Thread: 305 cranking

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I have a 305 chevy smallblock that I just rebuilt and I'm having trouble getting it to crank fast enough to start up for the first time. I tried jump starting it. All the bearings have the correct clearances. Any Ideas?

Need more info than what you given us. Engine problem or electrical problem? Starter bad? I have a 305 myself in my 37 chevy that was bored .060 over. You said engine rebuilt. Back to stock,bored,new cam,pistons,Etc.?

Originally posted by carym123
I have a 305 chevy smallblock that I just rebuilt and I'm having trouble getting it to crank fast enough to start up for the first time. I tried jump starting it. All the bearings have the correct clearances. Any Ideas?

Tell us more. Did you bore it? new pistons? Did it turn over O.K. by hand once assembled. Dies it have a new starter? If you have a load tester, see how many amps the starter draws when you try to start the engine.

Originally posted by chevy 37
Need more info than what you given us. Engine problem or electrical problem? Starter bad? I have a 305 myself in my 37 chevy that was bored .060 over. You said engine rebuilt. Back to stock,bored,new cam,pistons,Etc.?

Looks like we had the same thought Chevy? HE He He

I don't think that it is an electrical problem because it tries to crank but it is to stiff. I did not rebore, I just built it back to stock. standard size crank bearings. I can turn it by hand but it is difficult.

Also I put a new battery in it before attempting to start it. It cranked faster for about 10 seconds then it wouldn't. I replaced the starter about 6 months ago because the gears on it and the fly wheel were chewed up

When you say it cranked faster for about 10 seconds, did you mean faster like a normal engine turning over would sound, or are you talking about something that sounds like a dead battery.

it cranked not quite as fast as a normal turn over but alot faster than now where it won' even crank over one whole turn

Do you have the motor grounded good to the battery, a bad ground will cause the symptoms your stating?

The engine is grounded through the stock locations. On the alternator bracket etc.

Sounds like a bad starter, bad grounding, or the crank bearings are too tight. Or in wrong.

I took back off the oil pan and checked the bearings they are all free. There is a good ground, I even tried hooking up the battery directly to the starter. I think maybe it has too much compression to overcome, but I did not replace the pistons or rebore the cylinders, just new rings.

bad starter

try a new starter me and my boyfriend are having to do the same thing