Valdosta, GA haha come on down
I’ve been fighting this for about 3 months now.
No start on rebuilt 360LA
- Thread starter jtn2655
- Start date
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I’ve been fighting this for about 3 months now.
dartfreak75
Restore it, Dont part it!
You really need to get a points distributor and get that thing broke in. The endless cranking is not good on that cam assuming its a flat tappet. Have you checked to make sure your getting fire on all 8 wires? Still sound like your 180 out to me if the firing order is correct.
Would a new distributor make a difference? All 8 wires are sparking, 100% not 180 out. Made absolutely sure it was correct.
dartfreak75
Restore it, Dont part it!
The only thing that would make it backfire out the carb is its firing with the intake valve open. So either the timing is way off or your valves are stuck open. If the msd is messing up the timing then a points dissy would solve it because you can just hot wire it and run the dissy and coil straight off the battery no msd box! Then you know your timing is straight off the dissy no msd in the equation.
MOPAROFFICIAL
Oogliboogli
Too far advanced will pop out the carb...as well a non sealing intake valve or like you said.. firing with an open intake valve.
Some might think to much timing would just make it harder to crank, but not if it has low compression/low cranking . The pistons are decent but it could have 72 cc heads.
180 out is what I think too.
Tdc on the damper should have the rotor at no.6.
Let's see if it shows compression, compression test.
Professor Fate
Push the button, Max...
Umm... if that pic is your current setup, you're 180* off.
Your rotor is pointed at #6.
MOPAROFFICIAL
Oogliboogli
One technically can be anywhere on the cap... as long as its timed to 1.
Yours, if pointing toward #1 wire, as in ..if you have no.1 where no.6 would be...is 180 out.
Can you just arrange the wires on the cap like stock... no.1 front right on cap n so on... it would make it easier to show that you are 180 off!
how so? Because I followed the directions given by everyone on setting it so far, and even if I am, I have tried both ways and it still doesn’t work.
MOPAROFFICIAL
Oogliboogli
Yeah it might take some cleaning of the plugs after trying so many time 180 off.
People need to understand that its NOT THE ROTOR YOU WANT POINTING AT THE FRONT DRIVERS SIDE INTAKE BOLT... ITS THE SLOT ORIENTATION THEYRE TALKING ABOUT. POINT THE DRIVE SLOT AT FRONT DRIVER INTAKE BOLT....SO IT CAN BE 1 OR 6 AND THATS IT...AND THAT MEANS 'ON OR 180 OUT' POINTING AT ONE.. IF IT WERE ONE... IT WOULD HAVE ALREADY FIRED AT TDC AND BE ONTO ANOTHER CYLINDER... UNDERSTAND THAT.
Professor Fate
Push the button, Max...
Image stolen from WWW.
Remove distributor, rotate the rotor 180* so it's pointing at #1 terminal. You have it pointing at #6.
Professor Fate
Push the button, Max...
Once you get the timing issue corrected, if the issue persists:
Compression check, as previously stated. With those rockers, your valve lash could be off or you may not have the correct pushrod length- could be holding the valves open a skosh. No idea what your build is, what length you're running, what block decking/head surfacing may have been done. Lots of variables.
Cam timing. As previously stated.
Compression check, as previously stated. With those rockers, your valve lash could be off or you may not have the correct pushrod length- could be holding the valves open a skosh. No idea what your build is, what length you're running, what block decking/head surfacing may have been done. Lots of variables.
Cam timing. As previously stated.
furrystump
Well-Known Member
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Polarity on distributor leads reversed? With change the timing a bunch!
67Dart273
Well-Known Member
If you look at the cap it appears "he might" have it wired correctly for were the rotor is pointing. IE no1 at the rear??
67Dart273
Well-Known Member
Let's go through this again.........
I would do a leak down compression test and RE check valve lash ABSOLUTELY FOR CERTAIN
What is called "EOIC" works well. This positions valves so that they are on the back circle of the cam. It stands for "Exhaust Opening, Intake Closing" and here is how you use it:
Bump engine until an exhaust valve STARTS TO OPEN some. Then check/ adjust the intake on that cylinder
To check the exhaust, bump engine until an intak opens, goes up over open "max" and is starting to and almost closed. Check that exhaust valve. If this is hydraulic, you should be able to easily spin pushrods. If solids, set valve lash.
TIMING
1...Establish no1 compression as I previously posted. FOR SURE
2...Bring marks on up to NOT to TDC but rather where it is you want initial timing, IE say, 15 BTC
3....IT REALLY DOES NOT MATTER where the rotor points. Sit the dist in, and if possible put the dist in so rotor points to the "factory correct" tower. THIS IS NOT IMPORTANT
3...AND THIS IS IMPORTANT. The ROTOR does NOT determin "the firing point." The TRIGGER position is what does this. There are several ways to do this
A....If this was a points dist, rotate retard, hook indicator lamp to points, slowly rotate advanced (CCW) until points open, snug down dist
B....If this was a Mopar magnetic, you can get reasonably close by simply centering the reluctor in the pickup coil core
C....All other electronic dist.........use your head. If the trigger point/ wheel is visible, than adjust dist so it seems to be triggered
4....Position cap/ look/ remove/ position/ look/ remove carefully to determine WHICH TOWER the rotor IS COMING TO WHILE GOING CLOCKWISE. In other words now that the trigger point is set, you want the rotor just approaching but certainly not "past" a tower in quiestion. THIS TOWER WILL BE your no1 wire
5...Wire up the cap
6...If possible check timing "on the starter" with a light. If you were using MSD CDI (multispark/ 6 etc) DO NOT USE a newer "dial up" light. Us an old conventional light. You want plenty of advance with a cammed up engine perhaps 15 BTC
ALSO IMPORTANT
Since you are having problems, I would "dewire" the igntiion from the harness. Hook the ignition to the coil and hook power to the system with a jumper wire. This will eliminate the possiblility that the igntiion switch/ harness is somehow dropping power
BEFORE ATTEMPTING START
I would pull all plugs and inspect for oil/ fuel fouling. Be wary of gas washing down the cylinders. If plugs are wet, clean with acetone, thinner, or even spray "parts cleaner" and blow them dry.
While you are at it be CERTAIN the fuel is fresh. If this has been sitting around a year, I'd drain the tank and get fresh in there, or else "rig" a small external tank temporarily. I've even gone so far (at times) of "riggin" a gravity feed tank hung from above. Boating equipment can be handy for this.
I would do a leak down compression test and RE check valve lash ABSOLUTELY FOR CERTAIN
What is called "EOIC" works well. This positions valves so that they are on the back circle of the cam. It stands for "Exhaust Opening, Intake Closing" and here is how you use it:
Bump engine until an exhaust valve STARTS TO OPEN some. Then check/ adjust the intake on that cylinder
To check the exhaust, bump engine until an intak opens, goes up over open "max" and is starting to and almost closed. Check that exhaust valve. If this is hydraulic, you should be able to easily spin pushrods. If solids, set valve lash.
TIMING
1...Establish no1 compression as I previously posted. FOR SURE
2...Bring marks on up to NOT to TDC but rather where it is you want initial timing, IE say, 15 BTC
3....IT REALLY DOES NOT MATTER where the rotor points. Sit the dist in, and if possible put the dist in so rotor points to the "factory correct" tower. THIS IS NOT IMPORTANT
3...AND THIS IS IMPORTANT. The ROTOR does NOT determin "the firing point." The TRIGGER position is what does this. There are several ways to do this
A....If this was a points dist, rotate retard, hook indicator lamp to points, slowly rotate advanced (CCW) until points open, snug down dist
B....If this was a Mopar magnetic, you can get reasonably close by simply centering the reluctor in the pickup coil core
C....All other electronic dist.........use your head. If the trigger point/ wheel is visible, than adjust dist so it seems to be triggered
4....Position cap/ look/ remove/ position/ look/ remove carefully to determine WHICH TOWER the rotor IS COMING TO WHILE GOING CLOCKWISE. In other words now that the trigger point is set, you want the rotor just approaching but certainly not "past" a tower in quiestion. THIS TOWER WILL BE your no1 wire
5...Wire up the cap
6...If possible check timing "on the starter" with a light. If you were using MSD CDI (multispark/ 6 etc) DO NOT USE a newer "dial up" light. Us an old conventional light. You want plenty of advance with a cammed up engine perhaps 15 BTC
ALSO IMPORTANT
Since you are having problems, I would "dewire" the igntiion from the harness. Hook the ignition to the coil and hook power to the system with a jumper wire. This will eliminate the possiblility that the igntiion switch/ harness is somehow dropping power
BEFORE ATTEMPTING START
I would pull all plugs and inspect for oil/ fuel fouling. Be wary of gas washing down the cylinders. If plugs are wet, clean with acetone, thinner, or even spray "parts cleaner" and blow them dry.
While you are at it be CERTAIN the fuel is fresh. If this has been sitting around a year, I'd drain the tank and get fresh in there, or else "rig" a small external tank temporarily. I've even gone so far (at times) of "riggin" a gravity feed tank hung from above. Boating equipment can be handy for this.
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Could you confirm what you have for a distributor cap. Just incase it's not one of those "correct-a-cap" things with internal routing for left bank/ right bank set up.
67Dart273
Well-Known Member
HOLY DISTRIBUTOR CAP batboy!!
I've never heard of these you have a link, etc?
EDIT (Back from search) Looks to me like any of these are side exit "crab" style caps, "correct a cap", "crossfire", "vortec", or "hei corrected" to name a few. Does not look to me like this could be a possibility??
Moroso
MSD vortec
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Having worked all day, trying every suggested fix. It is still not working. Continuing to backfire through the carb. We have changed carbs, distributors, wiring, troubleshot the msd box, checked all 8 spark wires for spark, coil wire has spark, moved plug wire positions, rotated 180 then back 180 multiple times. Set initial timing, adjusted valves, you name it, we spent 8 hours doing it. Thanks for all your help fellas, but I am out of ideas.
67Dart273
Well-Known Member
You are not helping yourself here by not being specific. Please DETAIL how EXACTLY you set up the timing. By the way have you CHECKED THE TIMING MARKS themselves for accuracy with a piston stop?
What I think I'd do at this point:
1....Use a piston stop to verify timing mark accuracy.
2....Look up cam specs, and figure some redneck way of monitoring valve lift, and by temporarily marking the balancer (masking tape, etc) estimate valve timing to see if it is correct
3....Carefully rotate the engine through an entire 4 stroke cycle of no1 cylinder. watch for compression with a gauge or your finger, watch for intake vacuum on down stroke, and watch the valves This will help confirm valve timing AND whether you somehow got a reverse ground cam
If all the above checks out, I'll say it again
JUST HOW exactly, step by step did/ are you setting timing?
WHAT have you done EXACTLY to determine that you do not have a valve(s) hung open that is allowing backfire?
67Dart273
Well-Known Member
This is a two-way street. You say you have put a lot of time into this, but there are some pretty smart guys on this board, WHO PUT IN THEIR TIME with no expectation of payment, or even an occasional thank you. You owe it to the rest of the guys here to answer questions exactly, and not be flippant and "I've checked that a million times."
MAYBE you have checked it a million times INCORRECTLY
And by the way...........we've all made mistakes.
I once installed a great big unknown (used) solid cam in a 440.....and somehow missed setting one valve TWICE through the procedure..........AND dropped a plug that hit a header ...........and didn't notice the electrode became "pounded" shut. I spent over an hour or more back, around 1972, fighting a poor sounding engine, missing, and popping, that was "all me"
MAYBE you have checked it a million times INCORRECTLY
And by the way...........we've all made mistakes.
I once installed a great big unknown (used) solid cam in a 440.....and somehow missed setting one valve TWICE through the procedure..........AND dropped a plug that hit a header ...........and didn't notice the electrode became "pounded" shut. I spent over an hour or more back, around 1972, fighting a poor sounding engine, missing, and popping, that was "all me"
jay27
Well-Known Member
I am not trying to undermine you here , just looking at your dist cap and the plug wire orientation , your firing order may be the issue unless I'm seeing things wrong.
Backfiring while cranking can be several issues but most engines will still fire if timed correctly even with mechanical issues , best of luck to you.
Backfiring while cranking can be several issues but most engines will still fire if timed correctly even with mechanical issues , best of luck to you.
I don't see anyone asking how you set your cam timimg.
If you set your cam gears dot to dot, you have it set to fire on #6 at TDC on compression.
Roll the engine over one revolution (360*). Now the upper cam gear dot is at 12:00 o'clock, and the lower crankshaft gear should up at 12:00 o'clock too.
This is where you want to drop the distributor in to fire on #1 cylinder that is up on compression stroke. Usually pointing to the front driver's side, intake manifold mount bolt.
Take a straight edge across the upper cam gear to the top of the crank gear and make sure they are in proper alignment.
Firing up on #1 cylinder on compression stroke. Reposition wires on the distributor cap to correspond to firing on #1 and work around the cap with the mopar firing order going Clockwise looking down at it.
Turn the key and it starts right up. Amazing!
☆☆☆☆☆
If you set your cam gears dot to dot, you have it set to fire on #6 at TDC on compression.
Roll the engine over one revolution (360*). Now the upper cam gear dot is at 12:00 o'clock, and the lower crankshaft gear should up at 12:00 o'clock too.
This is where you want to drop the distributor in to fire on #1 cylinder that is up on compression stroke. Usually pointing to the front driver's side, intake manifold mount bolt.
Take a straight edge across the upper cam gear to the top of the crank gear and make sure they are in proper alignment.
Firing up on #1 cylinder on compression stroke. Reposition wires on the distributor cap to correspond to firing on #1 and work around the cap with the mopar firing order going Clockwise looking down at it.
Turn the key and it starts right up. Amazing!
☆☆☆☆☆
Also you have not stated if you have solid lifters or hydraulic lifters. We see you have adjustable roller rockers.
If you have hydraulic lifters and your oiling system pumped up and primed. On compression per cylinder set intake and exhaust lash to 0 lash (Zero lash) then one half additional turn to preload the hydraulic lifters.
On solid lifters set intake and exhaust to .018 ths valve lash up on compression stroke per cylinder.
Having the valve lash set too tight will keep the valves open and will cause backfiring upon ignition.
If you have hydraulic lifters and your oiling system pumped up and primed. On compression per cylinder set intake and exhaust lash to 0 lash (Zero lash) then one half additional turn to preload the hydraulic lifters.
On solid lifters set intake and exhaust to .018 ths valve lash up on compression stroke per cylinder.
Having the valve lash set too tight will keep the valves open and will cause backfiring upon ignition.
From what the pics show, here are my observations.
1. The cap appears to be wired for #1 to coincide with the rotor position in the distributor as pictured.
2. The timing mark is about 9-10 degrees after TDC. Is it #6 or #1 ATDC?
3. The intake valve is open at that point. Should it be?
4. The pushrods are way too short, which could cut off oil supply to the adjuster cup, and it kills the rocker ratio.
5. The rocker geometry is poor. The excessive sweep across the valve tip is visually noticeable on the open intake valve vs, the closed exhaust valve.
What you need to do.
1. Verify #1 TDC. Watch the valves on #1 cylinder and turn the engine over until the exhaust closes and the intake starts to open. That is overlap, not TDC compression/firing. Continue turning the engine until the intake valve closes, and the timing mark is roughly 15-20 degrees before TDC. If the mark is already past TDC when the intake valve closes, as I suspect, your cam timing is wrong. Pull the front cover and fix it.
2. Check rotor position. Does it still point to #1? If no, remove distributor and turn, or rewire cap to match #1 wire to rotor position. If yes, or after correcting, remove the rotor and with the timing mark still at 15-20 degrees before #1 TDC, turn the distributor until the reluctor tooth aligns with the pickup tooth. Reinstall rotor and verify alignment with #1 plug wire. If the cam timing isn't off, it should fire immediately.
3. If the cam timing needs fixing, take the time to degree it properly. Regardless whether it needs fixing or not, you should pull the intake, and re-lube all the lifter bottoms. As much cranking as has been done, there isn't going to be any lube left for a successful break in of the cam.
4. Call me to get the rocker geometry corrected. You need longer pushrods anyway, so correcting the geometry first means only buying pushrods once, not twice.
5. The rocker adjusters should only be 1 to 1-1/2 turns out from seated to provide a good supply of oil to the cup and pushrod tip.
Overall, it looks like a pretty decent combination. It just needs some details addressed to be successful.
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