1958 Plymouth Belvedere

[WikedPlymouth]

I used 20w-50 weight oil. Would 15w-40 be better or maybe a straight 30 weight? I also added some additional zddp when I changed it. As for mileage, the odometer shows about 120k miles.

 

[Finsinthemirror]

Being in CA where the weather is pretty stable, on old engines I'd run straight 30 weight and look into diesel oil with high zddp content or use a zinc additive. Since it's been sitting for so long maybe run a little lucas in there to soften the seals but you might be getting into it at some point unless you are very, very lucky.

 

[WikedPlymouth]

Good morning Forward Look group. My "low to me oil pressure" has still been bother me. At cold start, the 318 in my 1958 Belvedere starts and runs at about 45 psi at idle. Once it warms up it sits around 15-17 psi at an idle of 700 rpms. It will go up to about 25 psi at 1k rpms and up to 35 psi at around 2k rpms. Looking at the FSM did make me feel a little better. On page 480 of the FSM it says the oil pressure indicator light goes off when oil pressure is above 8-12 psi. So, I guess anything over 8-12 psi is considered ok from the factory at idle.

 

[3175375]

Oil pump

 

[WikedPlymouth]

Are you saying the oil pump needs replaced? Seems like the FSM thinks it's ok. Can you drop the oil pan on these engines while it's still in the car and change the oil pump? Does not look like it but maybe it would be possible to unbolt the engine mounts and lift it slightly?

 

[3175375]

It’s marginal in my opinion. I don’t know if you can change it in the car easily z. Others will likely chime in…

 

[57fury440]

What are your plans with this engine? If you are looking to make more horsepower and are going to do some power modifications, then I would say that the oil pressure is marginal for that usage. If you just plan on driving it normally then the pressure should be good. You can drop the pan with the engine in the car, but you will have to unbolt the mounts and raise it some. It is possible the pressure reading you are getting is because the pick-up is partially clogged.

 

[WikedPlymouth]

Right now, I have absolutely no plans to try and make more power with this engine. It's a 4 door and I'm happy just having it run and drive around. I know it will need a rebuild in the future if the blow by continues, but it idles well, does not over heat and sounds good. I was just bothered because I'm use to higher oil pressure in my other cars. I was just sharing that the FSM seems ok with where my car is at.

As for the oil pressure, I installed the gauge adapter on the port by the oil filter housing.

 

[Jakter]

Try pulling the oil pressure sensor and hook up the gauge there and see what the oil pressure is.

 

[58Belvedere]

The heavy-duty Mopar Performance cast stroker crank was internally balanced, polished, and fitted with Clevite full-groove main bearings like those found on the 340 (PN MS1344P), ensuring complete lubrication throughout the rpm band. The reciprocating mass was fully balanced and trial-assembled for fit; only minor block clearancing was needed for the rods to maintain a safe journey. A Melling high-volume oil pump (PN M72HV) and a Mopar small-block Milodon windage tray (PN 32230) with adjustable stud mounts keep the "black gold" circulating rapidly without splashing on the crank and rustling ponies. Confident with the integrity of the bottom end, a high-quality Rollmaster billet timing set (PN MRE1262) and a BHJ damper (PN BHJMP-IB816) were obtained from Mancini Racing to keep our Poly singing in tune. For Fun: https://www.motortrend.com/how-to/mopp-0110-how-to-give-a-318-poly-engine-more-power/

 

[57fury440]

?????

 

[57fury440]

Back around 1965 my cousin had a 58 Plymouth with a 318 2 barrel. It had over 100,000 miles on it, and it smoked out of the valve cover breather. An older mechanic told us to remove the valve covers and use a wire hanger to open up the oil return passages in the heads. We did it and it worked. The oil back then was nowhere as good as today's blends. If you did not do frequent oil changes, there was a good chance you would end up with a gummed-up engine.

 

[58Belvedere]

''A Melling high-volume oil pump (PN M72HV) and a Mopar small-block Milodon windage tray (PN 32230) with adjustable stud mounts keep the "black gold" circulating rapidly without splashing on the crank and rustling ponies.'' https://redirect.viglink.com/?forma...110-how-to-give-a-318-poly-engine-more-power/

 

[WikedPlymouth]

Will give that a try next time I remove the valve covers. Thanks!!