Street/race motor - which battery??

[chateau la fete]

Hi

Currently running a 2332 ida street/race motor with Mallory CDI and unilite dizzy inc electronic ignition.

Using a Bosch silver 62AH 480A battery, but always have problems starting even after a long run!!

Any recommendations??

Cheers

[chateau la fete]

Optima Red tip, yellow top??

[Iryanu]

That battery should crank it no problem. What starter do you have? Is the wiring all OK? Maybe the Mallory box is demanding on voltage during cranking. I'd run a few tests and see what the voltage is before you try starting, then with the key to "accessory" then whilst cranking.

Is it slow cranking or cranks at full speed but just doesn't fire? What's the voltage of it "resting" 12.7v is where you want to be. If it's at 12.2v or so resting (car not running) that is 60% of it's full charge, when you crank it you might be dropping below the needed volts for the ignition box.

https://us.v-cdn.net/6024911/uploads/attachments/67/650.jpg

If it cranks at normal speed but doesn't fire I'd start looking at power to the ignition box and any earth points it uses.

[chateau la fete]

Everything is A ok after a few tests.
The battery won’t hold its charge and will not charge to 100%.
Definitely the battery, just good to get recommendations on which one to replace it with.

[Iryanu]

I'd just put a good standard battery on like you have, optima is a nice weight saving but for the money the cranking amps are the same and you get all the hassle of having to get terminal adaptors / special chargers. I believe red tops are not meant to be for deep cycle but the yellow top is. If you're feeling rich by all means go for it, I almost did but got a Bosch 063 silver for cheap and it does me fine being left for months at a time without even a battery tender on it will crank forever until the car sees fuel.

[chateau la fete]

What motor and electrics are you running?
What is your alternator rated at?
Cheers

[Iryanu]

Mines a 2161 with a pertronix billet distributor on, mechanical fuel pump, IHI high torque starter motor and all new modern blade fusebox / loom. Standard dynamo and external regulator under the rear seat. But my electrical system is very simple, I don't have any draw downs other than the coil.

http://www2.cip1.com/ProductDetails.asp?ProductCode=ACC-C10-5768-HC

I always like the idea of an optima, they are meant to be able to lay dormant without use for much longer. Personally, my car hasn't been started for 4 months, I'm going to run it up on Friday, and I bet it starts fine without any need for a charge. For the price I'll stick with the bosch for now.

[Martin S.]

I've had a couple Optimas and they are nice, but not that much better than a regular battery in any respect. All batteries get old and crap out eventually. Optimas still weigh 40 pounds so don't buy it for weight savings. I like having newer batteries in my cars, so buy whatever is cheap at Costco or similar. I also bought this battery tester which can help you decide whether a new one is needed. One tip for using this tester is that you need to fully charge the battery before testing for accuracy.
http://www.batterychargers.com/btf-250/