Timing Chain Tensioners: A comparison

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cleverusername
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Re: Timing Chain Tensioners: A comparison

#46 Post by cleverusername »

Toledo Man wrote: Fri Jun 27, 2014 7:47 am This is a classic example of where we should pay that bit extra for a decent quality part. A small price to pay for total peace of mind.
The problem with that is there isn't always a direct link between quality and price. I have been burnt when going for the more expensive option in the past.

The problem is the attitude of parts supplies, who sell parts they know are substandard, grumpily saying that people won't pay more for quality; when that isn't the case. People want to get the best price, cars are expensive to run and nobody wants to be ripped off. If I can get the same part for a lower price or with cheaper postage elsewhere, I will. I make no apology for that. In the same way parts supplies will expect the best deal from their supplier.

I do expect parts to be fit for purpose and parts that fail virtually instantly are not fit for purpose. I can't think of another industry that sells to the public that gets away with selling defective products as a matter of routine.

We only know the Rolon tensioners are garbage, because people have had their cars damaged by them. Until then people people bought the part in good faith.

The other issue is that a part that is quality now can suddenly have a bad batch or the manufacturer cuts corners and it becomes bad. I wonder how many cars have been lost, because people have lost patience with all of this?
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Re: Timing Chain Tensioners: A comparison

#47 Post by tony g »

So Im a bit confused here (not uncommon :) ) does the hole in the shaft drop oil onto the chain Before it gets to the pad due to the angle of the chain relative to the pad? Ive not got enough here to mock one up yet.

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sprintchris
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Re: Timing Chain Tensioners: A comparison

#48 Post by sprintchris »

Just fitted this to my rebuild.

May have a spare if anyone's interested.

Chris.
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Re: Timing Chain Tensioners: A comparison

#49 Post by tony g »

Chris can you PM me with a price please if you have another?

Cheers

Tony
sprintchris wrote: Mon Jul 03, 2017 11:09 pm Just fitted this to my rebuild.

May have a spare if anyone's interested.

Chris.
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xvivalve
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Re: Timing Chain Tensioners: A comparison

#50 Post by xvivalve »

OK, time for an update...

I have only just found out as I tried to replace the last Jaguar unit I had by me which I recently sent out to Geoff Sparkes in New Zealand, how much the trade price for the Jaguar ones has risen by over the last few years; put it like this, with Robsport charging £72.00 for them, they're not making a lot of profit!!!

The Rolon slipper pad failure is now affecting MGA/B/C owners and basically anything that uses 'B' series engines; one MG forum has even referenced this thread, so quality tensioners are now in demand. It has been the case for a while that some Jag specialists have superseded the EAC3629 part number and will supply Rolon rubbish instead.

The New Zealand connection continues as I've been conversing with Bob Wyber over recent months having sent various parts out to him in Dunedin, and during their lockdown Bob has been doing some sterling research into alternatives, so my thanks to Bob for sharing his knowledge with me, which I'll now share with the forum plus a bit more.

The OE MGA/B/C timing chain tensioner is very similar to 'ours', but it too is now copied by 'Made in India' Rolon and is no better quality with many slipper pad failures being reported. Bob found a UK supplier who had a quantity of new old stock, boxed OE 'British Leyland' made in the UK slipper pads for the MG tensioner, which I have now acquired. They differ from the Triumph and Jaguar parts in that where ours have a 'push to release' function post installation which applies the spring tension, the MG version relies on an allen key to rotate the plunger inside the slipper pad shaft post installation to release the tension; this relies on the chassis casting of the tensioner having a co-axial hole so the allen key can be inserted. The hole is tapped to receive a blanking bolt to prevent the oil pressure escaping in use. Other than this hole and bolt the chassis seems identical to Triumph OE with the correct bolt hole spacings to mount to our engine block and with a locating dowel on the back face through which the oil feed runs. The dowel does seem to be a 'gnat's cock' width too big to fit into the hole on a Sprint block, but the only block I have to hand to test it on at the moment is one that has been sitting in my back garden for the last 20 years as an ornament, so it may be the hole in it is contaminated or oxidised...but even if there is a compatibility issue, opening up the hole in the block for the 5 mm or so the dowel protrudes isn't going to be difficult, or alternatively grind the dowel off. The BMC slipper pad has the hole in the rubber to directly lubricate the chain which has been missing on some aftermarket versions.

Anyway, to cut to the chase, there is no known problem with the chassis component of the Rolon brand tensioners, just the slipper pads. Therefore, sourcing a BMC Rolon tensioner, discarding the slipper pad and replacing it with one of the NOS OE slipper pads I've acquired will give a reliable tensioner combination which isn't going to fall apart. I've bought a couple of the Rolon tensioners (with hole and bolt variety) to do just that, and am looking into sources for economic supply of more.

Shortly, I hope to be able to provide costings for supply of a tensioner and OE BMC slipper pad combination, or if you are lucky enough to have the type of chassis with hole and bolt already, I'll be able to supply a quality slipper pad on its own. No doubt some of you are equipped and competent to drill and tap the 'blind' type of chassis also.

Anyway, pictures, as they say are the equivalent to a thousand words:

This is the BMC style tensioner, note the bolt on the back face of the chassis and the dowel on the mating face:

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This is the new old stock OE slipper pad:

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This is the NOS BMC slipper pad (top on first photo', bottom on second) next to a Jag slipper pad to show the fundamental difference between the two; there is a very slight difference in the curvature of the rubber profile, but in my opinion this is not significant:

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This is the NOS BMC slipper pad (LHS) next to the Rolon rubbish variety; note how the NOS BMC one envelops the edges of the metal pad, whereas the Rolon one just sits on top of it:

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So, whilst stocks last (should be a while, I might even be able to let MG owners have one or two!) we now have an economic solution to the Sprint timing chain dilemma.
Last edited by xvivalve on Tue Aug 17, 2021 10:53 pm, edited 1 time in total.
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Well done….

#51 Post by sprint95m »

:thumbsup:



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Re: Timing Chain Tensioners: A comparison

#52 Post by Tony Burd »

Great stuff

We need to get through to people don't throw away your old renold slipper, even if it is a bit worn you can reuse it by resetting the curved guide to take up the slack with the tensioner 'reset'.

I know people want new when doing a rebuild, so the above is a great option, but won't last forever so we need to keep the used stuff.

Hope that makes sense, I'm a few beers in😀
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Re: Timing Chain Tensioners: A comparison

#53 Post by new to this »

Just an idea,Chris Witor had made poly engine mounts,how feasible would it be to have a new Slipper made in poly ?

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Re: Timing Chain Tensioners: A comparison

#54 Post by Bish »

Good work Alun & Bob.

I too had been looking at the MGA/B Renold versions, and was set to buy one, but thanks to Aluns supply of a Jag tensioner I didn’t have to take that gamble.

There were still a couple of original BL / Renold boxed tensioners for the MG on eBay last time I looked. Cheap too!
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Re: Timing Chain Tensioners: A comparison

#55 Post by xvivalve »

I can now supply the following:

1. Original NOS BL branded 'Made in England' slipper pad: £24.00 including postage (if you already have a tensioner chassis with the access port and blanking bolt).

2. Original NOS BL branded 'Made in England' slipper pad together with a new Rolon branded tensioner with the access port and blanking bolt: £35.00 including postage.

Send me a PM for details.

IF YOU BUY OPTION 2 I WILL REMOVE THE CRAP SLIPPER PAD AND DESTROY IT TO PREVENT THEM BEING PUT INTO A TOOL BOX AND FORGOTTEN ABOUT UNTIL FOUND IN YEARS AHEAD AND USED WITH THEIR ORIGIN HAVING BEEN FORGOTTEN!

I note this morning the Jaguar spec items are now a heady £81 from one supplier!
Last edited by xvivalve on Mon Apr 14, 2025 3:05 pm, edited 4 times in total.
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Re: Timing Chain Tensioners: A comparison

#56 Post by xvivalve »

new to this wrote: Tue Aug 17, 2021 11:22 pm Just an idea,Chris Witor had made poly engine mounts,how feasible would it be to have a new Slipper made in poly ?

Dave
Do the properties of 'poly' lend themselves to resist abrasion by a chain under tension running at 6500 rpm?
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Re: Timing Chain Tensioners: A comparison

#57 Post by yorkshire_spam »

xvivalve wrote: Sun Aug 22, 2021 12:44 pm
new to this wrote: Tue Aug 17, 2021 11:22 pm Just an idea,Chris Witor had made poly engine mounts,how feasible would it be to have a new Slipper made in poly ?

Dave
Do the properties of 'poly' lend themselves to resist abrasion by a chain under tension running at 6500 rpm?
I would have thought something with a higher hardness and better wear properties would be more suitable
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Re: Timing Chain Tensioners: A comparison

#58 Post by xvivalve »

New Rolon branded tensioners with the access port and blanking bolt now seem to be in short supply globally and whilst I have some on back order I don't have any by me...so a short delay...
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Re: Timing Chain Tensioners: A comparison

#59 Post by xvivalve »

I have now secured half a dozen Rolon units with the blanking bolt.
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