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Cal-look/High Performance => Technical stuff => Topic started by: Karlos99 on September 26, 2021, 15:30:35 pm



Title: Oil pressure
Post by: Karlos99 on September 26, 2021, 15:30:35 pm
What is the ball park figures for oil pressure? There is a lot of conflicting opinions

Got a 2110in a 1970 bus, with 30mm berg pump & relief cover, remote, filter and a sandwich plate going to a 36 row cooler in front of the gearbox and AN-10 lines throughout running on Lucas 20w50

Oil pressure is 45psi cold at idle, 10psi hot/180f at idle and about 35psi when cruising at 3500rpm


Title: Re: Oil pressure
Post by: ibg on September 27, 2021, 01:01:21 am
I'd say that's in the ball park, 10 psi idle and 10psi per 1000 rpm which is exactly what you have.
Though i am a bit surprised... with 20 / 50 and a 30 mm pump I would have expected more. So 2 thoughts, is your gauge accurate? or are your bearing clearance on the high side?


Title: Re: Oil pressure
Post by: Karlos99 on September 27, 2021, 06:56:33 am
I'd say that's in the ball park, 10 psi idle and 10psi per 1000 rpm which is exactly what you have.
Though i am a bit surprised... with 20 / 50 and a 30 mm pump I would have expected more. So 2 thoughts, is your gauge accurate? or are your bearing clearance on the high side?

I’ve got Autometer gauges which I always thought were meant to be accurate? Bearing clearances are good, my thinking behind the pressure not being as high as what’s normally expected with the 20w50 & 30mm  was I’ve got an10 lines and as it’s a bus my oil lines are quite long as the cooler is In front of the gearbox under the cargo floor?

Nice to know things are where they should be though


Title: Re: Oil pressure
Post by: PPRMicke on September 27, 2021, 12:24:11 pm
I see it another way 3 bar (43.5 psi) it should be cold as well as hot
  Many things happen in a VW block when it is hot
What happens is that the dimensions increase in the block Often the oil leaks between layers and blocks When they get hot (layer no. 2 in steel (steel and alum have different expansion
I often measure the block when I have heated the block to 40 Gc then I measure the position so you do not get it to leak between layers and blocks
The stock position needs to be 64.95-65.00 because it must be well above the max +0.02 mm
/// M


Title: Re: Oil pressure
Post by: pupjoint on September 27, 2021, 14:23:29 pm
my 2332, Berg 30mm, stock relief blocked using external Jaycee Relief filter head, 80psi dumps back to the sump. 5-40 Motul 300V synthetic, hot idle 15-18psi, also AN10 oil lines


Title: Re: Oil pressure
Post by: Martin S. on September 27, 2021, 14:46:04 pm
What weight oil are you using? I've found a big diff between using 5w40 and 10w60 synthetic. When hot 10w60 helps keep mine at 10psi or higher at idle, and when cruising that oil helps keep at the recommended 10psi/1000rpm or higher. Oil pressure depends on bearing clearances and mine are likely wearing out.


Title: Re: Oil pressure
Post by: brewsy on September 27, 2021, 20:02:33 pm
I see it another way 3 bar (43.5 psi) it should be cold as well as hot
  Many things happen in a VW block when it is hot
What happens is that the dimensions increase in the block Often the oil leaks between layers and blocks When they get hot (layer no. 2 in steel (steel and alum have different expansion
I often measure the block when I have heated the block to 40 Gc then I measure the position so you do not get it to leak between layers and blocks
The stock position needs to be 64.95-65.00 because it must be well above the max +0.02 mm
/// M
Micke,
Do you mean clearance between the saddles and the back of the bearings? So you heat the case to 40C and then measure to make sure the case is the right size?
How do you adjust if it is out? Line bore?

Cheers
Marc


Title: Re: Oil pressure
Post by: PPRMicke on September 28, 2021, 14:35:53 pm
I see it another way 3 bar (43.5 psi) it should be cold as well as hot
  Many things happen in a VW block when it is hot
What happens is that the dimensions increase in the block Often the oil leaks between layers and blocks When they get hot (layer no. 2 in steel (steel and alum have different expansion
I often measure the block when I have heated the block to 40 Gc then I measure the position so you do not get it to leak between layers and blocks
The stock position needs to be 64.95-65.00 because it must be well above the max +0.02 mm
/// M
Micke,
Do you mean clearance between the saddles and the back of the bearings? So you heat the case to 40C and then measure to make sure the case is the right size?
How do you adjust if it is out? Line bore?

Cheers
Marc
'
Yes 
Line bore 
if you read vw spes it should be below measure
So even the  bearing is stuck when the block is hot
One way is to heat the block and check
You often forget to check how the block is in a hot state. Then you lose the oil pressure when it is hot
/// Micke


Title: Re: Oil pressure
Post by: Karlos99 on September 28, 2021, 18:01:38 pm
So, is the general opinion my oil pressure is fine???


Title: Re: Oil pressure
Post by: Martin S. on September 28, 2021, 21:36:40 pm
Sounds fine, although I would have thought that with the 30mm pump and 20w50 you'd have higher pressure than 10 idle/ 35 cruise. I had a problem with my engine at one point when a chunk of metal got sucked in the sump (no screen) and jammed the pump. My mechanic also checked the bypass spring(s) for tension saying that they can be a problem, especially the non-original ones and also the bore of the relief valve being wonky. He checked the spring and tweaked it from what I recall, using this calibration tool for springs.

ps Looking online for bypass spring info yielded this interesting solution for:

"The problem with the plunger and spring set-up is that the plunger begins to wear the walls of its chamber inside the case after normal and/or extreme engine use. This wear eventually allows oil to flow around it, "an internal oil leak", causing low oil pressure issues that are common with vintage VWs."

http://www.headflowmasters.com/vw-oil-pressure-valve-body.html#.YVN-5i1h0dk