360 Engine issues

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tubbedamx

tubbedamx

Location Boise, Idaho
Joined
Jan 7, 2007
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Location
Boise, Idaho
I have a stock late 70’s 360/727 in my 67 Barracuda that has a couple problems. I think I have a solution but would like to run it by you
First: Engine vibrates at idle.
When I say vibrate it’s something I can feel it in the steering wheel and kinda see it in the engine bay. Seems to fade away when above 2000rpm. Motor and tranny mounts are new and tight. Looking at converter I don’t see a weight welded to it anywhere. Also the harmonic balancer Is starting to spit out the rubber.

Would installing a B&M flexplate and replacing the balancer potentially solve the vibration?

Second: Oil pressure at startup after it sits for a day.
Turn the key, engine cranks and starts and for 3-5 seconds there’s no oil pressure. Then you can hear and feel the engine load up. Oil pressure climbs up to 65lbs and the engine quites down. Engine has 65psi cold and 35 hot. Stock oil pan with 6qts of 10w-30 and wix 51515R oil filter.

Guessing the oil is draining back into the pan through the oil pump? Should the pump hold oil on the discharge side? If the oil pump needs replaced will the pan clear the cross member?

Thanks for any input
Jim

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Change oil filter to anti drain back one. Sounds like oil is draining back and motor is goi g dry. All old cars do this to some extent. But a good oil filter like a 1515 Napa gold I run stopped this in my 340.

also you have something out of balance. TQ converter or balancer or both.
 
Stock 6 quarts of oil? What oil pan? Because stock takes 5 quarts unless for a truck. In my stock 360 I run 5 quarts.
 
Agree on filter. 51515 is fine That IS the proper Mopar filter. You may have a crack in the pickkup tube hard to say If it's been stressed/ overtightened at the pump

The PROPER BM flex will fix the out of balance, and yes replace the balancer.
 
I'm assuming your oil pressure readings are at a normal idle? If so, good. If not (say 1500 RPM hot, then you need to pull the engine and pull the pan and see what's going on with bearings). Unless the engine has been modified, a 360 should have weights on the converter, or, the special aftermarket flex plate made for an externally balanced 360. If the balancer has any wobble, or, the rubber is deteriorating and coming out, it needs to be replaced. Pulling the pan with the engine in the car is a real pain. If you're going to replace the flex plate or converter, do it while the transmission is out. If you have to do more to the engine, I'd just pull the engine out and make it easy on myself.
 
Thanks.
Bought a external flexplate and ordered a balancer from Summit.

I might pull the engine. I wouldn’t mind replacing the cam and lifters along with the timing chain. With winter coming nows the time
 
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