Heat dissipation from engine bay

[Johnson]

Comparing the engine venting on the Emira to other rear-engined supercars, I’m wondering how effective the heat removal will be. Particularly if we’re not driving fast (so not a lot of intake); the temperature is 40 degrees Celsius (common in Oz); and the air conditioner is going full pelt (is it in the engine bay?).

My SW20 MR2 lid above the engine used to *cook* on hot days (vented metal). And it was only an atmo four…

 

[frazzer]

its been tested at Hethel, Norfolk, so should be fine

 

[TomE]

Thermal management has had a lot of attention. It was a minor issue on the Evora: heat soak of the supercharger in some conditions, insufficient heat shielding on hydraulic lines on earlier cars. It was also one of the limitations on increasing Evora power over 450hp, as well as the V6 manual gearbox.

The thermal management for the i4 has been a particular area of concern and hence a lot of development and testing. The engine bay has been enlarged by moving the bulkhead forwards and there is more air intake (side and underbody vents) and exit (chimneys alongside the rear hatch, gap under the hatch rear edge). There's also been a lot of hot climate testing.

Remember too that a lot of the space under the bonnet is radiators, oil coolers and fans. My hunch is the aircon condenser is up front too.

I think the V6 will be fine. I'm not so sure they've got it all fully resolved for the i4 yet, which is why that is running about 6 months longer than the V6 development programme. That extra 6 months was planned from the outset due to the engine being new to Lotus.

 

[CarGuy07]

Is the engine fully open to the cabin? If so, I do wonder how much harder AC needs to work to counteract the heat going into the cabin.

 

[virtualmacho]

There's a piece of glass between the engine bay and cabin. I wish you could roll it down to hear mechanical noise, but no such luck.

 

[Rudolph]

Thermal management has had a lot of attention. It was a minor issue on the Evora: heat soak of the supercharger in some conditions, insufficient heat shielding on hydraulic lines on earlier cars. It was also one of the limitations on increasing Evora power over 450hp, as well as the V6 manual gearbox.

The thermal management for the i4 has been a particular area of concern and hence a lot of development and testing. The engine bay has been enlarged by moving the bulkhead forwards and there is more air intake (side and underbody vents) and exit (chimneys alongside the rear hatch, gap under the hatch rear edge). There's also been a lot of hot climate testing.

Remember too that a lot of the space under the bonnet is radiators, oil coolers and fans. My hunch is the aircon condenser is up front too.

I think the V6 will be fine. I'm not so sure they've got it all fully resolved for the i4 yet, which is why that is running about 6 months longer than the V6 development programme. That extra 6 months was planned from the outset due to the engine being new to Lotus.

* * * * *
The 2.0-liter turbo-4 is the replacement for the 381-hp engine found underhood the CLA45, GLA45. The new engine, which comes in two tunes including a 382-hp base version and a 416-hp S version, uses a more efficient turbocharger and upgraded cooling to improve performance and could arrive in future AMG 45-Series cars including the GLA45, CLA45, and A45—perhaps more.

The new turbo-4 uses a new all-aluminum cylinder block with identical dimensions to the outgoing engine, and most of its components are new. Compared to the outgoing version, the new engine is flipped in the engine bay and places the turbochargers and exhaust manifold closer to the firewall with the intake up front. It’s an evolution of the AMG principal, “Hot stuff and cold stuff don’t mix,” although it created very specific problems.

Hot and cold
Namely, cooling the new engine with turbos placed so far into the engine bay was a significant challenge, according to engineers. The new engine features separate cooling systems for the block and the cylinder heads, 18% larger exhaust valves, and a specially designed engine cover that redirects air toward the turbochargers for more cooling. The air conditioner can also further cool the engine. The cylinder coating is slicker too, and the 0W-20 oil it uses in is a lower viscosity for better cooling. The electronic wastegate, which is more efficient this time around, was designed to handle more heat.

At its heart, new turbos force-feed the turbo-4 more air for bigger power. The compression ratio was increased from 8.6:1 to 9.0:1, and although its 416 hp (in S versions) was rated with 95-octane fuel, AMG said when it arrives in the U.S. the new engine should rate well on 93-octane gasoline—even run on lower octane fuel if needed. The new turbochargers spin up to 169,000 rpm and create 30.5psi of boost pressure, compared to 26.1 psi for the outgoing turbocharger. That’s partially due to roller bearings used in the twin-scroll turbo that let it spin more freely, similar to the AMG GT 4-Door Coupe’s twin-scroll turbos found in the twin-turbo 4.0-liter V-8.

When it was announced, the outgoing engine’s 187.5 hp per liter of displacement in the GLA45 and CLA45 was the most power dense production engine on the planet. The new engine unveiled Thursday takes over that top spot and is the most powerful production turbo-4 built from a mainstream automaker with 208 hp per liter

The new turbo-4 also debuts AMG’s newest production process that still pairs one engine technician with one engine, but partially automates the manufacturing process with carts and tools that travel along the production line with engineers automatically.

AMG’s Chief Operating Officer Emmerich Shiller said the new process is 25-30 percent more efficient for the engine builders who take about two hours to hand-build each turbo-4 engine.

Power move: AMG's new turbo-4 aims higher with more horsepower

Mercedes-AMG's new 2.0-liter turbo-4 makes up to 416 horsepower in top models, making it the most power-dense 4-cylinder on the market.

www.motorauthority.com

 

[Leonard]

* * * * *
The 2.0-liter turbo-4 is the replacement for the 381-hp engine found underhood the CLA45, GLA45. The new engine, which comes in two tunes including a 382-hp base version and a 416-hp S version, uses a more efficient turbocharger and upgraded cooling to improve performance and could arrive in future AMG 45-Series cars including the GLA45, CLA45, and A45—perhaps more.

The new turbo-4 uses a new all-aluminum cylinder block with identical dimensions to the outgoing engine, and most of its components are new. Compared to the outgoing version, the new engine is flipped in the engine bay and places the turbochargers and exhaust manifold closer to the firewall with the intake up front. It’s an evolution of the AMG principal, “Hot stuff and cold stuff don’t mix,” although it created very specific problems.

Hot and cold
Namely, cooling the new engine with turbos placed so far into the engine bay was a significant challenge, according to engineers. The new engine features separate cooling systems for the block and the cylinder heads, 18% larger exhaust valves, and a specially designed engine cover that redirects air toward the turbochargers for more cooling. The air conditioner can also further cool the engine. The cylinder coating is slicker too, and the 0W-20 oil it uses in is a lower viscosity for better cooling. The electronic wastegate, which is more efficient this time around, was designed to handle more heat.

At its heart, new turbos force-feed the turbo-4 more air for bigger power. The compression ratio was increased from 8.6:1 to 9.0:1, and although its 416 hp (in S versions) was rated with 95-octane fuel, AMG said when it arrives in the U.S. the new engine should rate well on 93-octane gasoline—even run on lower octane fuel if needed. The new turbochargers spin up to 169,000 rpm and create 30.5psi of boost pressure, compared to 26.1 psi for the outgoing turbocharger. That’s partially due to roller bearings used in the twin-scroll turbo that let it spin more freely, similar to the AMG GT 4-Door Coupe’s twin-scroll turbos found in the twin-turbo 4.0-liter V-8.

When it was announced, the outgoing engine’s 187.5 hp per liter of displacement in the GLA45 and CLA45 was the most power dense production engine on the planet. The new engine unveiled Thursday takes over that top spot and is the most powerful production turbo-4 built from a mainstream automaker with 208 hp per liter

The new turbo-4 also debuts AMG’s newest production process that still pairs one engine technician with one engine, but partially automates the manufacturing process with carts and tools that travel along the production line with engineers automatically.

AMG’s Chief Operating Officer Emmerich Shiller said the new process is 25-30 percent more efficient for the engine builders who take about two hours to hand-build each turbo-4 engine.

Power move: AMG's new turbo-4 aims higher with more horsepower

Mercedes-AMG's new 2.0-liter turbo-4 makes up to 416 horsepower in top models, making it the most power-dense 4-cylinder on the market.

www.motorauthority.com

Interersting. That's a bugger if you need a few significant mods (Inc turbo) to safely uprated the Emira i4 to anything meaningful.
Makes sense though

 

[VL3X]

I'm sure the V6 setup will be fine at stock boost, but the turbo heat management has yet to be proven... I did notice that the upgraded power stages offered for the Evora and Emira (soon) by Jubu Performance requires hatch glass removal and vented louvers to assist with cooling.

 

[Johnson]

The air conditioner can also further cool the engine...

How does this work? A heat-exchange air conditioner will heat up the engine bay, not cool it.

Great article, by the way. Thanks @Rudolph.

 

[First Lotus]

That's brought something to my attention...
Can any of you knowledgeable lot tell me if the V6 can run on E10? Or does it need E5?
I'd assumed E10 was OK until read that article

 

[Leonard]

That's brought something to my attention...
Can any of you knowledgeable lot tell me if the V6 can run on E10? Or does it need E5?
I'd assumed E10 was OK until read that article

I'm sure it will with a bit of performance loss and mpg. Will appreciate E5 like most performance motors (all motors!)

 

[First Lotus]

Thanks @Leonard . Sometimes it can get a bit tricky finding the good stuff in the Welsh back country!

 

[Leonard]

Thanks @Leonard . Sometimes it can get a bit tricky finding the good stuff in the Welsh back country!

I could only find the data from Lotus regards Evora 410. But I imagine it's almost a legal requirement to be able to run on the lower octane

 

[First Lotus]

I could only find the data from Lotus regards Evora 410. But I imagine it's almost a legal requirement to be able to run on the lower octane

On doing some research for my older car, it appeared anything 2006 onwards should be able to run on E10. However mine (2006) is on a list specifically excluding it

 

[Climber]

On doing some research for my older car, it appeared anything 2006 onwards should be able to run on E10. However mine (2006) is on a list specifically excluding it

I could only find the data from Lotus regards Evora 410. But I imagine it's almost a legal requirement to be able to run on the lower octane

why would you want it to run on lower octane? I thought that higher octane gives you better performance and cleaner? Am I miss infórmed ?

 

[First Lotus]

I wouldn't deliberately want to. But when tripping around Wales it can sometimes relieve the stress knowing I can put E10 in if I need to. Not every (in fact relatively few) in north/mid Wales seem to stock E5.

 

[Leonard]

It does. Purely in case 95+ is not available

 

[Nova]

I was smoking a brisket yesterday in my Weber kettle grill and the whole time I was watching the dual temp read out of the cook and the grill temp, I thought of this thread. When I get my Emira I am going to put my wireless grill thermometer in the trunk and watch the curve on my phone. This curiosity must be satisfied.

 

[Eagle7]

I was smoking a brisket yesterday in my Weber kettle grill and the whole time I was watching the dual temp read out of the cook and the grill temp, I thought of this thread. When I get my Emira I am going to put my wireless grill thermometer in the trunk and watch the curve on my phone. This curiosity must be satisfied.

Actually I've been thinking about this as well. I'm thinking about putting heat reflective foil on the outside of the trunk facing the engine, and on the bottom above the mufflers, if it's possible to get access to those areas. The stuff racing teams use in their engine bays reflects 95% of the heat away. I would like to shield the casing around the battery too. That would keep the trunk and battery area temperatures to whatever the normal ambient is.

 

[TXEMIRA]

Actually I've been thinking about this as well. I'm thinking about putting heat reflective foil on the outside of the trunk facing the engine, and on the bottom above the mufflers, if it's possible to get access to those areas. The stuff racing teams use in their engine bays reflects 95% of the heat away. I would like to shield the casing around the battery too. That would keep the trunk and battery area temperatures to whatever the normal ambient is.