Fitz’ 2016 Sprinter 4x4 RB 150S Build

[Fitz]

We have driven the van fast and slow, on pavement and off, for hours in heat in the 100-107 degree range with never an issue with the transmission. (No codes, no performance changes)

I don't have the second alternator so I have no related experience, but to look at the placement of the skid plates, heat buildup due to them is not a concern of mine that jumps immediately to mind.

Any other experience out there with these concerns? If so, please chime in.

[TomH]

Tim, are the skid plates aluminum or steel? What gauge or thickness?

[JFlo]

Originally Posted by Fitz

I don't have the second alternator so I have no related experience, but to look at the placement of the skid plates, heat buildup due to them is not a concern of mine that jumps immediately to mind.

Any other experience out there with these concerns?

I've got the Nation's auxiliary alternator and the VanCompass skid plates. As you can see, there is no air flow issue. In fact, I was thinking about adding some side protection to help with water intrusion.



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[Fitz]

Originally Posted by TomH

Tim, are the skid plates aluminum or steel? What gauge or thickness?

Tom,

The front-most plate in the engine skid plate package is called the "Bash Plate" and is 3/16" steel. All the rest are made of 1/4" aluminum. According to Van Compass, the total weight is 115 lbs.

Here is the link to the Van Compass website with the details: https://vancompass.com/products/van-...d-plate-system

[Fitz]

Originally Posted by JFlo

I've got the Nation's auxiliary alternator and the VanCompass skid plates. As you can see, there is no air flow issue.

JFlo,

Great clarifying picture, thank you! Have you ever submerged the 2nd alternator? By all accounts it shouldn't bother it, but there is nothing like a first-hand report from someone who has done it to know for sure.

[jrobe]

Originally Posted by JFlo

I've got the Nation's auxiliary alternator and the VanCompass skid plates. As you can see, there is no air flow issue. In fact, I was thinking about adding some side protection to help with water intrusion.



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That skid plate has completely blocked the cooling airflow from the front of the van as you are driving. I have no idea what the implication of that is but if there have been some overheating issues with the Nations Starter alternators, it can't really help to block a steady stream of cooler air from the front. It certainly works well though for rocks.

[Wrinkledpants]

Originally Posted by jrobe

That skid plate has completely blocked the cooling airflow from the front of the van as you are driving. I have no idea what the implication of that is but if there have been some overheating issues with the Nations Starter alternators, it can't really help to block a steady stream of cooler air from the front. It certainly works well though for rocks.

Most alternators aren't in direct airflow, nor do they depend on it for cooling. Since the factory location for the primary alternator is higher up, most of the airflow going over the alternator comes off the radiator.

Alternators will have an internal steel fan that produces the cooling. Overheating alternators are more a function of design and power output, rather than the location to cool air. The only way to ensure reliable power output from an alternator is to liquid cool it. I know our Cayenne has a liquid cooled alternator, and I believe some BMW's do, too.

A lot of the 2nd alternator setups on Sprinters are powering lithium batteries. Because the peak charge for a lithium is higher than peak power on the alternator, a 270 amp alternator from Nations could be asked to produce peak output for hours on end. This is quite a bit different than if you had a lead acid group where the batteries simply can't take that kind of power, and the alternator isn't being stressed too much at the lower current levels. No amount of direct airflow will keep the insides of an alternator cool when it's working at peak power.

I think as lithiums become more mainstream, we're going to see a shift to substantially bigger alternators. Not because we need more power going to the lithium bank, but because any part producing 100% duty is going to have a short life compared to a bigger alternator where it's not straining so hard to produce power. Or someone will design a smaller liquid cooled alternator (which would be my choice).

[Wrinkledpants]

Originally Posted by Fitz

JFlo,

Great clarifying picture, thank you! Have you ever submerged the 2nd alternator? By all accounts it shouldn't bother it, but there is nothing like a first-hand report from someone who has done it to know for sure.

Offroad vehicles have been submerging alternators for years. They'll fully submerge the engine bay with the only real modifications are a snorkel and maybe a fan disconnect. The only issue is if you're in mud - it could destroy the alternator just with the rocks and debris that don't clear out. Think jeeps with huge tires driving through bogs - something a Sprinter will never do.

You'll have no issue doing water crossings in the van. One thing you will want to do is cap your D5 intake and exhaust, if you happen to have one. Other than that, you'll likely get water intrusion inside the van before you run into any potential engine-related issues. We'll be doing a fair amount of deep water crossings with our 2nd alternator - zero worries from my end. I'll be much more concerned with the various holes in the floor sealing properly if we happen to hit a deeper than expected crossing. That's the great thing about living in the west - most of our water crossings are extremely clear water

[Fitz]

Wrinkledpants,

Good info, as always. Thanks for adding your comments!

[Fitz]

6/25/17, at the Reno Rodeo, discovered on the drive home. This was a very civilized easy-to-manage slow leak...




7/15/17 (three weeks later), up on the top of Coyote Flat, going off on a side trail where the guide book clearly told us not to go...Total time from hearing the bang to a complete flat, approximately 15 seconds, fortunately enough time for my quick-witted driver (Laura) to get the van to a relatively level spot.



Do these things happen in 3's???? If so, stay tuned...

In neither case do I blame the tires (BFG KO2's). To date we have 15k on them and have been very happy with all-around performance and wear and I fully intend to keep running them. Heck, I just got the opportunity to buy two more!

The lesson learned came from changing the tire on the trail up on Coyote Flat. These vans are heavy, and while I had placed and started the Hi Lift Jack in the back yard (having plenty of past experience with one on past vehicles), I didn't go past a couple of clicks on the jack when testing it. Going all the way up at an elevation of almost 10,000 ft. was a chore and took all of my 210 lbs. to get the job done! I learned a couple of things from the experience and will make a few changes, stay tuned for updates as I translate what I learned into (hopefully) labor saving ideas for the future.