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Engine Specific Info and Questions => IDI Engine => Topic started by: jb86 on September 22, 2011, 06:58:33 am
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i posted on a thread about the dial indicator settings.
i understand that the timing belt is done first and was hoping to get specifics on that.
new rebuilt engine going into my restored 1991 jetta.
1V engine w/hydraulic head from eco, installed K24 and a giles performance IP with LDA boost enrichment. and a AAZ head gasket.
engine is assembled and in the car, just need a timing belt installed.
1. vince waldon website states do not turn bolt on cam sprocket with the locking plate. sounds logical - could distort cam bearings or shaft. is preferred way the crescent wrench on a #1 lobe or the sprocket holding wrench?
2. new crank bot installed at proper torque with locktite. ive read that its not safe to turn bolt CCW to turn crank. but any reason it would loosen as i have it?
3. cam sprocket loose (still loose from engine build, havent pulled valve cover off yet for alignment), IP pinned, flywheel on mark (near as i could tell). i started to install new belt. but section between IP and crank wouldnt engage cogs and the belt has very little slack around the entire length of it. so i used the old belt as a dry run.
i had to turn crank slightly CCW to engage cogs between IP and crank. then turn again CW to tension slightly. at that point the flywheel and IP still line up.
4. as for tensioning. when i set tension across the top of the belt will the tesnion between the IP and crank equalize?
i leave a slight amount of slack between the IP and crank. i leave the cam sprocket loose. i tension the adjuster. i figure that i should rotate the crank several revolutions witht the cam sprocket loose and that will equalize the belt tension between the IP and crank pulley. right?
otherwise. i can only get an approximation of what i think the slack below the IP should be.
5. tension amount. bentley specifys a pressure tool. or twist the belt 45 degrees. how much pressure do you apply to the belt to get 45 degrees?
i think thats it for the belt.
6. dial indicator. i bought the emiata/hans autoparts/prothe. it has a adapter base that i tested into an old IP and it fits. im going to go on youtube and get a video lesson on how to use a dial indicator before i keep asking newbie questions on how to. what i can say is it has 1" of travel and appears to be in .001". the small dial turns 10 times to move the rod in 1". is that an ok dial indicator to use or is the a better suited one?
any help is appreciated.
jon
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you need to take a deep breath and get a bently,
lots of confusion here...
do you know anyone who has done this (properly) before?
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1. vince waldon website states do not turn bolt on cam sprocket with the locking plate. sounds logical - could distort cam bearings or shaft. is preferred way the crescent wrench on a #1 lobe or the sprocket holding wrench? If you are talking about tightening the cam bolt , yes use a crescent wrench as noted. But you can turn the tightened cam by the bolt IF it's only the cam that you are turning
2. new crank bot installed at proper torque with locktite. ive read that its not safe to turn bolt CCW to turn crank. but any reason it would loosen as i have it? Not a good idea to turn crack CCW. Why would you need to?
3. cam sprocket loose (still loose from engine build, havent pulled valve cover off yet for alignment), IP pinned, flywheel on mark (near as i could tell). i started to install new belt. but section between IP and crank wouldnt engage cogs and the belt has very little slack around the entire length of it. so i used the old belt as a dry run.
i had to turn crank slightly CCW to engage cogs between IP and crank. then turn again CW to tension slightly. at that point the flywheel and IP still line up. This doesn't sound right. With the tensioner loose you should have all the slack you need
4. as for tensioning. when i set tension across the top of the belt will the tesnion between the IP and crank equalize? Yes- the tension "readings" are for a belt that is basically in running condition
i leave a slight amount of slack between the IP and crank. i leave the cam sprocket loose. i tension the adjuster. i figure that i should rotate the crank several revolutions witht the cam sprocket loose and that will equalize the belt tension between the IP and crank pulley. right? Wrong tighten the tensioner. Turn the crank CW a couple of turns . Then check tension by twisting the belt
otherwise. i can only get an approximation of what i think the slack below the IP should be.
5. tension amount. bentley specifys a pressure tool. or twist the belt 45 degrees. how much pressure do you apply to the belt to get 45 degrees?
i think thats it for the belt. Not a whole lot. Firm grip, but not a death grip on it
6. dial indicator. i bought the emiata/hans autoparts/prothe. it has a adapter base that i tested into an old IP and it fits. im going to go on youtube and get a video lesson on how to use a dial indicator before i keep asking newbie questions on how to. what i can say is it has 1" of travel and appears to be in .001". the small dial turns 10 times to move the rod in 1". is that an ok dial indicator to use or is the a better suited one? Sounds OK to use
any help is appreciated.
jon
Buy a Bentley manual . I can tell you are confused. Just make sure when you get it done to rotate the crank by hand twice and check you r timing marks and tension. If you get the pump out of whack a bit nothing bad happens. If you get the cam off or the belts slips you have a bad day.
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Installed new belt
As per bentley (which I do have and follow), 45degree twist with mild pressure and tightened tensioner
I made a tool to hold cam sprocket for tightening
3/16"x1 1/2" bar 16" long
Welded to it (2) 1/2"npt pipe about 1" long to fit into 2 of the sprockets holes
I turned crank with the crank bolt CW a couple revolutions. I heard a metallic scraping
A bolt behind the IP sprocket - holds the bracket from below it to the plate, was cutting into the sprocket. I added 2 more flat washers under head to shorten it. was no extra room there
Not sure if that extra tension on the belt has any affect
however, i will now re-torque the IP sprocket nut.
Then a few more revolutions
I notice that the belt slackens and tightens at different positions of the crank
The top will get tighter and the section below the tensioner will get looser
Then it will be the opposite
i can understand that while the crank is turning, the IP and cam are creating tension of their own on the belt which i would expect will cause changes in tension in varying places on the belt.
too tight will wear IP bushing, too loose will cause it to fall off.
I stopped at TDC
Everything is still aligned, belt is slightly tighter now
As per bentley, one mild strike with a rubber face mallet centered between cam and IP
Considerably looser, too loose
At this point do I just loosen cam sprocket, re-tension and turn engine by crank bolt a few times to verify?
Does anything I wrote sound right or wrong?
next ill use the dial indicator. still not 100% on that but ive gotten as much info as i can so far.
jon
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1. vince waldon website states do not turn bolt on cam sprocket with the locking plate. sounds logical - could distort cam bearings or shaft. is preferred way the crescent wrench on a #1 lobe or the sprocket holding wrench? If you are talking about tightening the cam bolt , yes use a crescent wrench as noted. But you can turn the tightened cam by the bolt IF it's only the cam that you are turning
*Cringe* Use a sprocket holding wrench. :o Only use the crescent wrench for aligning the cam at TDC
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why turn crank ccw... how do you set pump timming??? so thats why.. .best too have all belts on and turn ccw via alt.. never center crank bolt...
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4. as for tensioning. when i set tension across the top of the belt will the tesnion between the IP and crank equalize?
i leave a slight amount of slack between the IP and crank. i leave the cam sprocket loose. i tension the adjuster. i figure that i should rotate the crank several revolutions witht the cam sprocket loose and that will equalize the belt tension between the IP and crank pulley. right?
I would not turn the crank several revolutions with the cam sprocket loose because #2 exhaust valve is almost fully open when cam is locked at #1 TDC.
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*Cringe* Use a sprocket holding wrench. Shocked Only use the crescent wrench for aligning the cam at TDC
Actually, I never do this, though I don't see the harm if you protect the cam with a layer of cloth. I clamp a vice grip to a non-machined area of the cam as a counter.
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i did not turn the crank until the cam sprocket was tightened.
as i stated in the first line - installed belt per bentley.
set tensioner to allow 45 degree twist, as per bentley
took out the cam lock and the ip lock.
i made a tool to hold the cam sprocket - to short pipe sections slide into 2 holes on the sprocket to allow me to hold the sprocket while the bolt is tightened.
i have a fairly large crescent wrench, but still not big enough, so i decided to do this.
i am now at a point where im uncomfortable with how the belt tightens and slackens.
i guess that it has to be right, i just dont know.
any ideas to my original questions?
jon
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Big thing once you have the belt on with eveything aligned tighten the tensioner some, tighten the cam sprocket recheck and tighten belt to where you think it needs to be then pull the cam plate and injector pin. Flywheel should still be aligned after everything is taken off. Rotate engine and you should be just fine.
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thanks for the reply.
i do tend to be overly cautious and try to think of every way that i can to be carefull of.
im never in a hurry with something this critical.
i checked the tension this morning.
bentley states - mid point between IP and cam sprocket a 45 degree twist and no further.
i would say i have, mild pressure to twist it to 45 degree. i held a drafting square along the belt.
i then called giles at performance diesel, since i got the IP from him.
he says "an easy 45". so is that the same as what i would consider mild pressure?
these tension specs will haunt me - 45 degree and no further, mild pressure, easy 45
he then explained the settings for the dial indicator in 0.001's. i'll do that tomorrow.
he explained that as the belt turns, that both the cam and ip will increase tension on the belt, causing changes in tension at different spots of the belt. to answer one of my questions.
jon
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Just sayin, you'll never undo the crank bolt with a ratchet just turning the engine over. That thing is torqed to hundreds of foot pounds. You would need a pipe on your wrench and you would also have to me mashing the valves into the faces of 2 pistons...
there would have to be an AMAZING amount of tom-foolery going on to do that.
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oh right a more relevant reply would be...
turn the engine over a few times by hand.
Your belt will always give a little when its brand new. Run it for a couple minutes and re-check your tension.
Of course only do this is you've triple checked the cam to crank timing.
I can always eyeball the belt to within a tooth when i put it on (in regards to the ip timing) then will the mounting bolts loose and the thing idling (usually rough and chaotically) i advance or retard the pump accordingly.
for the next couple trips in the car ill keep a 13mm deept socket on my smallest ratchet and adjust the pump until i have the power curve over the rpm to match my driving style.
Ive never used a gauge.
After some practice you will find spots that work best for highway, city and hard driving.
I also change the timing based on the season. I get pretty decent fuel economy all year by doing that and it will always start in the cold.
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oh right a more relevant reply would be...
turn the engine over a few times by hand.
Your belt will always give a little when its brand new. Run it for a couple minutes and re-check your tension.
Of course only do this is you've triple checked the cam to crank timing.
I can always eyeball the belt to within a tooth when i put it on (in regards to the ip timing) then will the mounting bolts loose and the thing idling (usually rough and chaotically) i advance or retard the pump accordingly.
for the next couple trips in the car ill keep a 13mm deept socket on my smallest ratchet and adjust the pump until i have the power curve over the rpm to match my driving style.
Ive never used a gauge.
After some practice you will find spots that work best for highway, city and hard driving.
I also change the timing based on the season. I get pretty decent fuel economy all year by doing that and it will always start in the cold.
Have you thought about making up linkages to your IP so you can advace or retard the timing while driving?
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he explained that as the belt turns, that both the cam and ip will increase tension on the belt, causing changes in tension at different spots of the belt. to answer one of my questions.
jon
Exactly. You need to set belt tension with the pump locked and the cam gear loose. I would say within 45-90 degrees, or 45 easy and 90 hard.