oil pan - rear main - rope seal?

[chorty55]

1969 block cast 318la
Never done a rope seal, not wanting to experiment on this particular 318 for a learning curve. But i'm pretty sure i need a new oil pump, and may as well stuff in some new rods and mains. I'm debating on a high volume pump, or standard pump and new bearings. Now, granted i did set the oil pressure switch a bit high, just to error on the better odds of avoiding engine destruction, BUT....

5w-20 cold = 60-70 psi with a fast idle.
5w-20 hot = can't satisfy the oil pressure switch with the starter to juice the coil after turned off. Switch must be bypassed if engine block is hot.

drained oil.

15w-20 hot = sometimes the starter will satisfy the oil pressure switch if the battery is good and hot, usually it doesn't. It's a very low RPM/high torque starter. I just had it rebuilt for a tune of $650. So it's a good starter. Solenoid pulls 7 amps instead of 125. That's a step forward.

15w-20 hot= 800-900 rpm idle = needle barely twitches at most 5-7 psi. I'm using a mechanical glycerin gauge right on the bell housing tap after the lifter galley, so we know everything downstairs is on the edge of disaster.

question, can i drop the pan and not have a rear main nightmare? or should i just plan to take out the whole block?

Block removal i would really like to avoid. I think i can clear the oil pump lift screen if i lift the engine 3-4 inches. I may still have to pull all the hydraulics and tank. All that jazz is right above the accessory drive/bell housing. I found enough channel iron laying around to weld up a hoist right on the machine itself. This is turning into quite a project.

 

[Oldiron440]

What’s with the 5/20?

 

[chorty55]

What’s with the 5/20?

i don't understand your question?

This is 5w-20 oil.

 

[chorty55]

The first oil change was this jug of light weight garbage to flush out anything from the timing gear install.

Unfortunately going to a heavier weight oil made very very little gain with oil pressure, hence the question regarding pulling the pan, but seems the 5/20 is the focus? annoying.

 

[chorty55]

Note

I thought the pickup screen might be clogged with debris from oil change neglect, but the fact it builds healthy high pressure when cold, on either 5w20 or 15w20 oil, i think it's safe to say the rods/mains/pump are quite worn out and shows it's face of failure when good and hot.

 

[remytherat]

i don't understand your question?

This is 5w-20 oil.

5-20 is crazy light. These motors are not designed for that, especially with unknown bearing clearances. Try running 10-30 or 15-40.

I do not think ignition wired to the oil pressure switch makes any sense. I would fix that and take the thin oil out first.

 

[Dana67Dart]

How many miles on the motor?

My 160,000 on the last rebuild 273 on 30w will flicker the 8psi oil light when hot and at idle.

Doesn't do that with 40w. Also I get that you have a low oil cut out so bypass it ( like the ballast Resister) during cranking (IGN 2 cir)

10w-30 new rebuild or 10w-40 for an old tired engine, look in the 68 FSM.

20 weight is for modern engines with superior metallurgy and tighter tolerances

 

[chorty55]

as mentioned, the 20 weight was a flush and drain fro mthe timing chain install, any old antifreeze or whatever.

And i apologize for the typo, i drained and refilled with 15w-40, not 15w-20.

The terrible gains with 15w-40 were minimal. It's worn out without a doubt. Hence the reason of the low oil cut out wired into the ignition, which makes perfect sense. When she's good and hot, ~2500-3000RPM, i can't even make 25PSI with the 15w-40.

I do have a few jugs of 25w-50, and a case of STP, but thatll have to be a summer time only thing. Twizzler oil pump drives are a bump in the schedule too....


SOOOOOOOO back to the orginal question. did the 69's have a rope seal, and can i drop the oil pan without a huge PITA with the rear main? I'm assuming it's original back there. When i did the timing chain, it's 3rd timing gear and chain, i spilled my beer and choked what i swigged when i saw the huge deep groove cut into the harmonic balancer. I laughed and continued assembly. No leaks up front. Even with 5w-20.

 

[Dana67Dart]

It may have had a rope seal but there are rubber seals now for the same application.

Pan can drop might need to remove the steering cross bar and maybe raid the engine can inch or two.

As for rear main seal difficulty, never easy but you can always loosen all the main caps and remove the torque converter bolts and let the crank have a bit more room

 

[chorty55]

I just don't like how the mechical gauge twitches around 5PSI when slow idling. I highly highly doubt the rod bearings are getting 5psi.....

It may have had a rope seal but there are rubber seals now for the same application.

1 does oil pan removal upset the rope seal?
2 can a rope seal be installed without separating transmission?
3 i highly doubt a rubber seal can be installed without removing the transmission.

 

[tonysrt]

Rope seal is more difficult to install because you have to trim it to fit. You may nick crankshaft trying to trim it. Rubber seals are easier because you can slide it in being careful. Of course, best installation would be with crank out with rope seal.

 

[chorty55]

Rope seal is more difficult to install because you have to trim it to fit. You may nick crankshaft trying to trim it. Rubber seals are easier because you can slide it in being careful. Of course, best installation would be with crank out with rope seal.

Well, I guess that's one bearing I won't install.

Unless I can roll in the rubber upper half without a headache.

 

[RustyRatRod]

Just fill the pan up with STP and let it ride. It'll have oil pressure and probably stop the leak too. Win/win.

 

[chorty55]

Just fill the pan up with STP and let it ride. It'll have oil pressure and probably stop the leak too. Win/win.

it doesn't leak, bu i do plan to try 5 bottles of STP.

Maybe ill get lucky and need to replace an oil pump shaft instead of bearings. Win/win.

 

[4eighteener]

Hey Chorty,
It probably goes without saying, but did you change the oil filter before and after the flush?
It sounds like an oil filter running in bypass mode. It might be worth a cheap $5 fram filter from Walmart to replace and see.
If you are getting those pressures cold, there is nothing wrong with the pump.
I am leaning towards a clogged filter from debris from the timing chain replacement if the motor was gunky

 

[chorty55]

Oil filter galore.

I found 7 new filters for the engine in some boxes.

Ran a 1773 for the 30mins, 32 micron on the 5w-20 for the flush.

Dumped the 5w-20, spun on a ph8a, 21 micron? Added 15w-40, no real gain.

 

[4eighteener]

Okay, I assumed you did and wanted to address the obvious

 

[RustyRatRod]

I'dda run it full of Dexron for the flush......BUT from what it sounds like, you've pretty much diagnosed a wore out POS.

 

[chorty55]

I'dda run it full of Dexron for the flush......BUT from what it sounds like, you've pretty much diagnosed a wore out POS.

Yup.

I need 2 good weeks and 200 gallons of fuel.

I might be worth an oil pump and set of bearings. In this high heat during summer,maybe I can get by with some STP to satisfy the oil pressure switch

Running a thermostat really thinned it out.


I got a lot of iron to mop up while the price is right.

 

[RustyRatRod]

Yup.

I need 2 good weeks and 200 gallons of fuel.

I might be worth an oil pump and set of bearings.

I got a lot of iron to mop up while the price is right.

You think it'd take that much fuel to burn it up?

 

[4eighteener]

Off the main topic, but can I ask what is happening with your timing chains?
3rd replacement, so I wonder if you are using nylon gearsets, running heavy valve springs pressure, or putting a ton of migears etc, to go through that many?

 

[4eighteener]

Mileage

 

[Daves69]

How hot is your engine getting? Seems to me a 60 psi cold dropping to 5 psi hot idle is excessive.
Outside chance the pump relief is hanging. I had one hang on a 360. Oil pressure was good cold and dropped as the engine heated. When I broke the first pump bolt loose the valve popped back. That pump was replaced.

Trying to install a rope seal while in vehicle may have you creating words never even thought of previously.

Looks like around '70 was the year of the rope replacement per the TSB. Not sure when the factory actually stopped using rope though.

 

[chorty55]

Off the main topic, but can I ask what is happening with your timing chains?
3rd replacement, so I wonder if you are using nylon gearsets, running heavy valve springs pressure, or putting a ton of migears etc, to go through that many?

Nylon replaced back in 1980 with steel when engine was swappwed 40 years ago.

For 30 years it ran double shifts. We averaged 60-70 gallons of fuel a day through it.

Last month it gods its 3rd gear and chain.

 

[chorty55]

How hot is your engine getting? Seems to me a 60 psi cold dropping to 5 psi hot idle is excessive.
Outside chance the pump relief is hanging. I had one hang on a 360. Oil pressure was good cold and dropped as the engine heated. When I broke the first pump bolt loose the valve popped back. That pump was replaced.

Trying to install a rope seal while in vehicle may have you creating words never even thought of previously.

Looks like around '70 was the year of the rope replacement per the TSB. Not sure when the factory actually stopped using rope though.


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View attachment 1716400378

For 30 years it ran without a thermostat. I installed a 180* yesterday, and an temp switch of 200* for electric fan. Its not boiling over. I've been testing had adjusting with the cap loose.

There might be a gob of **** stuck in the pump. There's a lot of gumbo and crud under the valve covers.

I think I'm going to leave that last bearing cap if I decide to pull pan and stuff in rods and mains