Hello all! I've got a new Roush stroked 427 SBF that I installed into a Factory Five MKIV Roadster. Fired it up for the first time this week and everything went perfect. I spun the oil up with a drill before start and was getting about 67lbs of pressure, which was great. After start, when the engine is cold, I get about 62 lbs. of pressure, and the gauge needle is pretty much solid. As it warms up, the electric oil pressure gauge settles to roughly 40-45 lbs. of pressure but the needle likes to fluctuate a couple of pounds up or down. The cam is somewhat lumpy and I'm idling at about 800-900. Timing all in at 34 degrees @3000 with the distributor vacuum cannister hooked up and base timing at 10 degrees BTDC. Engine starts on first blip of key when warm and no issues at shut down. Are there any issues with the oil pressure gauge fluctuating a couple of pounds at hot idle? I wasn't sure if it was moving because of the lumpy cam as my rpms are moving a bit? Gauge smooths out as rpms increase. Maybe increase the idle screw a bit to 900-1000?
Most probably called..."vibration". I have a 2.63" dia., Autometer oil pressure gauge in a 2006 car, that does the same thing. At the first start of the day, the engine, at fast idle, the engine / car has a high pitch vibration that causes the gauge panel to...vibrate. With vibration, the needle also vibrates. If I push hard on the gauge, the gauge vibration stops, the needle vibration stops. Try putting pressure on the gauge with your finger(s), see what happens. It "may"...take a bit of pressure with your fingers !!! If the vibration stops...have no worries. Mike
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