Technical 56 Plymouth 230 flat six no start

Hi guys and gals!

Haven't posted for some time now but back in 2009 I started a thread about trying to restart my daughter's 56 Plymouth after replacing the timing chain and gears following an ill-fated compression test attempt. I received many good observations and tips from fellow Hambers, all of which I tried but to no avail. Exasperated, I closed the hood and left it.

Fast forward to the present day and I am trying again to bring it to life. Today, I went over everything again. We have fuel to the engine. We have spark (not the greatest, but spark none-the-less) to all six plugs. Distributor is timed correctly and everything else appears to be correct as far as I can tell. The only thing that now is different is that #4 cylinder has very little compression (this was ascertained by the thumb-over-the-spark-plug-hole method of testing compression). Probably just a stuck valve from sitting. Even with this problem, SOMETHING should be happening! But, still not even the slightest hint of wanting to start. It just turns over and over and over and over.

Any fresh ideas or thoughts would be very greatly appreciated, to say nothing of saving my automotive sanity!

Thanks in advance!

Regards,
Dave

 

Is it really spinning over? Sometimes when a engine is cranking the battery draw reduces the voltage causing a very weak spark. Hook up a battery that is only attached to the ignition. use a different battery to crank it over. Spray WD 40 in the carb when trying to start it. Maybe rig two 12 volt batterys in series for 24 volt and really spin it over. The sticking valves are a problem. Maybe remove the cover on the side of the block behind the intake 7 exhaust manifold and see if you can free up the sticking valves. spray penetrating oil on them pry gently ect? If it where mine I would hook it to the wrecker remove all the spark plugs and place it in gear and drag it down the road & back for about tem miles. It would be warmed up and loose ready to start. I once was pulling a corvair with a automatic trans & generator. Somehow it slipped in gear and started up. the throttle was half open and it was pushing. I stopped and ran back and turned off the key. it was smoking the rear tire big time.

 

Many thanks for your reply Old wolf! No, it isn't really spinning over and it has a freshly recharged batttery too! I will try your battery and WD40 suggestions. The 24 volt start one reminds me of when back in the day we used to initially fire up our oval track racecar engines on dual batteries to bring them to life. I can see #4 cylinder's intake valve moving up and down as it should so it must be the exhaust that's hung up. Will check that too! Your Corvair story was a good one! Thanks again for your help! Regards, Dave.

 

got a Stude I wanted after 38 yrs or so....turned over real good....good spark...no compression...was told to put some Marvel Mystery oil in it - put the plugs back in -and bump it over....did this a few times...and wham-0....she started and smoked like the dickens....but she came back to life.....

 

Try timing the ignition to TDC using the plug in the head over #6 cylinder. And check #1 is on compression when its plug fires.

You can get the spark 180 degrees out quite easily, also the crank pulley can slip on old cars and throw the timing marks off.

 

Thanks for the tip stillrunners - I'll put it on my list of things to try! That's an awesome-looking Stude - I always liked the Lowboys. A buddy had a '63 Grand Turismo back in the day.

 

When something doesn't work after a change has been made, it often is related to that change. One possibility is that you incorrectly timed the cam and crankshaft when replacing the the timing gear/chain set. Not all engines get timed in the same manner.......

All the symptoms you cite, especially low compression, can be attributed to incorrect cam timing. Were I trying to solve your dilemma, I would be tempted to pull the timing cover and verify that the cam timing is in accordance with the factory service manual procedure.

Ray

 

Find a compression tester and see where you are really at. 35 LBs. will blew your finger off but isn't to good for running.

 

Thanks Rusty - Will do!

Many thanks for your input Ray! When we got the car, it came with a well-worn factory shop manual and I checked the gear alignment procedure part when I replaced the gears and double-checked it before I buttoned up the front of the engine. But, hey, if nothing else works you can bet I will triple-check it! Thanks again Ray!

 

Thanks sunbeam! It was a compression tester (or more correctly, my misuse of one!) that started this whole fiasco. Too long of an adaptor on the end which stopped #1 intake valve dead in it's tracks which blew the cast cam gear apart. I will recheck compression minus the offending adapter. Thanks again for your tip!

 

AV8 Dave.....it was a guy on my paper route....that's a 1964 Honda Super Hawk next to it.....ended up with both at the estate auction.....the guy never sold anything.....

 

If the spark is weak plugs removed, there might not be any spark under compression. Try a jumper wire to coil + and see if anything changes. Try with another coil if not. You have fuel to the engine, do you have fresh fuel into the cylinders...

 

A double score! Well done!

 

Thanks Fireball! I did try a jumper with no change and had the coil checked by a local auto electric shop who reported that it was in good shape. The spray nozzle in the carb seems to be putting in a good shot of fuel when I crank the linkage so I assume it's getting to the cylinders OK. Going to try and pick up a new battery today as the one I have, although fully charged, took two days to bring to full charge and is several years old and may not be putting out what is needed to pull the engine out of it's slumber. Thanks again for your help!

 

If you haven't done so I'd get a can of Marvel Mystery oil, pull all six plugs squirt two or three squirts of the Marvel Mystery oil in each cylinder and crank the engine over a few times with the plugs out. Then put the plugs in and see if it's a go. I'm like Stillrunners and a couple of others in that it has sat so long that the rings may be stuck or dried out and it doesn't have enough compression to fire.

These always come down to. Compression, ignition working and timed correctly and fuel/air mix delivery.
Now days with the crappy gas it also comes down to how old is the gas? The gas around here deteriorates pretty quickly and gas that is over six months old is already breaking down. I've seen that in one of my OT rigs that doesn't get driven enough.

 

Best way to see if you are timed correctly is to watch the valves. Forget the thumb over the hole deal or the TDC finder etc. Turn your engine over ( I usually do it by hand) until the number one intake valve closes. Now it is ready to fire the number one hole. This will not make you timed correctly in most cases but it will be close enough to start and run.

Someone mentioned Marvel Mystery Oil in the weak cylinder, this is good advice. Actually any motor oil will work. Sometimes a cylinder wall gets washed down and with no oil on the cylinder wall the rings cannot seal shazaaam no compression.

 

Thanks for your thoughts Mr48chev! Not sure if we have Marvel oil up here in Canada but I will check it out!

 

Many thanks porknbeaner! Will do!

 

Beaner does't the intake valve close at the bottom of the stroke?

 

We actually have afew of those flathead 6 engines. My son bought a 1944 WWII WC the engine was shot and I took a engine out of a 48 2 ton truck. that truck engine was longer and wouldn't fit. So I pulled the engine from a 48 pickup and installed it in the WC. we have another 51 Pk/. couldn't make it run until we pulled the cyl head and freed up the sticky valves. A scrap yard had a Chrysler industrial six engine on a crane. it was equipped with a magneto and I wasn't firing. the sent the mag off and had it rebuilt. they never could get it running. the experts fron the diesel shop failed. I came by and when I was in the office. Some guy I didn't even know told the owner that guy there can fix your crane. So I was willing to look at it. wanted to show off I suppose. any way they had the front pulley sanded and cleaned up like it was chrome it had four marks on it. I took out a cap plug on the bellhousing and lined up the timing marks on the flywheel with the pointer. set the mag to just before the pulse on number one cyl. of course it started and ran perfect. those engines when running good will idle so smooth & slow you can count the fan blades.

 

I guess that depends on the cam shaft all I know is any old mechanic will tell you exactly what I said and it works every time with any 4 stroke piston engine.

 

If you can't get it running come back and I will go back to first principles.

 

Rusty is right. A dodge/ply six is timed off number six not number one! That little pipe plug is to put a wire down and see when the piston is at TDC. I used a dial indicator.

Once it is at TDC with the valves closed line up the rotor with the #six spot in the cap. Turn the distributor untill the points close, I used a light bulb with two alligator clips.

This is the way it is to be done, straight out of the canadian military manual for a M37.

 

One and six are companion cylinders they are at TDC at the same time one compression the other exhaust so the timing mark will at the same place for both cylinders.

 

Are then turning it more to match the timing marks on the damper?

 

Nope that's not how I was taught and when I have one that is unknown and no one can make it start that's what I do.

 

As others have said - get a compression tester, if the compression is under 100psi there is a good possibility it won't run. After you check the compression use a pump style oil can and put a couple of squirts in each cylinder. If the compression jumps up after the oil it tells you either stuck or worn rings (or both) if it doesn't change its a valve problem. If its rings it might have enough compression after the oil was added to start.

You might be interested in reading through this thread: http://www.jalopyjournal.com/forum/threads/322-nailhead-wont-start.604550/ lots of good tips on chasing down weak spark and slow cranking.

Good luck!

 

Your timing is impeccable 3spd as I just did a comp. test (albeit after adding Marvel Mystery oil to each cylinder).
Four engine revolutions per cylinder produced: - #1 - 90 #2 - 78 #3 - 60 #4 - 0 #5 - 88 #6 - 85.
I gave 3 shots of MMO to each cylinder (even attached a small diameter rubber hose to the pump oiler and shoved it in as far as I could to direct the spray to the outside of the piston!) prior to the test followed by a short cranking session.
I strongly suspect that #4's exhaust valve is stuck open but I will have to wait for a good day to jack up the car and remove the right front wheel and inner fender panel so I can access the valve in question.

I also tried almost all of the other suggestions put forward by everyone (my thanks to all!) but still not a twitter from the old girl. Any further thoughts?

 

How old is the "gas" ?

 

Sounds like you're getting on the right track here. But I've also seen them burn an intake valve, as strange as it sounds. Seems to be the result of having the valve lash set just a skosh too tight. If in doubt, don't feel bad about running them a couple thousandths loose.