2.7L CAST IRON BLOCK - WHY?

[BraptorAddict]

I've been really curious, and maybe some of you experts know's the answer... why is the 2.7L TTV6 the _only_ ecoboost engine with a cast iron block?

The 3.5TTV6 is aluminum, and the 2.3T4 is aluminum... why the odd construction for the 2.7?

TIA

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[Weedwaka]

Economy typically

 

[toughtoaster]

Planned rust obsolescence. Can’t have these things out lasting Wranglers can we?

 

[A_Locke]

My guess is probably to handle higher boost pressures. The 2.7L is Twin Turbocharged, which results in higher boost. Because it is smaller than the 3.5L TT and the 2.3L only has a single charger, they probably went with an Iron block. Also, based on wikipedia, it is a "compacted-graphite" iron block, which should result in more weight savings over a more conventional Iron Block.

 

[fomoco]

I prefer cast iron. Less risk of damage during overheating. As with everything, there are tradeoffs. But not sure of specific reasoning in the engines you mention.

 

[Spooled]

The 2.7 is not cast iron. It's CGI (compacted graphite iron). It's tougher and lighter than cast. The 2.7 was engineered from the very start to be turbocharged and be able to have extreme durability.

 

[Big Boss]

My guess is probably to handle higher boost pressures. The 2.7L is Twin Turbocharged, which results in higher boost. Because it is smaller than the 3.5L TT and the 2.3L only has a single charger, they probably went with an Iron block. Also, based on wikipedia, it is a "compacted-graphite" iron block, which should result in more weight savings over a more conventional Iron Block.

This ^ and someone correct me if I am wrong I believe when Ford designed the 2.7 the designed the block similar to the way a diesel block would be designed for durability

 

[chicknwithabeer]

It's the same material as the 7.3 power stroke.

 

[Spooled]

It's the same material as the 7.3 power stroke.

This is incorrect. The 7.3, 6.0, and 6.4 were cast-iron blocks. CGi wasn't used until the 6.7

 

[frinesi2]

The 2.7 is not cast iron. It's CGI (compacted graphite iron). It's tougher and lighter than cast. The 2.7 was engineered from the very start to be turbocharged and be able to have extreme durability.

Exactly.

Also, it's a hybrid block. The cylinder walls, upper section, and main bearing caps are CGI, the lower end is aluminum.

The 3.5 is based on the Duratec V6 engines so they carried over the aluminum construction. Same with the 2.0/2.3 I4s. All of Ford's newest turbo motors (1.0, 1.5, 2.7/3.0 nano) seem to be going back to iron.


Also, remember kids - everything is for emissions. Every. Thing.

Like the smaller 3 cylinder ecoboosts, a big reason for Fe vs Al construction is Fe retains heat better which improves startup emissions. Same reason they use the in-block manifolds - heat retention means faster catalytic converter warmup times.

 

[Laminar]

edit: frinesi beat me by a minute! Same picture and everything

As Spooled said, it's not cast iron, it's CGI. And it's not entirely CGI - the cylinders and main structure are CGI for extreme strength and durability. The rest of the engine's body is made out of aluminum and bolts to the CGI structure. It's a very novel design, I'm not aware of any other engine built this way, though there may be some.

It allows the extreme strength, vibration resistance, and pressure holding capacity of CGI (like a diesel block) but saves on weight like an all aluminum engine.

It's the only EcoBoost built this way because Ford designed it from the ground up to be a turbocharged engine.

The 2.0/2.3 EcoBoosts were adapted from the naturally aspirated Duratec 2.0/2.3 engines, which are just Mazda engines. They've always been all-aluminum. The 3.5 EcoBoost is based on the 3.5 Cyclone, was started life as a naturally aspirated engine as well. When those engines were designed, turbocharging wasn't necessarily in the design plan (see the 3.5's open deck). The 2.7/3.0 was designed from the start to handle extreme pressures and conditions seen with big boost.

 

[frinesi2]

edit: frinesi beat me by a minute! Same picture and everything

As Spooled said, it's not cast iron, it's CGI. And it's not entirely CGI - the cylinders and main structure are CGI for extreme strength and durability. The rest of the engine's body is made out of aluminum and bolts to the CGI structure. It's a very novel design, I'm not aware of any other engine built this way, though there may be some.

It allows the extreme strength, vibration resistance, and pressure holding capacity of CGI (like a diesel block) but saves on weight like an all aluminum engine.

It's the only EcoBoost built this way because Ford designed it from the ground up to be a turbocharged engine.

The 2.0/2.3 EcoBoosts were adapted from the naturally aspirated Duratec 2.0/2.3 engines, which are just Mazda engines. They've always been all-aluminum. The 3.5 EcoBoost is based on the 3.5 Cyclone, was started life as a naturally aspirated engine as well. When those engines were designed, turbocharging wasn't necessarily in the design plan (see the 3.5's open deck). The 2.7/3.0 was designed from the start to handle extreme pressures and conditions seen with big boost.

Fun fact - the Duratec V6 was originally engineered by Porsche but they decided not to finish it and sold the IP to Ford/Cosworth.

The Duratec I4 engines were, as mentioned, Mazda motors.

 

[Laminar]

Fun fact - the Duratec V6 was originally engineered by Porsche but they decided not to finish it and sold the IP to Ford/Cosworth.

I had a Mystique with the 2.5, an SVT Contour with the 2.5, and when the SVT's engine let go, it got a 3.0 from a Taurus. Fun car.

 

[TripleB]

To act as a wheelie bar.

 

[BraptorAddict]

Wow I love this group! Such great, technical information all-around!

The hybrid-construction was something I had run across previously, but I didn't understand why it was done... I wonder if they'll use this architecture when they redesign the 3.5 sometime soon. It'd be interesting to see how big they can make an engine using this CGI/AL architecture.

Thanks all for great info!!

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