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Something that has alway's had me wondering! Specifically, slop resulting from normal usage?
The resulting effects who's cause is something that cannot really be called out by the standard troubleshooting methods. So these effects are many times just "lived with'!
1. What is the physical effect and resulting disfunction that occurs? 2. How prevalent is "Timing chain slop"? 3. What amount of slop, constitutes too much?
Inquiring minds want to know? (probably a few non-inquireing one's too!)
Something that has alway's had me wondering! Specifically, slop resulting from normal usage?
The resulting effects who's cause is something that cannot really be called out by the standard troubleshooting methods. So these effects are many times just "lived with'!
1. What is the physical effect and resulting disfunction that occurs? 2. How prevalent is "Timing chain slop"? 3. What amount of slop, constitutes too much?
Inquiring minds want to know? (probably a few non-inquireing one's too!)
...I'm confused... and a little loopy from my pain meds right now... are you asking these questions or offering answers?
I don't know specifics of how it affects engine performance. I think the main concern when replacing a worn timing chain is that if it you let it go too long it will eventually break or skip teeth on the gears, which can then throw the engine out of time and before it has the chance to die, valves and pistons can collide resulting in major engine damage.
I believe if there's more than 1/2" slack, the timing chain should be replaced.
But how's about the more knowledgeable folks you're referring to confirm all this.
I don't know specifics of how it affects engine performance. I think the main concern when replacing a worn timing chain is that if it you let it go too long it will eventually break or skip teeth on the gears, which can then throw the engine out of time and before it has the chance to die, valves and pistons can collide resulting in major engine damage.
I believe if there's more than 1/2" slack, the timing chain should be replaced.
But how's about the more knowledgeable folks you're referring to confirm all this.
Well, It certainly sounds like your "Meds" have worn off. Time to "Re-dose"!!!!
Slop in the timing belt allows the cam timing to change relative to the crankshaft angle. Moving cam timing will shift the power curve slightly, although this is probably not likely to be noticed by the average driver unless it's a large change (i.e. the chain skips a tooth). Since it's driven by the camshaft, any slop in the timing chain will propagate to spark timing and injection timing through the timing pickup used by the engine computer. I don't know an exact power figure, but all these things will affect overall performance of the engine.
You can check for timing chain slop without opening the engine. Just take off the distributor cap, rotate the crankshaft to TDC moving in only one direction, then slowly turn the crankshaft in the opposite direction until the rotor just begins to move. Take note of the new crankshaft angle - if it's more than 4 or 5 degrees, it's time to replace the timing chain or both the timing chain and timing gears.
Slop in the timing belt allows the cam timing to change relative to the crankshaft angle. Moving cam timing will shift the power curve slightly, although this is probably not likely to be noticed by the average driver unless it's a large change (i.e. the chain skips a tooth). Since it's driven by the camshaft, any slop in the timing chain will propagate to spark timing and injection timing through the timing pickup used by the engine computer. I don't know an exact power figure, but all these things will affect overall performance of the engine.
You can check for timing chain slop without opening the engine. Just take off the distributor cap, rotate the crankshaft to TDC moving in only one direction, then slowly turn the crankshaft in the opposite direction until the rotor just begins to move. Take note of the new crankshaft angle - if it's more than 4 or 5 degrees, it's time to replace the timing chain or both the timing chain and timing gears.
Yeah thats the best way to check the chain slop , i don't like to see more that 3 deg, the only otherthing that would cause it to test loose is if it has a bad dist gear ...Lew
Yeah thats the best way to check the chain slop , i don't like to see more that 3 deg, the only otherthing that would cause it to test loose is if it has a bad dist gear ...Lew
True, and most likely you would be able to move the distributor shaft a little bit with the rotor if the dist. gear were worn very much....
True, and most likely you would be able to move the distributor shaft a little bit with the rotor if the dist. gear were worn very much....
Working on my son's 1994 F-250 with 351. How much rotation on the distributor is too much using the rotor to turn it? This one moves about 1/2", i.e. the full width of the "blade" on the tip of the rotor.
Thanks,
Peter
Something to also think about is alot of the smallblocks had nylon coated teeth on the gears to reduce the noise. Just thought I'd throw that in there.