[CraigG.]

Hey everybody,

I've done most all of the grounds and wiring and starter changes that I can make and I'm looking at a 12 V battery for a large cube and 13 to 1 motor that I can be relaxed will start hot in staging with locked timing.

Also using standard hundred amp 12 V alternator.

What do you guys know that works?

Thanks again, Craig

[R 70 Judge]

I’m very pleased with my antigravity lithium battery. They are pretty pricey, but nothing else comes close for cranking power. My motor is almost 14:1 and it spins over at 325 rpm+. Weighing in at 19lbs doesn’t hurt either.

[steve25]

The cheapest and fastest and most trouble free way to go is to wire in a kill switch for the power to the coil.

This will allow you to get the motor rolling over before you allow the spark to take place..

I will assume you already have a gear reduction starter.

[steve25]

The cheapest and fastest and most trouble free way to go is to wire in a kill switch for the power to the coil.

This will allow you to get the motor rolling over before you allow the spark to take place..

I will assume you already have a gear reduction starter.

[Pigeon]

Just saying. I put an antigravity ATX-30-HD in my 64 GTO.
488 cubic inch 12.5-1 with a power master starter.
75 amp denso alternator. I can’t believe the way it spins the motor and the alternator keeps it fully charged at the track and the thing is tiny and it weighs nothing! I’m thinking it must be some kind of Alien technology reverse engineered from the Roswell crash.

[mgarblik]

The battery itself would not be the single item to assure reliable starting from what you described here. Having excellent large gauge battery cables and connections is most important. Utilizing an ignition cutout or timing retard for cranking would be second on my list. Finally, a high capacity, gear reduction starter properly shimmed would be next. If the above items are all addressed, honestly a battery from Rural King would start that car. Nothing fancy would be required. A battery with 700-800 CCA would work just fine. Not very sexy I know, but the truth. If a Lithium Ion battery or an Optima (six pack), battery is desired for looks or the much lower weight, or power density, that's why they are available. An AGM to avoid spilling hazards and vibration issues could be used as well. If you need to keep an eye on your batteries condition with your smart phone than some sort of integrated battery system may be cool. But none of that stuff is needed to start your engine in the staging lanes at the drag strip. Let your wallet and desire for gizmos help you decide.

I reread the above suggestions and will add. You didn't mention if your engine was fuel injected or had a carburetor, (s). With a carburetor, you need 90-110 RPM cranking speed to start reliably. Electronic FI engines, especially Holley stuff needs 130-180 RPM's to start. It needs time to find the #1 cylinder for sequential FI so both cam and crank signals need to be evaluated and synchronized. The higher CCA's will help maintain cranking speed longer.

[lakefect]

the best thing i ever did was to go 16 volts, 15;1 comp spins over like the plugs out

[mysticmissle]

if you need to buy a battery anyway, 16v is way to go. you can get a cheap charger on amazon, that will maintain and charge, and you can get a new recitcifer to convert your alternator. zero adverse events in my experience (12yrs) i have a turbo start 16v

[R 70 Judge]

Originally Posted by Pigeon

Just saying. I put an antigravity ATX-30-HD in my 64 GTO.
488 cubic inch 12.5-1 with a power master starter.
75 amp denso alternator. I can’t believe the way it spins the motor and the alternator keeps it fully charged at the track and the thing is tiny and it weighs nothing! I’m thinking it must be some kind of Alien technology reverse engineered from the Roswell crash.

These batteries are truly amazing! I have the Antigravity Group-24 Lithium Car Battery in my TA.

Honestly, I'd go with the lithium option over converting to 16V. I'd wager that at 1800 CCA my battery is far more powerful than any 16V AGM out there. Plus, you don't have the expense of a new alternator.

Link to my battery test thread -- https://forums.maxperformanceinc.com...hlight=Lithium

[CraigG.]

Thanks guys you are very helpful all of your suggestions.

1050 dominator E 85 carburetor

I have used the timing retard and had mixed results
.
I have a cutout switch which does help just not quite there turns over and then hitting ignition switch stops the motor.

I use an interstate premium AGM helps just not enough

I have a high quality gear reduction starter

I have multiple grounds even a ground from the battery to the starter

I have heavy gauge welding cable as positive – could be potentially heavier cable

RobMc performance products starter

I wonder where to find information about battery pulse power

If converting to 16 V what will that do to MSD 6 AL and other gauges and electronics?

[mgarblik]

Sounds like you have all the bases covered. That's great. Have you ever watched the cranking voltage while the engine is cranking? Also, have you ever checked the voltage drop on the + or - side of the circuit. If your cranking voltage starts at 12.6v and drops below about 11.2-11.5 during a cranking event, that's too much. I have not personally used an LI battery and have heard great things about them on this board. I have used 16 volt wet and AGM batteries from Turbostart and XS Power batteries. They worked great and cranked fast, but are heavy. When I raced with 16 volts, I didn't run a charging system on the drag race only car. I made no modifications to the electrical system for the 16 volt system. MSD, Tons of nitrous, fans, electric water pump, lights were all just fine on the 16 volt system as well as the data acquisition. However adding an alternator to the system might change things.

[mysticmissle]

No issues with any component or light in a 1964 lemans, head lights, water pumps fuel Pumps tail Lights fans
E85 was a deciding factor when I did switch to 16v also.
Timing retards and starter retards did not work as well as cranking over with the ignition off. And even then
Kicked the teeth off once in a while, rob macc starters hurt occasionally, ati flx plates nothing can survive or stop the kick when it happens

[mgarblik]

If you decide to go 16V, I have a TurboStart charger that has been modified to charge the AGM style 16V batteries I no longer need. PM me if interested.

[CraigG.]

Hey guys,

I appreciate all the good information and suggestions and wondered what is a good size copper fine strand welding cable for positive posts and negative post for relocated battery?

Thanks, Craig

[mgarblik]

You would need to balance out weight vs voltage drop for your application based on the length of the run. (s) If weight is not a factor for you, I have run cable as large as 0 gauge. For a relocated battery and the issues you are having, I would think 2 gauge would be the smallest you would want to use. I have seen some people using 00 gauge but that can get difficult to package around headers, starter and other tight areas. As you mentioned, fine wire conductor is easier to bend and will carry more current. Welding cable is excellent. I am sure there are charts available listing the gauge size, length of run, number of conductors and voltage drop. Good luck with the car. We were fortunate to run several race cars with tons of electrical loads with virtually no electrical issues. Our secret was to keep each circuit discrete, power and ground. Use only ring terminal connectors, no spades or bullets. Use only heat shrink crimps or solder. Best of luck to you.

[mgarblik]

Here is a sample on-line calculator you could play with to help you decide what you want/need. I am not an electrical engineer by any means so maybe someone else who is can chime in with more details.


https://www.electricaltechnology.org...p-formula.html

[R 70 Judge]

Battery is located in the trunk. I did the "big 3" upgrade. Wires are from GP Audio oxygen free copper (OFC) 2/0 power and grounds. 1/0 OFC from battery to starter. Very heavy duty/nice wiring. This is an old picture of the group 65 AGM