Cooling the Harvester gas engine / heat management

[BradScout]

Wondering how the Harvester gas engine is going to be cooled.
It may not be possible while sitting still due to Carbon Monoxide and heat buildup. Ya know there is that one dude that will try to run Harvester in their garage. ?

 

[Stumpy]

Here's the oil cooler for the Harvester engine -- from these photos of the underbody: https://www.scoutevforum.com/electric-solid-rear-axle-ebeam-rear-axle-underbody-photos-analysis/

 

[Probity]

Wondering how the Harvester gas engine is going to be cooled.
It may not be possible while sitting still due to Carbon Monoxide and heat buildup. Ya know there is that one dude that will try to run Harvester in their garage. ?

A good question with a planned rear-mounted engine. My bias initially thinks of current conventional water-cooled IC engines, but this is VW at heart, maybe a return to air-cooled like the older Beetles?

 

[@POY]

Thanks for the info.

Couple questions I have in mind after seeing the photo. Does anyone know if the under body is protected by a “shield” from off road hazards? Also, whats the expected maintenance of EV + Range Gas Extender?

A full EV doesn’t have to worry about oil change and everything else a gas engine would need. So I’m curious how the engineering/mechanics work with Harvester.

 

[Macallan 18]

Does anyone know if the under body is protected by a “shield” from off road hazards?

Yea here's the underbody shield / skid plates on the revealed Scouts

Skid plates / shield (underbody protection) on 2027 Scout

 

[Melrose]

I’ve read that the Harvester is a generator, designed to charge the EV battery, and that it can add 150 miles of range on top of 350 miles of range supplied by the battery pack. OK, sounds good!

If the EREV models average ~3 miles per kWh, then the generator would need to produce 50kWh to add 150 miles of range (leaving efficiency losses aside). So you head out, traveling 60mph. In less than 6 hours your battery would be empty, but thankfully the generator kicked in at the 100 mile mark, and ran for ~7 hours generating 50kWh. This scenario suggests a 7kW generator …+/-12hp. It will be interesting to learn how heat is managed, especially if it can run while parked. Hoping that sharper and better schooled minds can fine tune these assumptions and shed some light on how Scout has solved this.

 

[justinjas]

They said in the presentation that the harvester will have a smaller battery to account for the engine and gas tank. No one knows what the percent split will be though. Honestly if it’s just there as an emergency backup for an extra 150 miles and not an option for using on road trips as your primary power I don’t think I’ll be getting one. Charging on road trips is a pain (I say this as a first year model 3 owner, which has a great charging network) and it’s even more difficult if you are towing.

 

[Miranda]

They said in the presentation that the harvester will have a smaller battery to account for the engine and gas tank. No one knows what the percent split will be though. Honestly if it’s just there as an emergency backup for an extra 150 miles and not an option for using on road trips as your primary power I don’t think I’ll be getting one. Charging on road trips is a pain (I say this as a first year model 3 owner, which has a great charging network) and it’s even more difficult if you are towing.

I’m wondering if that 150 miles extra is replenishable, like once you hit 500 miles, are you done till you can find a place to plug in? Or can you refill the gas tank and wait for it to recharge itself for another 150 miles?

 

[MikeRudolph]

I’ve read that the Harvester is a generator, designed to charge the EV battery, and that it can add 150 miles of range on top of 350 miles of range supplied by the battery pack. OK, sounds good!

If the EREV models average ~3 miles per kWh, then the generator would need to produce 50kWh to add 150 miles of range (leaving efficiency losses aside). So you head out, traveling 60mph. In less than 6 hours your battery would be empty, but thankfully the generator kicked in at the 100 mile mark, and ran for ~7 hours generating 50kWh. This scenario suggests a 7kW generator …+/-12hp. It will be interesting to learn how heat is managed, especially if it can run while parked. Hoping that sharper and better schooled minds can fine tune these assumptions and shed some light on how Scout has solved this.

I've heard different numbers, 150 mi range from just the battery, the engine adds over 500 mi. In pure EV without the Harvester option, 350 mi range.

 

[Chuckles]

I've heard different numbers, 150 mi range from just the battery, the engine adds over 500 mi. In pure EV without the Harvester option, 350 mi range.

Harvester models have a smaller battery. 150 mi of range. The gas engine generator will provide approximately 350 mi of range for a total of 500

 

[PMurphy]

Others have explained that the Harvester is a “series hybrid”. The onboard generator is NOT a high capacity unit capable of quickly re-changing a depleted battery.

Best guess that the Harvester unit will “likely” kick in when a heavy sustained draw occurs on a well charged battery (long uphill grade) or once the battery reaches a software defined balance point. At a pre-determined battery charge level the Harvester will kick in and likely continue to run (almost constantly?) to limit further drawdown of the battery and offer some net recharge under low load conditions while continuing to drive.

Once the Harvester runs low on fuel you will need to gas up to continue to maintain your battery charge balance OR go into battery discharge mode which will likely SOON require a battery recharge stop to restore balance to the energy management system.

Think of Harvester as a charge/discharge balancing device NOT a battery recharger.

NOTE: the Harvesters engine cooling system will likely only function for extended periods when the vehicle is moving to allow increased cooling efficiency. Likely will not have the cooling capacity to sit and charge for extended periods of time using the engine. This level of cooling capacity would add too much weight and size to efficiently package without giving up the frunk (a deal breaker to some pre-order holders).

The soon to be released(?) RAM EV pickup sounds like it will have the capacity to recharge it’s own battery while stationary BUT also has a V6 engine with traditional radiator etc for cooling to run its generator.

 

[Chuckles]

There will likely be a liquid cooling system for the batteries. It could be modified to assist with engine cooling. I'm sure Scout is working on it. Their engineering choices for the Harvester will continue to be hot topics.

 

[maynard]

Others have explained that the Harvester is a “series hybrid”. The onboard generator is NOT a high capacity unit capable of quickly re-changing a depleted battery.

Best guess that the Harvester unit will “likely” kick in when a heavy sustained draw occurs on a well charged battery (long uphill grade) or once the battery reaches a software defined balance point. At a pre-determined battery charge level the Harvester will kick in and likely continue to run (almost constantly?) to limit further drawdown of the battery and offer some net recharge under low load conditions while continuing to drive.

Once the Harvester runs low on fuel you will need to gas up to continue to maintain your battery charge balance OR go into battery discharge mode which will likely SOON require a battery recharge stop to restore balance to the energy management system.

Think of Harvester as a charge/discharge balancing device NOT a battery recharger.

NOTE: the Harvesters engine cooling system will likely only function for extended periods when the vehicle is moving to allow increased cooling efficiency. Likely will not have the cooling capacity to sit and charge for extended periods of time using the engine. This level of cooling capacity would add too much weight and size to efficiently package without giving up the frunk (a deal breaker to some pre-order holders).

The soon to be released(?) RAM EV pickup sounds like it will have the capacity to recharge it’s own battery while stationary BUT also has a V6 engine with traditional radiator etc for cooling to run its generator.

The Ramcharger will certainly be something to watch (if it's what was promised...) Might be a good stepping stone to a Scout...

 

[Chuckles]

The Ramcharger will certainly be something to watch (if it's what was promised...) Might be a good stepping stone to a Scout...

Ramcharger has been delayed until first quarter of 2026. Some people are making a big deal out of that, but I'd rather see them work out all of the bugs as opposed to releasing an unfinished product.