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By DANIEL TINDER - 16 Years Ago
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As I am nursing along a high-mileage motor until replacement block build-up is done, I have been running with zero coolant pressure (two adjoining cylinders are burning antifreeze). Lately, when the engine gets hot, restart cranking is unusually slow (I assume one possible explanation could be coolant incompressibility?). Is this likely an accurate guess?
Even with no radiator pressure, when things get hot it might allow more coolant to seep into the cylinders and accumulate? And yet, cold starts are normal.
Regardless, I won't waste much effort solving what is not a REAL problem with a motor nearing retirement (if starter wear is the culprit, new motor should exhibit same symptom). Just curious about the cause, and wonder if it's common with leaking head gaskets?
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By simplyconnected - 16 Years Ago
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Dan, slow cranking can be from: Timing is too advanced,
Solenoid contacts are going,
Cables need to be changed (put your ground cable as close to your starter as possible)
Weak battery, loose or corroded connections, undersized conductors (from metal fatigue & vibration cutting the copper strands inside the insulation). Oh yeah, higher compression from cylinder liquid-lock, although unlikely because it cranks fine when cold. Are you seeing smoke? Do you see radiator overflow or bubbles when you take the rad cap off? Are you making up for lost coolant? I don't know where you live, but if you are thousands of feet above sea level, your boiling point is lower than 212*, which puts air between your hot metal and the coolant. End result is hotter metal because air is a good insulator and it stops the liquid from removing heat. Possible electrical fault, try this: While it's cranking slow, ADD a jumper cable from the Battery (hot) to your starter. If speed increases, well, you know... Also try adding a jumper cable from Batt-Chassis to your bellhousing just to see if that improves starter speed. I have to be careful with these terms because you have a POS GND, but you understand. We're not mixing voltages. Sorry to be long-winded. I hope this helps. - Dave
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By DANIEL TINDER - 16 Years Ago
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Dave,
Weak battery a possible (it's 6 years old). I'll jump with my charged spare, and see if hot motor/minor fluid lock might be a tipping point to a compromised starting system?
I pretty much quit regular cable/contact cleaning, since positive ground system (and sealed Optima battery posts) never seems to corrode (points & solenoid contacts last near forever).
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By simplyconnected - 16 Years Ago
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DANIEL TINDER (5/20/2009)
...I pretty much quit regular cable/contact cleaning, since positive ground system ... ...solenoid contacts last near forever). My '55 Customline came with the same setup as your '55 Bird. Two things come to mind, Dan: * A sitting car would have longer opportunity to 'hydraulic-lock' than a running car. You may be sucking antifreeze, but your car starts nicely when cold. IMHO, I would rule this lock theory out. * Just when you think your connections/contacts/wires are good, surprise! Fortunately, they are all easily checked by bypassing (shunting) with a jumper cable. Wires (including starter windings) increase resistance with heat. When you only have six volts max, even the smallest resistance will mess you up. Cars with 12-volt batteries run with one dead cell for a very long time. You only have three cells and they must all work well. I hope your new engine comes soon. In the mean time, treat your Bird to some electrical maintenance. One thing NOBODY ever checks is their starter brushes. It's real easy to do, just pull back the band and look! Brushes are cheap. It seems like everyone waits for the commutator to burn from short brushes, before they maintain. This is something we all can do before it's too late. I use a small mirror, and pull on the brushes to check spring tension, and wear length. Sometimes, oil and dirt will bind the brushes, so it just needs to be cleaned. Running 600-800 amps through them is serious business. Hope this helps. - Dave
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By DANIEL TINDER - 16 Years Ago
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Dave,
Booster battery/jump no help. Regardless, cleaning electrical connections, new battery, & changing starter brushes can wait until motor swap, when everything is apart already.
Here is my reasoning re: gasket leak/hydro-lock.
Slow cranking only occurs immediately after shut-down. Motor is hot, everything is tight/expanded (compression at maximum) and only coolant pressure is that supplied by recently running water pump, which could likely still force enough fluid through the leaky gasket (on the final coast-down revolutions) so as to leave some in an unfired cylinder. After cool-down, compression is low (worn rings/valves) so the tiny amount of residual coolant not enough to slow cranking.
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By charliemccraney - 16 Years Ago
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Is there coolant in the oil? If it's filling the cylinder enough to slow starting, there must be coolant in the oil. Does the starter sound like it is under greater load at a certain point in the revolution? I would think that after the first 2 revolutions, much of the coolant that may be in the cylinder was pushed out the exhaust valve and should not allow the starter to drag.
Easy way to rule it out. Let it get hot, to the point at which you experience this, remove the spark plugs, crank the engine over and see if coolant comes out.
I don't think that is your problem. I really can't see how you're driving it if the leak is that bad.
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By DANIEL TINDER - 16 Years Ago
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Charlie,
No obvious indication of coolant in the oil, but I have to assume that since it's leaving residue on the plugs, it must be getting past the rings and into the crankcase. Not really a concern since antifreeze is propylene, and motor change imminent. Other head gasket leaking also, but only to the outside. Original engine still running very strong also.
Slow cranking IS a bit jerky. Could be the first few revolutions sends most fluid out the exhaust valve (improving the mixture), and after cranking speeds up, it catches.
Didn't mean for this thread to get so involved. It was originally just a bit of "mental masturbation" about a non-problem.
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By Ted - 16 Years Ago
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Because the cold starts are normal and you’re only experiencing this during hot starting situations, I’d consider other causes other than hydraulic locking. Dave had already suggested too much initial igntion spark and your symptoms do point to ‘ignition lock’ where the initial timing is just too far advanced. Although this would be unusual on a stock compressioned Y, it can not be ruled out. In these cases, giving the engine 2-3 pumps of the throttle and waiting ten seconds just before cranking on the hot engine typically helps get past that initial ‘slow crank’. If this helps, then just revisit the intial timing on the engine.
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By Pete 55Tbird - 16 Years Ago
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Slow hot cranking and having to reduce the ignition advance are the reason so many have changed over to 12Volts negative ground. It just works better. Pete
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By DANIEL TINDER - 16 Years Ago
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I'll retard a bit and see if that helps. Would be unusual, as periodic timing adjustment has always involved advancing to compensate for rubbing-block wear.
So, 12V cars can run more advance than 6V (everything being equal)? When I set timing by ear, hard starting and pinging usually go hand-in-hand. Perhaps a more thorough warmup is required for successful adjustment. Regardless, slow cranking still likely a viable trade-off for increased economy/performance since it always starts.
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By simplyconnected - 16 Years Ago
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DANIEL TINDER (5/24/2009)
...So, 12V cars can run more advance than 6V (everything being equal)? ... Think of it this way, if your starter cranks the engine faster (and it does on a 12-Volt system), you have more kinetic energy pushing the piston over the top even though it's combusting BTDC. It's all about crank speed, which will start your engine faster so you don't need the key on as long.If retiming is a trade-off for economy and more hp, maybe you can use an ignition system that has a wider spread (more retarded just for starting purposes). BTW, what's "rubbing-block wear?"
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By Hoosier Hurricane - 16 Years Ago
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Slow cranking has been a problem on 6 volt Fords for many years now. I believe it is the battery. The newer 6 volt batteries of the original size just don't have the cranking power the old ones did. My 6 volt '53 truck with a 324" Y used to crank like it had a 12 volt, but it was an industrial size 6 volt. I doubt if it would fit the battery box in a '55 car. The truck is now 12 volt so I can use a modern radio and CB. If you have a battery store (not a WalMart or KMart or such) in your area, check with them to see if they have a more powerful battery, such as a golf cart battery or a farm tractor battery (some tractors used 2 six volts in series) or an 18 wheeler battery (some used 4 6s in series) that will fit your carrier.
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By Moz - 16 Years Ago
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rubbing block wear is the rubbing block on the ignition points as it wears the points close up.
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By simplyconnected - 16 Years Ago
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Thanks, Moz. (I wasn't familiar with that term with regards to points.)
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By DANIEL TINDER - 16 Years Ago
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[quote]DANIEL TINDER (5/24/2009)
I'll retard a bit and see if that helps. Would be unusual, as periodic timing adjustment has always involved advancing to compensate for rubbing-block wear.
Dave & Ted nailed it. The initial advance HAD creeped up (color me embarrassed). I forgot I've been burning premium exclusively of late, so no pinging alert. I had also overlooked a subtle increase in idle speed. Just rotating the distributor a tiny bit (until the idle dropped back) cured the hot slow-cranking.
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By simplyconnected - 16 Years Ago
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I'm just glad you found the problem and didn't have to spend money fixing it, Dan. I think using premium is a good idea, too.
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