I just rebuilt my 69 350. It has approximately 400 miles on it. When I shut the engine off and restart it later, the lifters rattle and it takes around 10 seconds for the oil pressure to pick up. It does this even if it sets for as little as 10 minuets between shutting it off and starting it back up. Any ideas on what it could be or if this is normal. I have never noticed it in my turbo car, except when it has set for over a week. Thanks, Brandon
Did you rebuild the oil pump and set the clearances when you rebuilt the motor? Were the main bearing and rod bearing clearances set right by whoever rebuilt the motor? Do you have an oil pressure gauge? If so what is the pressure fully warmed up at different speeds and idle? What oil filter are you using?
Larry, I'll have to restate the time it takes for the oil pressure to rise after sitting. I counted it last time it was started and it was around 5 seconds not the 10 that I had in my original post. The oil pump was rebuilt with a very good used cover. I did not use a booster plate like I have previously on my V6s. I think the oil pump and bearing clearances were set correctly, but I'll have to check with the shop who built the motor. The motor was also primed before started for several minutes with the oil pressure reaching 60 psi. When started up cold the oil pressure is around 50-55 psi. When warm, at about 40 mph (calculates to 1900 rpm) it drops to around 45-48 psi on the gauge. At idle fully warmed up it carries about 12-15 psi, but instantly goes up with rpm. It is still running on the 30wt break in oil with a NAPA 21258 filter, which I think is made by Wix. Wix's web site stated that their equivalent 51258 filter had an anti-drain back valve, which is what I was thinking might be the problem. It has a new Auto Meter gauge, so I'm confident that it is fairly accurate. The time it takes for the oil pressure to pick up might be normal, but I guess I might be paranoid and expecting something to go wrong with a new engine. Thanks, Brandon
Brandon, It's kind of typical for a Buick V-8. The anti drainback filter may help. Also realize that there is a lag time with any mechanical oil pressure gauge. As long as you're not hearing bearing knock or extreme lifter noise, I think you'll be OK. Your pressures sound fine to me. Definitely check to see what the shop set your main and rod bearing clearances at.
