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Joined: Jun 2000
Posts: 2,621
Redneck Troll
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Redneck Troll
Joined: Jun 2000
Posts: 2,621 |
Originally posted by procyon:
Originally posted by bnoon:
The valvetrain has very little resistance on it when assembled properly.
Brad, in reality the timing chain is a extremely stressed component in the engine. True, there isn't much resistance from actually turning the cams. However, I know you timed your engine and you must have felt the large amount of torque needed to open the valves by turning the crankshaft. (and no there isn't much compression resistance when you just turn the crank a few degrees to line up the chain)
In addition to the above, the chain is subject to large torque pulses as each cylinder fires and applies torque to the crankshaft. The damper and flywheel do provide some help but it's still not an easy life for the chains.
Still, I have not seen any issues *in my experience* with the Duratec timing chains (small or large size). I would have to guess that PuckPuck's failure was due to some other cause than an inherent design flaw with the smaller pitch chain.
While I agree that the cam chains don't lead an easy life, I don't agree with the "large amount of torque needed to open the valves by turning the crankshaft". These engines are far easier to turn over, even with the plugs in, than say any pushrod engine I've ever come across. "Very little" was used as a relative term. Superior chain design compared to those older designs lead me to the same conclusion about Puckpuck's failure.
Originally posted by procyon:
They are all numbered. On a 2.5L the LH head cam caps will be numbered 1L, 2L, ...9L. The RH caps will be 1R, 2R,...8R. LH head has one extra cam cap on the intake cam for water pump drive.
There are no measurments stamped on the heads.
Ahhhhh, how could I forget about the 1L, 2L, etc. Sorry 'bout that gents! There are measurements cast or stamped into the lash caps though... I was sure of it... 
http://www.bnmotorsports.com
"And I will strike down upon thee with great vengeance and furious anger those who attempt to poison and destroy my CEG brothers. And you will know I am the Moderator when I lay my vengeance upon you."
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Joined: Dec 2000
Posts: 317
CEG\'er
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OP
CEG\'er
Joined: Dec 2000
Posts: 317 |
Originally posted by procyon:
PuckPuck, how did you install the damper on your engine and how did you torque it down?
ummmm.... first with an impact gun (to prevent engine from turning while putting it on)... then wedge a screwdriver in there and torque it down to spec... ask me what that is and i'll tell you to look it up 
I have been going around to a few places with my chain and the pieces of it i could find in the oil pan.... basically each link has 4 blades (pardon the horrible terminology but this is how i'm explaining it)... of the 4 blades, i have all the pieces but a small section of one of them... the pin that came out looks to be the cluprit... it seems to me that when they put the pin on, then punch the end so it won't come out (flare it for another term)... well this pin is not as obviously flared as the other ones.... so now i'm leaning even further to just a fluke bad link and improperly assembled... perhaps during the production of my chain the machine broke and they didn't repress the one link...
as of now, i have gone over every possibility, and taken every suggestion i can and seen if that was the culprit... everything always leads back to the chain breaking from stress or poor workmanship....
i would also like to note, when i picked up the engine it had low miles, something like 18K or so, was owned by a retired man, and the taurus was totalled from the rear... i only put just over 1000 miles on it... of which only a few short times did i romp it... so overall the chain had less than 20K miles all of which but a few short moments were babied.... and the chain let go doing 70mph down the highway in 5th gear....
2000 Cougar V6 MTX
2001 3.0L Swap w/ PnP Heads - It ran, it boomed, it RUNS AGAIN
Nearly all suspension mods
Big ass stereo
...and more...
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Joined: Jan 2002
Posts: 344
CEG\'er
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CEG\'er
Joined: Jan 2002
Posts: 344 |
Originally posted by PuckPuck:
Originally posted by procyon:
PuckPuck, how did you install the damper on your engine and how did you torque it down?
ummmm.... first with an impact gun (to prevent engine from turning while putting it on)... then wedge a screwdriver in there and torque it down to spec... ask me what that is and i'll tell you to look it up
I'm was wondering if it might be possible that the damper was pressed on with too much force. This could have cracked the crankshaft sprocket and led to the failure. Just throwing out alternative ideas here.... I was wondering more about the install/pressing on operation than the torquing.
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