priming a Hemi

Due to time restraints, can you prime the 392 hemi and than 24 hours later start it without priming again? Fresh motor never been stated before.

 

just my 2 cents
to be safe re-prime that eng

 

once you have initialy primed an engine its good for a bit till you start it, but you can always do it again for peace of mind.

 

The assumption is that you're talking about the oiling system, right? 'cause if you're talking about priming by dumping a little fuel down the carb throat, then it's a different story.

For the oiling system, I wouldn't worry about it if it's just a day later. If it were a couple of weeks, I'd run the pressure up again with a drill, and slowly turn the motor over a couple of rounds. The hemi's only send oil to the rocker shafts when the cam is in a specific position, through oiling holes in the cam journals #2 and #4. If I recall, journal #2 oils the drivers side, and journal #4 the Passenger. And they oil 360 crankshaft degrees apart. So don't expect there to be a flood of oil at the top end of the motor, because they just squirt a little bit up there every now and then.

 

Hello Gary..How are you doing..My Red Ram Dodge Hemi is running great, thanks to your help..
Duane

 

360 degrees apart?

 

The rocker shafts need to be full before there is any oil pressure to the rockers.
I know I wouldn't gamble that they didn't drain out.

 

yes. 360 crankshaft degrees, because the camshaft spins one turn for every two crankshaft spins. So it's every 180 degrees as measured at the cam but 360 as measured at the crank.

 

Hey Duane, I am finally gettting around to firing the hemi. Been really busy around the place and at my daughters house so my projects have been on the side.
It is the oil prime I am talking about.
I went ahead and primed motor today at 3 PM and should be able to fire by noon tomorrow.
Thanx ebbspeed, I had the same feeling, I had primed the motor about two weeks ago and it was still draining oil today, so I felt it would be OK. I will start tomorrow .

 

Yes, like Johnunit said, and like I posted. 360 crankshaft degrees.

It's highly unlikely that there's measurable oil pressure in the rocker shafts of most any older Mopar V8. They basically have a little oil squirting into them through one little hole, and that oil drools out of other holes along the bottom of the shaft under each rocker arm. Trust me, when you shut one off, the oil will drain out of the rocker shafts within the hour.