Are there any internal differences between gen-3 engines and gen1&2 , stronger rods? Pistons ? Etc other than different tuning for the 400/500 gen 3 engine .

3.5tt ecoboost

 

What engine?

 

"400/500" should be enough of a clue.

OP, I want to say I read that Ford put some of the 3.5l HO internals into the '21+ 3.5l. Not sure what though.

 

3.5tt eco

 

I know for sure on the gen3 3.5 Ecoboost(non HO) they added galley oil sprayers from the HO model and are using the exhaust manifold from the HO.

The rest is just tuning difference AFAIK

 

There is no Gen 3 yet - 2017 and up are all Gen 2, even with different turbos, and outputs, they are all the same Gen.

The HO models have some different internals, turbos and tuning, but it’s the same generation and architecture.

The 5.0 in the F150 is currently Gen 4

 

2017 & up had separate timing chains to each cylinder bank rather than the previous single timing chain for both left & right cylinder banks. That change must have reduced the chance for timing chain stretch enormously.

 

The problem with the gen 2 is the cam phasers. I would not buy a pre 2021 gen 2 3.5 eco. I only hope they have fixed it for the 21+ models. But only time will tell that. The gen 1 3.5 engines imo were quite a bit more reliable. If I didn’t need to tow heavy. I would get a 2.7. Also more reliable were the pre 2018 5.0 engines.

 

Or maybe I’m lucky, but I have 2 2020 3.5’s and haven’t noticed any noises on either of them.

Maybe it’s because I use remote start, or maybe I’m just not into noticing things that don’t affect me….

 

how many miles. The first phaser repair didn’t need to be done till after about 50k miles on my 2017