anyohow 86 camaro, put in a 305 from 1969, and it has good spark and gas, wouldnt start and timing marks were at stock, anyhow when it ran, it ran good!!!!.

Then you come one day and go to start, just cranks REAL FAST, THEN SLOWS DOWN, THEN FAST THEN SLOW, NO RUN. !! NEW DIZZY, COMPUTER AND ALL.

Removed the timing chain cover and its looks somewhat worn, a buddy says my double roller may have jumped a tooth.

Anyhow, before I go to replace the chain and sprockets, I SEE THE CAM GEAR HAS TWO OTHER HOLES, ONE TO ADVANCE 4 DEGREES, THE OTHER TO RETARD 4 DEGREES, Id like some performance, which hole?????

 

the 305 was intoduced in 1976 so something is off there.
put the sprocket in the "straight up" no advance hole. I would also do more problem solving then parts changing though. just my opinion

 

I doubt the timing chain jumped a tooth. Was the motor just built? If it sat for a wile the rings could be stuck and not building enough compression to fire. I poured oil down my carb to unstick them wile turning it over, took about 5 mins. Dont pour it fast, should take you a good wile to pour half a qt, and dont spin it over continuisly. Spin it for 5 secs then let it sit for 10

 

well I read a few post on here using search, where the chain jumped a tooth.

Im gonna try the oil trick , the 305 came out of a truck and was put in this 1986 camaro. Ive heard you must have compression, spark and fuel. I have tested everything but compression.


Ill be very dissapointed, if the guy sold me a void that only starts when it has enough compression. But, Ill verify the number one piston is at TDC as the cam dot is at 12:00 and crank dot at 12:00, not facing each other.

The other thing, is ill crank it over and watch the rotor spin to check the cam and dizzy gears, make sure they are not worn.


Id really like a non computer controlled dizzy and carb, to outfit the motor as well,. Its never been rebuilt.

 

UPDATE! I turned the motor over, the crank gear remained at 1:00 and the cam gear at 12:00 , stayed the same several passes. #1 TDC, the chain has jumped a tooth, new sprockets and chain ordered.

Also noticed slack and the crank gear tooth worn up a bit.

 

how much deflection did the chain have?

 

Most likely, the chain didn't "jump a tooth", since that NEVER EVER happens.

What probably went wrong, is the phenolic plastic teeth all stripped off of the chinesium cam sprocket, leaving nothing but little plastic gums; so now the chain just slips all around it.

The crank gear ALMOST NEVER shows any significant damage, because it's REAL METAL; unlike the cam one.

You're right though, a new timing set is the correct answer.

Look CLOSELY at the timing cover; down low, around the crank sprocket, toward the passenger side, on the inside. The chain will often wear a hole completely through the cover right there as the cam gear disintegrates and the chain gets slung way out off of the crank gear. Best to have a new timing cover on hand too, while you're doing this, because even if you haven't noticed it yet, it's probably smoked.

 

NO, THE CRANK AND CAM SPROCKETS ARE METAL AND HEAVY, I HAD TO USE A PULLER TO REMOVE THE CRANK SPROCKET, THE TEETH ON BOTH OF EM SHOWS SIGNS OF WEAR.

Also I did the oil through carb trick, incase the rings were sticking, used thick gear oil, 1/2 quart.

 

that probably wasnt what the motor needed...

 

Like sofa said the chain will never jump a tooth. It will eather stay or come completly off. What probly happend is the gears are worn and the chain stretched, causing it to apear to be a tooth off.

And you can eather line the dots up or put them both at 12 o'clock. The cam spins half as fast as the crank so when the crank spins one turn they will be eather lined up or both at 12, dosent matter which way you origionaly put them.

 

thanks that good advice when I put the new one on. .


The chain is stretched so much, i can turn the crank almost an half an inch before the tension is tight enough for the cam sprocket to begin turning.

The oil trick , I only did because the motor had been sitting outside without an intake and rain water come out of it when I changed the oil and coolant.

 

that engine is toast! if you had rain water in a unsealed motor it needs to be torn down... who knows what else is in there

 

I agree!!

 

well the engine had a ton of power and runs like new when it wants to run, n knocks, ticks smoke, or anything.

Im waitin on the chain, ill do a compression test as soon as I can, but
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doubt this engine is toast, all the power it had.the rain water got in cause the intake manifold was off, but it all drained into the oil pan

but ill let you all know as soon as it stops raining and thunderstorming