Ram vs Dodge/Chrysler - how complete is the separation?

[5030]

Could be, don't know, all Massey engines are silver..

 

[5030]

The hemi keeps both intake AND exhaust valves closed during cylinder deactivation. This allows the trapped air to act as an air spring.

Really?? All gas engines have valve overlap.

 

[DarkBlack]

Really?? All gas engines have valve overlap.

Yes. Really
Overlap has nothing to do with it

 

[Wombat Ranger]

In the EU product finder, i cannot specify a G56 equipped Atego anymore, even the 816 with 7.5 ton GVW and 156hp at 1800rpm lists a G90 six speed.
The Atego ranges from 7.5 to 16 ton gvw with four and six pots from 156 to 299hp

Off course in a pickup truck is a much lighter duty application.

Sure, I only gross 40-50k with my 4500, not sure what an Atego might gross out at.

Of course, the G56 in my single cab Hemi pickup never sees that. I did take it from Michigan to NW Montana grossing 23k once though.

 

[Renze]

The hemi keeps both intake AND exhaust valves closed during cylinder deactivation. This allows the trapped air to act as an air spring.

T he piston vacuum will always cause more air to leak along the valves held closed by just the valve springs, into the cylinder, than there is leakage at the exhaust stroke when compression plus valve spring pushes it shut.

Either way its a suboptimal solution...

 

[Renze]

Sure, I only gross 40-50k with my 4500, not sure what an Atego might gross out at.

Of course, the G56 in my single cab Hemi pickup never sees that. I did take it from Michigan to NW Montana grossing 23k once though.

With the G140 9 speed and 7.7 liter 299hp, 1200Nm (885 Ft-lb) OM 936 engine 16 ton GVW and 26 combined. Or 53.273 vehicle weight and 57.320 pounds combined.

 

[DarkBlack]

T he piston vacuum will always cause more air to leak along the valves held closed by just the valve springs, into the cylinder, than there is leakage at the exhaust stroke when compression plus valve spring pushes it shut.

Either way its a suboptimal solution...

The engineering notes state , the intake opens normally, drawing in fresh air to the cylinder, then on the proceeding compression stroke, both valves are deactivated, keeping a positive pressure within the cylinder while it cycles.
I also read, if the deactivated state stays on too long, past a predetermined time, the cylinders will temporarily resume normal operation, then revert back to deactivated.
I’ve never learned, what engineering was actually trying to avoid by doing this. I’ve always assumed, cold exhaust manifold temperatures on deactivated cylinders which would lead to uneven thermal expansion.
Would explain all the broken exhaust studs they’ve had.

In any case, I favor turbo inline 6 technology over this compromise V8 designs.

 

[Renze]

I’ve never learned, what engineering was actually trying to avoid by doing this. I’ve always assumed, cold exhaust manifold temperatures on deactivated cylinders which would lead to uneven thermal expansion.
Would explain all the broken exhaust studs they’ve had.

Mercedes had the 402/403/404/405 series engines from the mid 70s onward. It was a weight optimised naturally aspirated engine family consisting of V6 of 9 liter, V8, 10 up to V12 for special applications. They all shared the 90 degree block angle optimal for the V8

There were later iterations of this engine, 20 years ago a water wagon at a paving firm i worked for at the time, so it must be built 40 years ago. It was the 90 degree V6, they ground the fuel pump helixes so that it idled on 3 cylinders to get even firing intervals at idle. Nonetheless when idling it still hogged like a pig on a cold morning. I think the last iteration of the V6 had offset crank pins because the engine was so rough that it became unacceptable in the early 2000s..

Anyways, when you tried to idle it on a cold morning to warm up, the other cylinder bank remained cold. It worked but it was an awful engine.

 

[Oaktree]

Agreed, We bought a '85.5 Escort wagon, junk. We were 33 years before we tried Ford again.

But wasn’t the Escort supposed to be junk? I thought that was its entire branding. “It sucks, but it’s cheap!”

Had an '86 I took to settle a debt from someone who owed me money. Had over 150k on it when I got it, put on another 100+k. Wasn't a bad car at all. Not really a Ford guy, but I'd say it was comparable to anyone else's econobox of the era.

 

[ruffdog]

Sounds like american brands of Stellantis are way down on sales.

https://www.motor1.com/news/725325/stellantis-sales-q2-2024/