Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[WillCJ]

Ok, so I have a second hand 360, '78, unknown mileage but crank journals ok and oil galleries /rockers etc very clean, cooling galleries a bit clogged.
It has been stood for a few months with no oil in so well drained out, put it in my CJ and at first crank, no plugs in I got no oil pressure, quick look on the web, normal procedure to get pressure up is to pull the dissy and spin the pump with a drill, there are even special tools for this!. So did that, took a bit of oil at the filter head and reverse drive to get it primed, spun the right way and good pressure with just the drill (70 psi)  Then put filter and dissy on and spun the motor, got around 25 psi, so went for start up. got around 40 plus at tick over so was messing about with the ignition timing and shut it off (no cooling sytem)
I had a mechanical guage on it where I could see it, and noticed the needle had settled a bit off the stop, but tried it again to set the timing and find a cylinder off(plug lead not right in), and was seeing 100 psi at the gauge when I revved it, which is not good as it WAS only a 75psi gauge!
So, I am thinking stuck pressure relief valve, so pulled that and all looked ok, put it back in and spun it over , no pressure, had to prime it all up again...unusual all round by my experience? So... think blocked passages etc, but pressure is gettin round everything to show at the guage, so maybe the gasket on the pump body is home made or gunged up?  Well , did not feel like a major strip down, or a minor one for that matter, so back on the web.
Mad Americans.... this apparently can be normal! 100psi when cold, 20psi when hot, and all sorts in between?! don't worry unless zero(blows engine) or 130psi blows filter and then engine)!
I have not run it long enough to warm it up yet, no exhaust, nor charging circuit and more imporantly, no cooling system, so don't know if it will settle.
The 258 I took out just ran, the original electric oil pressure gauge was erratic, but usaully pionted above half way which I was happy enough it registered so reckoned safe.

This is my first V8 amc (pause for jokes etc), so those with experience, what do you find or expect?

Cheers! 

[IrishCJ6]

My AMC 360 (year unknown, mileage unknown, good old Bulldog engine) runs about 55-60psi cold (startup) and once warm about 25-30 psi at 2000 - 2500 RPM and about 10 psi at idle. This is using 15w40 oil plus Lucas Oil Stabiliser. However my oil pressure fluctuates erratically sometimes, even stays stuck on a particular pressure even when reved, this has me baffled as it can read zero, 20 or even 40 PSI at anytime it wants, oh and I'm using a good quality mechanical gauge and I know the oil pressure drops to zero as the oil light comes on (well say 5psi or below). However as soon as I stop and let it cool down it will always give me good pressure on startup so I'm sure the bearing are OK. I thought it might be low on oil and sucking air but it's always there or thereabouts on the dip stick. I thought it could be a sticking pressure release valve but haven't pulled it out yet and after hearing about your issues priming again I'm not sure if I want to go messing around with it. I have asked questions before on the US forums and no one will give me a straight answer so I'm just going to keep driving until the pressure is non existent and then I'll give it a full rebuild. I have heard that they have very slow oil drain back from the heads, this worsens with age and deposits of crud so mine may be a case that the oil is being sucked up into the block/head and thus is sucks air due to lack of oil in the pan, however only about 1 litre is used throughout the engine thus 4 litres +/- is still in the pan so I can't make this one out either.

[WillCJ]

Thanks for your input Irish. I have got to the bottom of it. No oil pressure next time I fired it up, (stood a week), so , fearing the worst started strip down. I removed the brand new (fitted by some previuos ownwer) filter housing, had a good look at it on the bench. The valve was sticky, there was some shaving blocking its travel, and after a close look at asecond hand one I got off J33pky, the seat was pushed out of the bottom! also the spring was a bit longer and heavier, and the filter bypass (I think) was not blocked off. So, I cleaned up the second hand one, refit, spun pressure up no problem with drill, and fires up and away with 50(ish) psi, so see how that goes, and a big thanks to j33pky!