Factory Gauges... what should they read?

[midlife]

"Factory Gauges... what should they read?"

English, at least at a fourth grade level...and Mad Magazine.

 

[rackerm]

A quick update. I swapped a mechanical oil test gauge in place of the factory gauge and the oil pressure when fast idling cold was 80 psi and at normal operating temp is 69-70 psi. It's a newly rebuilt 351C with a high volume pump and I am using a non-synthetic 10w 30 weight oil with zinc added.

The pressure seems a bit high, but not where I should be alarmed .... or should I be? Appreciate your thoughts here. Thanks

 Hate to tell you this, but a high volume oil pump is not what you need unless the clearance on the crank etc. have been allowed for and/or your engine is modified. This very problem, my engine builder chose to put one in my 351 C rebuild back in 2012, cause the cam to go out resulting in them doing a warranty rebuild last year. At least, that is what he told me the cause was and put in a standard pump. Oil pressure is 65 psi and I have a good almost stock engine now.

I'm no engine guru and I'm sure some will disagree, just going  by what I have read and have been told.

Thanks Don and Stanglover. I am going to talk to my engine builder. My oil pressure at hot idle is 70psi. Don, do you know what yours was after the rebuild in 2012 and before the failure? I'm no expert either so I ask if 65 psi is typical for a stock Cleveland and does 5 psi increase I have enough to potentially create a problem? Should I consider changing to a thinner oil? 

Thanks all.

 

[Stanglover]

A quick update. I swapped a mechanical oil test gauge in place of the factory gauge and the oil pressure when fast idling cold was 80 psi and at normal operating temp is 69-70 psi. It's a newly rebuilt 351C with a high volume pump and I am using a non-synthetic 10w 30 weight oil with zinc added.

The pressure seems a bit high, but not where I should be alarmed .... or should I be? Appreciate your thoughts here. Thanks

 Hate to tell you this, but a high volume oil pump is not what you need unless the clearance on the crank etc. have been allowed for and/or your engine is modified. This very problem, my engine builder chose to put one in my 351 C rebuild back in 2012, cause the cam to go out resulting in them doing a warranty rebuild last year. At least, that is what he told me the cause was and put in a standard pump. Oil pressure is 65 psi and I have a good almost stock engine now.

I'm no engine guru and I'm sure some will disagree, just going  by what I have read and have been told.

Thanks Don and Stanglover. I am going to talk to my engine builder. My oil pressure at hot idle is 70psi. Don, do you know what yours was after the rebuild in 2012 and before the failure? I'm no expert either so I ask if 65 psi is typical for a stock Cleveland and does 5 psi increase I have enough to potentially create a problem? Should I consider changing to a thinner oil? 

Thanks all.

 I looked up the specs from the 2012 build and they used a Melling high volume pump @ 65 psi. From what I see, a high volume does not necessarily mean high pressure. It depends on how the pump was set up when it was installed. Many say a new pump must be stripped and checked for spring pressure, but as I'm no expert either, I'll leave that for someone like Don C to answer in more detail. What happens with a high volume is the oil goes through the bearings too fast for the appropriate oil 'wedge' to form and that is what stops ware, unless the engine has been built for the oil pump used. I believe I've got this right, I'll be corrected if not and that's how we learn.

On my engine, not only was the cam out for number 1 cylinder, but all the mains and rod bearings were completely worn out, down to the bronze, because of all the metallic bits from the cam and insufficient oil wedge. This engine only had 5K miles and would not have lasted another summer's driving. That's what the builder told me, so I hope they got it right this time!!

 

[goodnigh]

Just got my rebuilt 351C running and my factory oil gauge reads High and the temp gauge reads Low after idling for about 20 mins. The car is not over heating so the Temp gauge may be fine in spite of the low reading. The High oil reading is worrying me. I just ordered a oil pressure test gauge to get a more precise pressure reading. The Alt gauge is quite a bit left of center, but with the engine idling I checked the Alternator charge at the battery with a Multi-meter and its nearly 14v with nothing else on and high 12v with all the electricals on, so I am not concerned with that gauge.

I should mention the oil pump, water pump and alternator are new units.

I could use a point of reference from those who are familiar with these factory gauges for where typically the factory Oil and Temp gauge needles land when the engine is at normal operating temperatures. Also, what is the typical PSI range for oil pressure? A picture of my gauges below...

Thanks!

My gauges look just like that when the engine is warm, except the center AMP gauge which has never moved.

mike

'71 M-code Grande w/toploader