sjwelds
Full Access Member
My truck...92...only mod is a 1/4" aluminum plate cut to lay in the tray. Got a bungee holding it all down. Need to rig up a real hold-down. Things move around.
Brick nose group 31 question
- Thread starter Rot Box
- Start date
These hold downs are working well for me. Two j bolts down each side of the battery. The top piece is a molded rubber strap that secures the battery pretty well. 5 bucks at advance auto. Probably everywhere else too.
You do have to cut off the j bolts for length, unless you want to use them for hood pins too.
Backside picture.
You do have to cut off the j bolts for length, unless you want to use them for hood pins too.
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Backside picture.
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Those are the hold downs I've tried and have broke within a few months each time. I also don't like the thin j bolts, just small rod bent up at the bottom. If the clamp doesn't fail first, the rod will pull through the battery tray where it hooks. I use the more robust J bolts that are like 5/16" or 3/8" threaded rod and on the bottom J portion are flattened and wide. These don't pull through. I ended up using some aluminum I had handy to make two hold down for over the top. Glued some rubber from a tire tube to the bottom.
I only got the drivers side group 31 in since it was raining really hard and the truck doesn't fit inside. New ground cable and new positive crossover cable. Old cable to starter and old ground on pass side. Wow the engine spins over a lot faster. Not a good comparison as it was an old 675 cca gr34 replaced with a 950cca gr31. I think the cables made the bulk of the difference as the ground was really bad. The crossover was junky but not horrible compared to a lot of cables I've seen. Used new 2/0 crimped and soldered then the joint slathered in liquid electric tape and heat shrink over that. Will do the other side this week and hoping for more improvement. The real test will be in a couple months when it gets real cold but I'm thrilled with the improvement with just one side done.
Another observation is the voltage doesn't bounce around as much. It charges but has always bounced around like 13-14 volt every second or so up and down. Now the gauge stays right at 14 and just twitches slightly, headlight flicker is much less. We'll see what it does after the other battery and cables are done. I plan to do a 3g 130+ amp swap soon. Don't really need the extra amps as I don't have crazy added power draws but since this alternator doesn't do a steady voltage I figure it's prudent to replace it before it fails, and I'd like to eliminate the voltage regulator and that extra wiring to clean up and simplify things under the hood. I have 4 ga cable and a mega fuse ready for this.
I also found two small grounds not hooked up (now cleaned and attached), and a random scraggy wire that apparently lets my glow plugs work. I'd like to figure out how the button was rigged up and do that more cleanly than some falling apart wired tapped to the battery. Speaking of glow plugs, pushing the button now hardly makes voltage drop at all, previously it would drop to10v or just under, now just under 12v when pushing the button.
I think the whole group 31 and cables modification is more about good clean electrical connections and adequately sized cables making the difference a lot more than the batteries themselves. Honestly an 850cca gr27 vs a 950cca gr31 shouldn't be a huge difference unless you're in northern Canada or somewhere similarly inhospitable.If you gotta make new cables you may as well accommodate gr31 and enjoy more cca or the same or slightly lower price.
One thing I have read that concerns me is that posts are superior to studs. I prefer studs for the utility and ease of connecting anything. I've read that studs are only good for so many amps where posts are good for a lot more as they have more surface area. Anyone have thoughts or comments on this?
I only got the drivers side group 31 in since it was raining really hard and the truck doesn't fit inside. New ground cable and new positive crossover cable. Old cable to starter and old ground on pass side. Wow the engine spins over a lot faster. Not a good comparison as it was an old 675 cca gr34 replaced with a 950cca gr31. I think the cables made the bulk of the difference as the ground was really bad. The crossover was junky but not horrible compared to a lot of cables I've seen. Used new 2/0 crimped and soldered then the joint slathered in liquid electric tape and heat shrink over that. Will do the other side this week and hoping for more improvement. The real test will be in a couple months when it gets real cold but I'm thrilled with the improvement with just one side done.
Another observation is the voltage doesn't bounce around as much. It charges but has always bounced around like 13-14 volt every second or so up and down. Now the gauge stays right at 14 and just twitches slightly, headlight flicker is much less. We'll see what it does after the other battery and cables are done. I plan to do a 3g 130+ amp swap soon. Don't really need the extra amps as I don't have crazy added power draws but since this alternator doesn't do a steady voltage I figure it's prudent to replace it before it fails, and I'd like to eliminate the voltage regulator and that extra wiring to clean up and simplify things under the hood. I have 4 ga cable and a mega fuse ready for this.
I also found two small grounds not hooked up (now cleaned and attached), and a random scraggy wire that apparently lets my glow plugs work. I'd like to figure out how the button was rigged up and do that more cleanly than some falling apart wired tapped to the battery. Speaking of glow plugs, pushing the button now hardly makes voltage drop at all, previously it would drop to10v or just under, now just under 12v when pushing the button.
I think the whole group 31 and cables modification is more about good clean electrical connections and adequately sized cables making the difference a lot more than the batteries themselves. Honestly an 850cca gr27 vs a 950cca gr31 shouldn't be a huge difference unless you're in northern Canada or somewhere similarly inhospitable.If you gotta make new cables you may as well accommodate gr31 and enjoy more cca or the same or slightly lower price.
One thing I have read that concerns me is that posts are superior to studs. I prefer studs for the utility and ease of connecting anything. I've read that studs are only good for so many amps where posts are good for a lot more as they have more surface area. Anyone have thoughts or comments on this?
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Thanks for the heads up. I will keep a watch on the hold down and see if it breaks. I really wanted and metal one, but haven't found a source for one of those yet.
My thoughts on the stud vs. post thing. I doubt a battery manufacturer would make a battery with a stud that wasn't rated for the amperage the battery could deliver. I would bet the stud would hold anything short of hooking positive and negative straight together.
My thoughts on the stud vs. post thing. I doubt a battery manufacturer would make a battery with a stud that wasn't rated for the amperage the battery could deliver. I would bet the stud would hold anything short of hooking positive and negative straight together.
One question. What body style is it? We had an 83 F-150 and had an issue with the headlights flashing. We were working on something over on the passenger side fender well and knocked this little "electrical doohicky" loose. It was a small rectangular device, about the size of 2 postage stamps, with 2 small studs that were connected to 2 small wires. Once we cleaned everything up, and put it back together, the top and a little metal strip popped out, and there was a small plastic holder on the fender. The flashing stopped and never returned.
Some good info here guys thanks again 
I pulled the trigger on those group 65 CAT batteries. I hope I don't regret it... They look tougher and feel a lot heavier than the no-name batteries they replaced so we'll see. Going through my cables and such while I'm into it.
When these die I'm going to go with the 31's.
HAHA I could see myself learning that lesson the hard way
I pulled the trigger on those group 65 CAT batteries. I hope I don't regret it... They look tougher and feel a lot heavier than the no-name batteries they replaced so we'll see. Going through my cables and such while I'm into it. When these die I'm going to go with the 31's.
HAHA I could see myself learning that lesson the hard way
82F100SWB
Full Access Member
The big gain with group 31's besides longetivity is not so much cranking amps, but reserve capacity, there is a very significant jump from a group 65 to a 31.
Enough that my IDI truck does not even have a drivers side tray installed,I have never ran duals in it, and as some of you know I deal with proper cold on a regular basis.
My Cummins is much less happy about only having one battery, and that's how it came from the factory, it will be getting a second very shortly after 8 years of owning it in hopes of making it as cold weather reliable as a 7.3 PSD now that I currently don't have one on the road.
Enough that my IDI truck does not even have a drivers side tray installed,I have never ran duals in it, and as some of you know I deal with proper cold on a regular basis.
My Cummins is much less happy about only having one battery, and that's how it came from the factory, it will be getting a second very shortly after 8 years of owning it in hopes of making it as cold weather reliable as a 7.3 PSD now that I currently don't have one on the road.
