PDA

View Full Version : head oil pressure



1985ShlbyChrger
02-04-2009, 10:35 PM
With a hybrid, I understand that the head doesn't need as much oil pressure as the bottom end, but how much is sufficient for the proper lubrication of the head parts? I am going to put a restrictor in the line but need to know what size and/or what psi the head should be at. Thanks

Nate

lancer402
02-05-2009, 11:45 PM
Not sure about a restrictor size. i have a needle valve in the line to my head which is a variable restrictor. But in the summer time with a thoughorly warmed engine i will have 10-15 psi at idle with 10w30 mobil1. a little more when I run 15w50 mobil 1. I measure this with a gauge downstream of the needle valve of course. I have over 100K on this engine so it must be ok. knock on wood.


andy

Russ Jerome
02-09-2009, 12:34 AM
I measured the oil pressure at the head of a SRT4 and it was
around 17psi hot idle. I use "flow control" valves from hydraulic
stores, adjusts pressure depending on oil viscosity.
http://www.indiamart.com/flutec/hydraulic-valves.html
The Parker valves are available at any hydraulic fitting store.
Mounting a 7-10psi idot sender in line is a nice safety measure.

lancer402
02-09-2009, 06:34 PM
I measured the oil pressure at the head of a SRT4 and it was
around 17psi hot idle. I use "flow control" valves from hydraulic
stores, adjusts pressure depending on oil viscosity.
http://www.indiamart.com/flutec/hydraulic-valves.html
The Parker valves are available at any hydraulic fitting store.
Mounting a 7-10psi idot sender in line is a nice safety measure.

Hey Russ, excuse me for butting in here. I believe flow control valves are needle valves with a check for free flow in the opposite direction. Fine, but really not needed in out application. Any flow or needle valve will allow more flow when viscosity drops but the valves on indiamart.com are regular valves and not pressure or temperature compensated. These type of valves are much more expensive. I use to work for Parker's fluidpower group and this is still impregnated in my brain, unfortuantely. I would like to delete it to free up some space.

Russ Jerome
02-09-2009, 08:40 PM
I stand cortrected, interesting info.

I've always used them (free for me!) because the spring in the ones
I use seam to buffer the oil pressure, rarely more than a 5psi swing
from hot to cold or high to low rpm. The units I've been using are the
type you would use to regulate the rate of drop on a plow or liftgate,
is that the same thing?

mboyek
02-09-2009, 10:56 PM
Hey Russ, excuse me for butting in here. I believe flow control valves are needle valves with a check for free flow in the opposite direction. Fine, but really not needed in out application. Any flow or needle valve will allow more flow when viscosity drops but the valves on indiamart.com are regular valves and not pressure or temperature compensated. These type of valves are much more expensive. I use to work for Parker's fluidpower group and this is still impregnated in my brain, unfortuantely. I would like to delete it to free up some space.

Thats interesting. I had a needle valve in the mockup stages and swapped it out for a parker "flow control" valve before the first start.

I just leave the valve wide open, as once hot it doesn't go above 13 psi or so idle. Cold with 15-40 is around 60 psi, but that's with a hi-vol oil pump and the high pressure spring. I haven't had the guts to crank the valve closed a bit on a cold start, closing it a bit hot drops it to 5psi quick.

So I leave it wide open.

lancer402
02-11-2009, 05:21 PM
I stand cortrected, interesting info.

I've always used them (free for me!) because the spring in the ones
I use seam to buffer the oil pressure, rarely more than a 5psi swing
from hot to cold or high to low rpm. The units I've been using are the
type you would use to regulate the rate of drop on a plow or liftgate,
is that the same thing?

that sounds like a pressure compensated flow control which will keep the flow constant no matter the pressure drop across it. You don't want the speed of your tailgate or plow changing as it moves.

how come they are free? where you work?


andy

lancer402
02-11-2009, 05:24 PM
Thats interesting. I had a needle valve in the mockup stages and swapped it out for a parker "flow control" valve before the first start.

I just leave the valve wide open, as once hot it doesn't go above 13 psi or so idle. Cold with 15-40 is around 60 psi, but that's with a hi-vol oil pump and the high pressure spring. I haven't had the guts to crank the valve closed a bit on a cold start, closing it a bit hot drops it to 5psi quick.

So I leave it wide open.

do you have the number of the parker flow control valve? it should be stamped on the side. something like f400B is a flow control with 1/4" npt ports and made from brass. n600s is a 3/8" needle valve in steel. but I think parker has other lines than these now so there may be different numbers all together.

I would like to understand you explanation more, little confused.

andy

Russ Jerome
02-11-2009, 06:27 PM
that sounds like a pressure compensated flow control which will keep the flow constant no matter the pressure drop across it. You don't want the speed of your tailgate or plow changing as it moves.

how come they are free? where you work?


andy

The flow control valves I've used are intended to control
drop on "gravity down" setups, a 1/4" valve opening would
cause the liftgate to plummet to the ground with no control
at all, causing a horrible crash on contact.

I've worked at several fabrication and install shops for
medium and heavy duty trucks with my main field being
class 7 and 8 truck repairs, those valves are "laying" all
over........

I think mboyek is refering to the operating range of the
valve he is using. A little experimenting with port size
keeps the pressure constant, our valves are probably
as you described earlier but we are just seeing a little
buffer by the spring piloted seat that houses our needle.
None of the ones I have or used are one way valves, I'll
get some numbers to see what we're using.

Russ Jerome
02-11-2009, 06:38 PM
I was digging thru some old (blurry) pics:
http://sites.google.com/site/miscmicsforlinks/_/rsrc/1234391894648/Home/154.jpg
On the left into the forward galley plug is one of the valves
I've had great luck with....car was sold so no part #. Its
missing the little handle but that one would spike up to
35psi cold (70+psi feed) and 20psi at head hot (40psi
feed). Not exactly perfect viscosity wise but more than
workable being the higher pressure cold was undoubtably
less volume for the head to have to drain...right?

lancer402
02-11-2009, 08:02 PM
I was digging thru some old (blurry) pics:
http://sites.google.com/site/miscmicsforlinks/_/rsrc/1234391894648/Home/154.jpg
On the left into the forward galley plug is one of the valves
I've had great luck with....car was sold so no part #. Its
missing the little handle but that one would spike up to
35psi cold (70+psi feed) and 20psi at head hot (40psi
feed). Not exactly perfect viscosity wise but more than
workable being the higher pressure cold was undoubtably
less volume for the head to have to drain...right?

Yes right about that. higher pressure cold doesn't mean more flow.
I have seen flow control like the one in the picture.

you have a filter in the line to the turbo?

general question - is it possible to over pressurise a turbo bearing and or seal?

andy

Russ Jerome
02-12-2009, 12:29 AM
Just a universal filter holder plumbed in line to turbo, see's full engine
oil pressure, never had a new turbo fail using a filter. The low oil pressure
dummy light is on the rear cam journal.

Turbos by design (gravity drain) should be able to handle about anything
a motor throws at it for pressure provided there is no coaking in the drain
ports or around the dynamic seal. If you look at an OE oil feed line and the
adapter at the block the hole is barely a restriction at all. I've read people
say the turbo flow should be limited but its pressure not flow that would
overcome a dynamic seal is my feeling.

mboyek
02-12-2009, 11:28 AM
do you have the number of the parker flow control valve? it should be stamped on the side. something like f400B is a flow control with 1/4" npt ports and made from brass. n600s is a 3/8" needle valve in steel. but I think parker has other lines than these now so there may be different numbers all together.

I would like to understand you explanation more, little confused.

andy

Yes, it is a F400B. As far as I remember it was the only 1/4" npt flow control valve the grainger store had in their catalog. It was like $40 w/a commercial account through my work! Much more than the $10 needle valve I took off.

http://i441.photobucket.com/albums/qq135/daytonaer/100_2893.jpg

I have the valve wide open, all the way open. My oil pump is the high volume pump, it also has the Mopar performance High pressure spring installed. You can't really see in the picture, but that white nylon line is the oil pressure gauge for the head. It is in the second oil galley in the head.

Hot idle is around 10 psi in the head. I don't know what the block is, but its around halfway on the stock cluster.

I attempted to lower the oil pressure in the head using the valve one day, started closing the valve a little bit at a time. I'm not sure if I closed it 1/2 or 3/4 of a turn (takes more than one turn to close completeley) and I went into the cabin to check the gauge and it was reading under 5 psi, so I opened it up again.

Cold idle will run 60 psi. with the valve wide open. I have not watched the oil pressure driving around at higher rpm's.

t3rse
02-12-2009, 11:45 AM
almost all turbos have restrictors built in, so like Russ said, unless the oil drain clogs, there won't be too much pressure before the turbo at normal operating presssures

lancer402
02-15-2009, 11:48 PM
Yes, it is a F400B. As far as I remember it was the only 1/4" npt flow control valve the grainger store had in their catalog. It was like $40 w/a commercial account through my work! Much more than the $10 needle valve I took off.

http://i441.photobucket.com/albums/qq135/daytonaer/100_2893.jpg

I have the valve wide open, all the way open. My oil pump is the high volume pump, it also has the Mopar performance High pressure spring installed. You can't really see in the picture, but that white nylon line is the oil pressure gauge for the head. It is in the second oil galley in the head.

Hot idle is around 10 psi in the head. I don't know what the block is, but its around halfway on the stock cluster.

I attempted to lower the oil pressure in the head using the valve one day, started closing the valve a little bit at a time. I'm not sure if I closed it 1/2 or 3/4 of a turn (takes more than one turn to close completeley) and I went into the cabin to check the gauge and it was reading under 5 psi, so I opened it up again.

Cold idle will run 60 psi. with the valve wide open. I have not watched the oil pressure driving around at higher rpm's.

Hey very good. Good to see another parker manatrol valve out there.
So your gauge is downstream of the f400b. 5 psi is a little low, mine is around 10psi at idle with thinner oil. But as soon as the engine comes off idle, the pressure will jump up to 20 or 30 psi, because the pump is turning faster and the oil clearances are not really changing, so the pressure has to go up to force the increased flow through the bearings.

I have shut the valve all the way off for a second or two. Obviously the tappets start making a noise. but as soon as you re-open the valve they quite down. It only takes a few psi to supply oil to a relaxed tappet and fill it with oil.

I would just make sure you have enough oil staying in the bottom end for the mains and rod bearings. The only way is to put a gauge before the f400b and compare it to the gauge after the f400b. you can see how they both change as you open and close the valve.

andy

lancer402
02-15-2009, 11:55 PM
one other thing about how much oil a head needs.

I know a guy here in cincinnati that put together a toyota engine and installed the head gasket backwards. This prevented any oil at all from getting to the head. it had mechanical tappets so there was no noise at startup because of tappets pumped down. it wasn't until the next day after start up, when a cam journal finally seized the cam shaft and broke the timing belt.