polara383500
Member
I think my motor is going? Oil pressure at idle is 25lbs driving is 40lbs! Then if it’s idling when I put it in gear it drops below 10lbs!
Engine could be on the way out
- Thread starter polara383500
- Start date
1970FuryConv
Old Man with a Hat
Have you tried cleaning out the oil pump pickup screen or replacing the oil pump?
Could be the gauge. Check it with another before you go too crazy.
polara383500
Member
It’s a new oil pump!
polara383500
Member
It is still break in oil that’s in it! Just got around 300miles on that oil gonna change it and see if that helps!
polara383500
Member
Yeah I’ll try that too!
FWIW, the 1950 Plymouth FSM indicates that ANY oil pressure at idle is fine, even if the gauge reads right a "0". 40psi at "road speed" is pretty much were modern engines run, too, but does not jive with the old 10psi/1000rpm orientation.
What oil pressure is the pump supposed to produce? Unless you put some thin oil it in for break-in, I suspect that new oil might not change things, much if any.
Please keep us posted of what you determine.
Just some thoughts,
CBODY67
What oil pressure is the pump supposed to produce? Unless you put some thin oil it in for break-in, I suspect that new oil might not change things, much if any.
Please keep us posted of what you determine.
Just some thoughts,
CBODY67
57fury440
Well-Known Member
Why do you have break in oil in it? What was done besides changing the oil pump?
polara383500
Member
Heads were gone thru and freshened up,cam,cam bearings,oil pump and
The pressure is fine, it’s just not 50 at idle and 80 going down the road like most internet car guys would make you think you need.
Did you look at any rod or main bearings? Did you,even have the pan off?
What weight oil is on it now?
Put in a stiffer spring or shim the spring in the oil pump. Use thicker oil and turn the idle up a tad.
I had a brand X medium size V8 that was just like your oil pressure and it ran fine for 20,000 miles until I sold it.
Did you look at any rod or main bearings? Did you,even have the pan off?
What weight oil is on it now?
Put in a stiffer spring or shim the spring in the oil pump. Use thicker oil and turn the idle up a tad.
I had a brand X medium size V8 that was just like your oil pressure and it ran fine for 20,000 miles until I sold it.
polara383500
Member
It’s a melling oil pump? Where can I get the springs
57fury440
Well-Known Member
Mancini Racing sells the springs to boost the pressure in the pump.
68PK21 440.6bbl
Old Man with a Hat
Break in oil is only required to seat in the new piston rings to a fresh cylinder bore/hone.
Personally I've never used this so called break in oil on any re-ring job I've done.
Personally I've never used this so called break in oil on any re-ring job I've done.
polara383500
Member
It was for a new cam and lifters!
polara383500
Member
Yeah and the used amsoil break in!
68PK21 440.6bbl
Old Man with a Hat
Well did you take note of your oil pressure before this hop-up? I mean without doing a lot of Colombo work I take it from your nic & picture we're dealing with a 60's Polara 383 of the 500 class right? Before you delved into the top end work you really need to take a look at your bottom end if it is high mileage/age.
Plus also who installed the cam bearings? Are they in right? You may loose pressure there.
.
polara383500
Member
When I got the car it had no oil pressure gauge! I just peaked at the bottom end when I had the motor out! I did the cam bearings and they went in right! So I’m not sure what it was before the stuff was done!
68PK21 440.6bbl
Old Man with a Hat
Oh so you had the engine out, "peaked" was it on a engine stand? Did you remove the oil pickup tube and clean & inspect it? When I mean clean I don't just mean rinse it out in the safety clean tank but rap it on a hard surface to shake out all the little bits of old hardened valve seals, plastic timing gear teeth etc and also look in there with a strong flashlight? A lot of crap can get stuck way back in the screen.
Before you took the engine apart when it was running in the best tune that you could get it in, would be to get a baseline of the shape of the engine ie oil pressure at various RPM's, compression test both cold & hot, and vacuum readings before you go tearing things apart IMO.
.
57fury440
Well-Known Member
Isn't it possible that the oil pressure is better now after the work you did. If you have no idea what the pressure was before maybe it is better now. I would change the oil and filter and see what happens. A motor can run a long time on the pressure you have.
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