best way to awaken a flathead

[homer41]

I am new to this site but not new to restoration, I just bought a 41 plymouth p12 4door. The PO says it was last run 9 years ago.  When I looked at it Friday we were able to turn the engine over with the fanbelt, so not seized. The question is, what are the best recommendations for starting this engine to test it? Is there anything special to deal with the flathead? My experience so far has been with ohv engines. I believe it could be the original 201 engine, will check the numbers later when I get it home. Would I dare feed it 12 volts to test it? I will be using an external fuel tank for testing.  Dave

[Mortimer452]

Nothing special with the flathead really, just like any other motor it needs fuel, air and spark to run.  Standard procedure for any motor that's been sitting for awhile - change all fluids, pull spark plugs, squirt a teaspoon or so of motor oil into each of the cylinders and crank it over by hand a time or two to help lubricate the cylinders.

Some others with more experience will probably chime in - I think you can jump-start on 12 volts in a pinch but be sure to disconnect right away once it fires.  The starter is no problem and can handle 12V just fine.  If you have a 6v battery in the car, be sure to disconnect one of the leads, and just hook the cable up to the lead so you don't end up trying to charge your 6V battery with 12V, it will boil over and potentially leak/explode if you do this.  And make sure all the lights and radio are off or you'll burn them out.

[knuckleharley]

change the oil,Squirt a little ATF in each cylinder to lube the rings,pull the spark plugs,and spin the engine using the starter until you can see oil pressure build up on the oil pressure gauge. Be sure to only spin it over maybe 10 to 15 seconds at a time and then stop to let the starter cool. This is best done using a 12 volt battery because it will obviously build up oil pressure sooner.

When you hook up the battery remember these old cars use a positive ground. Make sure all electrical accessories are off before using a 12 volt battery.

Once you have built up oil pressure and gotten everything lubed up and spinning freely,you shouldn't have any trouble starting and running it with a 6 volt battery. Clean and gap the points,put new properly gapped plugs in it,clean and gap or replace the points,clean the coil connections to make sure you have good grounds,and it should start easily.

[DrDoctor]

   I just read knuckleharley’s reply to you with rapt interest, and I agree with everything he said. But, I’m not trying to be argumentative here, only inquisitive – my question: won’t a 12v battery overload the 6v starter? I’m guessing at this point that the intermittent usage of the starter for 10-15 seconds each is a method to prevent the starter from frying, since I’ve never put a 12v battery in our 6v car. Also, as our car’s a 6v negative ground system (who did that, or how or when it happened, is a mystery . . .), would that be another problem to his procedure? In any case, I’m confident that if you follow knuckleharley’s procedures in detail, you’ll encounter no problems. Thx.

[greg g]

Remember ohms law.  6 volt systems require 2x the amps of a similar 12volt load.  So 6 volt stuff is overbuilt compared to 12 v.  My suggestion is to bypass the battery during the 12 volt jump start process.  Connect the negative cable to the large terminal on the starter side of the solenoid, then use the positive clamp to ground the system to a head bolt to spin the starter.  When it is time to try to start, you can use the 6 volt to power the ignition as normal, and by bypassing the battery, it is out of the loop if when the starter is drawing, but back in when to disconnect the jumper to allow for regular running.

[knuckleharley]

42 minutes ago, The Dr's In said:

   I just read knuckleharley’s reply to you with rapt interest, and I agree with everything he said. But, I’m not trying to be argumentative here, only inquisitive – my question: won’t a 12v battery overload the 6v starter? I’m guessing at this point that the intermittent usage of the starter for 10-15 seconds each is a method to prevent the starter from frying, since I’ve never put a 12v battery in our 6v car. Also, as our car’s a 6v negative ground system (who did that, or how or when it happened, is a mystery . . .), would that be another problem to his procedure? In any case, I’m confident that if you follow knuckleharley’s procedures in detail, you’ll encounter no problems. Thx.

A 6 volt starter will probably last as long as a 12 volt starter,but will spin with "vigor" when hooked to 12 volts.

At one time LOTS of cars were positive ground,including Fords and all the British cars. I read a long time ago that a positive ground system was the best one to use,and why,but have forgotten the details.

Everyone in the US switched over to negative ground in the mid-50's. Probably for economic reasons as well as standardization. It was just easier to make everything electrical  for one grounding method than 2. GM sold more cars and trucks than Ford or Mopar and they were negative ground,so that's probably why negative ground was picked. Just guessing here,though.

[chrysler1941]

16 minutes ago, knuckleharley said:

At one time LOTS of cars were positive ground,including Fords and all the British cars. I read a long time ago that a positive ground system was the best one to use,and why,but have forgotten the details.

Due to the electrons moving from positive to negative, by using positive as ground, you'll reverse the ion wandering, (don't know if it's the correct term) and therefore minimum rust. Notice how all positive cars almost always have sound frames, no matter the age, ever then around ground clamping bolt.

Also remove the A from the generator or regulator when disconnecting the 6 v during jump starting to avoid frying the regulator's current coil.

Edited March 7, 2017 by chrysler1941

[oldasdirt]

Hi Guys -    on the 12 volts to a 6 volt starter, there is no issue there and I have had several cars that were switched over to 12 volts, but retained the 6 volt starter.  Its lots heavy enough. The issue isn't the starter, its the rest of the car.  The gauges, bulbs etc will not take 12 volts.  You risk tearing them apart.  Its not just accessories you have at right. As others have suggested, changing the oil, any filter if there is a bypass filter, the antifreeze, and squirting a bit of oil down each cylinder is a great idea. 

Check the points which may have corrosion after 9 years but that really depends what conditions it was stored in and endured.

I would also pull the coil wire, turn it over and make sure it is building oil pressure, before putting the oil wire on it and firing it.  A couple of times I have revived engines that were sitting for a long time where the oil  had I am sure been long over due for a change, sat for years and actually gummed up the oil pump We fired it up it only ran for a couple of minutes , but didn't have oil pressure and we tore bearings out of it.   George Asche actually gave me the tip to treat and engine that has sat for a long time like a fresh rebuild.  Turning it over and building up oil pressure before you give it ignition and fire it up could save you a rebuild and heart ache   If it doesn't build oil pressure its a lot easier task to pull the oil pump and make sure its clean and functional than rings.

That's my two cents.

[desoto]

56 minutes ago, oldasdirt said:

Hi Guys -    on the 12 volts to a 6 volt starter, there is no issue there and I have had several cars that were switched over to 12 volts, but retained the 6 volt starter.  Its lots heavy enough. The issue isn't the starter, its the rest of the car.  The gauges, bulbs etc will not take 12 volts.  You risk tearing them apart.  Its not just accessories you have at right. As others have suggested, changing the oil, any filter if there is a bypass filter, the antifreeze, and squirting a bit of oil down each cylinder is a great idea. 

Check the points which may have corrosion after 9 years but that really depends what conditions it was stored in and endured.

I would also pull the coil wire, turn it over and make sure it is building oil pressure, before putting the oil wire on it and firing it.  A couple of times I have revived engines that were sitting for a long time where the oil  had I am sure been long over due for a change, sat for years and actually gummed up the oil pump We fired it up it only ran for a couple of minutes , but didn't have oil pressure and we tore bearings out of it.   George Asche actually gave me the tip to treat and engine that has sat for a long time like a fresh rebuild.  Turning it over and building up oil pressure before you give it ignition and fire it up could save you a rebuild and heart ache   If it doesn't build oil pressure its a lot easier task to pull the oil pump and make sure its clean and functional than rings.

That's my two cents.

Right on Right on.   I remember all to well being told not to worry about using 12 volts just make sure everything is turned off.  Wrong again honey as I smoked very expensive to replace gauge and other items including cooking a coil.  Just forget 12 volts for what your doing.  Getting oil pressure before connecting the coil wire is just pure gold on the advice meter!

[dale]

I had a 1951 Plymouth way back when that was wired by a pro to start on 12 volts and then run on six..  Had two six volt batteries.. Before I knew better I would show off by driving it around the parking lot on just the six volt starter running 12 volts thru it.  Never did manage to burn out the starter.  An electric car in the 1960s   LOL

[knuckleharley]

3 hours ago, oldasdirt said:

....  A couple of times I have revived engines that were sitting for a long time where the oil  had I am sure been long over due for a change, sat for years and actually gummed up the oil pump We fired it up it only ran for a couple of minutes , but didn't have oil pressure and we tore bearings out of it.  ...

Which is why I recommended putting a little ATF in each cylinder and then spinning the engine without the spark plugs in it until it builds up oil pressure. Some take a while and a LOT of patience. I was just about ready to give up on my 49 Chrysler that had been sitting for over a decade in a barn in West Virginia,but eventually it started building oil pressure,and the damn thing would pump up 60 PSI oil pressure just with the starter turning it  once it started pumping.

Nothing is hurt by spinning the engine over with the starter and no spark plugs in it as long as you put a little ATF in each cylinder first,and only spin it for 15-20 seconds at a time and and let it cool down.

>>If it doesn't build oil pressure its a lot easier task to pull the oil pump and make sure its clean and functional than rings.<<

Yup. It's also a good idea to drain the old funky oil out of it and fill it with clean 30 wt non-detergent oil (in the case of these old flat motors) before trying to spin it. After all,why force all the old crap and condensation in your oil pan though your oil pump and bearings?

 

 

[garbagestate 44]

If you don't already know, the spark plug holes are located over the valve train. When I wanted to do the same thing,I used one of those baby formula things that look like a miniature turkey baster with a plastic hose on the end to direct the oil directly into the cylinders. Either way the oil gets in I guess but that way you know it all makes it instead of down through an open valve.

[knuckleharley]

31 minutes ago, garbagestate 44 said:

If you don't already know, the spark plug holes are located over the valve train. When I wanted to do the same thing,I used one of those baby formula things that look like a miniature turkey baster with a plastic hose on the end to direct the oil directly into the cylinders. Either way the oil gets in I guess but that way you know it all makes it instead of down through an open valve.

I use a little squeeze bulb pump with 1/4 inch clear plastic lines. I think I paid about 6 bucks for it at Car Quest.

[homer41]

Thanks folks, some great thoughts there! I am waiting for the weather and roads to get better before I go get the car. Gps says it is a 5 hour 21 min. Drive. I will be trailoring it home.

Edited March 8, 2017 by homer41
spelling

[51custom]

I used 12v to check my car for starting ability, however be advised as stated here it's not good continue using it.

 

Also I didn't have ATF so I used Marvels Mystery Oil.

Edited March 8, 2017 by 51custom

[knuckleharley]

19 minutes ago, 51custom said:

I used 12v to check my car for starting ability, however be advised as stated here it's not good continue using it.

 

Also I didn't have ATF so I used Marvels Mystery Oil.

Marvel Mystery Oil is,IMHO better than ATF. It's also a lot more expensive,and I don't always have it on hand when I need it. I live in a rural area,and it's a 40 mile round trip to the nearest parts store,so I use what I have on hand at the time.

IMHO,the primary advantage to ATF is that it is thin and on a engine that has been stuck,it lubricates the rings,piston grooves,and cylinder walls quicker than motor oil. Once you spin the engine enough to build up oil pressure,dry rings and cylinder walls are no longer a problem.

Mostly what I use to unstick stuck engines is either carb cleaner or brake fluid. Sometimes the brake fluid after the carb cleaner. The carb cleaner cleans away corrosion on the aluminum piston tops and ring grooves,making it easier for the brake fluid or thin oil to penetrate. My totally unscientific opinion is that brake fluid will "weep" and  penetrate tight spaces better than anything I have found,and when unsticking engines it's breaking the "seal" that is the important first step.

You should drain the crankcase and fill it with fresh oil and a new filter BEFORE spinning it over with the starter to build up oil pressure if you use carb cleaner or brake fluid,though. Probably best regardless of what you use to unstick an engine,but I personally consider it to be essential if you use brake fluid or carb cleaner.

IMHO,it's even best to drop the base pan and clean it out before refilling it with oil,installing a new oil filter, and spinning the engine to build up oil pressure. Why pump all the old crud from time and condensation back through your engine?

If the engine is still in the car and removing the pan would be a major PITA,fill it with the cheapest and lightest oil you can find to spin up oil pressure,and then drain the oil and replace the filter again,and refill it with good oil and a new filter before trying to start it. Run the engine enough to warm it up,and then change the  oil and filter again if the engine seems to be free of problems.

Edited March 8, 2017 by knuckleharley