Classic/Antique Car Repair/starting problem !

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Expert: - 12/10/2010


Question
hi.  i have a 66 gto, 389 bored to 409, ram air 4 cam, comp-10.5, headers, and 750 rochester.  the car runs great and strong, till i turn off, at which time the battery just about turns the engine over.  i have replaced with much larger draw amperage batt. and still same.  i have even gone to the extent of adding another battery in trunk, paralleled the wires, and have cured the problem a little bit.  at least it will turn over to start. i also have taken asbestos tape and wrapped the headers at the point they pass the starter, thinking i could reduce the resistance, due to the heat.  but no.  what do you think.  thanks

Answer
Summit Racing and a few others in the hot rod market sell High Torque starters. With a compression ratio of 10.5:1 this will probably be your best solution. I would also check the charging rate of your alternator to be sure that you are completely charging the batteries. When the batteries are fully charged and the engine running at 1500 RPM's I would want to see a voltage across the battery as close to 14.4 volts as possible but no less than 13.5. If you have a mechanical regulator, it is adjustable.

Classic/Antique Car Repair

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Brad Sears

Expertise

All automotive including antique and collectible. However if the car has been modified I can only answer in general terms and maybe get you pointed in the right direction.

Experience

Automotive tech instructor. Syndicated auto columnist 1970's though the early 1990's. Syndicated auto radio talk show, Ask Brad About cars, CBS Radio 70's through 90's TV Show "Last Chance Garage" 1980's PBS-TV syndicated. Auto instructor for the following companies: Fram Autolyte Holly Carter AMF Ford Motor University Of Conn Blue Hills Technical School Sugar River Technical Center Grew up in a family garage in Needham Mass and turned wrenches from the age of 14.

Publications
Manchester Union Leader, Nashua Telegraph, Motor Service Magazine, Yankee Magazine, Popular Mechanics (Saturday Mechanic early 80's), Los Angeles Times, New York Times, and lots more.

Education/Credentials
More than I care to remember. Basically Franklin Technical Institute in Boston, Northeastern University, Fitchburg State Teachers College, Tufts University, and a lot of factory schools along the way.

Awards and Honors
Moto Award winner. And much more.

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