Want my engine to start for Christmas

-
SgtLee511

SgtLee511

Well-Known Member
Joined
Aug 28, 2011
Messages
220
Reaction score
10
Location
Atlanta,Texas
Gentleman and Ladies, heres my issue new cam, installed, new carb 340 engine, Ive got fire at the plugs, but im not getting any backfire thru carb,no signs its firing,yet i can see it fire, at plug,i had noticed some burns on the top of the cap at the coil wire so i replaced cap, rotor and coil wire, i also checked the wires by rotating them each forward on the cap and back one having repositioned the them 3 times , moved it 180 degrees, same story. No sign of firing off a cylinder
 
SgtLee511 said:
Gentleman and Ladies, heres my issue new cam, installed, new carb 340 engine, Ive got fire at the plugs, but im not getting any backfire thru carb,no signs its firing,yet i can see it fire, at plug,i had noticed some burns on the top of the cap at the coil wire so i replaced cap, rotor and coil wire, i also checked the wires by rotating them each forward on the cap and back one having repositioned the them 3 times , moved it 180 degrees, same story. No sign of firing off a cylinder
Click to expand...

I would recommend starting by verifying that no.1 cylinder is at tdc, both valves closed, rotor positioned on no.1 cylinder. It's fairly typical to be 180 deg. off. 65'
 
Do you have gas? Are you sure of correct cam installation?

Start from scratch, put engine to TDC cylinder #1 follow firing order CW around cap, try again.
 
Yep gas and air lol, ill try again tomorrowl its just stangely inactive , had this car 40 years, i know it well, but something's off
 
Are you pulling a plug, hooking it up to the plug wire, and watching the spark across the plug gap? If so, that is in no way, shape, or form a valid test. It takes many times more spark voltage to jump that small plug gap in a compressed fuel air mixture than in open air. So you can observe a weak spark across a plug gap in open air that will never fire a cylinder in actual operation.

So if this is the test you are doing, then you don't yet know anything about if you have a good spark or not.
 
Make sure you have no.1 piston at tdc, point rotor at no. 6 terminal, splash a lil fuel down the carb and crank it over, advancing the distributor as it cranks till it fights and fires....rev and set idle soeed to 2400...then check timing and back it down if if necessary to 34 total.
 
MOPAROFFICIAL said:
Make sure you have no.1 piston at tdc, point rotor at no. 6 terminal, splash a lil fuel down the carb and crank it over, advancing the distributor as it cranks till it fights and fires....rev and set idle soeed to 2400...then check timing and back it down if if necessary to 34 total.
Click to expand...
Will do0
 
nm9stheham said:
Are you pulling a plug, hooking it up to the plug wire, and watching the spark across the plug gap? If so, that is in no way, shape, or form a valid test. It takes many times more spark voltage to jump that small plug gap in a compressed fuel air mixture than in open air. So you can observe a weak spark across a plug gap in open air that will never fire a cylinder in actual operation.

So if this is the test you are doing, then you don't yet know anything about if you have a good spark or not.
Click to expand...
Thats where Im coming from, It was running before, i tore it down but i discovered strange burns between coil wire and cap, the spark is there at the plug but, i think its not as bright as it used to be, and i was grounding the plug to look at the spark,like you u mentioned
 
MOPAROFFICIAL said:
Make sure you have no.1 piston at tdc, point rotor at no. 6 terminal, splash a lil fuel down the carb and crank it over, advancing the distributor as it cranks till it fights and fires....rev and set idle soeed to 2400...then check timing and back it down if if necessary to 34 total.
Click to expand...
why would he position rotor on 6 @ #1 tdc should be #1 terminal.
 
Oh okay , well...then at tdc, point the the rotor at terminal 1 and have fun.

When I do that, it backfires...lol ...maybe you have better luck:rofl:
 
MOPAROFFICIAL said:
Oh okay , well...then at tdc, point the the rotor at terminal 1 and have fun.

When I do that, it backfires...lol ...maybe you have better luck:rofl:
Click to expand...
well then, lmao, explain yourself. lol tdc compression stroke #1 or #6
 
SgtLee511 said:
Gentleman and Ladies, heres my issue new cam, installed, new carb 340 engine, Ive got fire at the plugs, but im not getting any backfire thru carb,no signs its firing,yet i can see it fire, at plug,i had noticed some burns on the top of the cap at the coil wire so i replaced cap, rotor and coil wire, i also checked the wires by rotating them each forward on the cap and back one having repositioned the them 3 times , moved it 180 degrees, same story. No sign of firing off a cylinder
Click to expand...

I wish I could be there for 1/2 hour I could teach you stuff that would save you DAYS

1...YOU DO NOT screw with timing, "try this or that". You DETERMINE where you are, and set it and IT WILL RUN.......unless the timing chain is wrong, or you have a reverse grind cam, or some other unforseen..................stuff

2....START WITH a piston stop to make certain the timing marks are actually correct. I made this one in about 1974 you can buy them

attachment.jpg


Remove the battery ground for safety, remove no 1 plug, and make sure the piston is "down a ways." Screw the stop device in. Carefully wrench the engine around until it stops on the device. Make a temporary mark under the 0 mark on the tab onto the damper. Rotate the engine around backwards until it stops again, make a second mark under TDC.

Now you will have two temporary marks and true TDC will be halfway in between. If the original mark is correct, that is where it will be
===========================================
SETTING TIMING.

Establish no1 ready to fire, IE "compression stroke." There are only TWO WAYS to do this

A.......Remove no1 plug, stick your finger in, bump the starter until you feel compression. Now wrench the engine around "watching for" the timing marks coming up. DO NOT SET the marks on TDC!!! Set them instead "where you want" the timing to be, AKA 10-15 BTC or so on a stocker, maybe 15-20 OR MORE BTC with a "hotter" cam

B........Second way is if one or both valve covers is off. Rotate engine to TDC on marks, look at no1 and no6 valves and SEE WHICH SET is closed. Be careful, other two will be "close to equally open." Move the engine a small amount to see which set moves. The closed pair will not. If no1 is closed, then no1 is "ready."

NOW put the dist in with rotor pointing to where you want no1 plug wire. If the distributor tang is different from "the book" don't sweat it, it will run WHEREVER it points as long as you "make that" the no1 tower.

Next rotate the dist CW (small block) to RETARD the dist, and then rotate slowly back CCW (advanced) until

the points just open if you have points

or the reluctor is in the center of the pickup coil

Double check the rotor is at the tower where no1 plug wire is inserted.

NOW PUT A LITTLE FUEL IN THERE AND START IT UP
 
Thank You 67Dart, I agree Ill go days screwing with the dam thing, already frustrated. I will run thru your suggestion....as soon as can
 
Post back if you get hung up. If you learn to set a breakerless dist. you can actually get it pretty close. You can slowly advance / retard the thing "slower and slower" with the ignition powered up, to get a "pop" spark out of the coil. Each time you move past the trigger point. You move it towards "advanced" last and try to "note" where it popped. You can get within just a few degrees

ALSO Crackedback (member) has pointed out that you can also get it close, and then check it cranking on the starter.
 
SgtLee511 said:
Thats where Im coming from, It was running before, i tore it down but i discovered strange burns between coil wire and cap, the spark is there at the plug but, i think its not as bright as it used to be, and i was grounding the plug to look at the spark,like you u mentioned
Click to expand...
You're not hearing what I am telling you.....I told you NOT to use the pluig as a test. Here is the reason: If you look at the spark across just the normal tiny plug gap in open air, and it looks weak there, then you WON'T have a working spark in the engine. A 3000-4000 volt spark (which is weak) will jump that plug gap outside of the engine, but it will take 20,000-25,000 volts to jump that same gap when IN the engine. DON'T use the plug out of the engine as a test method.

Form your description it sounds like you have a simple ignition system problem, which was indicated by the damage you already found. Concentrate there. The spark system should be able to jump a 3/8" gap to metal, so set up the end of a spark wire that far from metal and watch fro sparks jumping that large gap it as you crank the engine. Of course, if you had the distributor out, then you will have to reset it properly like has been discussed.
 
nm9stheham said:
You're not hearing what I am telling you.....I told you NOT to use the pluig as a test. Here is the reason: If you look at the spark across just the normal tiny plug gap in open air, and it looks weak there, then you WON'T have a working spark in the engine. A 3000-4000 volt spark (which is weak) will jump that plug gap outside of the engine, but it will take 20,000-25,000 volts to jump that same gap when IN the engine. DON'T use the plug out of the engine as a test method.

Form your description it sounds like you have a simple ignition system problem, which was indicated by the damage you already found. Concentrate there. The spark system should be able to jump a 3/8" gap to metal, so set up the end of a spark wire that far from metal and watch fro sparks jumping that large gap it as you crank the engine. Of course, if you had the distributor out, then you will have to reset it properly like has been discussed.
Click to expand...
GOTCHA
 
67Dart273 said:
I wish I could be there for 1/2 hour I could teach you stuff that would save you DAYS

1...YOU DO NOT screw with timing, "try this or that". You DETERMINE where you are, and set it and IT WILL RUN.......unless the timing chain is wrong, or you have a reverse grind cam, or some other unforseen..................stuff

2....START WITH a piston stop to make certain the timing marks are actually correct. I made this one in about 1974 you can buy them

View attachment 1715122979

Remove the battery ground for safety, remove no 1 plug, and make sure the piston is "down a ways." Screw the stop device in. Carefully wrench the engine around until it stops on the device. Make a temporary mark under the 0 mark on the tab onto the damper. Rotate the engine around backwards until it stops again, make a second mark under TDC.

Now you will have two temporary marks and true TDC will be halfway in between. If the original mark is correct, that is where it will be
===========================================
SETTING TIMING.

Establish no1 ready to fire, IE "compression stroke." There are only TWO WAYS to do this

A.......Remove no1 plug, stick your finger in, bump the starter until you feel compression. Now wrench the engine around "watching for" the timing marks coming up. DO NOT SET the marks on TDC!!! Set them instead "where you want" the timing to be, AKA 10-15 BTC or so on a stocker, maybe 15-20 OR MORE BTC with a "hotter" cam

B........Second way is if one or both valve covers is off. Rotate engine to TDC on marks, look at no1 and no6 valves and SEE WHICH SET is closed. Be careful, other two will be "close to equally open." Move the engine a small amount to see which set moves. The closed pair will not. If no1 is closed, then no1 is "ready."

NOW put the dist in with rotor pointing to where you want no1 plug wire. If the distributor tang is different from "the book" don't sweat it, it will run WHEREVER it points as long as you "make that" the no1 tower.

Next rotate the dist CW (small block) to RETARD the dist, and then rotate slowly back CCW (advanced) until

the points just open if you have points

or the reluctor is in the center of the pickup coil

Double check the rotor is at the tower where no1 plug wire is inserted.

NOW PUT A LITTLE FUEL IN THERE AND START IT UP
Click to expand...
Well right off the top, i have no timing marks showing, so theres is a problem, i have 1 up at top, and the rotor pointed in the direction of #1, I have done a spark test with the plug wire and screwdriver grounding it, getting about 1/4 spark, so Im fubar its has to be timing chain related, ill have to centerline camshaft again
 
Let's back up a moment and check something else. If your #1 cylinder is at the top of the stroke (TDC), then look to see where the mark is on the damper (not on the timing cover but on the damper).

Then look to see if the timing marks on the timing cover are over on the driver's side (near 1:30 on a clock face) or on the passenger's side near 10:00 on a clock face). Let us know.

You might have a pre-1970 timing cover mixed up with 1970-and-later damper, or vice versa.
 
nm9stheham said:
Let's back up a moment and check something else. If your #1 cylinder is at the top of the stroke (TDC), then look to see where the mark is on the damper (not on the timing cover but on the damper)


Then look to see if the timing marks on the timing cover are over on the driver's side (near 1:30 on a clock face) or on the passenger's side near 10:00 on a clock face). Let us know.

You might have a pre-1970 timing cover mixed up with 1970-and-later damper, or vice versa.
Click to expand...
Many years ago, like 30 i had this happen, I had mopar racer friendfix it at his shop, Hes deceased, so I cant ask what he did. The cover actually came off a 70 340, now I couldnt tell you if it was a for sure 70 cover, but it looks like my 72 cover. Here's a pic rotor towards 1, piston at top and as far as I can tell the mark must be at 12 oclock, Its where I cant feel or see right now . I HAVE CLEARLY MARKED WITH WHITE PAINT,NOT THERE.
20171221_201837.jpg
20171221_202018.jpg


20171221_201941.jpg
 
OK the angled 'ledge' by the damper ring where the timing cover's mark should be for a 70-or-later cover looks to be at the right location. (Are the marks covered by thick paint, or is it just the photo? I can't see any of the cast timing marks on that 'ledge'.) I'd be using a mirror to look all around the damper ring and see where that white mark is; that would be useful info.

In your pix of the rockers, are you showing the #1 valves at an equal amount of opening? Both slightly open? I do seem to see the piston top through the hole. Is it at TDC using a piston stop?

If the #1 piston top is truly at the top of the stroke (TDC) with a piston stop, and the damper ring is not at the right spot, then the damper ring has to have slipped. If the ring's mark is at the top, that would make sense; it would be expected to slip backwards (CCW looking from the front of the car).

Now that does not say if the cam timing is good or bad. Mark the damper ring with a temporary mark beside some fixed mark on the cover with the #1 piston exactly at TDC. Then rotate the crank 1 exact rotation so that mark is again aligned to your reference. See if the valves of #1 are open about the same small amount at that point. If not, then make exactly 1 more rotation and see if they are in that condition.

The above is a rough check of cam timing. To be sure, you gotta use the old dial indicator and degree wheel.
 
Thumb in #1 spark hole and bump, youll feel compression come up, then you can stick a drumstick in there and turn crank by hand and youll get it within 5 of TDC by feeling the stick. Look at your rotor, is it at the #1 plug wire (there is no #1 terminal) if not reroute plug wires and make it so. Now look at your balancer timing mark, it should be on driver side numbers OR passenger side where a tab whould have been. If not, your balancer is fubar. That will get you close enough to get something, ie a kickback, a puff, a start, a run. Assuming your ignition is up to par and dots lined up on your cam when the chain went on....and your not wiring the cap like a big block, ie. backwards.

TDC checker is the right tool. You can get by with a drumstick (it wont scratch the cylinder) by wedging it in there, and SLOWLY turning crank until it hits, mark it on ring and cover where you can see it Then back the crank around the other way and run it up again SLOWLY until you feel it hit again. mark cover only. if your stradling the 0 mark equally your good and close, if your stradling nothing visible, rotate the damper line to dead center of 2 marks on case and then remark 0 onto damper with white-out wherever that is on damper next to 0. Took me longer to write that than it takes to do it.
 
Last edited:
Ill work a bit more on Saturday on it, The timing mark is painted white, I marked it clearly on the groove, I could not feel it on the bottom and couldn't see it well where the hose is but, Ill double check sat. I went dot to Dot with this cam on set up, I did not centerline it, as most of the time it is so cloe, my last one was less than a degree off, If I have to tear down I will. Been wondering about the damper, needing to be replaced as well. Hey I really appreciate all the help you guys have been giving me, MERRY CHRISTMAS AS WELL
 
You must log in or register to reply here.
-

Back
Top