TR6 TR6 Oil Pressure Reading

[vettedog72]

What is your TR6 oil pressure?
cold 75+psi (1000rpm)
run (at operating temp) 50psi (2000rpm)
Idle (at operating temp) 20psi (600rpm)
What's you numbers?
Above numbers are for '74 TR6 with new standard rod and main bearings and new pistons w new pins. I expected a little more pressure at idle.

 

[Guest]

VD,
That idle number of 600 is kinda low. Most techs will say to idle at 750. Mine is set to idle at 1000, where my oil pressure will run about 35, if you can believe the gauge. Try bumping the idle up closer to 1000 and see what you read. At speed, I hover around 55 or so lbs of pressure (or is that inches of mercury?).

Bill

 

[trrdster2000]

vettedog72, you may need a new oil pump or at least the new spring kit. The spring kit is easy to put in, no tear down of a major part, all done from the outside, goes where your oil filter cover is. Wayne

 

[trboost]

Hey Vette,
Your readings are pretty much dead on for a fresh motor. Cold oil pressure readings are decieving. Of course the oil viscosity & chemical make up will also make reading vary. I always get lower readings & more valve noise with Castrol 10w-40. Is it bad oil, no, but the additives are designed to work differantly.
You'll get an accurate reading after 30 minutes of run time. This gives the oil enough time to reach normal operating temps. You'll also find your readings will decline after a nice stint at 50+ mph when you come to a stop but it should recover after a few minutes.
The spec reading at idle should be 800-850 rpm unless you have a lumpy cam. Anything above 15psi @ idle fully warmed is kosher. 50psi at 3,000 rpm is ok but 65-70psi with 10w-40 oil is desired. If your below 10psi it's time to think about some new parts.

PS Many engine rebuilds that include new large & small bearings to repair low oil pressure neglect the cam journals. The TR6 cam rides in the block with out cam bearings. This works remarkably well, until it wears. Engines with higher valve spring rates or over 100,000 miles that don't address the bores in the block will probably suffer a loss of oil pressure & lack of good lubrication to the rocker assembly. Installing cam bearings are not cheap but going through all that work TWICE isn't cost effective either.

 

[AltaKnight]

[ QUOTE ]
VD,
That idle number of 600 is kinda low. Most techs will say to idle at 750. Mine is set to idle at 1000, where my oil pressure will run about 35, if you can believe the gauge. Try bumping the idle up closer to 1000 and see what you read. At speed, I hover around 55 or so lbs of pressure (or is that inches of mercury?).



[/ QUOTE ]

Bill....
Is that Farenheit or Celcius? /ubbthreads/images/graemlins/tongue.gif

 

[Rabid_Dolphin]

[ QUOTE ]
vettedog72, you may need a new oil pump or at least the new spring kit. The spring kit is easy to put in, no tear down of a major part, all done from the outside, goes where your oil filter cover is. Wayne

[/ QUOTE ]

I really have no idea how to tell if the pump is crap by looking at it. Had it out in December. It was a pump, and it was oily. That's the extent of my assessment. Tell me more of this magical spring. /ubbthreads/images/graemlins/laugh.gif

 

[piman]

Hello VD76,
the figures you quote are fine and need no attention whatsoever.I see no reason to idle any higher if the engine is happy, my 2.5 SAH cammed injection unit will idle there all day.
Higher idle speeds merely make gear selection from rest harder.

Alec

 

[trboost]

The "magical spring" is for regulating high oil pressure. It's design is for over pressure conditions such as cold oil at start up. By using different springs or shims you can change the maximum pressure before it dumps oil back to the pan. Some times dirt lodges in the seat and can cause a loss of oil pressure. It's easy to remove & clean.
The oil pump itself is as basic as it gets. They rarely go bad but should be checked for scoring & wear at the gear lobes & end play. The Benley covers this I think. The "Country" brand sold by many parts houses today is a decent replacement but requires lots of deburring & port opening to make it camparable to original units.

 

[skikir]

My op is 50 cold. 5 at idle and maybe 25 at speed. Anyone have a spare engine?

 

[prb51]

Skikir, I'd check that with another gauge for accuracy. I believe 7 psi @ idle is the min safe psi.

 

[Rabid_Dolphin]

[ QUOTE ]
The "magical spring" is for regulating high oil pressure. It's design is for over pressure conditions such as cold oil at start up. By using different springs or shims you can change the maximum pressure before it dumps oil back to the pan. Some times dirt lodges in the seat and can cause a loss of oil pressure. It's easy to remove & clean.
The oil pump itself is as basic as it gets. They rarely go bad but should be checked for scoring & wear at the gear lobes & end play. The Benley covers this I think. The "Country" brand sold by many parts houses today is a decent replacement but requires lots of deburring & port opening to make it camparable to original units.

[/ QUOTE ]

I would say that the gear lobes looked good. They fit well when assembled with only the shaft, gear, and middle housing. There was also no endplay at this stage.

 

[skikir]

This engine is shot. I have another but I'm not wild about swapping engines in the rain so it'll wait until the PNW dries out a little. Until then all missions will not exceed walking distance from home.