Serp fan belt routing - no PAS or AC

Serp fan belt routing - no PAS or AC

Author
Discussion

_Cosmos_

Original Poster:

35 posts

5 months

Monday 8th July
quotequote all
I've been thoroughly enjoying putting a few miles on my new Chim over recent weeks and have also been trying to learn about the various bits and bobs along the way.

Car is running great but am keen to stay on top of things and slowly work through improvements/maintenance as needed - I'll definitely be using garages/specialists for the important stuff or anything I'm not comfortable with but I'd also like to try some things myself as that seems to be a really nice part of the ownership experience.

One thing I've been looking at was the fan belt - I'll try and attach some photos to this post so you can see the current routing which although seems to work perfectly, does seem a bit different from all the various photos of your cars on here as well as the engine bays I've been comparing it to in the classifieds....

Can you advise if there is a particular reason mine may have been done this way and is therefore best left alone, or should I use the new fan belt I've bought (Part number TVR E2212 from the Motaclan site) to try and re-route this so it looks more normal? Car does not have PAS or AC if that helps.

Do I need to get any special tools ready before I even think about trying to do anything here?









PabloGee

480 posts

27 months

Monday 8th July
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Certainly is different from mine, but mainly looks like the tensioner pulley is in a different position.
I have no idea why, nor whether it matters.


Belle427

9,750 posts

240 months

Monday 8th July
quotequote all
This should be the belt route.

The Three D Mucketeer

6,176 posts

234 months

Monday 8th July
quotequote all
Belle427 said:
This should be the belt route.
That's like my 450 but Isn't that WITH PAS ?

Edited by The Three D Mucketeer on Monday 8th July 10:14

_Cosmos_

Original Poster:

35 posts

5 months

Monday 8th July
quotequote all
Ah that's really helpful, Belle, thank you very much!

So if I am following the path of our belts as they currently are, it does actually seem that the way both Pablo and I have them routed means the different parts involved are all spinning in the correct way (i.e. everything other than what I think is the water pump is spinning clockwise)?

I guess I could try and loosen what seems to be a bit of rusty bolt on the tensioner and see if I can spin this around a bit to get it in a better position - does that seem a sensible plan to consider?

I'd guess that Pablo could quite easily just re-route his belt if needed/desired as all of the bits seems to be in the ideal location to match up with the diagram.





PabloGee

480 posts

27 months

Monday 8th July
quotequote all
In my car, this is the PAS pump, though you clearly have no hoses running from it, or a reservoir.
Therefore, what is it in your case?


Belle427

9,750 posts

240 months

Monday 8th July
quotequote all
Non pas should be the same as the pump is in the same place, the idler is just a gutted out pump.

PabloGee

480 posts

27 months

Monday 8th July
quotequote all
Are you meaning for both of us?
I can that my alternator has little contact...

Which direction should each element spin (clearly the crank pulley is going clockwise)?

spikep

477 posts

289 months

Monday 8th July
quotequote all
I went for a shorter belt (1260) and skipped out the aircon stand in pulley after seeing a picture on one going through the water tank when one of the engine supports failed. Was worried initially about water contact patch size but have been running it like this for over 2 years.

PabloGee

480 posts

27 months

Monday 8th July
quotequote all
I've just re-routed the belt on mine, same belt fits fine, similar tensioner position.

Also spotted a bit of belt debris on the alternator, suggesting that it has been slipping...
Might buy a new belt as part of the summer service!




BritishTvr450

417 posts

6 months

Monday 8th July
quotequote all
PabloGee said:
Are you meaning for both of us?
I can that my alternator has little contact...

Which direction should each element spin (clearly the crank pulley is going clockwise)?
Sorry my post was incorrect.
Both your cars the water pulley is running in an anti clockwise direction which is correct.
The issue will be extra strain on the tensioner pulley and or other wheels which all turn clockwise.
I think the way yours runs is usually because the correct size belt could not be sourced.

When it runs as per the drawing you’ll notice when you rev the engine the tensioner pulley takes up slack from the torque effect and then returns to a more neutral position when revs stabilise or you return to idle.

The only time you risk cutting through the water tank (swirl pot ) is when your engine mounts are knackered.
As any slacking of the engine mounts causes your nearside manifold to drop perilously close to n/s body the better solution imho is to check or replace those mounts.

If you look through the n/s front wheel arch you should see a 10 mm gap between manifold and bodywork. Anything less suggests the engine mount is failing.
Your engine should remain static when you blip or Rev your engine and if it moves because of failed engine mounts that movement is being transmitted to your gearbox mounts and slowly knackering those too.
In the past people complained the engine mounts or rubber fail. I replaced mine years ago (Powers supplied) and they have never sagged in probably 35,000 miles.

PabloGee

480 posts

27 months

Monday 8th July
quotequote all
Thank you for clarifying, after alarming me somewhat!

As you can see from my later post, I've re-routed the belt, and everything spins the way it should, as well as making more appropriate contact with each pulley.
I will take a look at the movement next time I start it up.

All mounts on my car were renewed in 2015 when it had a body-off, so I'm happy that's not an issue.

Anyway, I have unintentionally hi-jacked _Cosmos_'s thread, have corrected something on my car, and now I'll be quiet!
Thank you...!

_Cosmos_

Original Poster:

35 posts

5 months

Monday 8th July
quotequote all
Oh yes that new belt routing looks excellent, Pablo - I'm glad this thread has helped you make this little improvement too!

I think I have all the info now that I would need to be able to get this done, although I'll probably need a bit more time (and preparation) before I'd feel comfortable doing it as I really wouldn't want to break anything.

I'm still at that stage where everything on the car seems a bit intimidating so am building up the courage to start tinkering....

Thanks all for the guidance and info, amazing as always.

PabloGee

480 posts

27 months

Monday 8th July
quotequote all
Ah, I did mine wrong. I used a socket set, not a ratchet ring spanner.
An excuse to buy more tools... wink

BritishTvr450

417 posts

6 months

Tuesday 9th July
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_Cosmos_ said:
Oh yes that new belt routing looks excellent, Pablo - I'm glad this thread has helped you make this little improvement too!

I think I have all the info now that I would need to be able to get this done, although I'll probably need a bit more time (and preparation) before I'd feel comfortable doing it as I really wouldn't want to break anything.

I'm still at that stage where everything on the car seems a bit intimidating so am building up the courage to start tinkering....

Thanks all for the guidance and info, amazing as always.
Im not sure this post will be useful as it’s years since I replaced my tensioner but I seem to remember the tensioner case has a lug that should fit into a corresponding hole in the alternator bracket to orientate it correctly. Your tensioner is in such an unorthodox position it’s leaving me confused as to wether it’s simply been tensioned right over to that 3 o’clock position or the complete tensioner and case has been fitted in the wrong position.
Removing the belt should theoretically unwind it back to its correct position but if it doesn’t suspect it’s been fitted incorrectly.
A good tip
If you hear a slight whistling sound from that area it’s an indication the tensioner pulley bearing is worn and on its way out.
Some people suggest replacing the bearing but as this tensioner is an important component in keeping the belt at its correct tension its far simpler to just buy a new complete tensioner and replace it. It’s not expensive.
By removing the belt and spinning the wheel it should run silent. You might also notice the wheel might be slightly loose. This is a clear indication it’s cream crackered.
And to Pablo, sorry for the confusion earlier on in this thread, we all make mistakes wink

_Cosmos_

Original Poster:

35 posts

5 months

Tuesday 9th July
quotequote all
Does the fact we can see this part of the tensioner around at the 9 o'clock position help indicate how it has been mounted?

I am just guessing but I'd imagine this should be down near the 6 o'clock position?


PabloGee

480 posts

27 months

Tuesday 9th July
quotequote all
It actually doesn't look like there's any give left in it.
You can see mine sits more around 11.30-12 o'clock.
If you get a spanner or socket on the rusty nut in the middle and push clockwise, there should be a bit of movement in the whole tensioner arm and pulley.
You can try this without any risk of anything going wrong.
You also need this movement to replace the belt eventually anyway.

If you slip the belt off, you'll see the range of movement in the tensioner available to you - it's possible you'll find the tensioner is really pulled over.
You can also look at the belt length (the numbers printed on it) to cross check with hopefully someone helpful on here.

Your next move would be as suggested, to look at taking the tensioner off and rotating the mount 90 degrees anti-clockwise.
At the very least you'll learn more about your car, the biggest risk is that the rusty bolt is difficult to undo - but use some penetrating oil on it first, leave it to soak with a few repeated applications for a couple of days. Also use a socket set, not a spanner to minimise risk of rounding the bolt head.

BritishTvr450

417 posts

6 months

Tuesday 9th July
quotequote all
Unfortunately i’m not near my car today or I’d take look.
The easiest thing would be to do as suggested and try and move the tensioner to the right putting a socket on the pulley wheel nut. It should move quite easily. This will give some indication how much movement you have. At this point there’s no need to take belt off, just see if it will move freely.

Looking at your picture the tensioner is flush with the bracket which suggests it’s fitted correctly and just a shorter belt causing the tensioner to be pulled so far around.

The problem then is that position is likely to be making the tensioner weak over time or poor at actually tensioning the belt.
It’s simply there to restrict the belt from getting loose and falling off the various wheels.
It’s a service item as is the tensioner itself.
A lost belt could cause a catastrophic engine failure due to the water pump not spinning if you then miss the temp gauge rising very quickly.
Because the tensioner restricts to much pressure being applied to the various wheels it’s not something id leave for too long.

It’s times like these I found having a friendly TVR service centre very useful because they usually stock the correct sized belt.

I’d not be comfortable with using that tensioner if it is indeed simply wound that far round as it’s likely to be a bit weak.
That’s your call but for me I’d replace both the belt and tensioner for best overall life expectancy going forward.

BritishTvr450

417 posts

6 months

Tuesday 9th July
quotequote all
As a basic test try manipulating the belt between the various wheels. If it’s very tight or does not move at all that belt is too tight. They degrade and being very tight will increase that rate.