V8 Question - Battery vs V8 ram’s Horn Heat distance (1 Viewer)

[RWBeringer4x4]

Hi all,

I’m looking into fabricating a new battery tray for my V8 converted FJ40 after an “incident” on the trail last weekend.

Long sorry short - I’m wondering how far away from the exhaust most V8 batteries are mounted and what I can get away with as far as distance without heat damaging the battery.

The long story:

I’ve mocked up a piece of cardboard as to what I would LIKE, size wise, as it would allow me to mount a variety of battery types. However, it would only leave me with about 2 and1/4” inches between the back corner of the tray and the exhaust manifold. In terms of battery placement, it would probably wind up about 3” from the exhaust.

Just wondering if I’m overly worried about the battery getting too hot or if this gap is worrisome.

The corner of the old tray only sits about 3.5” away, with the battery riding roughly 4” away, so it’s still close. However, due to several battery related misshaps over the years none of my prior batteries have lived a full service life so I’m not sure if the heat is killing them (I sure do).

This tray as mocked up would be large enough to mount one of those huge 13x6.8x9.5 BCI group 31 batteries in the event I ever decide to go that route. I can’t mount the battery much higher due to hood clearance. I might have a half inch to play with, vertically.

I know a ton of V8 rigs mount the battery over here, some with overflow bottles, etc in front of them like mine. Naturally a shorter battery tray would free up a couple of inches but if the heat won’t transfer terribly across the 2 1/2” gap then it would be nice to have the option in the future. I'm not really interested in moving the battery to the driver's side or inside the truck as that would require a lot of re-wiring.

 

[RWBeringer4x4]

Just another thought - would mounting an aluminum heat shield in the gap be one way to potentially mitigate the issue? It's a tight squeeze already but I could potentially incorporate a 1/4" air gap between the shield and the battery tray and try to snug a piece of sheet metal in there...

This is also at the front of the engine bay so I imagine airflow from the fan would help mitigate heat transfer as well - but it sure does get hot under the hood in summer.

 

[bhsdriller]

I've ran batteries like this. Used a thermal heat wrap that they sell and it was good.

Something like this.
Amazon product ASIN B000GVOQDK

 

[Downey]

1. Many Chevota owners move the battery forward, and downward (so that the hood does not close down on it).
2. The steel battery tray is a very decent heat shield for the battery.
3. Was the V8 installed 1" towards the driver's side as it should have been ???

 

[pjohnson]

I think your mechanical fan will take care of moving the heat. It looks like you have a couple of bolt holes in the manifold for a small heat shield if you're still concerned.

 

[RWBeringer4x4]

1. Many Chevota owners move the battery forward, and downward (so that the hood does not close down on it).
2. The steel battery tray is a very decent heat shield for the battery.
3. Was the V8 installed 1" towards the driver's side as it should have been ???

1. It's already forward and down, and for anything other than a HUGE Type 31 battery, the clearance will be better when I relocate it further (probably 4-5"). Getting it more foreward will require moving the overflow tank.

2. I'm always curious if steel will deflect, or absorb, heat. But this is good to know

3. Yes, 1" to driver, mostly for optimal driveshaft position.

 

[RWBeringer4x4]

@reddingcruiser you’ve done a few V8 swaps - if you happen to see this, let me know your thoughts.

I’m thinking it’s probably fine but I may throw an aluminum heat shield on the tray just to be safe.

 

[reddingcruiser]

@reddingcruiser you’ve done a few V8 swaps - if you happen to see this, let me know your thoughts.

I’m thinking it’s probably fine but I may throw an aluminum heat shield on the tray just to be safe.

Rick
You're right in the ballpark. That's a pretty typical location. When space is tight I build a cardboard box the same size as the battery, drop the bib, close the hood, then start seeing where the box will fit.

In my personal rig the battery is recessed in the floor under the driver's seat and covered.

You can use a heat shield as you suggested and/or ceramic coat the manifolds to reduce heat.

Sometimes you just work with what you have.

 

[RWBeringer4x4]

Rick
You're right in the ballpark. That's a pretty typical location. When space is tight I build a cardboard box the same size as the battery, drop the bib, close the hood, then start seeing where the box will fit.

In my personal rig the battery is recessed in the floor under the driver's seat and covered.

You can use a heat shield as you suggested and/or ceramic coat the manifolds to reduce heat.

Sometimes you just work with what you have.
View attachment 2482155View attachment 2482151

Thanks. Yeah, I don’t think it would be much of an issue unless I find myself getting a winch and going to a big group 31/deep cycle battery. Any “normal” car battery will have 4-5” of clearance which seems way less scary. I just like to make sure when I build something I try to plan in future contingencies.

 

[bikersmurf]

In the future you could always build an aluminum heat shield spaced an inch away from the battery. It’ll absorb the hot spot and disburse it more evenly. Or insulate it on the inside and have it closer.

 

[RWBeringer4x4]

In the future you could always build an aluminum heat shield spaced an inch away from the battery. It’ll absorb the hot spot and disburse it more evenly. Or insulate it on the inside and have it closer.

I think I’m going to go the heat shield route - should be able to just squeeze an an aluminum shield on 1/4” stand-offs from the tray. So there will be a roughly 1” air gap between manifold and shield, 1/4” air gap between shield and battery tray, and then probably a 1/2”+ gap from there to the battery based on the design I’ve got in my head.

We will see how it actually winds up when I translate it to metal...

 

[pb4ugo]

I located my battery in a similar spot as what your thinking. I made a frame that bolts to the inside of the frame rail and bolted the stk batt tray on top of it. I use a deep cycle batt. The corner of batt is a little over 2" away from the corner of the ramshorn. The batt has been there since the early 90s, and I have been running ramshorns for the last 10yrs or more. I had zero issues with this location and no heat shield. I do think the air movement and being located ahead of the manifold helps. I could take a pic if you want.

 

[RWBeringer4x4]

I located my battery in a similar spot as what your thinking. I made a frame that bolts to the inside of the frame rail and bolted the stk batt tray on top of it. I use a deep cycle batt. The corner of batt is a little over 2" away from the corner of the ramshorn. The batt has been there since the early 90s, and I have been running ramshorns for the last 10yrs or more. I had zero issues with this location and no heat shield. I do think the air movement and being located ahead of the manifold helps. I could take a pic if you want.

Awesome glad to hear some firsthand experience with basically exactly this setup. A picture would be awesome if you have a second to take it but it certainly sounds like the heat hasn’t reduced the battery life (or exploded it) for you, and your setup sounds almost exactly like what I’m aiming for.

 

[pb4ugo]

Here ya go. The batt tray frame was a very early fab projject for me, so it's pretty crude.

 

[RWBeringer4x4]

Here ya go. The batt tray frame was a very early fab projject for me, so it's pretty crude.
View attachment 2482611View attachment 2482612View attachment 2482613

Hey if it gets the job done! The chain hold-down is a nice touch! That’s pretty much exactly where mine is looking to go but the plan is to have a roughly 14” long box. So I think it will wind up a bit closer. As mentioned, unless I’m using a 13” battery (which I’m not, yet. the physical battery will be 4”+ away so I am less worried.

Thanks for snapping the picture!

 

[pbgbottle]

Mines been in that spot for years. I would have to go look ,mine may be close to the manifolds. I used a BJ40 oem battery mount it sits the battery right in that location. Don’t think u will find a BJ40 battery mount in the US very easily. .

 

[RWBeringer4x4]

Here’s another oddball question - does anyone try to isolate their battery from vibration - ie: put some sort of rubber mount on it or is everyone basically just solid-mounting to the frame.

I’m 99% sure I know the answer to this but figured I’d ask. I found these “savior” battery trays with dampers and it got me thinking...