48 DeSoto engine start up after 40 year ago rebuild

[Sam Buchanan]

Hmmmm.....I perused the Service Manual for torque values and the only thing I found was in the Engine section where it stated 15-20 ft/lbs for manifold stud nuts. If only the outboard studs get the spherical washers and self-locking nuts but all the nuts are torqued to the same value what is the purpose of the special washers and nuts? I assumed the concern was the length of the exhaust manifold changing due to heat cycles but how do the special washers accommodate that change? Is 15-20 ft/lbs loose enough to allow the manifold to "slide" under the washer?

 

Beats me, maybe someone can offer more background details. The image below is from the thread Sniper referenced, looks like it is from a truck manual.

 

This probably needs to be in a separate thread. I'll start one.

 

Edited February 3, 2023 by Sam Buchanan

[TexasD]

Some would take exception to using 10W non-D, despite a 74 yr old manual.

Technology has come a long way

Edited February 5, 2023 by TexasD

[MarcDeSoto]

The someone who told me to use 10W ND oil was the shop manual for breaking in and seating the rings.  I know there are some guys who say it's not necessary to use ND to seat the rings, but since there are opposing opinions on this, I'm sticking to the manual.  It's only for the first 1000 miles or less and then I will switch to a good modern type oil.  

[Sam Buchanan]

text deleted

Edited February 5, 2023 by Sam Buchanan

[Sniper]

High zinc content oil is unnecessary for our engines.  valve spring pressure is virtually nonexistent even when it meets specification.  Just look at what was in the oil additives package when these things were built and they had no rep for eating cams.  Can you run it? Yes, do you need it? No

 

If you want to read up on the science of it all, or want to cure your insomnia

 

https://link.springer.com/article/10.1007/s11249-016-0706-7

 

 

 

[keithb7]

No ZDDP additives in my engines. From what I can tell the same valve springs and valve-train design was used for well over 25 years in our flathead 6 engines. If you are building a flathead V8, squeezing as much HP and torque out of it as possible with multiple mods and high performance parts, I'd probably go for it. Add the zinc.

 

For my 7:1 compression 110 psi flathead? I don't believe its needed. I guess I'm risking every dollar and hour I spent on my recent engine rebuilt. New cam, tappets, springs, valves, plus possibly and entire contamination of all pressure fed oil surfaces if cam lobes and tappets fail. I'm not feeling vulnerable here.

 

Needing zinc in our old Mopar flatheads seems a little bit like some internet folklore to me. Maybe.

Edited February 5, 2023 by keithb7

[TexasD]

Some would take exception to using 10W non-D, despite a 74 yr old manual.

Technology has come a long way.

 

How long will it take to seat rings with this 74 yo approach....

Edited February 5, 2023 by TexasD

[Young Ed]

2 hours ago, TexasD said:

Some would take exception to using 10W non-D, despite a 74 yr old manual.

Technology has come a long way.

 

How long will it take to seat rings with this 74 yo approach....

Technology has but the engine is still basically the same as when that recommendation was written. I broke in both of mine with 30non d and then switched to 10-40 after a couple 100 miles. 

[Los_Control]

Non detergent oils matter too  

 

Although they create sludge, the sludge helps to plug the oil leaks.

[Young Ed]

24 minutes ago, Los_Control said:

Non detergent oils matter too  

 

Although they create sludge, the sludge helps to plug the oil leaks.

I don't think a few 100 miles on a brand new engine will create much sludge. You did remind me that my fresh rebuild for the p15 had an oil leak because the pan was rusted through but had been plugged up with sludge 

[Los_Control]

1 hour ago, Young Ed said:

I don't think a few 100 miles on a brand new engine will create much sludge.

I agree 100% ...

 

I'm really just trying to throw out a funny there

1 hour ago, Young Ed said:

Non detergent oils matter too  

Black lives matter ... Blue lives matter .... Non detergent oils matter  ..... swing & a miss

 

There is so many opinions on oil, mines not needed.

There is a lot of truth to the sludge from non detergent oil though .... I already know my used engine will be pulled to replace seals after switching to detergent oil .... part of life.

[Young Ed]

44 minutes ago, Los_Control said:

I agree 100% ...

 

I'm really just trying to throw out a funny there

Black lives matter ... Blue lives matter .... Non detergent oils matter  ..... swing & a miss

 

There is so many opinions on oil, mines not needed.

There is a lot of truth to the sludge from non detergent oil though .... I already know my used engine will be pulled to replace seals after switching to detergent oil .... part of life.

Ha- I did catch the reference. I'm sure my P15 went to the junkyard at 76k in part to the non detergent 

[Conn47D24]

Congratulations ?

[desoto1939]

A while back I had posted a topic regarding the Castrol GT Classic 20/50 motor oil and that it had one of the highest amounts of ZZP and other additives.

 

During my discussion with their technical rep he stated that since our older mopar cars are only driven at moderate speeds and that we are not coming off from a stop sign or traffic light and pulling 3-5k rpms we really do not need the ZDDP protection. Also of note that all current motor oils do have and still have lower amounts of ZDP, Phosphorus and Boron and these new motor oils are 100% better than the oil oils that were used back in the 30-1950's. They have better properties and more antiwear agents.

 

So basically it is up to a persoanl choice to add zddp or use a racing oil in your older mopar car or truck.

 

Rich Hartung