Yellow Bullet Forums banner

Dart BBC oil pressure questions

10K views 40 replies 16 participants last post by  haberkorn 
#1 · (Edited)
I got a fresh 555 dart big m going and noticed oil pressure is lower than expected

I have valve spring oilers and remote oil filter with bar/plate style b&m cooler

Engine is in a 3rd gen camaro, so we have filter adapter in the block that has 1/2 npt to -10 outlet running 4 ft of -10 line to cooler mounted at radiator in front of car then 1 ft of line to remote filter housing behind driver headlights basically, thru filter then back to motor thru another 4 ft of -10.
Also from remote filter i have a -6 line takeoff to feed a distribution block near firewall, 4ft away from filter. Distribution block has my oil pressure sender for stock camaro oil gauge and a -4 takeoff to feed the valvespring oilers in the covers.

Two oil pressure sensors. One in the back bellhousing area. One in distribution block off the remote filter housing. Both read about the same

Engine has .0025 rods and .0029 main clearance. It has bushed lifter bores with howards/morel solid roller lifters and it does not appear to drop below or above oil band hole in the bore. Not sure of the exact lifter bore clearance however but they were sized

Melling 10774 std pressure std volume pump

Had lucas 30w break in oil and then moved to 15w40 rotella to see if it changed pressure. It did help hot idle but wot was same

Its idled in the mid 30’s to near 40 cold (80 deg ambient) and hot idled in the 20’s psi at 1000-1100 rpm. At wot up to 6500 its only seeing 43 psi but flat and stable and gets to that pressure immediately on the hit.
It almost seems like i have alot of line and bleed off from the oilers which would drop prssure and the pump is on the bypass spring. Do i just need to swap out to high pressure spring?
 
See less See more
#10 · (Edited)
Curious, why the complexity on the oil system. I'm seeing 9 Ft of -10. that's a bunch. plus the cooler/filter. Bunch of oil that's not in the motor. This a street rod?. Only guys i know that run oilers are at 800 CI plus. Better pump is an understatement. More lines the more chances of leaks. Too close for comfort at that oil pressure for me. My 598 and 632 run at 60 idle and 70 on the pedal. but with a Moroso billet pump. Be safe there..
 
#11 · (Edited)
Yeah street car. And is going to be turbo’d just breaking it in all motor right now. Figured a valve spring oiler would help keep springs and rockers well lubed at idle and cool on long drives. More life out the parts

Oil cooler for heat load and it has to be mounted up front because no where else to put it. Thats 4 ft away either way. Ran same setup for few yrs on my turbo sbc no issue. Remote filter since the headers are in the way.

I just tested the engine semi warm, 160’s coolant temp, without the oilers and its 50 psi idle and quick rev to 3500-4000 i see 65 psi so it may be good now at higher rpm. My buddy ran drag week with a solid roller 1100 lb open springs just fine without oilers so likely wontneed them anyway. Just thought it was a good idea. I dont have near that spring pressure.

Only issue now is if i plumb the turbo feeds off the system it may drop pressure again so may need a high pressure spring anyway
 
#12 ·
Yeah street car. And is going to be turbo’d just breaking it in all motor right now. Figured a valve spring oiler would help keep springs and rockers well lubed at idle and cool on long drives. More life out the parts

Oil cooler for heat load and it has to be mounted up front because no where else to put it. Thats 4 ft away either way. Ran same setup for few yrs on my turbo sbc no issue. Remote filter since the headers are in the way.

I just tested the engine semi warm, 160’s coolant temp, without the oilers and its 50 psi idle and quick rev to 3500-4000 i see 65 psi so it may be good now at higher rpm. My buddy ran drag week with a solid roller 1100 lb open springs just fine without oilers so likely wontneed them anyway. Just thought it was a good idea. I dont have near that spring pressure.

Only issue now is if i plumb the turbo feeds off the system it may drop pressure again so may need a high pressure spring anyway

Did you use the cam bearings with 3 holes that is a huge bleed off if you prime the engine with out the intake on you would see what I am talking about.


Valve spring oilers eat up some volume of oil and its best to compensate with a pump that puts out more volume as you figured out.
 
#13 ·
Not sure, sheet says gmp-12LT cam bearings. Pics of them online show 1 hole?

Either way i’m seeing atleast 65 psi now on small revs vs 43 at full song without the oilers connected. So they def bled off more oil than anything else in the system. I’ll see what it does at rpm but i still may put in a high pressure spring
 
#14 ·
#15 ·
Valve spring oilers are usually another 3-4 GPM.... there's your 20 psi. If i had a dollar for every "I have low oil pressure" tech call I get after someone adds accessory oiling I wouldn't have to work anymore. People don't realize how big of a leak valve spring oilers and piston squirters add.
 
#16 ·
Yeah first i heard of it but makes sense. Dont know anyone running oilers personally. The pin holes in the oilers didnt seem to me that they would flow that much. Wish i had known better ahead of time and bought the higher volume pump and higher pressure spring. For now i will run without and maybe replace things after i get the turbo stuff done later this year
 
#18 ·
Said standard pressure and two extra springs were included but they are plain and look identical. Mellings description says low pressure spring included so maybe it is a higher pressure spring in it? My understanding is plain is 52 psi, pink is 70 and there may be a blue spring thats 60? I ordered some 70 just in case but sounds like i’d be better off with more volume of a 10778. I’ll try restricting the oilers first
 
#23 ·
Yeah , Exactly what Scot said. Pressure cant go up if you dont have the volume to make it. Having said that, if your oil pressure doesn't come down as revs go up, you probably have the right size pump. Your oil pressure will go up with revs only because the pump is too big and the clearances/leaks in the engine cant allow more flow of oil so pressure must go up which only beats up and heats the oil more than necessary.
 
#25 ·
just an update

I took oilers off for now and was seeing mid 40’s psi cold start idle pressure as of a month or so ago.
Took oil cooler off and saw 50-52 psi cold idle. Did some wot pulls to 7k. Rock solid pressure at 49-50 psi. 52-54 ish going down the road cruise. So it was up a bit from before. Was low mid 40’s wot.

Just now upgraded my remote oil filter lines from -10 to -12 and moved filter mount around 9-10” closer to eliminate some line length. I see 58 psi cold idle now, slight rev to 1600-1800 rpm it was 65. So now shall see what it does when warm at wot. Hopefully its nearer 60-65 in wot now.

So it seems bbc really wants -12 large line for coolers or remote filters. My sbc didnt seem to have such issues with -10
 
#29 ·
just an update

I took oilers off for now and was seeing mid 40’s psi cold start idle pressure as of a month or so ago.
Took oil cooler off and saw 50-52 psi cold idle. Did some wot pulls to 7k. Rock solid pressure at 49-50 psi. 52-54 ish going down the road cruise. So it was up a bit from before. Was low mid 40’s wot.

Just now upgraded my remote oil filter lines from -10 to -12 and moved filter mount around 9-10” closer to eliminate some line length. I see 58 psi cold idle now, slight rev to 1600-1800 rpm it was 65. So now shall see what it does when warm at wot. Hopefully its nearer 60-65 in wot now.

So it seems bbc really wants -12 large line for coolers or remote filters. My sbc didnt seem to have such issues with -10
Moving the remote closer probably made more difference than changing the size of the lines but that didn't hurt either. You eliminated 18-20" of line. That's a lot of additional demand on the pump you eliminated. Between that and the oilers, now hopefully your pump can keep up! Keep an eye on the pressure during a run.
 
#30 ·
Reason i did the -12 was cuz i made a 18” loop of -10 to just connect the out/in connection at the oil filter adapter boss on the block. Quick fire it was in the low 60’s psi, so the 8-9 ft of -10 brought that down to low 50’s. Figured -12 would decrease losses from pumping that far. Seemed to work

Did a quick hit, saw 57-58 psi during the pull that lasted very shortly. Went down the road abit further and did another hit saw 53-55 psi. Oil was well hot by this point. So its up more than before but not as high as i would like.

Thats as good as its gonna be with this pump im afraid. I’ll live with it til i have to take motor out for inspection. Maybe i’ll do high volume then. Lifters and cam bearings probably bleeding off alot. No idea how guys claim to have 80-90 cold start pressures
 
#31 ·
Reason i did the -12 was cuz i made a 18” loop of -10 to just connect the out/in connection at the oil filter adapter boss on the block. Quick fire it was in the low 60’s psi, so the 8-9 ft of -10 brought that down to low 50’s. Figured -12 would decrease losses from pumping that far. Seemed to work

Did a quick hit, saw 57-58 psi during the pull that lasted very shortly. Went down the road abit further and did another hit saw 53-55 psi. Oil was well hot by this point. So its up more than before but not as high as i would like.

Thats as good as its gonna be with this pump im afraid. I’ll live with it til i have to take motor out for inspection. Maybe i’ll do high volume then. Lifters and cam bearings probably bleeding off alot. No idea how guys claim to have 80-90 cold start pressures
53-55 hot at rpm is plenty of pressure. Run it. If it starts dropping ~7000, it's most likely cavitating.
 
#32 · (Edited)
I got a fresh 555 dart big m going and noticed oil pressure is lower than expected

I have valve spring oilers and remote oil filter with bar/plate style b&m cooler

Engine is in a 3rd gen camaro, Showbox jiofi.local.html tplinklogin so we have filter adapter in the block that has 1/2 npt to -10 outlet running 4 ft of -10 line to cooler mounted at radiator in front of car then 1 ft of line to remote filter housing behind driver headlights basically, thru filter then back to motor thru another 4 ft of -10.
Also from remote filter i have a -6 line takeoff to feed a distribution block near firewall, 4ft away from filter. Distribution block has my oil pressure sender for stock camaro oil gauge and a -4 takeoff to feed the valvespring oilers in the covers.

Two oil pressure sensors. One in the back bellhousing area. One in distribution block off the remote filter housing. Both read about the same

Engine has .0025 rods and .0029 main clearance. It has bushed lifter bores with howards/morel solid roller lifters and it does not appear to drop below or above oil band hole in the bore. Not sure of the exact lifter bore clearance however but they were sized

Melling 10774 std pressure std volume pump

Had lucas 30w break in oil and then moved to 15w40 rotella to see if it changed pressure. It did help hot idle but wot was same

Its idled in the mid 30’s to near 40 cold (80 deg ambient) and hot idled in the 20’s psi at 1000-1100 rpm. At wot up to 6500 its only seeing 43 psi but flat and stable and gets to that pressure immediately on the hit.
It almost seems like i have alot of line and bleed off from the oilers which would drop prssure and the pump is on the bypass spring. Do i just need to swap out to high pressure spring?
This a street rod?. Only guys i know that run oilers are at 800 CI plus. Better pump is an understatement. More lines the more chances of leaks.
 
#34 · (Edited)
You can take a Weldon Teflon fuel regulator set it for 40lbs and feed your spring oilers that way you always have enough to feed bearings. I used a oil regulator out of a rotary motor to turn my piston squirters on and off under 60psi took a little work. It needs to be efi regulator once it’s at set pressure will bleed off to springs.
 
#35 ·
Old rule of thumb is 10 psi per 1000 rpm hot. Every 90 degree fitting reduced oil pressure by 5 psi - check your routing and fittings - try to eliminate as many 90’s as possible. Then there’s always an Accusump if you’re seriously worried about momentary loss of pressure. Definitely need a High volume pump to make up for extended oil galleys.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top