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Need some help from some miata guys


Aquafi Racing
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I do not race a miata, we race a bmw but I am building a miata for my granddaughter.  Got the car cheap as head gasket was bad. Pulled the motor did rings, main and rod bearings new gaskets everywhere.  My problem is the timing belt is way to tight.  I even ordered one from Mazda and the same thing.  We had to give them the vin number to ensure the part was right.  There are no race parts just a standard car.  Brand new water pump, idler and tensioner.   The belt that was on the car was to tight and not correct.  Is there something I'm missing?

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The basic steps are:

 

- Get crank and camshaft pulley timing marks aligned and install belt

- Rotate 2 turns to re-check marks

- Rotate 1-5/6 turns to a different mark on the oil pump (I believe) which is where you position things to tension the belt

- Torque the tensioner to spec

- Rotate the remaining 2-1/6 turns to check timing marks a final time

 

Is it possible that you're torqing the tensioner at the "wrong location" which us holding it too tight against the belt?

 

There is some info about 3/4 of the way down this page which calls out some of the details / pictures - might help to just quickly have a read through:

 

https://www.miata.net/garage/timingbelt.html

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Something is amiss with the idlers.  The belt should be all floppy and loose if it is only on the crank, intake, exhaust and drivers-side idler.  Unless something went seriously wrong with the installation of the head, but if you got that far on your own, you're smart enough to get the head bolted down correctly.

 

I'm going to ask a dumb questions, don't be offended - the idler pulley on the passengers side - it slides back and forth w/o effort until you put the belt on?  Belt isn't hung up at the bottom where it goes around the cog on the crank?

 

These motors are one of the simpler ones to do a timing belt on, don't over think it, just look at all the options for where the issue could be. 

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38 minutes ago, MMiskoe said:

Something is amiss with the idlers.  The belt should be all floppy and loose if it is only on the crank, intake, exhaust and drivers-side idler.  Unless something went seriously wrong with the installation of the head, but if you got that far on your own, you're smart enough to get the head bolted down correctly.

 

I'm going to ask a dumb questions, don't be offended - the idler pulley on the passengers side - it slides back and forth w/o effort until you put the belt on?  Belt isn't hung up at the bottom where it goes around the cog on the crank?

 

These motors are one of the simpler ones to do a timing belt on, don't over think it, just look at all the options for where the issue could be. 

The only variable is the water pump and the locations of the idler and tensioner.  I can get the belt on and everything timed right it just feels tight. Might just get another water pump.  Thank you for the help

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So, safe to say you've run the motor around a few times by hand.  It doesn't look like it is at TDC in the picture.  Safe to say you did this with both of the idlers loose?  Let them settle in and find a home where they are happy.

 

With the idler as it is, in its max-loose position, how much too tight is the belt?  I've had them where the idler is closer to one side than the other when everything is right.  Wondering if you've got a tolerance stacking going on.

 

Is this a 1.6?  The t-stat housing is not 1.8.

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On 9/19/2020 at 7:41 AM, MMiskoe said:

So, safe to say you've run the motor around a few times by hand.  It doesn't look like it is at TDC in the picture.  Safe to say you did this with both of the idlers loose?  Let them settle in and find a home where they are happy.

 

With the idler as it is, in its max-loose position, how much too tight is the belt?  I've had them where the idler is closer to one side than the other when everything is right.  Wondering if you've got a tolerance stacking going on.

 

Is this a 1.6?  The t-stat housing is not 1.8.

 

yes it was run around by hand.  It is tight enough that I can't put the belt on by hand.  yes it's a 1.6.  Tight enough that the tensioner spring cannot move the belt with everything loose.

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There should be a mounting point on the intake side of the water pump where the alternator bracket mounts to, I'm not seeing that from the picture you posted. 

 

To be fair it's been a few years since I've had a 1.6 in the car, but the orientation of the idler that is spring loaded, looks out of sorts to me. 

 

image.png.987c41a0b09a2631ddc62f14858a4f66.png

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My 1.6 is a fight every time to get the timing belt on. We use the Gates blue belt, so I'm not sure if other belts are easier to work with or not. The idler looks ok to me....I'm judging that off mine, which you can kind of see in this picture if you zoom way in on it. You can see the slot on either side of the bolt head and it looks like it's close to the same angle yours is.

20190922_124307.jpg

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On 9/22/2020 at 9:49 AM, T-PAP said:

My 1.6 is a fight every time to get the timing belt on. We use the Gates blue belt, so I'm not sure if other belts are easier to work with or not. The idler looks ok to me....I'm judging that off mine, which you can kind of see in this picture if you zoom way in on it. You can see the slot on either side of the bolt head and it looks like it's close to the same angle yours is.

20190922_124307.jpg

Thank you, I feel much better about it now.  we are finishing up the install

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