73Swinger18
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Any luck starting her up?
Rebuilt 318 Refuses to Start
- Thread starter 95dakotadude
- Start date
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73Swinger18
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rustycowll69
Well-Known Member
me thinks we may never get the resolution to this mystery, but we can learn something from this. Degreeing in the cam isn't a luxury, it's a necessity, and it goes a long way to help diagnose should problems arise later on. I like the idea someone had about taking a picture of the timing gears timing marks in the lined up position. It requires very little time, money, or effort and saves tearing back into it, if you start having doubts.
Another lesson learned should be don't introduce a bunch of unknowns on top of an unknown. Use a proven working carb on a new engine. If you want to add a new ignition system, do so after the engine is running, and the cam is broken in.
Document the engine. So you know, later, what was done to the engine, what parts were installed, and how they were installed.
Another lesson learned should be don't introduce a bunch of unknowns on top of an unknown. Use a proven working carb on a new engine. If you want to add a new ignition system, do so after the engine is running, and the cam is broken in.
Document the engine. So you know, later, what was done to the engine, what parts were installed, and how they were installed.
73Swinger18
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I learned that the hard way. When I installed my reworked engine, I installed all new components from the ballast resistor to the fuel pump. Bad idea.
T56MaxTorq
Well-Known Member
Always take a pic before the cover goes on! It's so easy. I screwed up a timing chain install. Put the crank and cam on the advanced keys but lined up a dot for zero and a dot for advanced. Finally got it to run by cranking initial timing 30+ degrees! Sounded like a diesel and had no more power than a riding mower. We all make mistakes but the lesson learned was valuable. Luckily I didn't hit piston to valve.
Some people have had MSD problems with the ignition source and run the 'ign 12V' source to a constant 12V toggle. It might be worth a test. I wonder if your box has timing control too. Is it somehow getting a false signal to retard the timing.
73Swinger18 is right make sure no. 1 piston is tdc on compression stroke not on exhaust stroke then make sure rotor is pointing to the plug wire going to no. one cyl.
95dakotadude
Well-Known Member
It's suspect that the timing chain was installed 180 off. I will be working on it this week and will get back.
As for RustyCowl's comment: I stated before that everything was the same except for new main and rod bearings. All equipment is brand new (600miles old) and proven to be working.
As for RustyCowl's comment: I stated before that everything was the same except for new main and rod bearings. All equipment is brand new (600miles old) and proven to be working.
just because you installed the timing chain with the cam at 6 o'clock and the crank at 12 clock does not mean the chain is 180 out. You are at number 6 firing...not number 1.....If you put the distributor in at that point the distributor is 180 out...pull the distributor and rotate it 180...
If you enlarge this picture you can see the cam sprocket at 6 oclock...you wont be able to see crank sprocket dot...
If you enlarge this picture you can see the cam sprocket at 6 oclock...you wont be able to see crank sprocket dot...
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nm9stheham
Well-Known Member
Make it simple to understand:
- If you install the timing chain sprockets dot-to-dot, make sure the distributor rotor points to plug wire #6.
- If you install the timing chain sprockets with both sprockets at 12 o'clock, make sure the distributor rotor point to plug wire #1.
- Make sure to use a straight edge to align the dots along the vertical centerline of both the crank and cam. Just eyeballing it can lead to being a tooth off.
- If you install the timing chain sprockets dot-to-dot, make sure the distributor rotor points to plug wire #6.
- If you install the timing chain sprockets with both sprockets at 12 o'clock, make sure the distributor rotor point to plug wire #1.
- Make sure to use a straight edge to align the dots along the vertical centerline of both the crank and cam. Just eyeballing it can lead to being a tooth off.
95dakotadude
Well-Known Member
If the valves are opening 180 off, could I just take off the chain, spin the cam 720 degrees and reinstall it? That would put the cam on the next stroke, wouldn't it?
Also, how do I know for sure that I'm on the compression stroke? I can't use the finger blowoff trick because I have the chain off, etc.
Lastly, which way does the engine spin? If I'm at the front of the car looking at the engine, does it spin clockwise?
Also, how do I know for sure that I'm on the compression stroke? I can't use the finger blowoff trick because I have the chain off, etc.
Lastly, which way does the engine spin? If I'm at the front of the car looking at the engine, does it spin clockwise?
nm9stheham
Well-Known Member
Yes CW as you look from the front of the car towards the engine.
Spinning the cam 720 degrees puts it back right where you started. I am not clear what you are intending to do with this tactic.
Do this: If you can, get and use a piston stop into the #1 spark plug hole to find TDC.
1. You insert the stop in the #1 plug hole and thread it in a bit and slooowly rotate the crank CW until it contacts the stop. Put a mark on your damper aligned with the 0 timing mark on the timing cover.
2. The rotate the crank back CCW until it contacts the stop again. Put another mark on your damper aligned with the 0 timing mark.
3. Rotate the crank so you can see both of your marks and measure the distance between them accurately
4. Divide that measured distance in 2, and measure that distance from either of the 2 marks towards the other mark (i.e., find the exact halfway point between the 2 marks), and make a 3rd mark. When that 3rd mark (which is exactly halfway between the first 2 marks) is aligned with the 0 mark on the timing cover, you ARE at true TDC. That 3rd mark is the REAL #1 TDC point on the damper.
If the damper and crank are machined accurately, then the original mark on the damper and your 3rd mark from the above procedure will be exactly the same. If not, then the damper or crank have machining errors, or you have a later damper on an early crank or vice versa. Use your 3rd mark from now on, for cam timing and ignition timing.
With the crank set up at true TDC, now you can install the chain and cam with the crank sprocket dot at 12 o'clock and the cam sprocket dot at 6 o'clock and use a straight edge aligned along the exact centers of the cam and crank to be sure that the dots are centered right on that same edge. IF the cam and sprockets are machined right, then the cam is set up basically right. I say 'basically right' because there can still be small errors that throw the cam timing off a bit. But small errors are not going to cause the engine to never fire off.
With the cam and sprockets set up as above, then align the distributor rotor so it points at the wire for #6, while at the same time, making sure any tooth of the reluctor trigger wheel on the distributor shaft is aligned perfectly with the metal blade in the reluctor. Again, I am assuming you are using the Mopar distributor to trigger your MSD ignition system. Please confirm this. (You are unfairly wasting people's time if you don't answer these questions.)
BTW, did you ever test your spark across a 1/4" to 3/8" air gap like instructed? You won't ever know if the ignition system is working right until you do this. It don't care if it worked before; something may have gotten broken. DO this test once the cam is back in, and let us know.
Spinning the cam 720 degrees puts it back right where you started. I am not clear what you are intending to do with this tactic.
Do this: If you can, get and use a piston stop into the #1 spark plug hole to find TDC.
1. You insert the stop in the #1 plug hole and thread it in a bit and slooowly rotate the crank CW until it contacts the stop. Put a mark on your damper aligned with the 0 timing mark on the timing cover.
2. The rotate the crank back CCW until it contacts the stop again. Put another mark on your damper aligned with the 0 timing mark.
3. Rotate the crank so you can see both of your marks and measure the distance between them accurately
4. Divide that measured distance in 2, and measure that distance from either of the 2 marks towards the other mark (i.e., find the exact halfway point between the 2 marks), and make a 3rd mark. When that 3rd mark (which is exactly halfway between the first 2 marks) is aligned with the 0 mark on the timing cover, you ARE at true TDC. That 3rd mark is the REAL #1 TDC point on the damper.
If the damper and crank are machined accurately, then the original mark on the damper and your 3rd mark from the above procedure will be exactly the same. If not, then the damper or crank have machining errors, or you have a later damper on an early crank or vice versa. Use your 3rd mark from now on, for cam timing and ignition timing.
With the crank set up at true TDC, now you can install the chain and cam with the crank sprocket dot at 12 o'clock and the cam sprocket dot at 6 o'clock and use a straight edge aligned along the exact centers of the cam and crank to be sure that the dots are centered right on that same edge. IF the cam and sprockets are machined right, then the cam is set up basically right. I say 'basically right' because there can still be small errors that throw the cam timing off a bit. But small errors are not going to cause the engine to never fire off.
With the cam and sprockets set up as above, then align the distributor rotor so it points at the wire for #6, while at the same time, making sure any tooth of the reluctor trigger wheel on the distributor shaft is aligned perfectly with the metal blade in the reluctor. Again, I am assuming you are using the Mopar distributor to trigger your MSD ignition system. Please confirm this. (You are unfairly wasting people's time if you don't answer these questions.)
BTW, did you ever test your spark across a 1/4" to 3/8" air gap like instructed? You won't ever know if the ignition system is working right until you do this. It don't care if it worked before; something may have gotten broken. DO this test once the cam is back in, and let us know.
95dakotadude
Well-Known Member
Spark is good with the 1/4 gap trick. I have also stated more than once in this thread that I'm using a full MSD system. Box + Distributor. Apologies for the 720 spin on the camshaft, I was mistaken and meant 360.
I'm currently out there with my dad now and we're figuring it out. What we need to know is: how can we be sure we're on the compression stroke with regards to the valves? I understand the intake and exhaust valves should be closed at TDC. Is this all we have to go off of?
I'm currently out there with my dad now and we're figuring it out. What we need to know is: how can we be sure we're on the compression stroke with regards to the valves? I understand the intake and exhaust valves should be closed at TDC. Is this all we have to go off of?
rustycowll69
Well-Known Member
If you crank the engine over with your finger in no 1 spark plug hole, you'll hardly be able to hold your finger in against the air pressure. There are two piston strokes that push air out, compression and exhaust strokes. So if you hold your finger in for 5 or 6 revolutions, you'll know what I'm talking about. You want the one that pushes the most air out, that is the compression stroke. On the exhaust stroke, the exhaust valve is open, also, and bleeds off most of the air pressure so it pushes less against your finger.
This is impossible. Each time the crank turns 1 turn, the cam is "1/2 turn off." In other words it does not happen. The cam may or may not be out of time, but it's not by 1/2 turn
95dakotadude
Well-Known Member
I'm familiar with the finger down #1 hole, but I can't really bop it over right now because the timing cover and all that stuff is off right now; hence why I asked how to tell by just looking at the valves. We're pretty certain everything is straight now, though.
It's a very odd situation. We just got done resetting the chain at TDC with dots at 6 and 12. I will be attempting to start it sometime today and will update.
It's a very odd situation. We just got done resetting the chain at TDC with dots at 6 and 12. I will be attempting to start it sometime today and will update.
cookietruck
Well-Known Member
was the cam timing off?
also, as stated multiple times in this thread. if the cam dot is at 6 and the crank is at 12, you are firing cylinder #6.
rotate the crank a full turn and you should have both dots at 12 oclock and you are firing #1.
so rotor is pointing to the number one spark plug wire...
95dakotadude
Well-Known Member
I finally got her to fire up. It was a combination of an out of sync timing chain and the mysterious #6 as #1. When I spun the chain so they were both at 12, the rotor wasn't pointed towards the #1 plug, so I put it back to 6 on the cam and 12 on the crank and placed the #6 plug where the rotor was. Fired up instantly. I'm putting it back together now and I just have two further questions:
Is it normal that one side of the timing chain is tighter than the other? The looser side has play like it should, but the other is tighter.
and:
Are all v8s with the same firing order going to have this #6 as #1 when the timing dots are aligned? I've never heard of it before.
I also want to give a HUGE thank you to everybody involved. Hopefully I'll get to enjoy my baby before she needs more work. Couldn't have done it without you. Even the pros I talked to didn't tell me about the 6 trick.
Is it normal that one side of the timing chain is tighter than the other? The looser side has play like it should, but the other is tighter.
and:
Are all v8s with the same firing order going to have this #6 as #1 when the timing dots are aligned? I've never heard of it before.
I also want to give a HUGE thank you to everybody involved. Hopefully I'll get to enjoy my baby before she needs more work. Couldn't have done it without you. Even the pros I talked to didn't tell me about the 6 trick.
nm9stheham
Well-Known Member
Woo-hoo! Good deal.
Yes, the right side (passenger side) of the chain will have some slack in it as you turn the engine over in the (normal) CW direction. However, if that slack is as much as 1/2" total side to side, or more, then either your chain is worn, or the sprockets are worn, or the crank main bearing may be up into the block due to some excess machine work. The chain is the first suspect. Did you put in a new one?
Don't take this '#6 firing when the sprockets are dot-to-dot' as gospel. Distributors are in different positions in the block, cams don't get designed the same, and cylinder numbering varies between some brands, just for a few variables. Ma Mopar could just as well have laid out the cam design so that #1 was firing when the sprockets were at 6 and 12. Or re-keyed the crank snout so that ANY of the 8 cylinders was firing when the sprockets were at 6 and 12....
Yes, the right side (passenger side) of the chain will have some slack in it as you turn the engine over in the (normal) CW direction. However, if that slack is as much as 1/2" total side to side, or more, then either your chain is worn, or the sprockets are worn, or the crank main bearing may be up into the block due to some excess machine work. The chain is the first suspect. Did you put in a new one?
Don't take this '#6 firing when the sprockets are dot-to-dot' as gospel. Distributors are in different positions in the block, cams don't get designed the same, and cylinder numbering varies between some brands, just for a few variables. Ma Mopar could just as well have laid out the cam design so that #1 was firing when the sprockets were at 6 and 12. Or re-keyed the crank snout so that ANY of the 8 cylinders was firing when the sprockets were at 6 and 12....
Nice to hear you got it fired up, way to keep at it. When I degreed one of my first cams I got the #1 and #6 confused as you did when I was measuring pushrods on # 1, took me a few minutes before I realized why my pushrods were way to long.
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Glad ya got it figgered out! Remember crank gear is smaller than cam gear, so when crank turns one full turn the cam (bigger gear) turns 1/2 turn. ( Think pedal bike).
Remember the firing order 18436572....1/2 thru that firing order is #6. That is why there is a #1  relationship/trick.
If your timing cover was off you could turn crank 1 revolution and your dist only turned 1/2 revolution.
I hope my explanation makes a little sense. Im lousy at splaining sometimes.
Also remember crankshaft 2 revolutions (720*) for every cam and rotor revolution.
Glad ya got it!
Ps for me it helps to have a visual. YouTube is loaded with good videos.
Remember the firing order 18436572....1/2 thru that firing order is #6. That is why there is a #1  relationship/trick.
If your timing cover was off you could turn crank 1 revolution and your dist only turned 1/2 revolution.
I hope my explanation makes a little sense. Im lousy at splaining sometimes.
Also remember crankshaft 2 revolutions (720*) for every cam and rotor revolution.
Glad ya got it!
Ps for me it helps to have a visual. YouTube is loaded with good videos.
95dakotadude
Well-Known Member
nm9, I didn't replace the chain because it's almost new. It only had maybe 1/4 of play on the slack side.
GTS, how did you go about measuring your pushrods then? I had previously broken all of my pushrods before I spun the bearing because I guess they were too long? So, I remeasured them by getting one of those extendable pushrods and put it on the #1 rocker arm while the lifter was at the base lobe of the cam and then tightened it were it should, and extended it just a half turn more for lifter preload. My new measurement was only .1 shorter. Granted, my engine is far from stock. Is there anyway to tell if I got it right this time? Before, when I had the valve cover off looking at the valves I tried twisting the exhaust pushrod while at TDC because you're supposed to be able to do so, I could. Is that a good enough insurance? I'm pretty sure I measured them right, but your comment puts a seed of doubt in my mind. Does it matter if I checked them on #1 or #6?
GTS, how did you go about measuring your pushrods then? I had previously broken all of my pushrods before I spun the bearing because I guess they were too long? So, I remeasured them by getting one of those extendable pushrods and put it on the #1 rocker arm while the lifter was at the base lobe of the cam and then tightened it were it should, and extended it just a half turn more for lifter preload. My new measurement was only .1 shorter. Granted, my engine is far from stock. Is there anyway to tell if I got it right this time? Before, when I had the valve cover off looking at the valves I tried twisting the exhaust pushrod while at TDC because you're supposed to be able to do so, I could. Is that a good enough insurance? I'm pretty sure I measured them right, but your comment puts a seed of doubt in my mind. Does it matter if I checked them on #1 or #6?
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