Is this normal for my DD 8V71 Naturals?

[BFDfirefighter16]

Hello everyone,

Last night I started up my engines which are 8v71 naturals for the first time in about a month since I have been rewiring my lower helm station with new gauges and restoring the wiring to a proper state since the former owners made a disaster of the wiring. I noticed with the engines running that at idle the stbd engine is set slightly lower in rpm's but the oil pressure was reading under 20psi at idle while my port engine was at about 30psi. Is this normal for it to drop pressure? If I give it a little throttle the pressure rises. Should I be concerned? Since they hadn't been run in a while I turned over the engines a bit before I let them start up. They fired right up with no effort at all and no smoke from what I could see after startup. Both my engines are at about 6200 hrs. and never smoke but for a second during startup. Below is my gauges as it was running and slowly dropping pressure.

Thanks,
Alex Sherard

IMG_1440.jpg

[Scarlett]

If you are just at idle that temperature on the stbd. Engine looks a little high on that gauge also. My ti’s don’t have equal oil pressure either but it doesn’t really concern me as long as they both have enough pressure and run ok, could just be the gauges. My temp gauges at the lower helm both read 10 degrees higher than on the fly bridge or with an IR gun. John

[racclarkson@gmail.com]

Mechanical gauges in ER?

[dsharp]

May be getting a little wear in the bearings. 20 lbs at idle isn’t going to hurt anything though. I was thinking there was a bysping on the oil pump but I haven’t been around a Detroit in about 30 years. What weight oil are you running?

[dsharp]

May be getting a little wear in the bearings. 20 lbs at idle isn’t going to hurt anything though. I was thinking there was a pressure relief spring on the oil pump but I haven’t been around a Detroit in about 30 years. What weight oil are you running?

[BFDfirefighter16]

The only mechanical gauges in the boat are the tach's there are no gauges in the engine crawlspace. I was thinking about putting some in there but haven't got to that priority on my list yet. The oil I run is straight 40 weight Rotella. The picture was taken after the engines had been running for about 10 minutes. The oil pressure gauges are brand new the coolant temp gauges are newer but are at least 4 years old and before I started working with the wiring the stbd temp gauge was always way off. I have to back flush the heat exchangers yet to clean them out or take them out and have them gone through which is on my list. Also looking to put new Aqualarm alarm systems on both engines.

[racclarkson@gmail.com]

The only mechanical gauges in the boat are the tach's there are no gauges in the engine crawlspace. I was thinking about putting some in there but haven't got to that priority on my list yet. The oil I run is straight 40 weight Rotella. The picture was taken after the engines had been running for about 10 minutes. The oil pressure gauges are brand new the coolant temp gauges are newer but are at least 4 years old and before I started working with the wiring the stbd temp gauge was always way off. I have to back flush the heat exchangers yet to clean them out or take them out and have them gone through which is on my list. Also looking to put new Aqualarm alarm systems on both engines.

If your systems monitor is working, take comfort. With a 7 PSI oil pressure trigger, your readings are well within specs.

[Sonic Boom]

It also appears the engine with lower oil pressure is slightly warmer and at a slightly lower RPM. At idle a couple RPM makes a difference on our 871's oil pressure