VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1912-1928 Starting a rebuilt tight engine

I have finally got the 25 Sup K engine together with all of its parts rebuilt...complete engine rebuild, carb, generator, oil pump, starter, distributor, new pistons, new rings, crank redone, etc. All the torques are correct and presumably no vacuum leaks anywhere. I am feeding the carb directly at this time. When I attempted to start the engine (I checked to make sure the oil pump was working) the engine would barely turn over. I took the plugs out and the engine turns over easily. The "slow roll" of the engine with plugs in does not happen, rather I get a punctuated turn over that stops on the each cylinder after the intake opens and closes. I tried another battery (new) and another rebuilt starter with the same results. Checked the distributor timing. Is there any way to "loosen the engine up". I have been running the engine with the starter and no plugs in it to help. It seems to be working a little. I am working with a rolling chassis without a body on it. I'm not sure I want to go to the emergency room with a broken wrist and have not tried to hand crank it. I was hoping that if I could get it to fire it would run and loosen up. Any advice would be greatly appreciated.

Are you using the correct size positive battery cable, and a 6 volt battery with high cold cranking amps?

:confused: :confused:

Junkyard Dog,
The battery cable is 4 gauge (seems a little light compared to the original) and the battery is new with 650 cca.

The 4 ga cable is too small. I have found that 2 ga are ok but 0 ga better and 00 even better. You also need to make sure that all connections are clean and tight.

I have a 0000 gauge positive cable on my car and it works great. I had it made up out of copper welding cable at the local starter shop.

Thanks, I'll pick up some new cables and let you guys know...

Yes, large cable size is CRITICAL, I had the very same problems. Also large, and very clean, connections and grounds are needed.

The timing being too far advanced can cause the stopping at each cylinder when cranking, but you do need better than adequate current capacity on a tight engine.

The cables did the trick. Was able to find 2/0 here in Charleston. Engine has fired...now just needs to run. Down on lever is retard and up is advance...??????

Start it with the lever in the down position. When it starts running push it up as high as it will go.

Good. That's how I had it figured out. I timed the distributor with it in the "retard" down position. Thanks again for all your help...The VCCA is invaluable with everyone that helps!!!!!! I'll let everyone know when it starts.

When you start trying to get it to run, the flex tube that wraps around from the stove on the exhaust system to the carb intake is also pretty critical. It really needs that hot air.

Sorry, got in late on this one.

Remove spark plugs. Remove all wires from the starter terminal. (Remove the battery cable from the battery and the red wire that is connecter to the starter.) Connect a GOOD set of jumper cables to the starter. One connection to the terminal on the starter, other(-)not connected to anything. Check polarity, connect the (+) jumper cable to the (+) on a 12-volt battery. Connect the (-) jumper cable to the (-) on the battery. We now have three of the 4 connections made. Find a good bare spot on the frame or the engine and clamp the (-) jumper from the battery. Leave connected for just a few seconds and disconnect. When the starter has cooled down a bit, reconnect, again for just a few seconds. Repeat as necessary.

Morning Up-Date: Charged the battery overnight (as well as the spare), tried to start the engine and it turned over well (thanks to the new cables) and I checked the distributor timing for the umpteenth time. All I can get out of it is a "white puff" of smoke coming out of the exhaust and carb when it "backpuffs" (new word for backfire when there is no bang). Flex pipe is in. Plugs don't seem wet and I'm wondering if it is getting fuel. My "white puffs" may be the oil that I put in earlier on the cylinders while I put it all back together. How does one check the carb function on the RXO? I'm sure that there is something I'm not doing correctly or the carb is not doing its thing. I have the idling jet at 1 1/2 turns, and the float bowl has gas in it when I loosen the bowl nut. Any suggestions?

Put a small squirt of carburetor cleaner (I don't like starting fluid as it can easily damage an engine.) into the carb throat and try to start. It should fire if the timing is right. If it fires with the CC but not run then you have a fuel or carb problem. I also don't recommend trying to put gasoline into the throat of an updraft carb.

I tried your suggestion and got the same results. "White puffs"... not a real firing. I watched the timing and and when No#1 cylinder intake opened and closed, a moment later the #2 cylinder fired. I assume that is correct. I timed it according to the manual and the positioning of the drive pin. I have good fire on the plug. Puffing along in Charleston.

Viola!!!!!!Everything is copesthetic!!!!! It was my problem...1 space off on the cap to get the plugs to fire. Fixed the problem and it roared to life...."HOW SWEET THE ROAR OF THE CHEVY FOUR"!!!!! Thanks to everyone for their help and advice during this tyro's attempt to get this engine running.

We've all been there before. Those darn GGs were at it again. Could you hear them laughing when ever a white puff came out? But you got them this time! So who had the last laugh? Beware they are still there and will try their best to mess things up again.

There are few things finer in life than when an old engine roars back to life!

Thanks to all!! I'm sure I'll have more questions and I do know those darn GG's will show their heads again...That's why I need you guys to help show me the way. Truly...Thanks. It was great to realize that that poor engine had probably waited 50 years to come back to life and it did it!!!! What a sweet sound and now a memory that won't soon be forgotten!