Question on my oil pressure readings-happy father's day

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Alright thank you guys again I appreciate it, I will do my repairs and report back with results. Just odd cause I had the engine bay open two days ago and it's was clean and the valves were on the day before and I drove it with no mess
 
Alright thank you guys again I appreciate it, I will do my repairs and report back with results. Just odd cause I had the engine bay open two days ago and it's was clean and the valves were on the day before and I drove it with no mess

Chop chop Hop Sing. You ain't done yet? lol
 
Hey guys I know I have went over this in the past but I wanted to touch base and get some opinions. So if u don't already know I have a brand new built 340 to 373 stroker. Bearings across the board were .0025. I currently run 10w40 lucat hot rod oil. Engine now has hit the 6000 mile mark. When hot idling at a light 850rpm I'm seeing 20-22 psi. Is this normal and also if not should I go to a 20w50? I live in CA so we have warmer weather as well. Car temp usually sits at 185-190 fully warmed up. I'm just concerned on the oil pressure. Please let me know what u guys think? Also happy father's day

If you use 20 50w you'll see higher idle oil psi readings, like around 35-40 psi.
You might gain 5 psi fully hot @ RPM over the 55-60 you have now as well.

Is it necessary? Prove one way or the other and let me know. Does it give peace of mind, you bet.
 
Make sure your using copper tube or AN-3 braided line for the oil pressure gauge if using a mechanical one....
 
Make sure your using copper tube or AN-3 braided line for the oil pressure gauge if using a mechanical one....

Why? Copper can break from vibration (I've had it happen) and AN is expensive. The plastic line is fine as long as you route it away from heat and sharp edges.
 
Why? Copper can break from vibration (I've had it happen) and AN is expensive. The plastic line is fine as long as you route it away from heat and sharp edges.


I try to use #4 hose when I can. It’s expensive but it makes the gauge more sensitive. I also use that on my fuel pressure gauge.
 
I try to use #4 hose when I can. It’s expensive but it makes the gauge more sensitive. I also use that on my fuel pressure gauge.

Well I'm not tryin to be cheap..well dammit yeah, I am cause I have to be. lol But you know as well as I do that the plastic works fine as long as you don't route it like a dumbass.
 
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Try 10w/50 oil. You still have the cold weather pour ability of 10W with the higher viscosity at the hot end for warm climates.
 
What would be the tightest clearance on the mains you could get away with on this type of engine build?
 
Try 10w/50 oil. You still have the cold weather pour ability of 10W with the higher viscosity at the hot end for warm climates.

Hopefully he won't have to. Did you read where his oil pressure line was loose and leaking? Maybe he won't have to go to a higher grade oil. I consider that a band aid anyway.
 
Hopefully he won't have to. Did you read where his oil pressure line was loose and leaking? Maybe he won't have to go to a higher grade oil. I consider that a band aid anyway.


And, the bigger the split between the winter grade and the high grade the more shear you have. They have way more VI improvers and that’s not always a good thing.

All multi-grade oils start out as the winter grade. I’m not a fan of a big split like that.
 
And, the bigger the split between the winter grade and the high grade the more shear you have. They have way more VI improvers and that’s not always a good thing.

All multi-grade oils start out as the winter grade. I’m not a fan of a big split like that.

I have my 9 qt milodon pan off , helps w/ header installation , an debating which synthetic oil to put back in it --------??
 
And, the bigger the split between the winter grade and the high grade the more shear you have. They have way more VI improvers and that’s not always a good thing.

All multi-grade oils start out as the winter grade. I’m not a fan of a big split like that.

Yeah like the 10/50. Never been a fan. All the Ford rustang boys love it.
 
Well I won't be able to tackle it till Wednesday but even so is the 1000 rpm 10psi rule still good to go by? Just in case my results don't change is that still bad numbers? When I built the motor all the tolerances were .0015 so I thought I was on the tighter side that's why I just stepped the up to .0025 cause I thought I was making a good move on my part? If that's what's causing it to be on the lower side then should I run it or possible looking at pulling motor to replace bearings soon to tighter tolerances?
 
Well I won't be able to tackle it till Wednesday but even so is the 1000 rpm 10psi rule still good to go by? Just in case my results don't change is that still bad numbers? When I built the motor all the tolerances were .0015 so I thought I was on the tighter side that's why I just stepped the up to .0025 cause I thought I was making a good move on my part? If that's what's causing it to be on the lower side then should I run it or possible looking at pulling motor to replace bearings soon to tighter tolerances?


Even at .0025 with a HV pump you should have enough volume to get the pressure higher than that at idle.My biggest concern is the bushings in the rockers don’t have enough oil up there to keep them off the shafts. It’s not like a stock stamped rocker where they sit in oil, or a needle bearing that can run much less oil.

The 10/1000 rule is ok if you understand when to apply it. Some engines can (and do) use much less oil pressure. I was consulting on a MFI SBC on a dyno and at 8500 they had 48 pounds of oil pressure. I didn’t say anything because I wasn’t getting paid to question the build, only to unscrew his injection. After 60 pulls on the dyno it came off and I looked at the parts. Looked like they all just came out of the box.

I was running my junk to 8500, and had I run my oil pressure that low it would have exploded before it was at 6500. My stuff looked the best when I had 100 plus PSI at 8500. Both of those examples violate the 10/1000 rule.

If you go to a higher grade oil, you are just increasing the pumping resistance, not the volume of oil. If that makes sense. IOW’s, your pressure WILL go up, but not because you have more volume of oil moving through the system. It will be because it’s harder to pump that thicker oil. It’s resistance to flow.

Everything I’m building (and it’s not much anymore) is set up to run thin oils (its all about flow because flow means more oil passes through the engine and that oil cools many of the parts its lubricating) and tighter clearances.

I think I’d run what you have for a while and then pull a rocker shaft and see if it’s leaving bushing materiel on the shaft. If it is, you’ll have to fix it somehow. If it’s not doing that, send it and go run it’s guts out.
 
While it’s already messy and needs cleaned up, pull the rocker cover at idle and see how much oil is getting supplied up there if you’re worried about it. Lay tin foil over the rockers, then cardboard, then lots of rags to soak up the oil that will splash. If you’re still concerned, change the rocker shafts if they’re worn. They’re cheap.
 
From the '70 FSM........
upload_2021-6-21_15-46-42.png


Then you have the MP engines take............
upload_2021-6-21_15-50-5.png
 
From the '70 FSM........
View attachment 1715754392

Then you have the MP engines take............
View attachment 1715754395
Well so according to the first one I'm halfway good except for the operating temperature 45. I'm at a loss lol im confused so is my oil pressure bad? I plan on checking my rockers but other than that if it only increases a few psi am I still on a really low side?
 
Sorry for all the questions just concerned and it's on my mind a lot. Can't wait till Wednesday to work on it?
 
Well so according to the first one I'm halfway good except for the operating temperature 45. I'm at a loss lol im confused so is my oil pressure bad? I plan on checking my rockers but other than that if it only increases a few psi am I still on a really low side?

Dude. Fix the dang leak before you make a decision. That might make a big difference. It is in a main pressure port.
 
Dude. Fix the dang leak before you make a decision. That might make a big difference. It is in a main pressure port.
It's in the port by the distributor but I tightened it slightly while it was running yeaterday just to see and it stopped, not sure if it needs to be tightened more and it's a stainless steel -4 an line. Saw maybe a 2psi pressure difference but maybe needs to be tightened more. I'll be able to do more work on Wednesday
 
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