Subject: Re: [Healeys] Timing Chain Tensioners

From: Bob Spidell <[email-masked]>
Date: Mon, 22 Feb 2021 09:22:09 -0800

I can't answer your question definitively, but can say--in 
hindsight--that I wish I'd installed DWM's upgraded tensioner on my 
BJ8's last overhaul. Expensive (relatively), sure, but failure of this 
part would be near-catastrophic, and I've heard anecdotally that 
aftermarket versions have failed (and I have an inherent distrust of any 
aftermarket part with rubber). How much is (relative) peace of mind worth?

I installed DWM's flexible oil pump pipe in my BN2 on DWM's 'advice' and 
I'm glad I did. I know of at least one failure of the original, metal 
pipe (from someone on this list).

On 2/22/2021 9:10 AM, Michael Salter via Healeys wrote:
> I note that the usual suspects all now seem to be selling 2 grades of 
> 6 cylinder timing chain tensioners.
> As far as I know the more expensive variety, which are 5 times the 
> cost of the less expensive type, are relatively new on the market. 
> They are apparently made in France and come in a Jaguar/ Land Rover 
> package.
> These are slightly different from the originals in that there is a 
> lubrication hole in the rubber pad that I don't recall seeing on any 
> others that I have used.
> In my experience until very recently the rubber slippers were not a 
> problem on these tensioners but wear of the piston was pretty common 
> on higher milage ones.
> My question is are these "Premium " grade tensioners significantly 
> better and are they worth the extra cost?
>

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From: "m.g.sharp--- via Healeys" <[email-masked]>
Date: Mon, 22 Feb 2021 15:08:53 -0500

The DW tensioner is significantly different from either of the two  that Michael is referring to, and substantial more expensive than either.  I did some "research" on the web (as a scientist I struggle calling that research) when investigating tensioners for my current rebuild and from what I can figure out there are at least three tensioners on the market that will work.  This same tensioner fits MGBs, Jaguar XK engines and Land Rovers, and the majority of chatter on the web is from Jag and MGB owners.

1.	This is the “base” model which is readily available and is a copy of the original part.   The web revealed a number of reports of the rubber pad un-bonding or the whole piston popping out.  I suspect the latter must be due to a stretched chain allowing the piston to come out too far.  Many of the failures of the rubber un-bonding are from racing applications but there are a lot from road cars as well.  One English builder who races MGBs says that all his failures were on race engines and he thinks failures on road cars are very rare, but he is talking of MGBs.   Many reports name the manufacturer as “Rolon”, although there could be more than one source of this base model.  This is the “base” one that MOSS supplies and you can see “Rolon” stamped into the casting in their illustration.  It is $13 USD
2.	A French company called Renolds makes an upgraded tensioner that is visually similar to the original but apparently has better pad material  this is the one Mike has illustrated on his post.  I could only find one report of the bonding failing on this tensioner.  Reports vary, but it seems this part is the OEM Jag replacement available from dealers as part # EAC3629.  Some people had reported getting the Rolon part supplied from Jag dealers, and one report said both were available as OEM and “upgraded” OEM from his Jag dealer.  This is the tensioner sold by MOSS as their “premium” tensioner.  It appears available from other sources including Jaguar dealerships.  It is $90 USD.
3.	The third one is described as a “hydraulic” tensioner.  This is  the one sold by DW for 130 GBP.  I think that A-H spares sells the same one for 90 GBP, but the difference may be the VAT.  The one from DW has “DWR” stamped into it, but they may be adding that themselves.  This has a nylon slipper and it is narrower than the chain, whereas the other two have rubber pads slightly wider than the chain.  I cannot find any reports of this type failing, but I did find a report of it being a poor fit.  Oddly, the chat lines that had extensive discussion “Rolon” vs “Renolds”, do not mention this tensioner at all, so no information on reliability, which really means no failures (who takes the front end apart to check the tensioner is OK?).  However, I am sure that relatively speaking, very few of these have been fitted relative to all the Jag rebuilds using the Renolds unit and there are probably 1000s of the Rolon units running in MGBs.

Regarding them all being hydraulic, there is a bit of confusion, but several sources say that the oil feed is just to lubricate the pad and the tension is all provided by the spring.  However the DW one is said to be truly hydraulic.  Whether oil pressures assists with tension on the first two, or dampens the piston movement caused by oscillations of the chain, has been raised as a question, but no definitive answer.

That is the sum total of what I know about timing chain tensioners.  For the record, I opted for Moss' "Premium" tensioner (#2 above).

Cheers, Mirek
'59 BT7

-----Original Message-----
From: Healeys <[email-masked]> On Behalf Of Bob Spidell
Sent: February 22, 2021 12:22 PM
To: [email-masked]
Subject: Re: [Healeys] Timing Chain Tensioners

I can't answer your question definitively, but can say--in hindsight--that I wish I'd installed DWM's upgraded tensioner on my BJ8's last overhaul. Expensive (relatively), sure, but failure of this part would be near-catastrophic, and I've heard anecdotally that aftermarket versions have failed (and I have an inherent distrust of any aftermarket part with rubber). How much is (relative) peace of mind worth?

I installed DWM's flexible oil pump pipe in my BN2 on DWM's 'advice' and I'm glad I did. I know of at least one failure of the original, metal pipe (from someone on this list).

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From: Bob Spidell via Healeys <[email-masked]>
Date: Mon, 22 Feb 2021 13:22:21 -0800

Thanks for the good info, Mirek.

On the topic of tensioners, my '08 Mustang with 4.6L V8 used plastic 
rail-type tensioners, that were tensioned by oil pressure. Ford calls 
for their 5W-20 semi-syn oil in most (all?) of their big V8s, but some 
owners decided they knew better than the Ford engineers and put 5W-30, 
10W-30 and even thicker oil in their engines (Ford does spec a heavier 
oil for track use, to be added before and drained after track use). As 
it turns out, this caused some chain tensioners to break as the thicker 
oils didn't pressurize the tensioners as quickly on startup, allowing 
the tensioners to vibrate to destruction (an expensive fix, probably not 
covered by warranty).

I can't find a definitive source--forums don't usually count--but I 
think the 5.0L in my current Mustang has an ECU-controlled oil pressure 
relief solenoid. OP in that car pops up to 100PSI on startup--assuming 
the gauge is telling the truth--for a second, then drops to a more 
'reasonable' value (actually pretty low for unstressed cruising). I 
presume this is to assure that the top end, inc. the tensioners, get 
pressurized quickly.

Bob

[email-masked]

---

From: Michael Oritt via Healeys <[email-masked]>
Date: Mon, 22 Feb 2021 16:27:53 -0500

--===============7536524376565939272==

--00000000000029726d05bbf37ae8
Content-Transfer-Encoding: quoted-printable

When rebuilding the MGA 1622 engine in my former Elva Courier race car I
used an "upgraded" tensioner sourced from Jaguar--apparently same or
similar to the unit of which several folks have spoken.
I did so because it was "cheap insurance" for a part that is difficult to
inspect, the failure of which can have dire results.
I don't know if I made the correct decision because while the new tensioner
worked just fine so too did the "standard" one it replaced.

Best--Michael Oritt

On Mon, Feb 22, 2021 at 3:09 PM m.g.sharp--- via Healeys <
[email-masked]> wrote:

> The DW tensioner is significantly different from either of the two  that
> Michael is referring to, and substantial more expensive than either.  I d=
id
> some "research" on the web (as a scientist I struggle calling that
> research) when investigating tensioners for my current rebuild and from
> what I can figure out there are at least three tensioners on the market
> that will work.  This same tensioner fits MGBs, Jaguar XK engines and Lan=
d
> Rovers, and the majority of chatter on the web is from Jag and MGB owners=
.
>
> 1.      This is the =E2=80=9Cbase=E2=80=9D model which is readily availab=
le and is a copy
> of the original part.   The web revealed a number of reports of the rubbe=
r
> pad un-bonding or the whole piston popping out.  I suspect the latter mus=
t
> be due to a stretched chain allowing the piston to come out too far.  Man=
y
> of the failures of the rubber un-bonding are from racing applications but
> there are a lot from road cars as well.  One English builder who races MG=
Bs
> says that all his failures were on race engines and he thinks failures on
> road cars are very rare, but he is talking of MGBs.   Many reports name t=
he
> manufacturer as =E2=80=9CRolon=E2=80=9D, although there could be more tha=
n one source of
> this base model.  This is the =E2=80=9Cbase=E2=80=9D one that MOSS suppli=
es and you can see
> =E2=80=9CRolon=E2=80=9D stamped into the casting in their illustration.  =
It is $13 USD
> 2.      A French company called Renolds makes an upgraded tensioner that
> is visually similar to the original but apparently has better pad materia=
l
> this is the one Mike has illustrated on his post.  I could only find one
> report of the bonding failing on this tensioner.  Reports vary, but it
> seems this part is the OEM Jag replacement available from dealers as part=
 #
> EAC3629.  Some people had reported getting the Rolon part supplied from J=
ag
> dealers, and one report said both were available as OEM and =E2=80=9Cupgr=
aded=E2=80=9D OEM
> from his Jag dealer.  This is the tensioner sold by MOSS as their =E2=80=
=9Cpremium=E2=80=9D
> tensioner.  It appears available from other sources including Jaguar
> dealerships.  It is $90 USD.
> 3.      The third one is described as a =E2=80=9Chydraulic=E2=80=9D tensi=
oner.  This is
> the one sold by DW for 130 GBP.  I think that A-H spares sells the same o=
ne
> for 90 GBP, but the difference may be the VAT.  The one from DW has =E2=
=80=9CDWR=E2=80=9D
> stamped into it, but they may be adding that themselves.  This has a nylo=
n
> slipper and it is narrower than the chain, whereas the other two have
> rubber pads slightly wider than the chain.  I cannot find any reports of
> this type failing, but I did find a report of it being a poor fit.  Oddly=
,
> the chat lines that had extensive discussion =E2=80=9CRolon=E2=80=9D vs =
=E2=80=9CRenolds=E2=80=9D, do not
> mention this tensioner at all, so no information on reliability, which
> really means no failures (who takes the front end apart to check the
> tensioner is OK?).  However, I am sure that relatively speaking, very few
> of these have been fitted relative to all the Jag rebuilds using the
> Renolds unit and there are probably 1000s of the Rolon units running in
> MGBs.
>
> Regarding them all being hydraulic, there is a bit of confusion, but
> several sources say that the oil feed is just to lubricate the pad and th=
e
> tension is all provided by the spring.  However the DW one is said to be
> truly hydraulic.  Whether oil pressures assists with tension on the first
> two, or dampens the piston movement caused by oscillations of the chain,
> has been raised as a question, but no definitive answer.
>
> That is the sum total of what I know about timing chain tensioners.  For
> the record, I opted for Moss' "Premium" tensioner (#2 above).
>
> Cheers, Mirek
> '59 BT7
>
>
> I can't answer your question definitively, but can say--in hindsight--tha=
t
> I wish I'd installed DWM's upgraded tensioner on my BJ8's last overhaul.
> Expensive (relatively), sure, but failure of this part would be
> near-catastrophic, and I've heard anecdotally that aftermarket versions
> have failed (and I have an inherent distrust of any aftermarket part with
> rubber). How much is (relative) peace of mind worth?
>
> I'm glad I did. I know of at least one failure of the original, metal pip=
e
> (from someone on this list).
>
>
> Unsubscribe/Manage:
> http://autox.team.net/mailman/options/healeys/[email-masked]
>
>
> Unsubscribe/Manage:
> http://autox.team.net/mailman/options/healeys/[email-masked]
>
>

--00000000000029726d05bbf37ae8
Content-Transfer-Encoding: quoted-printable

<div dir=3D"ltr"><div class=3D"gmail_default" style=3D"color:#3333ff">When =
rebuilding the MGA 1622 engine=C2=A0in my former Elva Courier race car I us=
ed an &quot;upgraded&quot; tensioner sourced from Jaguar--apparently same o=
r similar to the unit of which several folks have spoken.</div><div class=
=3D"gmail_default" style=3D"color:#3333ff">I did so because it was &quot;ch=
eap insurance&quot; for a part that is difficult to inspect, the failure of=
 which can have dire results.=C2=A0=C2=A0</div><div class=3D"gmail_default"=
 style=3D"color:#3333ff">I don&#39;t know if I made the correct decision be=
cause while the new tensioner worked just fine so too did the &quot;standar=
d&quot; one it replaced.</div><div class=3D"gmail_default" style=3D"color:#=
3333ff"><br></div><div class=3D"gmail_default" style=3D"color:#3333ff">Best=
--Michael Oritt</div></div><br><div class=3D"gmail_quote"><div dir=3D"ltr" =
class=3D"gmail_attr">On Mon, Feb 22, 2021 at 3:09 PM m.g.sharp--- via Heale=
ys &lt;<a href=3D"mailto:[email-masked]">[email-masked]</a>=
&gt; wrote:<br></div><blockquote class=3D"gmail_quote" style=3D"margin:0px =
0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex">The =
DW tensioner is significantly different from either of the two=C2=A0 that M=
ichael is referring to, and substantial more expensive than either.=C2=A0 I=
 did some &quot;research&quot; on the web (as a scientist I struggle callin=
g that research) when investigating tensioners for my current rebuild and f=
rom what I can figure out there are at least three tensioners on the market=
 that will work.=C2=A0 This same tensioner fits MGBs, Jaguar XK engines and=
 Land Rovers, and the majority of chatter on the web is from Jag and MGB ow=
ners.<br>
<br>
1.=C2=A0 =C2=A0 =C2=A0 This is the =E2=80=9Cbase=E2=80=9D model which is re=
adily available and is a copy of the original part.=C2=A0 =C2=A0The web rev=
ealed a number of reports of the rubber pad un-bonding or the whole piston =
popping out.=C2=A0 I suspect the latter must be due to a stretched chain al=
lowing the piston to come out too far.=C2=A0 Many of the failures of the ru=
bber un-bonding are from racing applications but there are a lot from road =
cars as well.=C2=A0 One English builder who races MGBs says that all his fa=
ilures were on race engines and he thinks failures on road cars are very ra=
re, but he is talking of MGBs.=C2=A0 =C2=A0Many reports name the manufactur=
er as =E2=80=9CRolon=E2=80=9D, although there could be more than one source=
 of this base model.=C2=A0 This is the =E2=80=9Cbase=E2=80=9D one that MOSS=
 supplies and you can see =E2=80=9CRolon=E2=80=9D stamped into the casting =
in their illustration.=C2=A0 It is $13 USD<br>
2.=C2=A0 =C2=A0 =C2=A0 A French company called Renolds makes an upgraded te=
nsioner that is visually similar to the original but apparently has better =
pad material=C2=A0 this is the one Mike has illustrated on his post.=C2=A0 =
I could only find one report of the bonding failing on this tensioner.=C2=
=A0 Reports vary, but it seems this part is the OEM Jag replacement availab=
le from dealers as part # EAC3629.=C2=A0 Some people had reported getting t=
he Rolon part supplied from Jag dealers, and one report said both were avai=
lable as OEM and =E2=80=9Cupgraded=E2=80=9D OEM from his Jag dealer.=C2=A0 =
This is the tensioner sold by MOSS as their =E2=80=9Cpremium=E2=80=9D tensi=
oner.=C2=A0 It appears available from other sources including Jaguar dealer=
ships.=C2=A0 It is $90 USD.<br>
3.=C2=A0 =C2=A0 =C2=A0 The third one is described as a =E2=80=9Chydraulic=
=E2=80=9D tensioner.=C2=A0 This is=C2=A0 the one sold by DW for 130 GBP.=C2=
=A0 I think that A-H spares sells the same one for 90 GBP, but the differen=
ce may be the VAT.=C2=A0 The one from DW has =E2=80=9CDWR=E2=80=9D stamped =
into it, but they may be adding that themselves.=C2=A0 This has a nylon sli=
pper and it is narrower than the chain, whereas the other two have rubber p=
ads slightly wider than the chain.=C2=A0 I cannot find any reports of this =
type failing, but I did find a report of it being a poor fit.=C2=A0 Oddly, =
the chat lines that had extensive discussion =E2=80=9CRolon=E2=80=9D vs =E2=
=80=9CRenolds=E2=80=9D, do not mention this tensioner at all, so no informa=
tion on reliability, which really means no failures (who takes the front en=
d apart to check the tensioner is OK?).=C2=A0 However, I am sure that relat=
ively speaking, very few of these have been fitted relative to all the Jag =
rebuilds using the Renolds unit and there are probably 1000s of the Rolon u=
nits running in MGBs.<br>
<br>
Regarding them all being hydraulic, there is a bit of confusion, but severa=
l sources say that the oil feed is just to lubricate the pad and the tensio=
n is all provided by the spring.=C2=A0 However the DW one is said to be tru=
ly hydraulic.=C2=A0 Whether oil pressures assists with tension on the first=
 two, or dampens the piston movement caused by oscillations of the chain, h=
as been raised as a question, but no definitive answer.<br>
<br>
That is the sum total of what I know about timing chain tensioners.=C2=A0 F=
or the record, I opted for Moss&#39; &quot;Premium&quot; tensioner (#2 abov=
e).<br>
<br>
Cheers, Mirek<br>
&#39;59 BT7<br>
<br>
<br>
-----Original Message-----<br>
From: Healeys &lt;<a href=3D"mailto:[email-masked]" target=
=3D"_blank">[email-masked]</a>&gt; On Behalf Of Bob Spidell=
<br>
Sent: February 22, 2021 12:22 PM<br>
To: <a href=3D"mailto:[email-masked]" target=3D"_blank">healeys@aut=
ox.team.net</a><br>
Subject: Re: [Healeys] Timing Chain Tensioners<br>
<br>
I can&#39;t answer your question definitively, but can say--in hindsight--t=
hat I wish I&#39;d installed DWM&#39;s upgraded tensioner on my BJ8&#39;s l=
ast overhaul. Expensive (relatively), sure, but failure of this part would =
be near-catastrophic, and I&#39;ve heard anecdotally that aftermarket versi=
ons have failed (and I have an inherent distrust of any aftermarket part wi=
th rubber). How much is (relative) peace of mind worth?<br>
<br>
I installed DWM&#39;s flexible oil pump pipe in my BN2 on DWM&#39;s &#39;ad=
vice&#39; and I&#39;m glad I did. I know of at least one failure of the ori=
ginal, metal pipe (from someone on this list).<br>
<br>
<br>
On 2/22/2021 9:10 AM, Michael Salter via Healeys wrote:<br>
&gt; I note that the usual suspects all now seem to be selling 2 grades of<=
br>
&gt; 6 cylinder timing chain tensioners.<br>
&gt; As far as I know the more expensive variety, which are 5 times the <br=
&gt; cost of the less expensive type, are relatively new on the market.<br>
&gt; They are apparently made in France and come in a Jaguar/ Land Rover <b=
r>
&gt; package.<br>
&gt; These are slightly different from the originals in that there is a <br=
&gt; lubrication hole in the rubber pad that I don&#39;t recall seeing on a=
ny <br>
&gt; others that I have used.<br>
&gt; In my experience until very recently the rubber slippers were not a <b=
r>
&gt; problem on these tensioners but wear of the piston was pretty common <=
br>
&gt; on higher milage ones.<br>
&gt; My question is are these &quot;Premium &quot; grade tensioners signifi=
cantly <br>
&gt; better and are they worth the extra cost?<br>
&gt;<br>
<br>
_______________________________________________<br>
rer" target=3D"_blank">http://www.team.net/donate.html</a> Suggested annual=
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