Low oil pressure

[blackgn231]

I have a problem that ,I do not understand.I rebuiltt my motor about 5 yrs ago and it never had as good as pressure that it had before the rebuild.I t has good pressure on start up and going down the road but the more stops I make it seems to go down to about 35-40 psi at 50 mph if I did not make any stops it stays ok put a booster plate from postons in and a better spring from KenBell so not sure were to go from here can anyone help thanks

 

[Blazer406]

The old rule of thumb.... is you only need 10 psi per 1000 RPM. If yours is getting 35-40 psi going down the highway.... sounds adequate to me.

What clearances was the motor set up to?

What viscosity oil are you running?

HTH

 

[blackgn231]

Oil problem

I am running 20-50 and as far as the clearances not sure I just had the crank polished and stardard bearing TRW cleivite bearings.I did not do the crank shaft fwd and back to set the thrust bearing could this be a problem but the oil drop after stopping and going does not make any sense.:

 

[mikestertwo]

Sounds like your bearing clearances or pump clearances may be a little loose. Your pressure drops in stop and go traffic more because the oil is getting heated more and dropping in viscosity. What was all done in the rebuild?

 

[Lee Thompson]

oil pressure

Good pressure on startup but drops as oil gets hot= classic case of excessive bearing clearance. Keep clearances WELL inside factory specs (which very many seem to want to suggest) and all will be well.

 

[SouthernCal GN]

I am running 20-50 and as far as the clearances not sure I just had the crank polished and stardard bearing TRW cleivite bearings.I did not do the crank shaft fwd and back to set the thrust bearing could this be a problem but the oil drop after stopping and going does not make any sense.:

What were the clearances? Since you had the crank polished, maybe you should have gone with a +1 bearing.

 

[tomcatturbo]

What's the correct oil pressure?

What is the correct oil pressure for 86/87 Turbobuicks?

Idle-?
Running-?

I'm interested, cause it seems everybody has different numbers...

 

[blackgn231]

low pressure

Installed a new oil pump gears ,new bearings,rings,was not bored,basically the blockwas rebuilt stock,so if the bearing have to much clearance what should I do?Its been like this for 5 yrs now could I drop the pan an roll a new set of bearings in or would I have to take engine out and do it all over?Iam not a great engine builder so never did ckeck the the clearances but don't want to have it crash have a lot of money in this car so any help is great thanks to all that have helped with ideas .

 

[vacuum 6]

Typical psi is ~80 at startup, 45-60 mph ~50 psi, then once the engine is warmed up (at idle) ~20 psi.

See Quick Reference Page For the '86/'87 Turbo Regals and '89 Turbo T/A

 

[tomcatturbo]

Thanks! I appreciate this info. This is what I was estimating around as well. I've heard a little bit lower (around the 10-12 at idle, but I think it's all relative to engine life/wear, what size cam or rebuild), but your numbers seem very correct vacuum6.

Thanks again!

Typical psi is ~80 at startup, 45-60 mph ~50 psi, then once the engine is warmed up (at idle) ~20 psi.

See Quick Reference Page For the '86/'87 Turbo Regals and '89 Turbo T/A

 

[vacuum 6]

I have a new 200 mile engine in my car and the psi at idle is varying from 10ish-20. My old 100k motor at idle was the same.

 

[blackgn231]

I talked to the machine shop guy who did my motor work and he says I could have gottoen a bad bearing and since I did not check my clearances it happens some time ,he said I should put a one hundred thousand undersize bearing set in to help make up the clearance issue,would it be to hard to do with the engine in the car?it runs fine and no knock so mybe just a set of bearing would help.One more question could this be a cam bearing problem?Not sure but don't they have problems with the number 1 bearing on these motors thanks guy for all the help.