Resolved 2G Timing Belt Tensioner Pulley Question

[sschambers]

So, according to every manual I've come across, there is a specific way the tensioner pulley is suppose to go on. When the belt is on the cam gears, wrapped around the idler puller and tensioner pulley and wrapped around the pump sprocket and crank sprocket, the tensioner pulley is suppose to be torqued with the small holes to the LEFT of the bolt, both VERTICAL.

I'm re-assembling my motor and it came time to do the timing belt. Well I've tried having the tensioner pulley just like the manual says. The only problem is when I release the pin from the auto-tensioner, there is a TON of slack still left in the belt. So much slack that I can just pull the belt right back off of everything.

I drew up a quick diagram in MSPaint to show you guys what I mean...

The top one is the way the manual SHOWS.

The bottom one is the way I had to put it to get perfect tension on the belt.

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I spun the motor over by hand more times than I can count. Everything spins nicely with no weird noises, everything lines back up to the timing marks.

Is this really going to matter if I keep the tensioner pulley like this? Since it's impossible for me to adjust it so the small holes are vertical.

Thanks,

Steve

 

[Calan]

On my 1G 6-bolt, it usually ends up something like this when everything is correct:

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Looking at this VFAQ page for a 2G timing belt job, I can't tell how it goes. The diagrams show it in every position possible. If you look at the photos, it shows it with the two holes horizontal at the top, but that may be a 1G photo.

Edit:

After further study, in step #28 they rotate it CCW until it is in the position that you ended up with, so I think you are correct. This is the exact opposite of the 1G's...strange.

Can you tell I've never replaced a T-belt on a 2G?

 

[Killa_dsm]

On a 2g 7bolt motor you will want to rotate the tensioner pulley counter clockwise.

 

[VETTE_50_TH]

Would it matter either way? I did a timing belt on my friends EVO and I spun the tensioner counterclock wise and everything lines up. How does it affect it if you spin it the wrong way?

James

 

[97eclipseNT]

Not sure why but 2g's are rotated CCW and 1g's are CW. You'll have the long bolt (that you can make with a battery tie down bolt) holding the tensioner arm against the compressed hydro tensioner (with the pin still in it). You then tension the belt appropriately with the pulley before you go onto spin the motor around by hand 6 times and waiting the 15min before you pull the pin in the hydro tensioner.

 

[Calan]

As I understand it...

The tension is held by a combination of the pulley and the hydraulic tensioner. Turning the eccentric pulley sets the initial tension on the belt, and then the tensioner works to maintain it. (actually they are in a balancing act...if you over-tighten the pulley, the tensioner will extend less, and if the pulley is too loose, the tensioner will extend more to compensate for it). So the goal is to adjust the pulley to the optimum position so that the tensioner can operate over the widest range possible to compensate for belt stretch.

As for your question, my guess is that there are differences in the 2g tensioner or the belt geometry that causes the pulley's optimum position to be different than on the 1g's.

I have a similar thread running on this same topic here.

 

[jjrock5]

On a 2g 7bolt motor you will want to rotate the tensioner pulley counter clockwise.

^ Agreed. I followed the manual when I did my build about a month ago (since I hadn't done a belt in a while) and it told me what the OP says, I said 'screw the manual' and turned it CCW with my spanner wrench and it's been holding on strong with ALL my timing marks in place after 3K miles. *knock on wood* haha

 

[romeen]

Would it matter either way? I did a timing belt on my friends EVO and I spun the tensioner counterclock wise and everything lines up. How does it affect it if you spin it the wrong way?

James

I think that if you spun it the wrong way that the belt would immediately go from completely loose to super tight and then start to loosen up the more you cranked the pulley. Actually, it would get so tight right away (pulley at orientation of max belt tension) that you wouldn't be able to get very far.

 

[tljohnson1]

In my experience the position of the dots has not made a differnece as long as you achieve the proper tension on the timing belt everything is fine. I say run it how u have it since the proper tension is achieved and the belt is not jumping or making any sounds.

 

[Calan]

In my experience the position of the dots has not made a differnece

There are cases though where the eccentric pulley will rub the bracket. That's what we are discussing in that thread mentioned above.

EDIT:

And as mentioned below, I think that it may "appear" to work fine in several positions, but only because the belt hasn't stretched to the point that the tensioner can no longer correct for it

 

[steve]

IIRC it hits shit if you try and do it the wrong direction for the style of tensioner arm and pulley you have.
Normally 1Gs rotate clockwise into the belt where 2G's rotate counter-clockwise. I'm pretty sure it's not a simple 6bolts go up and and 7bolts go down sort of thing.

 

[Calan]

I'm pretty sure it's not a simple 6bolts go up and and 7bolts go down sort of thing.

Agreed^^^

I think it's based on some combination of 1g/2g/6-bolt/7-bolt components...whatever puts the pulley in the right position to allow a given tensioner to adjust over it's entire range of motion as the belt stretches. That is also why I think that it may "appear" to work fine in several positions, but only because the belt hasn't stretched to the point that the tensioner can no longer correct for it.

Brian (Snowborder) mentioned in the other thread that he has a 1g 7 bolt motor in his 2g, and the CW 1g adjustment is what works in his case, although his pulley does end up in a position I wouldn't expect.

 

[Nvisabl]

not sure why but 2g's are rotated ccw and 1g's are cw. you'll have the long bolt (that you can make with a battery tie down bolt) holding the tensioner arm against the compressed hydro tensioner(with the pin still in it). You then tension the belt appropriatly with the pulley before you go onto spin the motor around by hand 6 times and waiting the 15min before you pull the pin in the hydro tensioner.

A 2g will rub the water pump if you turn it like a 1g.

There are cases though where the eccentric pulley will rub the bracket. That's what we are discussing in that thread mentioned above.

EDIT:

And as mentioned below, I think that it may "appear" to work fine in several positions, but only because the belt hasn't stretched to the point that the tensioner can no longer correct for it

Where the dots are don't matter. The main thing is it doesn't rub and after you turn motor over 7 revolutions you can still put the pin back in tensioner. That is the litmus test

 

[VETTE_50_TH]

Well, on the Evo 8 I timed, if i turned it up, it didnt gain any tension on the belt after a half turn. But if i turned it down, counter clockwise, it gained tension after a quarter to half turn. So i assumed thats the way it wanted to go. I turned to motor over manually like 5 times and the marks lined up every time. And the tensioner never lost any tension and the belt stayed strong. Everything seemed to work. I just didnt want to turn it the wrong way when i read the manual for the 1g and it specifically stated, turn it clockwise. Thanks guys for the informative responses.

James

 

[Calan]

Where the dots are don't matter. The main thing is it doesn't rub and after you turn motor over 7 revolutions you can still put the pin back in tensioner. That is the litmus test

How many miles have you gone with the pulley installed in these non-specific ways?

Does it still maintain tension with a severely stretched belt?

Why did Mitsu go to the trouble and cost of specifying an exact orientation (that is different on different models), if "where the dots are don't matter"?

I'm just curious. If there is good evidence that the Mitsu engineers just enjoy extra work and it doesn't matter...I'd like to see it.

 

[rEclipserGST]

How many miles have you gone with the pulley installed in these non-specific ways?

Does it still maintain tension with a severely stretched belt?

Why did Mitsu go to the trouble and cost of specifying an exact orientation (that is different on different models), if "where the dots are don't matter"?

I'm just curious. If there is good evidence that the Mitsu engineers just enjoy extra work and it doesn't matter...I'd like to see it.

They don't enjoy extra work. That's the reason our cars break certain parts randomly in the first place.

 

[steve]

That's the reason our cars break certain parts randomly in the first place.

After owning mine for almost 18 years I can't say I'm aware of any randomly breaking parts except the ECUs and that's not random, they all fail from the defective part. Everything I've replaced either wore out in it's normal lifetime, was upgraded because I chose to, or I broke it.

 

[rEclipserGST]

After owning mine for almost 18 years I can't say I'm aware of any randomly breaking parts except the ECUs and that's not random, they all fail from the defective part. Everything I've replaced either wore out in it's normal lifetime, was upgraded because I chose to, or I broke it.

Well I am the 3rd owner that I know of on my car. It was stock when I recieved it from my grandma. It she drove it in the ground. I've owned it for almost 3 years. I've replaced more than 20 Parts since I've had it. But hey, like every batch of condoms, I probably got that bad one. 93,000 miles on the ODO.

 

[Nvisabl]

How many miles have you gone with the pulley installed in these non-specific ways?

Does it still maintain tension with a severely stretched belt?

Why did Mitsu go to the trouble and cost of specifying an exact orientation (that is different on different models), if "where the dots are don't matter"?

I'm just curious. If there is good evidence that the Mitsu engineers just enjoy extra work and it doesn't matter...I'd like to see it.

It is a Guideline for the un-informed. If you read carefully I believe it says to use the specific to at 15ftlbs. maybe ? I have done so many I do them by feel these days.The main thing to get right is the pre-load on the belt. the hydralic "tensioner" isn't a tensioner at all it is more a lash adjuster. to take the slack out of a belt. As to time frame I guess I have timed over 200 cars my personal car 89 colt turbo 4g61t motor went 353,000 mile on stock internals at 26psi (last 150,000miles) on a 60trim. Never blew up just wore out I built the SA winnest car in SO history won 4 years that car was stock internal went 12.49 @110 on a true small 16g thru a 1g maf , motor had 250,000 miles on it the last time it won.

 

[Calan]

It is a Guideline for the un-informed. If you read carefully I believe it says to use the specific to at 15ftlbs. maybe ? I have done so many I do them by feel these days.The main thing to get right is the pre-load on the belt. the hydralic "tensioner" isn't a tensioner at all it is more a lash adjuster. to take the slack out of a belt. As to time frame I guess I have timed over 200 cars my personal car 89 colt turbo 4g61t motor went 353,000 mile on stock internals at 26psi (last 150,000miles) on a 60trim. Never blew up just wore out I built the SA winnest car in SO history won 4 years that car was stock internal went 12.49 @110 on a true small 16g thru a 1g maf , motor had 250,000 miles on it the last time it won.

Isn't that like saying "the timing belt isn't really a timing belt at all; it's more like a belt that's used to keep the engine in time"

Anyway... Cool! Just put the pulley where-ever you want and you can expect 353,000 mile on stock internals at 26psi!

I always thought it was more complicated than that.

 

[lacroixdp]

If it was that simple, I don't think it would cause such a problem when the instructions aren't followed! I've seen plenty of botched timing belt jobs cause a nice mess from people not following directions.

 

[Nvisabl]

Never implied not to follow instructions. What I was saying is he is worried about a picture and didn't finish reading about getting the correct tension on belt prior to pulling the pin. Hey I guess to each his own. I often wonder why I spend so little time here, then I am reminded within a post or 3

Isn't that like saying "the timing belt isn't really a timing belt at all; it's more like a belt that's used to keep the engine in time"

Anyway... Cool! Just put the pulley where-ever you want and you can expect 353,000 mile on stock internals at 26psi!

I always thought it was more complicated than that.

NO Honda Prelude has a true tensioner it puts the tension on the timing belt, DSM "tensioner" is to keep the belt tight after it is TENSIONED Correctly.

SO go time yourself. If you know all these answers why you asking a basic ?'s

Did I say anywhere put the pulley where-ever you want? Nope I said tension was more important then position. When you hit 26psi on a BONE STOCK motor and make it live for any amount of time then you can be sarcastic. I was trying to help. You seem to have it all worked out GOOD LUCK with your project.

 

[Calan]

has a true tensioner it puts the tension on the timing belt , DSM "tensioner" is to keep the belt tight after it is TENSIONED Correctly

No offense (or if so, whatever) but this is one of the dumbest things I've read. Isn't the definition of a tensioner (in this case) a device that keeps tension on a belt? So if the DSM tensioner isn't a true tensioner, how exactly does it keep the belt tight without putting any tension on it via the pulley? And if it does keep tension on the belt (duh), why can't we call it a true tensioner?

If you know all these answers why you asking a basic ?'s

I didn't. I responded to the OP and offered some advice on where to find some answers. If you are referring to my similar thread, we were discussing if my pulley orientation (which has most likely changed due to new deck/head geometry) is now an issue because it's very close to rubbing the bracket, as well as the cams being off a degree or two after calibrating true TDC.

Did I say anywhere put the pulley where-ever you want ? Nope

Yep

where the dots are don't matter

BTW - they aren't dots. They are alignment holes for an ADJUSTMENT TOOL

I often wonder why I spend so little time here, then I am reminded within a post or 3

Because many of us trust that the automotive engineers know more than we do, and prefer to do things the correct way, rather than telling people to "just stick it anywhere. it doesn't matter"?


********

... wow.

I have no doubt you know what you are doing, and you have the skills to make it work for you. But I think telling people that something doesn't matter when a factory manual clearly states otherwise is both irresponsible, and just plain bad advice.

I have a pretty good idea (theory) why the pulley will work in different positions, and also why it's not recommended by the factory. If you change belts often or run a stretch-resistant belt, it probably will never be an issue. But depending on the components being used, the pulley position will change the belt geometry and the amount of adjustment that the tensioner can make in the long run.

For someone planning on getting 60k miles between belt changes, or running a cheaper t-belt, that may be an issue, so being concerned that it is done properly makes a lot of sense.

But like you say, to each his own.

 

[Fast-Orange]

I read a good article and it went something like this; get some long 90DEG needle nose pliers, cut the arms so their short otherwise you will hit the ac compressor and grind the ends so you can fit them in the tensioner pulley holes.

1- Remove the auto tensioner and compress it very slowly in a vise then when the holes are lined up insert a drill bit to keep it inline and reinstall it on the car.

2- Make sure the pivoting arm is against the auto tensioner and use your pliers to rotate the pulley CCW and put tension on it until you can freely slide the drill bit in the auto tensioner in and out, hold it there and torque the pulley bolt.

3- Rotate the engine a couple times and make sure your cam and crank timing marks are lined up then remove the pin and rotate some more and check the how much the auto tensioner is sticking out, it should be right in spec by doing it this way.

I did it about a week ago.

 

[blcknspo0ln]

http://www.dsmtuners.com/forums/art...l-installing-timing-timing-belt-6bolt-2g.html

I outline exactly WHY you need to either choose CW or CCW for your specific application. Of course, the article is written for a 2G motor mount, so YMMV. The difference is the tensioner ARM you are using. You can see the length and mounting differences in my pictorial. To answer the *IF* before, YES you can adjust a timing tensioner pulley either way and end up with a correctly tensioned belt (and pass the grenade pin test), BUT in my experience the pulley starts rubbing against timing belt teeth (I ruined a brand new timing belt like that).

Be wary and choose your specific application and all is gravy. The theory behind the mitsubishi tensioner system isn't exactly rocket science. I will agree with nvisibl and say that the autotensioner is more definitely a sub-system in which it really isn't active. The tensioner pulley is the key to maintaining proper tension.