as there is decent pressure off idle he didn't have any concerns whatsoever having 15 psi at idle. But it sounds like everyone is going to have their mixed opinions on this.
Mad Dart
Nothing to see Here!
Shoot my race car buddies have about 5 PSI at Idle. They don't even flinch and their cars Idle in the 1800Rpm range.
russhal
Well-Known Member
Only solution is to teardown the engine down. 10 psi for every 1000 rpm is Chevy talk. Even my race motors have had 30 psi.at idle. 70-75 from just off idle to wot. It's a clearance issue not a plug. If a plug ismissing. ..no pressure to speak of at any rpm. It'll be easy to figure out when you tear it down. You'll do more damage running it trying to figure it out. I had too much main clearance on a 360. Needed to line honed. Same issue you're having. Kept messing with it till I ruined the crank. Proper machining and it's 9 years on that build.
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