VCCA Home Forums TECHNICAL - GENERAL Electrical - 6 volt Same old hard start - '34 Master

You may want to find someone that can help you see how many amps your starter is drawing when cold and then see how many its drawing when hot. They make a starter draw tester that you can lay over the battery cable to test the draw.

Pat,
Hot starting problem is common with aluminum pistons. The problem is that aluminum expands with heat more than cast iron. The expansion depends on who made the pistons and what alloy was used as well as the gap when block was machined. Once you have 500-1000 miles on the engine the hot starting problem will go away.

Went for another ride today. I have a "rattle" type noise in the floorboard area. It comes on then increases until you depress the clutch. I suspect too much free play. What about the u-joint? It rides smooth, shifts nicely. Today, we got it to a shade over 40. I can think of worse things than going for rides.

Here's what I decided about the starting issue:

1-Since the tight aluminum piston syndrome is the likeliest culprit, I have removed the 6V lead from the battery and connected it directly to the car's circuitry. I'll carry a 12V battery to start it until it decides to start with the 6V.
2-I am still looking for another starter to eliminate that as a possible cause. Jason Smith tells me he can rebuild it with a high torque winding. I went through that before with my 1940 Packard and it had been the starter all along.
3-After I had the straight 8 in my 47 Olds rebuilt, we never had hard starting issues. But I also had a fork lift battery in it, one of those long narrow ones. I couldn't find the exact replacement so I had bought that. I might just install one in the engine compartment of the Chevy eventually.

I have aluminum pistons in all my cars (except my '50 which has never been apart) and never had a hard starting when hot problem. Especailly the T slot pistons you have. The bearings and ring drag are most common to cause the problem. The starters have very marginal power and need all the help thet can get.

I tend to agree with you. I still think the starter may be a big part of several causes. In all fairness, I should have said "tight engine" instead. Anyway, with my current arrangement I can at least drive it and get some miles on her.

I have aluminum pistons in my '33 and '37 and never had trouble when the overhauls were fresh. Tight bearings, rings and pistons will make them pretty tight to turn but with a good starter, cables, and battery it should start even when warm. I would check that starter.

One thing that apparently got missed was all aluminum pistons are not the same. Depending on when they were made, by whom and the alloy used the thermal expansion can differ. If the piston expansion is greater than the cast iron cylinder, the pistons will tend to stick when hot. Also is it critical to cut open the skirt slit if it was not done when the engine was assembled. Many aluminum pistons are just fine with the normal bore to piston tolerance. Others require a few thousandths more gap.

Make sure you have large enough battery cables and ground the battery directly to one of the starter mounting bolts. This has eliminated a warm/hot start problem for me on several cars.

Bill,

I have 00 cables. However the ground is to the frame behind the battery. I'll try that.

I have purchased a starter from Wisebri. I'll try that to see if it makes a difference. That should eliminate the starter as a possible cause. I had the same problem for years with my '40 Packard and all along it had been the starter.

And like the guys said here, the engine is still tight.

That ground to the engine may make a big difference. I don't think the ground going to the frame is a good idea on these old Chevys unless there is a ground strap from the frame to the engine.

There is a ground strap from the engine to the second crossmember.

Seems like that should do it Pat, but I might still try going directly to the engine.

I had the same problem with mine.I went directly to the engine and haven't had a problem since.

So I bought 36" of 00 cable and hooked it up to the upper starter bolt. It does make a difference. Went for a ride and parked it. Let it heart soak a bit. Now it cranks instead of doing its one groan, but it didn't start. Let it cool. It started again, went for another ride, 7-8 miles and went to our Wednesday night gathering spot. It had warmed enough to send some coolant out of the overflow. Started after a couple of hours though. Wisebri advised me the starter is on its way. We'll see whether that makes a difference too. So first time out and back with only the 6 volt battery. First time out at the weekly gathering. Things are looking up.

Well, things are looking up. Installed Wisebri's starter and what a difference! Started on the first turn. Went for a ride and parked it. Let it heat soak for 5-10 minutes and tied it. It started right up! Did some chores, tried it again about 30 minutes later, started right up again. Looks like it was the starter all along.



And by the way, it now has over 100 miles on the clock.

Glad to hear that you have your starting problem fixed! :D

Yes Ed, I just hope it is a lasting solution. I might get to like the car after all.

Pat,
Very happy that you got it fixed.