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346 flat head no start?

Started by cadillac60, July 04, 2013, 06:11:45 PM

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cadillac60

I am having trouble starting the engine, there is good spark, gas flow is good new plugs, new points new dist cap. there is 0 suction thru the carb. The car was driven into the garage & was running ok., left for a month & since then will not start. We have tried oil down the plug holes with the thought that we could have lost compression due to oil draining away from  the pistons.  Any thoughts on this problem would be appreciated.

B. Watson
Bruce Watson

n2caddies

Hi Bruce
I think all of us have been through this at one time or another. I just started a 390 that has been sitting in a horse pasture dice 91. Check your plugs to make sure they are not fouled from the oil. Double check the plug wires are connected to the correct ones. Sometimes changing the cap they can get mixed up. Check the point gap on the new points If you have verified voltage to the coil with the key on with the help of a friend you can try turning it over and trickle a bit a gas into the carb. Be prepared for a possible back fire. But if everything is working it should fire up even if the carb is not working right. The accelerator pump can dry out and  could be not working keeping it from priming itself. If it does not fire verify that the spark is at the plugs. If not you will need to check the coil and possibly the condenser.   Good luck
Randy
Randy George CLC# 26143
1959 Series 62 Convertible
1960 Series 62 Convertible
1964 Deville Convertible
2015 SRX

Richardonly

Did you write that there was 0 suction at the carb???  To me that MAY indicate a worn/broken timing chain or gear.
1948 Cadillac Fleetwood 60S
1995 Lincoln Towncar, Signature Series
1995 Jaguar XJ6
2001 Chrysler Sebring Convertible
1986 Yamaha 700 Maxim X motorcycle

cadillac60

Thank you all for your input into the problem .   I think the next step would be to pull the heads, my suspicion is that I have a valve or valves stuck open? That my be the reason for the 0 suction thru the carb? Does that make any sense?

B. Watson
Bruce Watson

harry s

That could well be the problem. I know it happens to me when the cars sit for awhile. I have been lucky enough to have spraying Marvel Mystery Oil into the spark plug holes (aiming  upward at the valves) to get them started and after running for a few seconds they are OK. I attribute the problem to ethnol cleaning the lubricating properties of the gas these engines were designed for.   Harry
Harry Scott 4195
1941 6733
1948 6267X
2011 DTS Platinum

kkarrer

I'd shoot a little marvel mystery oil or auto trans fluid in each spark plug hole and get another condenser (they're famous for failing).Put the plugs back in after wetting them with a bit of gas. Next put a little gas down the carb and give her a shot at the starter.  If you disturbed the distributor you may need to loosen the hold down bolt and rotate it as you turn over the engine.  I've had very good luck switching to Pertronix.  That way there's no doubt about points dwell or condenser or coil issues and the coil can be made to look just like the original.  You can do that with 6 or 12 volt system.
Ken Karrer
1941 6227D coupe
1955 62 convertible

LeRoy DeVol

Richard may be right!! Years ago i had the same problem with my 47 Cad. & the problem was on start up the timing chain jumped about 3 teeth and even though i had spark & gas the engine would not run. The way to check this is set the timing mark on the front vibration damper at zero & check the rotor in the dist & see if it lines up with the # 1 cylinder wire. Bear in mind that the engine may be on the exhaust stroke & you may need to turn it over 180 degrees to get the right results. If the valves are in the wrong position you will not get any air flow to the engine. It is quite common for the chain to jump in the starter mode.

Lee DeVol 

cadillac60

Lee,

Thank you for your input, I followed what you have suggested & so far still no start. Is there a way to check that No 1 is on the compression stroke or exhaust stroke, which might indicate the distributor is out 180 deg.?

Bruce Watson
Bruce Watson

LeRoy DeVol

#8
Bruce; With a jumped timing chain you will still get spark & fuel as the camshaft is still turning. The main thing is to make sure that the rotor lines up with the #1 cylinder wire which should be the first cylinder on the left bank with the timing mark on the
vibration damper lined up. The car not running for a month is not long enough for the valves or rings to seize up. If by turning the motor over twice to line up with #1 wire you don't get the right results then the timing chain is your problem. Replacing the chain is not a big job on that engine. First you remove the radiator, the fan, the gen., the vibration damper & pulley, remove 4 bolts that secure the the chain housing to the oil pan, & remove the fuel pump. After this you look to see if the marks on the crank shaft gear & the camshaft gear line up with each other. The most difficult part of the job is you will need a puller to remove the vibration damper.

Lee DeVol   

 

cadillac60

Lee,  thanks again for your interest on my no start problem.  No 1 cylinder lines up with the timing mark (A/G) on the damper. The rotor lines up with No 1 wire in the distributor. Would this exclude the timing chain as the problem?

Regards

Bruce Watson
Bruce Watson

Brett Baird

On a no start, after determining that there is fuel and spark, the next step is a compression test.
B Baird
17764
'41 Fleetwood 60 S  http://bit.ly/1jwgEWm
'59 Sedan DeVille 6339 "Flat-top"  http://bit.ly/1jwgUF1

cadillac60

Brett,  thanks for your input, I will check the compression, it certainly doesn't sound like a timing chain problem when # 1 lines up with A/G on the damper as well as the rotor lining up with No 1 plug wire ??

Regards

Bruce Watson
Bruce Watson

cadillac60

Thank all of you for your input on this no start problem, A compression test shows the left bank consistent at 50PSI (no great) the right bank has various compression reading from 20 to 30. Even though there is some compression ,would this not be enough for the engine to fire up? The lack of suction thru the carb & the no start problem  could this be a valve or valves stuck open?

Bruce Watson
Bruce Watson

Rod Dahlgren #19496

ZERO VACUUM at carb-----------------   A CLUE? Yes----- Next is to confirm that with a compression test...  But back to "ZERO" vacuum-- So you are saying that if you put your hand completely over the top of the carb and crank the engine, there is NO suction against your hand? OK---- If NONE at all..... ZERO---- But you have spark-- and the rotor point to #1 with timing mark right on....  THEN NEXT is to confirm the situation with a compression test.. ALL plugs OUT-- then test each cylinder.. crank-- boom boom boom three strokes-- WHAT did the gauge do on the FIRST stroke? And what did it do on each stroke after that?

OK-- Now you have a base-line to work with.. NOW we can begin a checklist:

Hmm-- DROVE it in the garage-- sat for a month--- Just how GOOD was it running during that drive into the garage?   BIG question, how DRY is the garage? Does the wife do her laundry in the garage and use a clothes drier that is, maybe not well vented? ---- How OLD is the gas in the tank? SMELL THE DANG GAS, is it rancid? KEEP FIRMLY in mind that this bad gas they are making has some nasty stuff in it that will STICK YOUR VALVE STEMS in the GUIDES............
Did You Drive Your Cadillac Today?

gene harl

some thing is not right..and with compression like that.....the first thing  I would do is pull the timing cover.... Gene.....

Steve Passmore

You cant drive a car perfectly OK, park up and then loose all compression for mechanical reasons.  You might get a stuck valve but unlikely on a worn engine and not on all the valves.

It still sounds to me that during attempts at starting the engine it has been completely flooded and washed all oil out the pistons. I have seen this several times and believe me there is no vacuum at the carb when this happens.  Perhaps you didn't squirt enough oil in the cylinders Bruce?
Remove all the plugs, make sure the manifold is dry and not filled with fuel. Give each bore 4 or 5 good pumps from an oil can, spin the engine over several times for about 5 seconds so's not to overload the starter, but leave the throttle alone, then check your compression and try to start it.
If it does start it will smoke like the devil for a while.
Steve

Present
1937 60 convertible coupe
1941 62 convertible coupe
1941 62 coupe

Previous
1936 70 Sport coupe
1937 85 series V12 sedan
1938 60 coupe
1938 50 coupe
1939 60S
1940 62 coupe
1941 62 convertible coupe x2
1941 61 coupe
1941 61 sedan x2
1941 62 sedan x2
1947 62 sedan
1959 62 coupe

cadillac60

Gene, I am just amazed at the response. When you mention the first thing you would do is pull the cover from the timing chain.  Even with the No 1 plug on the A/G mark as well as the rotor on No 1 is there still a chance that the chain has skipped a notch or two?

Br4uce Watson
Bruce Watson

Steve Passmore

  Even with the No 1 plug on the A/G mark as well as the rotor on No 1 is there still a chance that the chain has skipped a notch or two
Br4uce Watson
[/quote]

I'm pretty sure its not at all possible for the timing chain to jump its teeth.   It would have to be so worn out it was slapping the inside of the cover for thousands of miles. I have rebuilt a number of these engines and I have never seen a chain that could jump the teeth even when worn so much they were rattling the cover.
Remember Bruce, you have two TDC positions for number one piston, you must make sure your on the compression stoke of number 1 when rotor is pointing to number 1,   but if you have not touched the distributor since the engine was last running there can be nothing wrong with the timing, so leave the cover alone.
Steve

Present
1937 60 convertible coupe
1941 62 convertible coupe
1941 62 coupe

Previous
1936 70 Sport coupe
1937 85 series V12 sedan
1938 60 coupe
1938 50 coupe
1939 60S
1940 62 coupe
1941 62 convertible coupe x2
1941 61 coupe
1941 61 sedan x2
1941 62 sedan x2
1947 62 sedan
1959 62 coupe

cadillac60

Thanks Steve for your assistance.  I have recognized that you have to be on the compression stroke, and the rotor to be on  No 1 .
Am I on the correct path thinking that it may be a valve  or valves stuck open to have the complete loss of suction thru the carb?  As far as the timing chain, there never has been any noise or rattling even when I last drove the car into its parking spot.  The car has always ran very smoothly although I have recognized it does not have the power that my 38 has.

Bruce W

Bruce Watson

47bigcadillac

#19
I have had constant issues with gasoline sticking to the valves and making the engine hard to start and run very rough on my 1947  246 engine... and that after sitting only a week or so, hardly "old gas".

My engine was never rebuilt, I suspect that the valve springs are worn to the point that a bit of gum from gas is enough to cause these issues on the valves.

Never had such problems with my nicely rebuilt 1932  355b engine.

The solution: switch to high-octane gas. Premium evaporates a lot faster and cleaner.
After switching to premium, I never experience those valves issues anymore, even after sitting for 3 months.
R. Brandys

1932 355B  5 pass Coupe,  Fleetwood          
1935 LaSalle Coupe  5077
1947 Club Coupe      6207