Re-Rebuilding the 440-493 in a 1970 Charger

[moparedtn]

According to the FSM, "normal" pressure is 45-65 psi @ 1000 RPM for the Mopar big block.
Honestly, I don't see anything alarming with what pressures are displayed in Post 1038 myself.

The Driven HR5, by most any testing/review articles I've seen, is close to or is THE best stuff to
run in these older engines, especially those with flat tappet cams.
It's exactly what I run in Fred's 440, matter of fact.

 

[4406bbl]

There’s a video on YouTube where a guy tries to get to the bottom of the dreaded “Hemi Tick”. He found that the Hellcat is the only Hemi using a high volume pump. All others 5.7, 6.4, etc use a pump with thinner rotors and could starve lifters of oil while idling for long periods.

I saw that...what I see at idle tells me no way that is the real problem. Thin oil, bad parts, lack of oil changes maybe. 5.7 may have lower pressure with 5-20 at idle. But so many make it to 200k miles so who really knows.

 

[whayden2003]

maybe missing something but in this pic isn’t that over 60psi.

 

[moparedtn]

I saw that...what I see at idle tells me no way that is the real problem. Thin oil, bad parts, lack of oil changes maybe. 5.7 may have lower pressure with 5-20 at idle. But so many make it to 200k miles so who really knows.

I've only owned 3 5.7's so not exactly a representative sample - but the '04 pickup is pushing 200k and still
shows middle of gauge pressure, whatever that is (it's a pre-MDS engine).
The '12 Charger R/T (MDS, oh no! ) is at 110k miles and indicates around 42-43psi at idle to this day.
I've never experienced mechanical issues from either. They're stout little engines as far as I can see.

 

[moparedtn]

maybe missing something but in this pic isn’t that over 60psi.

View attachment 1652285

Looks a tick over 60, yes (gauge numbers being 0, 40 midway and 80 to the far right).

 

[4406bbl]

I've only owned 3 5.7's so not exactly a representative sample - but the '04 pickup is pushing 200k and still
shows middle of gauge pressure, whatever that is (it's a pre-MDS engine).
The '12 Charger R/T (MDS, oh no! ) is at 110k miles and indicates around 42-43psi at idle to this day.
I've never experienced mechanical issues from either. They're stout little engines as far as I can see.

That is kinda what we see around here too, granted we are not arizona with high ambient temps most of the year. It seems the fleet, police type vehicles had most of the problems, always blamed on idle time, I say oil change and proper oil is the key. I just do not buy the big oil pump on a 5.7 is fixing the problem, if it idles at 40-45 lbs and the hellcat pump gives 10 lbs more no way. More of a can't hurt kinda deal.

 

[Kern Dog]

maybe missing something but in this pic isn’t that over 60psi.

View attachment 1652285

Looks a tick over 60, yes (gauge numbers being 0, 40 midway and 80 to the far right).

The gauges on the right are angled like the stock ones, tilted slightly to the left. Often times, I have to shift my head over a bit to look squarely at the gauges to read them straight on.

 

[OKDart]

That is kinda what we see around here too, granted we are not arizona with high ambient temps most of the year. It seems the fleet, police type vehicles had most of the problems, always blamed on idle time, I say oil change and proper oil is the key. I just do not buy the big oil pump on a 5.7 is fixing the problem, if it idles at 40-45 lbs and the hellcat pump gives 10 lbs more no way. More of a can't hurt kinda deal.

The 6.4 in my truck has hot idle oil pressure at 30 PSI since new.

 

[dvw]

Oil pressure is very simple. It's flow volume minus internal leaks minus viscosity. At idle the volume can not be increased by a stiffer spring or shimming the spring unless the by pass is open at idle. Which is not the case at 20psi. The internal leaks can't be changed at this point w/o engine disasmbly. We will assume it has a quality filter and the gauge is correct. Then there are only two options to increase oil pressure. The first being thicker oil, which has resistance to flow. This would be a good idea if the oil temperature runs high. Without a oil temp gauge this parameter is unknown. No need to run "gear oil glue" at low or normal oil temperatures. The second is to increase oil volume. Greater flow fills the internal leak cavities faster than they can bleed. Thus more pressure. As long as the internal leaks aren't from heavily worn components more volume is what you need. 40 psi is fine for a cruiser. I wouldn't want to run 6000 rpm often. If the pump is with in spec? Then higher than factory bearing clearance (which hurt nothing) and loose lifter bores are the two main culprits to internal leakage causing lower than expected pressure.
Doug

 

[Charlie Brown]

Oil pressure is very simple. It's flow volume minus internal leaks minus viscosity. At idle the volume can not be increased by a stiffer spring or shimming the spring unless the by pass is open at idle. Which is not the case at 20psi. The internal leaks can't be changed at this point w/o engine disasmbly. We will assume it has a quality filter and the gauge is correct. Then there are only two options to increase oil pressure. The first being thicker oil, which has resistance to flow. This would be a good idea if the oil temperature runs high. Without a oil temp gauge this parameter is unknown. No need to run "gear oil glue" at low or normal oil temperatures. The second is to increase oil volume. Greater flow fills the internal leak cavities faster than they can bleed. Thus more pressure. As long as the internal leaks aren't from heavily worn components more volume is what you need. 40 psi is fine for a cruiser. I wouldn't want to run 6000 rpm often. If the pump is with in spec? Then higher than factory bearing clearance (which hurt nothing) and loose lifter bores are the two main culprits to internal leakage causing lower than expected pressure.
Doug

Doug,
This is a great explanation. Simplified and easy to understand. Thanks for this.

 

[Kern Dog]

Cold start. Barely idling over 1000.

View attachment 1652105

View attachment 1652106

Using this oil.

View attachment 1652107

Warmed up a little bit.

View attachment 1652108

Now at operating temperature. Forgive the blur… the phone was touching the steering wheel and it vibrates a bit.

View attachment 1652109

It drops below 40 but on the road at idle it hovers around 20.
At speed:

View attachment 1652111
View attachment 1652112

Over 50 at 3000 is okay but then….

View attachment 1652113

View attachment 1652114

By 4000 it is maybe 55? It peaks there. Pressure didn’t go any higher when I pushed to 5000 rpms.

I made an error. I was reading the gauge wrong.

I looked at this and was thinking 55 psi when it is actually 65.

This was at 4000 rpms. Every other 440 I've had was fitted with a high volume pump and was over 75 when I was at 4000 rpms and above. I was thinking that I was at 55 so it had me worried. Even that is within the 10 per 1000 guideline but it still didn't bring comfort.

 

[Kern Dog]

UPDATE:
The oil pressure with this 20/50 oil made a noticeable difference.
Cold pressure at about 1200 rpms is now 70-75 psi.
Pressure at operating temperature, idling around 1000 was 20 and is now 35.
I didn't get it up to 70 mph but rolling on around 60 in 5th is about 1500 rpms. I read 40+ there. In 4th gear at 60 it was over 50 psi.
I think I can skip the high volume oil pump for now.

 

[68 Sport Satellite]

UPDATE:
The oil pressure with this 20/50 oil made a noticeable difference.
Cold pressure at about 1200 rpms is now 70-75 psi.
Pressure at operating temperature, idling around 1000 was 20 and is now 35.
I didn't get it up to 70 mph but rolling on around 60 in 5th is about 1500 rpms. I read 40+ there. In 4th gear at 60 it was over 50 psi.
I think I can skip the high volume oil pump for now.

remind us - what oil were you running before when getting lower pressures? I normally run 10-40.

 

[Kern Dog]

I was running this:

I ran this oil for the break in. I had a leak in the pan after the rebuild so I ran the engine a short time after break in then drained and dumped the oil. The cam didn't need to be broken in since I'd used it before. I pulled the pan and fixed the leak, then used this same brand and weight again. The second run of this oil had about 1500 miles on it and still looked decent when I drained it.

 

[moparedtn]

From what I've read, going from 10W-40 to 20W-50 oil increases viscosity around 25%.
Yeah, that'll make a profound difference in pressures. The downside is that the thinner oil
flows quicker when cold, of course.

 

[1 Wild R/T]

From what I've read, going from 10W-40 to 20W-50 oil increases viscosity around 25%.
Yeah, that'll make a profound difference in pressures. The downside is that the thinner oil
flows quicker when cold, of course.

But honestly how many of us drive these cars when it's below 40 degrees? And those same looser clearances in a HP engine that lead to lower oil pressure means thicker oil isn't restricted by tight clearances...

 

[Kern Dog]

It probably makes no difference to this engine and I feel a bit silly for letting it worry me. It’s just that when you are accustomed to seeing a number and then the number is lower, it bothered me.

 

[moparedtn]

But honestly how many of us drive these cars when it's below 40 degrees? And those same looser clearances in a HP engine that lead to lower oil pressure means thicker oil isn't restricted by tight clearances...

I didn't make any statement in opposition to any of that; in fact, I didn't address any of that at all.
I merely stated supporting evidence to what Greg has observed with his changing viscosity.

 

[1 Wild R/T]

I didn't make any statement in opposition to any of that; in fact, I didn't address any of that at all.
I merely stated supporting evidence to what Greg has observed with his changing viscosity.

Easy Tiger... I didn't suggest that you did... Just pointed out a couple reasons I don't see any reason for concern on Greg's part...

 

[moparedtn]

Easy Tiger... I didn't suggest that you did... Just pointed out a couple reasons I don't see any reason for concern on Greg's part...

Hell, I tried to tell him that when he started all this - I'd be fine with the numbers he was seeing before.
That boy gets to obsessing sometimes...