• Welcome to 28Q29U Plymouth Forum.
 

News:

NEW FORUM version is here. 
If you are experiencing any problems, contact chetbrz@aol.com
WELCOME Auto Registration is turned OFF. 
In order to register for this forum please contact chetbrz@aol.com to request access.

Main Menu

A few gremlins with engine. Oil pressure Issue with resolution

Started by abradney, November 27, 2018, 07:17:31 PM

Previous topic - Next topic

abradney

Engine is running pretty good now:

https://youtu.be/fObzSnER4ro

However oil pressure is like 50psi. Even when hot. I put in a different oil gauge to verify and it's still reading 50.

What do you think? Just run it?

rwollman

Chet_ what r u running for oil - a little lighter viscosity would drop psi -  Only thing it might bother are frt and rear main seals but they r new so it should not, besides it is going to loosen up a tad anyways as it breaks in. Does it go any higher at higher revs???

abradney

Running fresh 5w20 high mileage stuff.

Oil pressure only fluctuates a few psi at higher revs.

chetbrz


I use a straight 30 weight oil initially with a zinc additive.  If the vacuum fuel pump is not connected and plugged, it will drive the pressure to the high side.  I would use 5w20 only as a break in oil for a short period of time.  The engine is designed for 30 weight oil.

My 2 cents
http://www.1948Plymouth.info           Web Master - Forum Administrator - AACA member

abradney

Not sure if it makes a difference but it's a mechanical fuel pump, not vacuum.

chetbrz

I'm not familiar with that setup so I assume that the oil pump doesn't have the vacuum port.
http://www.1948Plymouth.info           Web Master - Forum Administrator - AACA member

abradney

The oil pump is fully enclosed, no vacuum port.

chetbrz

Is this a recent rebuild or an engine that's been sitting for awhile.
http://www.1948Plymouth.info           Web Master - Forum Administrator - AACA member

abradney

It is a rebuild, but not recent. (Maybe 10 years ago the work was done to it, I'm not at all sure) When I got it it was clear that the bottom end had been rebuilt, clean valves, fresh seats, clean pistons etc. head was not on it. I resurfaced the head, new hg, set timing and fired it up.

The factory oil pressure gauge was maxing out at 50, I figured maybe the gauge wasn't calibrated, put an aftermarket unit in this afternoon to verify and got the same reading.

abradney

I should add I ran a compression test and got 60psi on all four. I'm at 5000ft ASL. Book calls for 68psi so I think I'm ok in that regard.

rwollman

Chet-  Sorry, thought this was your engine we were talking about - guess I spoke out of turn - again, sorry

Articifer Tom

Yeah Guys this is same engine set up as my truck . Mechanical fuel pump , brass bowl DRT carb , separate generator and starter , mechanical timing advance and non pressurized cooling with water pump . 
  You need to adjust your pressure down and first up oil to 30 weight's , my book calls for 40's in summer . I used 10w-40 in diesel grade . Lots of forum discussion on oils and weights . Refer to Chet's engine thread for copied info from my manual BOI . This has how to adjust pressure and test running pressure of oil system .
 

abradney

#12
Hey Tom, do you have a link to that thread on how to adjust oil pressure?  Considering this is a "newly" built engine, would you suggest I leave it to run in for a while or adjust sooner rather than later, the only running the engine is going to be doing is not driving, but running in the garage for testing, so 'no load'.

Edit: Found the method for changing oil pressure in my book, i'll report back.

Articifer Tom


abradney

So I adjusted the oil pressure regulator, I removed the cap, it was filled with sludge and the flat head screw was turned all the way in, cleaned the sludge, and turned the flathead screw stop 3 full turns counter clockwise, slapped it back together, oil pressure now reads 40ish at cold on startup.