whatusername
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In need of advice for a Timing Belt Install....
- Thread starter north42g
- Start date
Installshield 2
Gothenburg Superiority
Now imagine how much fun it was to time a pair of twiggy cams...5 times...with NO hex things ground into the cams haha...
The tensioner is confusing, but it makes sense if you took it off...torque the 14mm bolt to factory spec...and don't worry about it...A lot of guys used to say messing with that 6mm hole would 'loosen' it or something, and make it fail sooner...that 6mm thing is only to get leverage on it to push it into the belt and set the spring...the tensioner itself is simply internally damped...you can't actually adjust its pivoting resistance or anything...its supposed to rotate on its crush washers after torqued properly...it does make it easier though if you install it with the little spring eye-lit point up towards the cam gears; its a little easier to put the spring on the tensioner, then move it out of the way for the belt installation...
Also, for anyone else that comes into this thread for this work...set the belt opposite crank rotation...and figure on sliding the belt all the way on once all the teeth are lined up (on the crank sprocket, exhaust cam, then intake cam)...get the crank as close to TDC as possible...put only a 1/4" or so of the belt on the sprocket...then work from the exhaust side (opposite the tensioner side)...pull up all slack without moving the crank, and work it over both cam gears...with only 1/4" on the crank sprocket...its a lot easier to fit it over the cam gears...if you put it all the way on the crank sprocket...you'll probably start throwing wrenches at someone...
The tensioner is confusing, but it makes sense if you took it off...torque the 14mm bolt to factory spec...and don't worry about it...A lot of guys used to say messing with that 6mm hole would 'loosen' it or something, and make it fail sooner...that 6mm thing is only to get leverage on it to push it into the belt and set the spring...the tensioner itself is simply internally damped...you can't actually adjust its pivoting resistance or anything...its supposed to rotate on its crush washers after torqued properly...it does make it easier though if you install it with the little spring eye-lit point up towards the cam gears; its a little easier to put the spring on the tensioner, then move it out of the way for the belt installation...
Also, for anyone else that comes into this thread for this work...set the belt opposite crank rotation...and figure on sliding the belt all the way on once all the teeth are lined up (on the crank sprocket, exhaust cam, then intake cam)...get the crank as close to TDC as possible...put only a 1/4" or so of the belt on the sprocket...then work from the exhaust side (opposite the tensioner side)...pull up all slack without moving the crank, and work it over both cam gears...with only 1/4" on the crank sprocket...its a lot easier to fit it over the cam gears...if you put it all the way on the crank sprocket...you'll probably start throwing wrenches at someone...
^ what are your thoughts on this detail ??
The tensioner remains "active" when fully installed,.. which I question,... is it not possible for the crank shaft to decelerate faster than the cams at some point, forcing the tensioner out of the way and putting slack on the wrong side of the crank gear leading to a skipped tooth ???
You can see it happen if you turn the crank bolt slowly the wrong way. If the tensioner was fixed in place, that wouldn't happen.
The tensioner remains "active" when fully installed,.. which I question,... is it not possible for the crank shaft to decelerate faster than the cams at some point, forcing the tensioner out of the way and putting slack on the wrong side of the crank gear leading to a skipped tooth ???
You can see it happen if you turn the crank bolt slowly the wrong way. If the tensioner was fixed in place, that wouldn't happen.
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- Banned For Being A Troll
The belt will not jump a tooth.
I have the same belt and tensioner on an engine that went from having a -30 Lb Flywheel diet and a -5 Lb Crank Pulley.
It revs like a motorcycle, sharp and fast. Mine has never jumped a tooth so I don't know what you are all about..
I have the same belt and tensioner on an engine that went from having a -30 Lb Flywheel diet and a -5 Lb Crank Pulley.
It revs like a motorcycle, sharp and fast. Mine has never jumped a tooth so I don't know what you are all about..
^I suppose I'm always looking for potential issues or a better way of doing things,... like why not a chain instead of belt,... a chain will stretch till your car doesn't run then you know it's time to replace your chain,... a belt will break to let you know it's time to replace your engine.
Another small example of how my mind works is the switch for the rear wiper,... Who wants to turn the spray on without the wipers going, there's a spray setting at the top when the wipers are on, who need two? The bottom position should be for "mist" a single swipe of the wiper which I do all the time, but I have to turn the wiper on then off and normally turn it too far off and hit the spray then I have to do it all over again.
I suppose if I could just accept life the way it is I would get along with it a lot better but I guess I just wasn't wired that way.
SYMPTOM TROUBLESHOOTING [ENGINE CONTROL SYSTEM (FS)]
01–03B–28
NO.11 ENGINE STALLS/QUITS, ENGINE RUNS ROUGH, MISSES, BUCK/JERK, HESITATION/STUMBLE,
SURGES [FS]
A3U010318881W16
Diagnostic procedure
11
Engine stalls/quits — Acceleration/cruise
Engine runs rough — Acceleration/cruise
Misses — Acceleration/cruise
Buck/jerk — Acceleration/cruise/deceleration
Hesitation/stumble — Acceleration
Surges — Acceleration/cruise
DESCRIPTION
• Engine stops unexpectedly at beginning of acceleration or during acceleration.
• Engine stops unexpectedly while cruising.
• Engine speed fluctuates during acceleration or cruising.
• Engine misses during acceleration or cruising.
• Vehicle bucks/jerks during acceleration, cruising or deceleration.
• Momentary pause at beginning of acceleration or during acceleration
• Momentary minor irregularity in engine output
POSSIBLE CAUSE
• A/C system improper operation
• Erratic signal or no signal from CMP sensor
• Air leakage from intake-air system parts
• Purge solenoid valve malfunction
• IAC valve improper operation
• EGR valve malfunction
• Erratic signal from CKP sensor
• Low engine compression
• Vacuum leakage
• Poor fuel quality
• Spark leakage from high-tension leads
• Air cleaner restriction
• PCV valve malfunction
• Improper valve timing due to jumping out of timing belt
• Restriction in exhaust system
• Intermittent open or short in fuel pump circuit
• Inadequate fuel pressure
• Fuel pump mechanical malfunction
• Fuel leakage from fuel injector
• Fuel injector clogging
• Intermittent open or short of MAF sensor, throttle position sensor and VSS
• ATX malfunction
• Clutch slippage
Another small example of how my mind works is the switch for the rear wiper,... Who wants to turn the spray on without the wipers going, there's a spray setting at the top when the wipers are on, who need two? The bottom position should be for "mist" a single swipe of the wiper which I do all the time, but I have to turn the wiper on then off and normally turn it too far off and hit the spray then I have to do it all over again.
I suppose if I could just accept life the way it is I would get along with it a lot better but I guess I just wasn't wired that way.
SYMPTOM TROUBLESHOOTING [ENGINE CONTROL SYSTEM (FS)]
01–03B–28
NO.11 ENGINE STALLS/QUITS, ENGINE RUNS ROUGH, MISSES, BUCK/JERK, HESITATION/STUMBLE,
SURGES [FS]
A3U010318881W16
Diagnostic procedure
11
Engine stalls/quits — Acceleration/cruise
Engine runs rough — Acceleration/cruise
Misses — Acceleration/cruise
Buck/jerk — Acceleration/cruise/deceleration
Hesitation/stumble — Acceleration
Surges — Acceleration/cruise
DESCRIPTION
• Engine stops unexpectedly at beginning of acceleration or during acceleration.
• Engine stops unexpectedly while cruising.
• Engine speed fluctuates during acceleration or cruising.
• Engine misses during acceleration or cruising.
• Vehicle bucks/jerks during acceleration, cruising or deceleration.
• Momentary pause at beginning of acceleration or during acceleration
• Momentary minor irregularity in engine output
POSSIBLE CAUSE
• A/C system improper operation
• Erratic signal or no signal from CMP sensor
• Air leakage from intake-air system parts
• Purge solenoid valve malfunction
• IAC valve improper operation
• EGR valve malfunction
• Erratic signal from CKP sensor
• Low engine compression
• Vacuum leakage
• Poor fuel quality
• Spark leakage from high-tension leads
• Air cleaner restriction
• PCV valve malfunction
• Improper valve timing due to jumping out of timing belt
• Restriction in exhaust system
• Intermittent open or short in fuel pump circuit
• Inadequate fuel pressure
• Fuel pump mechanical malfunction
• Fuel leakage from fuel injector
• Fuel injector clogging
• Intermittent open or short of MAF sensor, throttle position sensor and VSS
• ATX malfunction
• Clutch slippage
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- Banned For Being A Troll
Umm Wierdo. The engine is non interference.
The belt flys off and you just put a new belt on and drive away.
Whats with all the drama.
did you read that list or did you read that list and understand it.
that is every possible thing that could cause poor operation. It is a cop out.
is is like someone made a list for a burnt lightbulb and said.
could be the power is out,
could be that the wires in the house are missing,
could be the switch is missing,
could be that the switch is off,
could be that the switch is broken,
COULD BE THAT THE BULB IS BURNT.
Could be does not mean anything. If the tooth is timed properly, then it's fine. If it skipped a tooth, that is because whoever installed the belt is incompetent and should not be under the hood.
Millions of FS engines were made on ford and Mazda cars. The system is solid, it will not just jump a tooth for no reason only on your car.
PS. Why the hell are you turning the crank the wrong way once the spring is attached.
It is obvious and fully documented that once the spring is installed the crank must never be turned backwards or it will stretch the spring and it will nee to be replaced.
This thread is so full of failboat.
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I've actually had a belt jump a tooth because the tensioner spring snapped, the car was running like s***. I just replaced the spring and re-timed it and all was well.. but yeah.. non interference. Belt snaps, your car is stranded until you put a new belt and drive away.
Apparently this IS an interference engine. When I first got my car 3 1/2 years ago, all the parts stores and even Rock Auto listed the FS engine as an interference engine. I couldn't verify that my belt had been done so I just went ahead and did it (turns out it had been done). During further research afterward, it seemed to come to light that the FS engine is not an interference engine. If I had known that I would have delayed my timing belt job and just inspected my belt periodically. I actually started a thread on Dec. 9 asking if the FS engine was an interference engine or not. Apparently there has been cases of bent valves due to belt breakage on this engine but it appears to be very rare, and the debate still continues to this day. I'm feeling 97% sure that this engine will not interfere and Mazda is just covering themselves to make sure they don't have to replace anyone's engine, but if any boat is gonna fail out there on the water,.. sure as shyte it's gonna be mine.
PS when I moved the crank backwards, I moved it very slow and only a few degrees. I wanted to see if the intake cam gear was going to move or if only the tensioner was going to move. Only the tensioner moved a few mm then I stopped.
Meanwhile,.. I'll try to keep my backwoods techniques and analysis to myself,.. I don't want to misinform or mislead anyone in a bad way.
PS when I moved the crank backwards, I moved it very slow and only a few degrees. I wanted to see if the intake cam gear was going to move or if only the tensioner was going to move. Only the tensioner moved a few mm then I stopped.
Meanwhile,.. I'll try to keep my backwoods techniques and analysis to myself,.. I don't want to misinform or mislead anyone in a bad way.
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- Banned For Being A Troll
I have built 6 forged FS Engines (for myself and others), I can and this forum can assure you that this is non interference. Let the Belt Fly buddy..
The only FS engines that are interference are modified engines with High Lift Cams, or Forged High Compression Pistons (NA), or if the Head was milled beyond it's wear limit (Bringing the valve tolerance down towards the piston)
R U Going to trust Pep Boys or are you going to trust the people who have done it for TEN YEARS and Thousands of "Hands On Hours"
Pistons dont look like this if they interfere. See the grove for the valve relief?
The only FS engines that are interference are modified engines with High Lift Cams, or Forged High Compression Pistons (NA), or if the Head was milled beyond it's wear limit (Bringing the valve tolerance down towards the piston)
R U Going to trust Pep Boys or are you going to trust the people who have done it for TEN YEARS and Thousands of "Hands On Hours"
Pistons dont look like this if they interfere. See the grove for the valve relief?
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I was thinking that that must be the case. In the thread I started, nobody replied that they had ever interfered their engine,.. just stories they heard of somebody else doing it but more than a few lost their belt with no ill effects.
Installshield 2
Gothenburg Superiority
I installed Japanese cams at ~25k miles, just about 1.5 years after i got the car...It was my first cam job, it was a new car, so i went a little over board...and replaced the belt at the time of the install...
at ~75k miles, a few years later, my girlfriend at the time had borrowed the car to go to a class or something...i wasn't with her...she said she was driving a long, and the engine just shut off...she had AAA, and it was towed to the dealership where i bought it...
the tech told me the tensioner spring had failed, and it skipped out of time and wrecked the belt...again, i wasn't driving, but there were no other problems other than a destroyed belt...no valves got clipped, etc...
as far as how the tensioner works...it has to be damped...it can't be fixed because its using a rubber belt and different parts the belt connects to are under different stress at different times...The crank spins clockwise, and 'pulls down' on the exhaust cam, which pulls on the intake cam, and pulls the belt up from the crank around it...when you decelerate, the cams will have their own internial load...and attempt to keep spinning...the engine crank shaft isn't attempting to slow the cams in anyway, valve spring pressure is the resistance force on the cams...deceleration in a lot of ways is somewhat of a controlled chaos...the cams and crank are actually very slightly out of sync, as are both cams because they are hitting the valve tappets at different times...by design...
and that is where the tensioner has to damp the belt to keep it on the right teeth...the out of sync nature creates some resonance through the belt, causing it to vibrate and kick around a little on the 'un-taught' side...the tensioner damping properties absorb that perfectly...and when its all over, the tensioner spring then pulls the tensioner back into the proper position for when everything is back under load...and then properly sync'd again...
if there was no tensioner...and the system only used a pair of fixed idler bearings...deceleration would eat the belt alive...the resonance would cause it to 'hop' on the different sprockets and quickly destroy it...so, what i'm getting at...is the factory design is actually very good, and those tensioners are tuned to deal with the change belt conditions very well...probably why they're not very cheap...If you've ever been around some antique equipment that uses drive belts, you've probably seen the physics at work here...old belt sanders for example: if you're sanding something and cut power while the object is still touching the sand belt...the belt will start popping all over the place as it slows down... because the resistance at the power pulley, and your object...are completely different...the tensioner is designed to remedy this exactly...
its easy to compare how that works with the accessory belts...the accessory pumps and alternator keep an even amount of load...if the crank slows down, the pumps simply slow down with it in uniform nature...the cams...can't do that..their load is dependent on valve pressure pushing on the lobes...so, there is absolutely no uniform pressure on them as they decelerate...
at ~75k miles, a few years later, my girlfriend at the time had borrowed the car to go to a class or something...i wasn't with her...she said she was driving a long, and the engine just shut off...she had AAA, and it was towed to the dealership where i bought it...
the tech told me the tensioner spring had failed, and it skipped out of time and wrecked the belt...again, i wasn't driving, but there were no other problems other than a destroyed belt...no valves got clipped, etc...
as far as how the tensioner works...it has to be damped...it can't be fixed because its using a rubber belt and different parts the belt connects to are under different stress at different times...The crank spins clockwise, and 'pulls down' on the exhaust cam, which pulls on the intake cam, and pulls the belt up from the crank around it...when you decelerate, the cams will have their own internial load...and attempt to keep spinning...the engine crank shaft isn't attempting to slow the cams in anyway, valve spring pressure is the resistance force on the cams...deceleration in a lot of ways is somewhat of a controlled chaos...the cams and crank are actually very slightly out of sync, as are both cams because they are hitting the valve tappets at different times...by design...
and that is where the tensioner has to damp the belt to keep it on the right teeth...the out of sync nature creates some resonance through the belt, causing it to vibrate and kick around a little on the 'un-taught' side...the tensioner damping properties absorb that perfectly...and when its all over, the tensioner spring then pulls the tensioner back into the proper position for when everything is back under load...and then properly sync'd again...
if there was no tensioner...and the system only used a pair of fixed idler bearings...deceleration would eat the belt alive...the resonance would cause it to 'hop' on the different sprockets and quickly destroy it...so, what i'm getting at...is the factory design is actually very good, and those tensioners are tuned to deal with the change belt conditions very well...probably why they're not very cheap...If you've ever been around some antique equipment that uses drive belts, you've probably seen the physics at work here...old belt sanders for example: if you're sanding something and cut power while the object is still touching the sand belt...the belt will start popping all over the place as it slows down... because the resistance at the power pulley, and your object...are completely different...the tensioner is designed to remedy this exactly...
its easy to compare how that works with the accessory belts...the accessory pumps and alternator keep an even amount of load...if the crank slows down, the pumps simply slow down with it in uniform nature...the cams...can't do that..their load is dependent on valve pressure pushing on the lobes...so, there is absolutely no uniform pressure on them as they decelerate...
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^I remember doing the timing belt on my Tracker and there was a tensioner spring but it was only used to set the proper tension, then you locked down the idler wheel and it had no movement after that. The spring could be essentially removed after lock down, and would make no difference. It was recommended to periodically loosen the idler wheel, let the spring take up any slack then tighten it down again. It was a gutless 84 horse 1.6 liter with only one cam shaft.
Installshield 2
Gothenburg Superiority
^ yeah, some cars use different designs...from what i've seen most DOHC with 2 cam gears will utilze a damper of some sort...as its just 'another' thing to get out of sync...although i've seen some DOHC engines that do not use the same design, but also don't use 2 cam gears...the cams themselves are meshed inside the head, and only one outside gear is turned by a timing belt...the mazd KL engines are like that...
I should've mentioned...its not the only way to fix the chaotic deceleration problem...its just one way to fix it...changing that design will involve a lot more than just locking a tensioner in place, though...thats all...
I should've mentioned...its not the only way to fix the chaotic deceleration problem...its just one way to fix it...changing that design will involve a lot more than just locking a tensioner in place, though...thats all...
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- Banned For Being A Troll
The spring is the most important $0.99 part on the car
Installshield 2
Gothenburg Superiority
^^exactly what brian said...
the spring keeps proper belt slack when accelerating...the teinsoner's damper keeps proper belt slack when decelerating...and everything is flipping out...
that $1 spring is the difference between a running engine...and one thats sidelined...just ask my ex girlfriend haha...
the spring keeps proper belt slack when accelerating...the teinsoner's damper keeps proper belt slack when decelerating...and everything is flipping out...
that $1 spring is the difference between a running engine...and one thats sidelined...just ask my ex girlfriend haha...