Tensioner sounds

[heyitsrama]

@Zed Head Both the old and new pulley have a hub depth of 27m.. The motor is a l26. I think it should be OK. Thanks for the heads up.

@Racer X I’ll have to double check the fan when this is all installed properly. There seems to be a slight resistance to the fan. I wonder if I can simulate the opening of the plate with a heat gun, just to bench test it. I’ll get a video up later.

there is a difference in diameter of the pulley.

the new one seems to be lighter so that’s nice.

 

[heyitsrama]

Ah crud. Does TDC matter in this case? I thought I’d be OK because I did not touch the chain. 🤧

[Zed Head]

That's what the keyway and key are for.

Check the timing notch on the damper.  Early 240Z's had several, 280Z's have one.  And they might be on the wrong sides.  Make sure new matches old or you won't be able to set your ignition timing.

[heyitsrama]

It’s slightly off, but I think that’s the diameter change, would the face plate used for an indicator make a difference?

[Zed Head]

I wasn't thinking that your damper had fallen apart.  Are you sure that the pulley matches the spot on the hub that it did before it fell apart?  Match the rust or paint marks, I guess.

[heyitsrama]

Ahhhhhhh you’re right! I completely forgot that i had pulled it apart, I don’t think I have markings I can check to align it back to its original spot. >.> 

[Racer X]

1 hour ago, heyitsrama said:

 I’ll have to double check the fan when this is all installed properly. There seems to be a slight resistance to the fan. I wonder if I can simulate the opening of the plate with a heat gun, just to bench test it. I’ll get a video up later.

There should be some resistance, easy to turn pushing on it with a finger, but doesn't spin freely. It is a viscous coupling. The bimetal spring moves a plate, closing the gap between the two parts of the clutch. The unique property of the silicone fluid is the more it is pushed on the more it resists. so the heat coming off the radiator changes the shape of the bimetal spring, which pushes the plate against the fluid, and the fan becomes increasingly coupled (although it never is fully coupled, similar to a torque converter in an automatic transmission), and the fan pulls more air through the radiator.

So sounds like yours is OK in that regard.

In my years as a mechanic I knew other guys who would grab the fan blade while the engine was running, and stop it from spinning, while the engine continued to idle away.

These were the same knuckle draggers who checked for the presence of spark, or leakage in the plug wires with their hand.

When you get it on the water pump hub, and the bolts tight (tip: use the belt to hold the pulley while tightening the nuts), check the fan clutch bearing for play. There may be a spec, but a feel can be developed for this. A used clutch will have a minor amount of play. As long as the fluid isn't leaking out, it should be good to go.

 

Quote

there is a difference in diameter of the pulley.

the new one seems to be lighter so that’s nice.

It will be lower in weight, there is a large difference in size, and with it, the rotating mass. I use the small single groove balancers on my race engines, to reduce the total rotating mass. when building engines, all the rotating parts should be balanced as a unit, but for street use changing a pulley 'shouldn't' be an issue. 

Just be mindful when winding it up tight, and note if there are any vibrations that weren't there before.

Edited January 6, 2021 by Racer X

[siteunseen]

I've always read 2 full turns when spinning by hand is okay, more than that and you need a new clutch. And for the knuckle draggers, some advice, use a piece of cardboard to go in and gradually try and stop it. If you can stop it you need a new one. My experience only. I'm no mechanic FWIW.

If you can stop it pretty easy you need a new one, IF YOU CAN'T STOP IT ALL, you need a new one. Sorry but I forgot they do freeze up and sound like an airplane.

Edited January 6, 2021 by siteunseen

[heyitsrama]

Looks like the balancer swap fixed the noise from the front of the car. It looks like there is a slight offset between the alternator pully and fan pully / crank pully. I think the belt is too long for the smaller diameter of the new pully, its almost at the end of the adjustment

 

@Racer X @siteunseen

Here is the resistance that I was facing on the clutch. I was thinking that with this much resistance on the clutch fan it might be `coupled` all the time. It does not sound like a vortex, but i can definitely feel the airflow when its cold. 

 

[Zed Head]

That fan clutch looks fine.  Loose when cold, tightens up when it gets hot.  

[Racer X]

1 hour ago, heyitsrama said:

Looks like the balancer swap fixed the noise from the front of the car. It looks like there is a slight offset between the alternator pully and fan pully / crank pully. I think the belt is too long for the smaller diameter of the new pully, its almost at the end of the adjustment

 

@Racer X @siteunseen

Here is the resistance that I was facing on the clutch. I was thinking that with this much resistance on the clutch fan it might be `coupled` all the time. It does not sound like a vortex, but i can definitely feel the airflow when its cold. 

 

For the belt, get one the next size smaller. Belts are designated by the overall length, usually in inches. The part number should have that length as a portion of the number. 

When you mention the pulley offset, are you referring to alignment, as viewed at right angle to the crankshaft centerline? If so, they should line up. Use a straight edge to check.

 

And the fan clutch looks fine. Did you check the bearing play?

Also, check that the engine is getting to operating temperature, as I described earlier? If the radiator tank and thermostat housing are close to the same temp, and that temp is low in both places, the most likely cause is a thermostat that isn't closing.

If you still feel the fan clutch isn't working right, take it off, and reattach the water pump pulley, and take a short drive. If the car gets to temp, then you can suspect it. If not, I'd go back to the thermostat as the cause.