A engine rebuild theoretical discussion...Piston Sealing

[kencombs]

2 hours ago, Sniper said:

 

We just had a discussion about this very thing here.  Turns out the clearances really are not any tighter, in fact the specified clearances for our 230's is a hair tighter than the modern 5.7 Hemi. 

 

 

I've read some sources that state the light oils are to improve city drive cycle MPG and get pressure to the cam timing mechanism immediately.   Lot of guys had issues with the cam phasers on Ford's modular v8s when they ignored the oil recommendation.

[Sniper]

My SIL had issues with his Ram when the quicky oil change place substituted a smaller filter.  Who knows what oil they actually put in it, he changed both and his error codes cleared up.  Dealership wanted to change all that phasing stuff for big money.  The factory TSB starts with "change the oil and filter and then retest first". 

 

Not sure I want that thin an oil myself.  10w30 works just fine for me.

[kencombs]

my F150 is pre-phasers, but they recommended 5w20.  I elected to use 10w30 since in its early life it lived in Phoenix.  Never saw freezing until it had 30k miles, but lots of 100 pluss.

 

The  13 Tundra get 0w20 as Toyota says.   Free oil changes at the dealer so why not.  75k and absolutely trouble free in all regards.

 

My 230 will get 10w30.   If hot pressure is not to my liking, 15w40.

[Adam H P15 D30]

On 11/27/2021 at 6:08 PM, kencombs said:

I've read some sources that state the light oils are to improve city drive cycle MPG and get pressure to the cam timing mechanism immediately.   Lot of guys had issues with the cam phasers on Ford's modular v8s when they ignored the oil recommendation.

A lot of factors caused the Ford phaser issues but running the recommended 5/20 oil accelerated the problem. Most recommended 5/30 or even 5/40 with higher mileage modulars. It’s the 5 that matters for cold flow. 
5/40 sure quieted my 250k old modular F150 up. 

[KevinF77]

+1 on the Nikasil and moly rings. Last forever. Perhaps the stock style long pistons could be lightened a bit? I would think the longer piston would contribute to less wear, provided it wasn’t overly heavy.