So, I'm getting ready to get back to my 67 RS/SS Conv. project (it used to be my daily driver, but marriage, kids, etc. robbed me of time). When I was driving the car, even at the best of times, it always was hard to crank. The guy that put the motor in the car had re-built it higher compression (350, bored .60 over, I believe).

Anyway, I decided to crank it up using a portable battery. Extremely slow cranking, would only turn a time or two, rest, again the same. I then looked under the hood, and smelled a little electrical smoke, wires going from the battery were pretty warm to the touch.

So, what should my steps be for diagnosing the always hard/slow cranking of the motor? I've read several things, from removing the wire to the coil, to removing spark plugs, to just trying a high torque after market starter.

Thanks in advance, I'm looking forward to getting this beast back on the road.

PS, if this is posted in the wrong place, please just put it where it belongs.

Jeff

 

if the starter has been overworked for a long time the poor thing is most likely on its last legs. a high torque gear recuction starter would be a good idea.

 

Make sure the cable ends, both of the ends of both cables, are clean and the surface they touch are clean.
Cables of min 1GA cable are better, molded clamps as well.
Freshly charged battery.
You might remove the spark plugs and squirt into each cylinder, some engine oil and let the starter crank the engine over distributing the oil about the rings. Engine should spin over at a good rpm, higher than normal cranking.
Ensure fuel bowl has fuel, might pour in through the vent tube, the 1/4 inch diameter tube sticking up, or if carb is an Edelbrock, the trapizod shape holes, about 1/3-1/2 cup of fresh gas.
As a troubleshooting aid, you might install a see-thru glass filter between the fuel pump and carb to view when the pump starts pumping fuel. The filter should be full during engine running.
Might go as far as removing the inlet hose on the f/pump and pressize the tank with shop air through the filler tube untiol fuel comes out, then re-attach hose - priming the pump.
You could go as far as replacing the fuel hose segments from the tank to the fuel pump. Should be three of them by OE design.
Smell the filler tube, if other than fresh fuel, you would drop the tank, remove the sending unit, use petro jelly on O-ring when resealing, and drain and clean the tank with fresh fuel. Ensure the sock is in good repair, or remove it. The filter will filter out the rust and foreign material.

 

Don't know why you'd want to rework the fuel system for a mechanical issue like a slow cranking engine? If cleaning the cables and a known good battery doesn't do the trick, then a new starter might be on your shopping list. If so, get a hi torque. Another thing you want to check before getting a new starter, if the problem still exists at that point, is your ignition timing. If the timing is set too far advanced, your engine can crank over slowly because the plugs would be firing way before the pistons are nearing TDC, basically they'd be getting pushed back down too soon before they reach the top.

 

Thanks for the advice guys. For getting a high torque starter, how do I get the correct one for my engine? I would guess that they would be pretty standard for the Chevy SB 350, but I happen to be wrong enough. I do think that it would be a good idea to crank the engine perhaps without plugs in, to see if the compression is preventing the motor from turning easily.

 

Removing the plugs won't tell you if it's compression or ignition causing it, but unplugging the coil wire will. You have one of two different starters, look at the mounting bolts. Straight across mount is for the smaller diameter 153 tooth flywheel, and angled bolts is for the 168 tooth flywheel.

 

He did not give an amount of time from being a driver until he got back to it - kids and the like - several years? Fuel doesn't last forever, even with copious amounts of Sta-Bil. Synthetic rubber hoses don't last either.

If a hard cranking engine, couple of things, too small of battery, too small of cables, or not enough recharge of the battery. If the Camaro is equipped with an ext reg'd 37A alt, it would need a good 30 minute drive on the interstate, or ran for 20 minutes at 2500 rpm to recharge the battery. Battery size several years ago, 350CCA, was standard size.
He may just need to get a high torque GM starter, the one with the copper extension between the solenoid and field windings, meaning longer field windings and longer armature with appropriate size battery cables. Most common starter is the short starter, the one with out the copper extension.

To the OP, if you do swap out starters, be sure to reconnect the front brace on the starter motor.

As Camaro 69 suggested, if pulling the coil high tension lead allows the starter to spin over the engine faster, then you might need to install a momentary 'push-to-off' button for the ignition power supply. Push in on the button to open ign power, thus removing the too far advanced initial timing, allowing the engine to spin over faster, then let go of the button supplying ign power to the ign to start the engine - old school high comp trick. Works very well.

 

Thanks to you all for the helpful ideas. I did remove the coil wire, but the cranking is still super slow. I've been using a battery booster pack to try to start the car, as the battery is really dead. In retrospect, this might not have been the best idea. I'll see if the battery will hold a charge, and if not, get another. Given that this car has always been hard cranking, I think that I'll go with high torque starter to rule that potential problem out.

Another discovery is that my carb (4 barrel) isn't operating properly. Now I'm reasonably handy, but have never rebuilt a carb before. Is this worth doing, and is it difficult? Or should I look around the classifieds here and see if I can find one at a good price?

Thanks!

Jeff

 

Did you ever mess with the timing in the past?

As 69 Camaro mentioned, your timing could be too far advanced.

Maybe do a simple test and loosen the distributor hold down clamp a little and just turn the cap clockwise a little and see if that helps.

What type of carb is it? A Holley is pretty easy to rebuild but if it's a Q-jet, I'd let someone that knwos how to rebuild them do that.

 

I think, Bruce, he would want to turn it CW to retard timing?

Anyway, after you pulled the coil wire, it still cranked slow.
Either not enough juice from battery, or not large enough cables to handle the current demanded, and this would include the copper disc and bolts in the solenoid - they get burnt to a crisp.

Any SBC/BBC with as much as 14° BTDC timing should be whizzing over at a good rate, 200 RPM, creating vacuum to start.
Also, may need to shim away the starter from the ring gear as it may be too close of fit.