Help!!!! With Timing Chain!!! Need Help Now Please!!!!

[jorgensensc]

Please help clear up something for me! I have been playing hell with my timing lately and decided to take the plung and replace the timing chain (350). I got everything pulled off and am looking at the timing gears and chain right now (only took me 30 min. to get everything off, Dang I'm getting better). Anyways, I understand the whole line up the dots on the new gears idea, but here is where I'm confused:
Obviously the dots on the old gears aren't lined up. And with the gears being different sizes they rotate at different rates. How do I know where to line up the dots on the new set. The chain is really loose and I don't know if it skipped any teeth at any point. how do I know if I am putting the crank and cam out of time when I hook it all up. My truck has not been wanting to start lately and I put a new battery, alt, and starter on. It will start fine with a jump, even though my battery says fully charged.
I bought a cloyes true roller timing kit.
Please!! Any help would be greatly appreciated!!! I've got to have this truck running again in 3 hours.
Shawn

[69ChevyLB]

With #1 cylinder at top dead center, the dot on each gear should be in the 12 O'clock position.

[HuggerCST]

The dot on the small(crank) gear should be at 12 oclock, and the dot on the big(cam) gear should be at 6 oclock. As long as your crank gear only has one dot, and one keyway slot, then it will be timed right if the dots line up in the 12 and 6 position.

[Super Duck]

it will make it easer and safer on your valves if you loosen all the rockers and then rotate the motor to tdc. after that turn the cam to match. if using a multi slot crank sprocket be sure you are ligning up the corect marks.

[69ChevyLB]

HuggerCST is correct. Looked at my cam installation sheet and that is what it shows. Haynes must have it backwards. My bad.

[HuggerCST]

You had me second guessing myself there for a minute, 69chevy!

[junkyardjohn]

HUGGERCST IS RIGHT ON THE MONEY.

(QUOTE BY SUPERDUCK) it will make it easer and safer on your valves if you loosen all the rockers and then rotate the motor to tdc. after that turn the cam to match . if using a multi slot crank sprocket be sure you are ligning up the corect marks. (QUOTE)
I'M NOT SURE HOW YOU CAN REPLACE THE CAM WHITHOUT LOOSENING THE ROCKERS, REMOVING THE PUSHRODS & LIFTERS??? JOHN
(PS) DON'T FORGET TO REMOVE THE FUEL PUMP & F/P PUSHROD.

[Super Duck]

I may be crazy but isnt he just changing the timing chain?

[junkyardjohn]

YOUR ABSOLUTLY RIGHT SUPERDUCK. I MUST BE THE ONE WHO IS CRAZY. FOR SOME REASON I THOUGHT HE WAS CANGING THE CAM TOO. SORRY ABOUT THE MISUNDERSTANDING. I SEEM TO CHANGE CAMS IN THESE 350s A WHOLE LOT MORE THAN THE AVERAGE GUY. (I'M ALWAYS TRYING TO FIND THAT 15 HORSE POWER) BUT WHY LOOSEN THE ROCKERS?? JOHN

YOU CAN DISREGARD MY WHOLE PREVIOS REPLY EXCEPT THE PART ABOUT HUGGERCST BEING 100% RIGHT

[Super Duck]

its cool we are all a little .

[Longhorn Man]

Why should anything need moved at all?
Bring the engine to #1 TDC, pop off the top gear and chain, remove the lower one with a puller, and re-install. Even if you do have to move one or the other a tad, you still can't mess it up. if the valves are closed, and the piston is all the way up, then nothing jumped.
And as far as hard starting...fully charged battery, but needing a jump. Try unplugging the coil (or the 12 volts wire on HEI) and crank it over. If it cranks fine, then you need to back down the timeing. If it is still a bear, then go to auto zone or where ever and have them test your starter.
I have had timing chains real loose in the past, and it never effected the starting of the engine. (never had one jump a tooth though) If anything it'll start easier since the cam will be opening the intake valve late, which in turn lets in less air/fuel. Even though the exhaust valve will also be late, the exhaust gasses are forced out with positive displacement of the piston coming up and should leave minimal gasses to cause a high cylinder pressure.
If the starter tests fine, and the battery tests fine (have auto zone do that too...it's free, why not?) Then you need to see if the carb is bumping tons of fuel into the cylinder and causing a mild hydro lock condition.

[Paul72]

I have had timing chains real loose in the past, and it never effected the starting of the engine.

The timing chain on the K/20 actually wore a hole in the cover by being so loose. It never jumped a tooth either.

[Longhorn Man]

yeah, that's how bad one of mine was. Sounded like marbles being swirled in a coffee can.

[jorgensensc]

Thanks for all the replies guys!! I got the job all done. I bumped the engine until the old gear dots lined up, then I removed them and installed the new Cloyes true double roller set. After I got it all put back together the truck cranked right up and has cranked up perfect since then (about 6 starts so far.)
Longhorn,
I went to autozone and pulled my starter, alternator, and battery in thir parkng lot, after I had them test the system on the truck running. The electrical checked out Good. I turned off the truck and couldn't get it started, so I pulled the above items. I replaced the battery (red top optima with a red top optima free 3 year replacement), replaced the alternator (thier machine was broke, so he couldn't figure out if it was good or not), and had the starter tested and it was good, without excessive draw on start. It started up good, for a couple of days, then nothing again.
The chain was so losse it could jiggle back and forth pretty easy on once side, but on the other side seemed tight enough.
Hopefully this will fix it all up and I won't have to mess with it again!
Shawn

[crazy longhorn]

Originally Posted by 69ChevyLB

HuggerCST is correct. Looked at my cam installation sheet and that is what it shows. Haynes must have it backwards. My bad.

Haynes probably wasnt back ward.....to set the chain in, (crank to cam), the booger needs to be 12 on the crank , & 6 on the cam.......however....if you are dropping a dist, both marks will be at 12(Tdc comp stroke On #1). You all had it covered.....just thought I would try to clear up the diffs......crazyL

[Gordo]

I'm with Longhorn Man on this one, if the chain didn't "jump a tooth" you may as well keep looking for the problem.

[Tx Firefighter]

Fellows, look at the big picture here.

Put the bottom gear where the dot is straight up.

Now, the upper gear can have the dot installed at either 6 o-clock or 12 o-clock. It doesn't matter which.

See, it's a 2 to 1 ratio. If you put it to where both dots are at 12 o-clock and turn the engine one complete turn to where the bottom gear comes back to 12 o-clock, the upper dot will be straight down now. Turn it another turn and the upper dot will be straight up again. And again, and again.

The upper gear turns 1/2 turn for every complete turn of the lower gear.

[jamis]

Originally Posted by Tx Firefighter

Fellows, look at the big picture here.

Put the bottom gear where the dot is straight up.

Now, the upper gear can have the dot installed at either 6 o-clock or 12 o-clock. It doesn't matter which.

See, it's a 2 to 1 ratio. If you put it to where both dots are at 12 o-clock and turn the engine one complete turn to where the bottom gear comes back to 12 o-clock, the upper dot will be straight down now. Turn it another turn and the upper dot will be straight up again. And again, and again.

The upper gear turns 1/2 turn for every complete turn of the lower gear.

100% correct, if the new chain still has some slack in it, and you are not satisfied you have it right on the money. Make sure the timming marks line up while turning the engine clock wise, the chain should be loaded to the right and slack to the left.

[cduster]

Originally Posted by Tx Firefighter

Fellows, look at the big picture here.

Put the bottom gear where the dot is straight up.

Now, the upper gear can have the dot installed at either 6 o-clock or 12 o-clock. It doesn't matter which.

See, it's a 2 to 1 ratio. If you put it to where both dots are at 12 o-clock and turn the engine one complete turn to where the bottom gear comes back to 12 o-clock, the upper dot will be straight down now. Turn it another turn and the upper dot will be straight up again. And again, and again.

The upper gear turns 1/2 turn for every complete turn of the lower gear.

Thats what I wanted to say, just couldn't explain myself so anyone would be able to understand.

[HuggerCST]

Originally Posted by jorgensensc

Thanks for all the replies guys!! I got the job all done. I bumped the engine until the old gear dots lined up, then I removed them and installed the new Cloyes true double roller set. After I got it all put back together the truck cranked right up and has cranked up perfect since then (about 6 starts so far.)
Longhorn,
I went to autozone and pulled my starter, alternator, and battery in thir parkng lot, after I had them test the system on the truck running. The electrical checked out Good. I turned off the truck and couldn't get it started, so I pulled the above items. I replaced the battery (red top optima with a red top optima free 3 year replacement), replaced the alternator (thier machine was broke, so he couldn't figure out if it was good or not), and had the starter tested and it was good, without excessive draw on start. It started up good, for a couple of days, then nothing again.
The chain was so losse it could jiggle back and forth pretty easy on once side, but on the other side seemed tight enough.
Hopefully this will fix it all up and I won't have to mess with it again!
Shawn

When it won't start, does it spin over slowly, or does it just click, or? You might want to check your battery cables. Make sure the ground cable is big enough, bolted solid to the engine, and that you also have a good body ground.(from the fender to the battery) One quick way to check for a ground cable problem- next time it won't start, put jumper cables between the neg. battery post and the engine, then try it.

[jorgensensc]

O.K here's an update!!
Very strange thing. I went outside this morning and tried to start the truck. Much to my suprise it wouldn't start. I tried the jumper cable negative thing and it still wouldn't start. Well, I happened to have another Dizzy from the other 350 in the garage and I put that one on, still not a good start. Finally I said what the He!! and put the starter for the other 350 on the truck (keep in mind I already had the starter on the truck tested and it tested good). Went to crank it up and the starter was strong and cranked the truck right up!!! I couldn't beleive it. Every time I have cranked it over and over she fires right up!! I thought the starter was the problem (I've had a similar problem before) but since it tested good I blew it off. Oh well. I changed the alternator (new), the battery(new), the dizzy(fairly new), and the timing chain(new true double roller), and now the starter(fairly new). It seems that this has finally cured the problem At least I know everything eelse is new now and I don't have to worry about them for awhile. If this doesn't fix the problem I don't know what will. The starter is a Pep Boys starter that was bougt in Jan 02. It has a lifetime warranty so it will be going back this week! Thanks again for all the great help guys!
Shawn