serp belt tension

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Seight-V8
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serp belt tension

Post by Seight-V8 »

Hello all,

Im struggling with some over heating problems, on my rover v8 4.6 westfield and I've noticed that the water pump pulley is slipping, unless i tighten the belt very tight, and that i dont have much contact on the pulley, due to the belt layout.....

I am thinking might be best to get the smooth pulley surface, slightly knurled at work, to see if this helps.

But I'm also wondering if i can squeeze a tensioner in on the right hand side of the engine somehow, but to get the pulleys to line up might be difficult.

Anyone done something similar or got a good suggestion on how to fit it all in?

The current tension is set via the little rack N pinion type wheel setup on the edge of the alternator bracket, not the best i know, but the recommended setup from westfield.

Image

regards
scott



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Re: serp belt tension

Post by garrycol »

You are missing an idler pulley on the RHS - I had the same issue on my Fc 101 - there is not enough contact between the belt and water pump pulley - it needs to go around the bottom of the water pump and up to the idler and back down to the crank etc. See my pic below

Do not burnish the water pump pulley, it will make the belt fail quickly.

I have the extra stuff on the left side but yours should work with just the extra idler on the right hand side - can you not fit a standard tensioner without the idler I have on the LHS - when setting mine up I did have the option of no LH idler but as I had the room I put it in.

Garry
My Truck Serp layout.jpg

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richardpope50
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Re: serp belt tension

Post by richardpope50 »

Yep, I had your set up and the belt slipped. So then I put a self-tensioner on the RHS (looking at your engine) and it made no difference. Then on this forum it was pointed out that the self-rensioner MUST be on the LHS as when you blip the throttle the pull simply slackens the belt. So I made up a strong bracket for an idler wheel (off the self-tensioner) that you can just see in this photo.

Image

I ended up with a simple W shaped belt run. BTW it is easy to get belts any size you want if you did not know. Just find a local belt motor factor.

Next thing, I was still having cooling probllems (turned out a blocked rad) but still decided to have a two way rad. Very easy to do by putting in a baffle plate in the header tank and move the outlet from the bottom to the top. This makes an enormous difference as the water is forced down the RHS and up the LHS and gets cooled by virtually the whole of the rad instead of the water just going from top right to bottom left.

My car is pretty much the same as yours.
Richard.
Dax Rush 5.0l TVR V8, EFI with Megasquirt ECU and wasted spark, Racelogic Traction Control and Quaife LSD ....... Now nut and bolt restoring a TR6

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richardpope50
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Re: serp belt tension

Post by richardpope50 »

+ I made my own adjustment mechanism using a long bolt pivoted between the alternator and water pump bolts just seen in the above photo. Again easy to do and like your solution.
Richard.
Dax Rush 5.0l TVR V8, EFI with Megasquirt ECU and wasted spark, Racelogic Traction Control and Quaife LSD ....... Now nut and bolt restoring a TR6

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Re: serp belt tension

Post by richyb66 »

I posted my solution in this thread

viewtopic.php?f=12&t=15309&p=117028#p11702
and a more detailed photo here

viewtopic.php?f=12&t=15409&p=117660#p117660

Done over 10k miles with no issue.

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Re: serp belt tension

Post by SuperV8 »

As suggested in several other posts about your overheating problem - this explains you overheating problem. Insufficient belt wrap arround the water pump pulley.

In this case you just need an idler pulley on the right hand side of your engine so the belt can wrap at least 180 degs arround the water pump pulley.
Dax Rush 4.6 supercharged V8 MSII

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Re: serp belt tension

Post by garrycol »

SuperV8 wrote:
Mon Sep 07, 2020 12:23 pm
In this case you just need an idler pulley on the right hand side of your engine so the belt can wrap at least 180 degs arround the water pump pulley.
As per my pic :D

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Re: serp belt tension

Post by Seight-V8 »

I've done some more work, found out the alternator wasn't directly in line with the water pump & crank pulley, as they belt looked a little frayed on one side so i've realigned it, will try it again later today.

I do need to get more belt on the water pump pulley, but as i run the intermediate front cover, i need something on the right hand side of the engine to bolt a idle wheel to.....

Does anyone know of any engine brackets that i could modify to fit a belt wheel?

Don't want to spend ages trying to make my own, if there's a quicker solution out there.

Cant seem to find any parts list of what engine the intermediate cover was on to start with....so i could look at belt layouts.

thanks
scott

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Re: serp belt tension

Post by garrycol »

In the vehicle the engine came out of, there would have been a bracket there for the power steering pump etc so go to a wrecker and get one. Or else make a simple spacer bracket - just a U shaped bracket bolted to the head and the pulley on the other end - easy peasy.

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Re: serp belt tension

Post by Seight-V8 »

sounds like that might work, i did some googling.... and came up with err6894.

https://www.ebay.co.uk/itm/Discovery-2- ... SwUHNe~NSe

Does anyone know if this does bolt directly to the holes on the right and side of the head?

Looks like i could cut it down to make it fit my space.

cheers
scott

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Re: serp belt tension

Post by garrycol »

Yes it will bolt but you have a 3.9 not a 4.0/4.6. The 4.0/4.6 does not have the dizzy so a shorter timing cover and water pump - you could use that mount but as is will not bring the pulley out far enough so you will need to space out the pully.

Get the same basic part but one off a 3.9.

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Re: serp belt tension

Post by richardpope50 »

The power steering pully bracket is huge and won't fit in my Dax Rush so very unlikely to fit in yours. The pullly bracket required sticks out several inches from the block so it is not just a U bolt thingy. I suspect you will have to make your own to miss chassis members as I had to do.
Richard.
Dax Rush 5.0l TVR V8, EFI with Megasquirt ECU and wasted spark, Racelogic Traction Control and Quaife LSD ....... Now nut and bolt restoring a TR6

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Re: serp belt tension

Post by SuperV8 »

Discovery series II bracket looks like it has an idler in a better position - so you get more coolant pulley belt wrap:

https://rimmerbros.com/Item--i-GRID800035

One of these?

https://www.ebay.co.uk/i/293439622538?c ... zcEALw_wcB

Would probably only need two mounting bolt holes into the head - and the one idler pulley mounting hole - the rest can be cut off and sanded smooth.

Actually the bracket you posted looks like it also has a idler mounting hole to the left of the bracket mounting holes but is not used in the ranger rover so either might work.

Would need to add spacers to get the alignment correct as these are from GEMS engines with lower profile front covers.
Dax Rush 4.6 supercharged V8 MSII

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