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Re: Belt issues
Posted by: DaveO90s4 ()
Date: May 05, 2022 03:15AM

Photos - before drilling the hole for the idler pulley axle. I wanted to mount it first to be sure of getting correct axle hole location.



Edited 1 time(s). Last edit at 05/05/2022 03:22AM by DaveO90s4.

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Re: Belt issues
Posted by: DaveO90s4 ()
Date: May 05, 2022 03:16AM

more photos

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Re: Belt issues
Posted by: Frank DuVal ()
Date: May 05, 2022 09:03AM

Great work Dave!

Frank DuVal

Fredericksburg, VA

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Re: Belt issues
Posted by: CREATIONBLUE ()
Date: May 05, 2022 01:19PM

Woah Dave. Thanks for posting, there’s a lot of information here so will digest in chunks.

Here’s my belt running in the grove, ran this way for years



The pointy part of the belt running in the groove as you would (I would) expect.

I was a little confused with you point of how the belt runs in the groove so let’s make sure this bits correct before going any further

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Re: Belt issues
Posted by: CREATIONBLUE ()
Date: May 05, 2022 01:41PM

OK

So just re-read your reply and went and looked at my pulley's and there isn't much in the way of room between the crank and the guide/alt pully's for the belt to twist is there! Both looked pretty much spot on as far as inline with the crank goes, The minimal movement involved by adjusting the tension doesn't seam to knock it off track or at least by eye it doesn't look like it would cause my problem.

I will take the belt off tomorrow and check how free moving everything is, Didn't do this when I had the chance on the side of the road as was more concerned with getting on my way thumbs down

Thanks for the great reply though and I'm sure I will find the answer thanks to your explanation

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Re: Belt issues
Posted by: DaveO90s4 ()
Date: May 05, 2022 02:22PM

You are fortunate that you can see what is happening with the belt. On my 914 installation, being mid-engine, the crank pulley is hidden down in the bowels of the car close to the firewall. So pretty hard to observe in my car.

But what I could see, before I had my vertical adjuster, and with everything else correct, that at correct tension the belt would flutter as it argued with the arrival at the crank V.

What I meant about how a V-belt is meant to run in a V pulley:- The angled sides of the belt are meant to run against the angled sides of the pulley. The narrow base of the belt is not meant to / must not be touching the narrow bottom V of the pulley. If the belt is too narrow, or the pulley V too wide, then that will occur. If that occurs the belt will slip, and both the belt and the pulley will get very hot. So if your alternator pulley is not a genuine corvair part, then that could be part of your issue.

That slippage and heat then leads to to other issues (in my view). Firstly, being so hot, the belt is likely to stretch / get thinner, to exacerbate the initial slippage problem. Secondly, by running too low in the V of the alternator, the effective length of the belt is increased. That means that more fore / aft adjustment is needed to get correct belt tension. That in turn means the belt is not arriving nice and straight at the crank pulley V and strips rubber off the side of the belt - thus making it then run even lower in every V groove, creating heat, increasing effective length, etc. A vicious (belt) circle :-)

I am not an expert in Corvair engines at all - in fact my engine is the only corvair engine I have ever seen. I have never even seen a Corvair car 'in the flesh'!!

But I have spent a lot of time worrying this particular problem to death on my reverse rotation engine. Plenty of people seem to manage without a modified belt tension system. I could not. Maybe because my car runs upside down, being DownUnder!!

You say yours ran fine for years - in which case I would suggest that you make absolutely sure that your alternator pulley is a genuine Corvair pulley (get another one to try? - don't be overly concerned about pulley fan blade orientation for testing purposes) and that your belt is the correct width for Corvair pulleys.

If that doesn't fix the problem, and everything else is fine, then you, like me, may need to consider replacing your tension adjuster with one that works vertically. Pretty well a 'set and forget' project.

Cheers
DaveO

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Re: Belt issues
Posted by: DaveO90s4 ()
Date: May 05, 2022 02:25PM

PS - how do you change you belt with your oil lines running as they do? Undo the oil lines each time? Have a look at the first photo I posted - you will see that the way I have run my oil lines they do not impinge on belt changes. Worth considering?

DaveO

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Re: Belt issues
Posted by: CREATIONBLUE ()
Date: May 05, 2022 02:43PM

I have to take the rear apron off, take the oil lines off then I’m good to go. Reason being the oil filter is sited under the N/S battery tray on my van. Did notice your pipes tho and the neat path they take. Previously only ever changed it once and that was a few years ago, that was kind of my fault as I refitted the original one I had on the engine even tho it had a nick in it then drove thru the night. Of course I wasn’t making a voltage and the battery ran out causing all kinds of fun power delivery issues lol

I’m pretty good with this engine now having taken it out frequently and changed seals etc. only seen 1 Corvair here in the uk, just love this motor tho for its sound and torque delivery



Edited 1 time(s). Last edit at 05/05/2022 02:50PM by CREATIONBLUE.

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Re: Belt issues
Posted by: American Mel ()
Date: May 05, 2022 05:57PM

Just adding a couple things here.
I remember someone posting some time back regarding the way the fanbelt entered the Harmonic balancer, and the solution, or at least a "help" they used, was to machine a small radius on the edge of the outer most side of the V-groove. (the side away from the engine)
The idea was that it would provide a smoother entry of the belt into the groove.
.
CreationBlue, Another thing I remember being mentioned by someone else who had oil-lines running the way you do it that when ever they replaced a broken belt, the installed ONE on the engine, and threaded a SECOND one through the oil-lines and kept it coiled up off to the side snugged out of the way with a couple of zip-ties.
That way, if they ever had one break/snap, or otherwise fail by the side of the road, it was a rather quick and simply job to replace it and be up and running again.

-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-
WA. state, 1 mile south of the Canadian border, I am not at the end of the world, but you can see it from here.

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Re: Belt issues
Posted by: chuckvh ()
Date: May 05, 2022 07:07PM

Maybe I’m seeing things, but that alternator pulley looks too big to me. The fan blade orientation is correct for RR, but if the pulley diameter is too large, then you will have multiple alignment issues as well as poor charging.

Chuck vonHofen
Brentwood, California

66 Corsa Turbo Convertible
64 Spyder Coupe
Too many boats
Amazingly Patient Wife

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Re: Belt issues
Posted by: American Mel ()
Date: May 05, 2022 07:23PM

Chuck, what you are looking at is not the pulley diameter, but rather a disc that was installed to help prevent the belt from jumping out of the pulley.

CreationBlue stated, "The alt has the correct fan for a reverse rota engine and a disk that helps to keep the belt on the alt (a prob on a reverse motor without it) all bought from Clarks."

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WA. state, 1 mile south of the Canadian border, I am not at the end of the world, but you can see it from here.




Edited 1 time(s). Last edit at 05/05/2022 07:26PM by American Mel.

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Re: Belt issues
Posted by: chuckvh ()
Date: May 05, 2022 08:39PM

Mel, I did read that but something still looks wrong to me. Per Clarks, that pulley/fan set is supposed to allow the belt to sit deeper in the groove and keep the belt away from the fan blades, but it looks like the belt is riding at the outer edge (you can’t see the pulley, which should be visible with the deeper groove). Also, look at the belt depth on the adjuster pulley and compare it to the 914 engine pic. Also looks like the belt is riding at the outer edge of the fan pulley. Maybe the wrong belt?

Chuck vonHofen
Brentwood, California

66 Corsa Turbo Convertible
64 Spyder Coupe
Too many boats
Amazingly Patient Wife

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Re: Belt issues
Posted by: 63turbo ()
Date: May 05, 2022 09:18PM

The alternator pulley looks looks like it has a "standard" rotation offset to it, meaning the belt is not tangent to the crank pulley. This is on purpose and is done to provide a little more clearance to the belt as it rotates into the crank pulley. On a reverse rotation set-up, this offset is wrong though- alternator pulley ought to be more forward, the idler needs to be more rearward.

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car
Test Start#2 [www.youtube.com]



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Re: Belt issues
Posted by: DaveO90s4 ()
Date: May 05, 2022 09:34PM

This is the alternator pulley that was on my reverse rotation engine when I bought it. It looks very similar to the pulley on the original poster's engine. Alternator pulley ran very hot, belt very hot etc etc.

When I eye-balled horizontally and sideways across the engine at belt height, I could see that, with my original pulley, that the belt at the alternator end and side was a different height from the belt at the tensioner end and side.

Replacing that with the '64 Corvair pulley made a very significant improvement in my case.

Is there a design or manufacturing fault with the shiny brass coloured pulleys with the outer 'keeper' and reversed alternator cooling blades?

Kevin, way way back I think I recall you making a similar suggestion to me, as you have just done above, re where the alternator pulley should be fore and aft. Maybe my use of the '64 pulley (different diameter from the original one in my photo immediately below) was enough to achieve what you suggest without actually doing anything other than change the pulley? And likewise my vertical belt tensioner adjustment probably achieved on that side what you are also proposing for that side?

To the original poster - your alternator pulley may be the prime suspect!

Cheers
DaveO



Edited 1 time(s). Last edit at 05/05/2022 09:35PM by DaveO90s4.

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Re: Belt issues
Posted by: DaveO90s4 ()
Date: May 05, 2022 09:44PM

And more.... (sorry!!)

CreationBlue - look how high your belt is running on your belt tension adjustment pulley compared to mine. And look how high your belt is running in your alternator pulley, compared to mine when equipped with the same alternator pulley (I think?) as you are using. Does it look to you as if your belt is running markedly higher than in my photos? What belt are you using? 5/16th wide or 3/8th (i.e.6/16th) wide?, metric or imperial? Or am I imagining things.

Can you please post the markings printed on the belt.

Maybe someone who has seen more than one Corvair engine in their life could comment - I could well be wrong.

EDIT - just saw chuckvh's post - I think he is on to something here.

Cheers again
DaveO



Edited 1 time(s). Last edit at 05/05/2022 09:46PM by DaveO90s4.

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Re: Belt issues
Posted by: 63turbo ()
Date: May 05, 2022 09:48PM

DaveO90s4 Wrote:
-------------------------------------------------------

>
> Kevin, way way back I think I recall you making a similar suggestion to me, as you have just done above, re where the alternator pulley should be fore and aft. Maybe my use of the '64 pulley (different diameter from the original one in my photo immediately below) was enough to achieve what you suggest without actually doing anything other than change the pulley? And likewise my vertical belt tensioner adjustment probably achieved on that side what you are also proposing for that side?
>
> To the original poster - your alternator pulley may be the prime suspect!
>
> Cheers
> DaveO

Yes, you made a HUGE improvement in that offset relationship with the changes you made. It also looks like you are using a belt that seems to be the correct width, but the original poster's belt looks like it is wide, which may be a part of the problem. The correct belt width is 3/8" or 9.5mm and that "wide" belt looks like 7/16" or 11.1mm, which is the belt width people have been known to run in a pinch. The 3/8 belt will sit down farther in the grooves.

------------------------------------

Kevin Nash
Friday Harbor Washington
63 Spyder, Daily driver, EFI read about my project here: [corvaircenter.com]
first test start on EFI here:[www.youtube.com]
first official EFI boost test here:[www.youtube.com]
My new fan! [corvaircenter.com]
engine less 62 Spyder
Canadian 64 Monza Parts car
Test Start#2 [www.youtube.com]



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Re: Belt issues
Posted by: DaveO90s4 ()
Date: May 06, 2022 01:00AM

CreationBlue - more grist to the mill:-

The alternator pulley that was originally on my engine - and looks remarkably like yours - was 67mm diameter. It was an engineering failure.

The '64 OEM Corvair alternator (well, generator back then) pulley that I replaced it with is/was 78mm diameter.

The 67mm (wrong) pulley coupled with the 3/8th (correct) belt meant the tension adjustment had to be so far adjusted that the belt arrived at an unacceptable angle to the crank pulley.

I wonder if someone has tried to 'correct' that by running a wider belt that then has to run higher up in each V?

(The OEM idler pulley is not a sound design for our reverse rotation engines. You may get away with it, as others have done, but....)

Cheers
DaveO

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Re: Belt issues
Posted by: CREATIONBLUE ()
Date: May 06, 2022 04:07AM

Ok

After having this issue last week I looked in this very forum and read that this belt was the one to get. Luckily I was able to order two from Amazon with shipping to the UK for a reasonable price.



Here is the measurement



I’m the passed I’ve not looked into the belt specifics and either bought from eBay or added one to a Clark’s order. Maybe I’ve been lucky?

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Re: Belt issues
Posted by: DaveO90s4 ()
Date: May 06, 2022 04:25AM

Are you saying that the 3V560 (10mm x 1422mm) is the belt shown in your photos to date, or that this is a new belt just ordered, different from the one already fitted, and is yet to be fitted? If the latter - good.

But if the alternator pulley is the wrong diameter, your tension adjustment will not be in the middle area and your belt arrival at the crank will be off

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Re: Belt issues
Posted by: CREATIONBLUE ()
Date: May 06, 2022 04:40AM

I ordered two of these belts, one is fitted.

Here is the one that’s now fitted and was causing flipping (not actually coming off) issues. The one pictured above may be the previous one that lasted a couple of miles before being thrown off completely.




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