Mk2 Escort strut / mod questions ...

[T i m]

Hi all,

I'm looking for some thoughts / understanding re how a (say) Mk2 1300
Escort saloon front suspension / spring relationship might work,
especially in regard to a coil-over conversion (and I know there are
some here who have done this sort of work / conversion).

The question is around how the springs are positively located on my
current setup (Mk2 Escort based kitcar) and how that might change post
conversion.

So, with the current / stock setup the lower spring cup is welded to
the strut / leg and is 'shaped' to match the shape of the bottom of
the spring to prevent the spring from rotating in the cup.

The damper rod then goes up though the spring, though a similar shaped
(but inverted etc) top cup that also locates on the spring positively.
This cup is located on the damper rod by the use of flats (or a 'D'
not sure), it then passes though the rubber bush in the top mount and
is fished of by a shaped and equally positively located fitting (that
would prevent the leg pulling though the mount should the rubber bush
fail).

The result of all this is that from what I can see in the HBOL and
from my own vehicle, the top cup is not allowed to rotate so therefore
as you steer, one spring will wind up and the other, unwind. [1]

This is further confirmed as the HBOL says after working on these legs
you should slacken the top damper-rod nuts slightly, set the steering
in a straight line and *then* torque and lock (peen) the nut in place.

What is happening there is the damper rod is being allowed to turn in
the metal bushing that is bonded though the rubber bush and then
locked to the insert (and then bush) once torqued up.

Now, if you replace the above with a coil-over conversion and assuming
you have the spring to have the same pre load as the stock setup, what
is to stop the springs moving on their seats as you turn and what
affect might that have on the steering (centring) if they did?

What I often see mention alongside coil-over conversions is roller top
mounts and this makes more sense as now the top spring cup can rotate
along with the spring, as the steering is turned.

So, can anyone help me pin down exactly what *should* be done if
applying one of these conversions please. Do I *have* to fit a bearing
with coil-overs to prevent the chance of the springs moving on their
cups (and either wearing the mountings, stressing the spring or
affecting the self-centring)?

Cheers, T i m

[1] I have previously tried rotating the top spring cup on our and
other (newer) vehicles and in most (all?) cases the top cup *does*
freely rotate as the steering is changed.

p.s. I would only be going to such as a last result and only because
my current setup has offset lower cups and seem to foul what should be
compatible wheels / tyres. ;-(

[Duncan Wood]

I'm failing to think of any advantage to not fitting one, Ford only left
it out to save money.

[T i m]

On Sun, 08 Feb 2015 12:47:51 -0000, "Duncan Wood"
<nntp...@dmx512.co.uk> wrote:

<snip>

>> What I often see mention alongside coil-over conversions is roller top
>> mounts and this makes more sense as now the top spring cup can rotate
>> along with the spring, as the steering is turned.
>>
>> So, can anyone help me pin down exactly what *should* be done if
>> applying one of these conversions please. Do I *have* to fit a bearing
>> with coil-overs to prevent the chance of the springs moving on their
>> cups (and either wearing the mountings, stressing the spring or
>> affecting the self-centring)?
>>

<snip>

>
>I'm failing to think of any advantage to not fitting one, Ford only left
>it out to save money.

Hi Duncan and thanks for your reply ... assuming we are talking about
a top bearing here, the only thing I can think of (that may play a
part) is any steering self_centring that may be created by the
springs? If there are models with the exact same suspension / steering
setup (trail / castor / whatever) that do have bearings as std then
(ignoring the cost issue), what impact it might have either way
removing / adding a bearing?

If a bearing is recommended in any case, is there a good vehicle to
use as a guide / donor for such please, if such a solution would work?

I'm assuming anything that is added to the existing setup is going to
cause the damper rod to sit slightly lower down (by the thickness of
any bearing), or would I replace the entire top mount for one that
includes the bearing (that seem quite expensive).

I just found this (that gives a little history and a price)[1]: ;-)

http://www.rallydesign.co.uk/product_info.php?products_id=21397

I suppose for a (very) short test I could just slacken the top damper
rod nuts, spray in some grease (allowing the top spring cup to rotate
under the bush better) and see just how much difference it makes?

I'm also awaiting for some replies from suppliers re locating a pair
of std disk_brake struts that have concentric lower spring cups as I
think that is all I really need to resolve the wheel fitment issue.

Cheers, T i m

[1] I believe those standard top mounts come in two hole (mounting)
sizes (one of the few things you had to stipulate when ordering the
kitcar from the factory) and knowing my luck ... ;-(

[Mrcheerful]

steering self centering is caused by the steering geometry and forward
motion (which is why it does not work when reversing), spring wind up
could adversely affect it, hence the caveat about centering and
tightening.
Changing to roller top mounts would not stop the steering centering itself.

[Adrian]

On Sun, 08 Feb 2015 13:27:03 +0000, T i m wrote:

>>I'm failing to think of any advantage to not fitting one, Ford only left
>>it out to save money.

> assuming we are talking about a top bearing here, the only thing I can
> think of (that may play a part) is any steering self_centring that may
> be created by the springs?

No - the centring comes from the castor angle in the wheel geometry. In
addition, if both springs are wound in the same direction, any centring
effect they may (fairly unpredictably) give would cancel each other out.

[Mrcheerful]

Burtons do a nice pair of coil over front legs for 500 quid.

[Duncan Wood]

It makes it slightly better, you could try Peter Lloyd Rallying for them
or Burtons still make them. I'd have thought you'll get away with the
solid spherica ones in a kit car.

[T i m]

Understood.

> (which is why it does not work when reversing),

Never considered that. ;-)

> spring wind up
>could adversely affect it, hence the caveat about centering and
>tightening.

Yes, quite, but why doesn't it affect it then when it does affect the
natural ability for the steering to self-centre, re the caveat. Either
it does or does not affect it?

>Changing to roller top mounts would not stop the steering centering itself.

No, quite, but I was more interested to know why roller mounts weren't
there as std (one reason offered by Duncan being 'cost') and what
impact they might have on a system designed to be without, given the
fact that they *do* have an impact on self centring.

ie, I don't (didn't) want to go to all the trouble and cost of
'upgrading' my front suspension to improve one thing (wheel choice)
and then ruin something else. ;-(

OOI, I have since found references to the very thing I feared could
happen mentioned here (and a novel solution to it). ;-)

http://www.driftworks.com/forum/drift-car-projects-builds/157179-sr20-mk2-escort-12.html

Specifically:

"With coil overs with spherical bearing top mounts, when you turn the
steering, the spring rotates with the strut, but binds up on it’s top
seat as the top seat is bolted to the top mount. If you hit a bump mid
drift you would often feel a twang as the spring re-seats. The problem
was that when it re-seats, it is then trying to bind up when you steer
the steering back straight again. This made the dead ahead sometimes a
little vague and quite inconsistent."

The exact same thing happens on the std design but that design caters
for it by positively locating the springs in the cups (forcing the
springs to wind up on steering but not move in their seats etc).

Maybe the other people who have modded their Escorts and Capris
(kitcars) to coil-overs but not fitted a roller top mount don't have,
notice or care about such things? <shrug> [1]

Cheers, T i m

[1] I could overcome some of my problems by fitting wheel spacers but
that isn't really what I want to do either. The original Ford Escort
wheels have a 19mm offset. The (slightly wider) wheels I want to fit
also have a 19mm offset, but because they are also wider (and in this
case with bigger wheels with full profile tyres, taller), foul the
'offset' lower spring cups I just happen to have ended up with on my
kitcar, because that was what was fitted to the donor Escort I used. I
guess all those who built their kitcars from donors that 'just
happened' to have the concentric springs and cups, can't understand
what the issue is when they fit the exact same wheels. ;-(

25 years ago (when I built the kitcar) I could have gone to any
breakers and had a selection of struts to choose from, had I know what
I might have to face in the future (re fitting different wheels). ;-)

[T i m]

On Sun, 8 Feb 2015 13:49:44 +0000 (UTC), Adrian
<tooma...@gmail.com> wrote:

>On Sun, 08 Feb 2015 13:27:03 +0000, T i m wrote:
>
>>>I'm failing to think of any advantage to not fitting one, Ford only left
>>>it out to save money.
>
>> assuming we are talking about a top bearing here, the only thing I can
>> think of (that may play a part) is any steering self_centring that may
>> be created by the springs?
>
>No - the centring comes from the castor angle in the wheel geometry.

Yes ... 'typically it only comes from that'.

> In
>addition, if both springs are wound in the same direction, any centring
>effect they may (fairly unpredictably) give would cancel each other out.

Quite, that is exactly how it works, but affect the centring they
certainly do (as I found out after tightening the damper rod nuts up
without the steering being straight and wondered WHF was going on!).
;-)

Cheers, T i m

[T i m]

On Sun, 08 Feb 2015 13:50:17 +0000, Mrcheerful
<g.odon...@yahoo.co.uk> wrote:

<snip>

>> So, can anyone help me pin down exactly what *should* be done if
>> applying one of these conversions please. Do I *have* to fit a bearing
>> with coil-overs to prevent the chance of the springs moving on their
>> cups (and either wearing the mountings, stressing the spring or
>> affecting the self-centring)?
>>

<snip>

>
>Burtons do a nice pair of coil over front legs for 500 quid.

Erm, yes, and some are even more ... and I guess as long as they come
complete with top bearing mounts they could be considered a positive
answer to my question. ;-)

All_I_want is a clean *pair* (you can even find new_old_stock singles
on eBay for 50 quid), either with concentric springs (that I can just
bolt on and use as-is) or another pair the same as I have on now that
I can be converting in the background (leaving the originals as-is, in
case I choose to go back to stock at any time).

As I said, I do have some feelers out in that direction and I have
been offered 'a' pair of struts at a reasonable price that are
supposed to be suitable but I just need to confirm the details
(tomorrow hopefully) etc.

I just wanted to clarify this 'locked' top mount question to see if I
had missed something and it appears I haven't.

Cheers, T i m

[T i m]

On Sun, 08 Feb 2015 13:59:16 -0000, "Duncan Wood"

Ok thanks.

> I'd have thought you'll get away with the
>solid spherica ones in a kit car.

I know the ones you mean but I'm not sure I've seen them included in
the std rubber mounts but more typically in the solid alloy type?

The reason that would be an issue for me is I am looking for a soft
and compliant ride, like it was when I first built the car from a 88k
mile 1978 Mk2 1300 saloon. This is a 'jeep' style, rather than a Lotus
7 clone and I do actually take it up tracks and trails on occasion and
it handle them very well, or at least it did ...

When I broke the Sierra I retain the 2L Pinto and 5 speed box with the
intention of 'upgrading' the 1300 Kent in the kitar at sometime. I
found a Cortina sump (that would clear the Escort X member), fitted a
Cortina rad, replaced the front springs and shocks, upgraded all the
rubber bushes to 'Poly' and got new throttle and clutch cables ready.

Then the taxation rules and other circumstances changed and I decided
not to bother.

So, I was then bouncing about with h/d springs so changed them back to
some std+1" I had made and whilst that helped, I think the h/d dampers
(inserts) and the Polybushes were still making the ride very 'stiff'.

One of my tests for compliance (for it's modest limits) is to slowly
drive one front wheel up onto a biggish kerb, stop, and see if I can
open the drivers door without it catching. If it catches, that tells
me the suspension is too stiff and isn't doing enough of the work,
making the ladder chassis / bodywork flex instead. It is ok now with
the std springs back in, but now I want (need) to change to tyres and
I have two sets of Weller wheels that are supposed to fit that would
help me do that, because they don't fit. The fit the hub, the PCD, and
in the arches and they fit on the rear. They don't fit on the front,
because the tyre fouls the (offset) lower spring cup so *everything*
is dependant of getting that sorted somehow.

It is my intention, once I know I can use them, to get a set of cheap
185/80/14's on a set of Wellers and I can then put them on and use
them. Then I can have the existing 8 spoke steels (not Wellers and
with a smaller offset) refurbished and keep looking for some
affordable 185/80/14's M+S to put on. I want the M+S pattern, partly
because I think it looks right on an 'off road styled vehicle but one
of the few things the kitcar does well (compared with any std road
going 2WD car etc) is go though a bit of mud and snow. ;-)

If I can't get some form of M+S tyre (maybe even going to a 195/70/14
etc) I can see it just not getting used and doing 1 mile between MOTs
again. ;-(

Cheers, T i m

[Mrcheerful]

On 08/02/2015 14:17, T i m wrote:

>>>
>>
>> steering self centering is caused by the steering geometry and forward
>> motion
>
> Understood.
>
>> (which is why it does not work when reversing),
>
> Never considered that. ;-)
>
>> spring wind up
>> could adversely affect it, hence the caveat about centering and
>> tightening.
>
> Yes, quite, but why doesn't it affect it then when it does affect the
> natural ability for the steering to self-centre, re the caveat. Either
> it does or does not affect it?

Spring wind up can increase the self centering ability, but it is not
the cause of it. Adverse spring wind up (not centred when tightened)
will affect the designed self centring in a bad way, but probably not
enough to negate it completely.

[Mrcheerful]

On 08/02/2015 11:31, T i m wrote:

> Hi all,
>
> I'm looking for some thoughts / understanding re how a (say) Mk2 1300
> Escort saloon front suspension / spring relationship might work,
> especially in regard to a coil-over conversion (and I know there are
> some here who have done this sort of work / conversion).

There is a pair of used coilovers on ebay today: 261766525363

[Mrcheerful]

You do realise that the rolling road tax exemption has restarted? So
anything that is registered 40 years old is now exempt, not just the pre
72 stuff. So you could stick any size lump in and not worry about the
tax cost.

[T i m]

On Sun, 08 Feb 2015 14:59:40 +0000, Mrcheerful
<g.odon...@yahoo.co.uk> wrote:

>On 08/02/2015 14:17, T i m wrote:
>
>>>>
>>>
>>> steering self centering is caused by the steering geometry and forward
>>> motion
>>
>> Understood.
>>
>>> (which is why it does not work when reversing),
>>
>> Never considered that. ;-)
>>
>>> spring wind up
>>> could adversely affect it, hence the caveat about centering and
>>> tightening.
>>
>> Yes, quite, but why doesn't it affect it then when it does affect the
>> natural ability for the steering to self-centre, re the caveat. Either
>> it does or does not affect it?
>
>Spring wind up can increase the self centering ability, but it is not
>the cause of it.

It's not the main / typical cause of it no. However, disconnect the
track-rod-end and watch the wheel centre (quite meaningfully) all on
it's own (with the wheel in the air of course). ;-)

>Adverse spring wind up (not centred when tightened)
>will affect the designed self centring in a bad way, but probably not
>enough to negate it completely.

Hmm, you may well be right but I think I took charge before I found
out (possibly the hard way)! ;-(

Cheers, T i m

[T i m]

Thanks for that MrC. ;-)

The stub axle / bearing surfaces look a bit better than a cheaper pair
I was watching but what is it with the threaded tubes welded on at
different heights?

As an aside, are the main part of the lower assemblies cast iron or
cast / forged steel? I ask because you often see those little
triangular gussets welded on and whilst I know it's easy to weld to
the steel of the leg itself, I'm not sure welding cast iron is a good
thing (if it was). Personally ... I think I'd prefer some un-welded
that way (and I don't mean the gussets ground off, unless someone
could set my mind at ease etc). ;-)

Cheers, T i m

[T i m]

I do indeed. ;-)

>So
>anything that is registered 40 years old is now exempt, not just the pre
>72 stuff.

Yup, but my Mk2 Escort was a 78 so I make that still 3 years to go?

> So you could stick any size lump in and not worry about the
>tax cost.

Yup, and I am holding onto the Pinto for that very reason. It still
might be more expensive to insure but that might be less of an issue
than the tax. I think we currently pay £140 Comp for the 1300 and the
two of us. ;-)

Cheers, T i m

[T i m]

On Sun, 8 Feb 2015 13:49:44 +0000 (UTC), Adrian
<tooma...@gmail.com> wrote:

Sort of, but not what happens in the real world I don't believe.

Ok, say you set the steering straight then applied 10% of 'toe in' to
the springs (by slackening the top nut, applying a 10 deg rotation
towards the centre and re tightening the nuts) then yes, the springs
would be counteracting each other and the net outcome would still be
that they would create a self centring effect.

However, IRL and with the springs set neutral to the centre, when you
steer you are applying a torsional movement to both springs (be it
winding up one and unwinding the other, it matters not) but both
springs will be attempting to return to their original positions (the
centre) and will therefore, take their wheels with them. ;-)

I'll give you that the whole thing wouldn't be very accurate but it is
pretty predictable (as would be easily demonstrated by setting one or
both 'off centre' and seen just how predictably it pulls the car in
that direction).

I'm guessing that if didn't matter what ended up where the springs
would have circular ends, the cups wouldn't have spring recesses in
them to hold the springs in one position, there wouldn't be a 'D'
shape in the top spring cup, the end of the damper rod wouldn't have
flats on it and the who lot wouldn't be torqued down to 30 ft/lb and
the (special) nut peened over?

No, it obviously matters 'a lot' where all these components sit
relative to each other and therefore how that affects any 'bias' (if
you don't want to call it self centring) it gives to what direction
the wheels end up facing when you are moving and take your hands off
the steering wheel. ;-)

That's why I asked the question .... that if it was all *designed* to
work like that, and you take it away (by fitting a revolving top
mount), what might that do to the steering (and specifically steering
bias) of the vehicle? An answer of 'very little' is acceptable
(preferred even) but that isn't the same as suggesting this
non-rotating top mount has no effect on the steering at all (not that
you have etc).

Neither is it the same question as why most cars are designed with
revolving top mounts these days (or even then). ;-)

When I replaced the stock 13" wheels with 14" wheels and 80 profile
tyres I knew pretty accurately what that was going to do to the
effective gearing of the vehicle. I also knew what alternative gearing
(diff) ratios were available and which one I would need to put the
mph/rpm back near what it was from the factory. So, I removed a 3.89:1
diff and replaced it with a 4.44:1 diff and that also allowed for the
heavier weight and worse aerodynamics. ;-)

And it was all working fine .... I just want to get it back that way
and ideally without having to pay 'Escort tax' ... ;-)

Cheers, T i m

[Mrcheerful]

It looks as though the threaded adjustment tubes are not a pair, so one
is longer and therefore goes further down the leg. Probably just not an
originally identical pair (which would make little difference as the
innards have been replaced)

You can weld to cast iron with the right rods and techniques, I do not
think it would make much odds to the overall strength of the stub axle,
but it will help a lot with maintaining the geometry when used hard by
resisting bending the upright where it leaves the stub axle.

[T i m]

On Sun, 08 Feb 2015 19:49:06 +0000, Mrcheerful

And would have to be replaced again so I'd only be buying the basic
tube and coilover stuff.

I believe the std 1300 saloon had 85 lb/in front springs and were
about 13" long (free length). They do a 14" 2.25" coilover at 80 or
100 lb/in (at that length) so the 100 lb/in might be about right to
compensate for the extra weight of the kitcar. Especially so because
the height would be easily adjusted.

I can could either re-fit the original (wet) damper shafts or replace
the current h/d inserts for 'std' once (available at my local car
spares place for 60 quid / side). I can either keep all the h/d stuff
till I can make use of the 40 yr classic exemption or sell it all and
either stick with the 1300, use the 1300GT or 1600 Xflows I already
have. ;-)

>
>You can weld to cast iron with the right rods and techniques,

I wonder how many doing these leg mods are using the right stuff
though?

> I do not
>think it would make much odds to the overall strength of the stub axle,
>but it will help a lot with maintaining the geometry when used hard by
>resisting bending the upright where it leaves the stub axle.

Understood (and assuming the welds hold and haven't made anything
weaker). ;-)

Since my last post here I've spoken to another Ranger owner and he
also has the offset springs, 19mm offset Weller wheels and 185/80/14
tyres. The tyre 'just' misses the lower cup.

Tyre choices:

They should be 185/80/14's but there aren't many available in 4ply
(non van) load rating and very very few in car spec in M+S pattern
(diameter 652mm). They would work with the set of steel 10 spokes I
have on there now.

I can get a greater range of 195/70/14's (91), some M+S in that size
(629 mm dia. -23mm) but a bit more expensive and less likely to clear
the strut.

I can get a very cheap (28 quid) chunky M+S pattern 185/70/14 (81)
that may just be big enough (615,mm, -37mm) and more likely to clear
the strut.

I think I'll see if I can get a selection of old tyres in those sizes
from my local tyre place, mount them on my spare set of Wellers and
offer them up. I already have a 205/?/14 on a Weller that I can try
again (but pretty sure it fouled the strut).

Cheers, T i m

[Duncan Wood]

However Escorts with revolving top plates definitely felt like tey had
better steering feel. Which is difficult to compare directly as that was
unlikely to be the only thing done to them, but there's many a solution to
eliminating the spring 'centreing' in the world, I've never seen anyone
try & add it.

> When I replaced the stock 13" wheels with 14" wheels and 80 profile
> tyres I knew pretty accurately what that was going to do to the
> effective gearing of the vehicle. I also knew what alternative gearing
> (diff) ratios were available and which one I would need to put the
> mph/rpm back near what it was from the factory. So, I removed a 3.89:1
> diff and replaced it with a 4.44:1 diff and that also allowed for the
> heavier weight and worse aerodynamics. ;-)
>
> And it was all working fine .... I just want to get it back that way
> and ideally without having to pay 'Escort tax' ... ;-)
>
> Cheers, T i m

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