Help identify my chassis.
super-ron - 6/3/17 at 07:51 AM
New member here. I've just bought a 'locost' as a base for a a project, it's going to change quite dramatically into something
special 
(internally and externally, will start a progress thread in due time) So don't worry about any dodgy bits, they'll all be
changed, chopped off and modified.
I want to identify what chassis/car I actually have so I can get the correct book and double check the dimensions and how it's been built.
I've been doing a lot of searching on here but there seems so many variations, and I see there are some Eagle eyed people on here that know their
stuff. Can't find a definate answer on the de dion rear setup?
Also what components have been used? Sierra front uprights? front brakes? Sierra cosworth diff and rear discs? steering rack? pedal box?
Plenty of pic's so if the experts could give me as much info as they can, there will be fully buffed progress diary to follow.
CosKev3 - 6/3/17 at 08:16 AM
The easy parts to ID are Sierra front uprights, Sierra brakes all around and a Sierra diff 
It could be a cosworth one,if it's a LSD.
Pretty sure the rack is a Escort one.
benchmark51 - 6/3/17 at 08:24 AM
There is a bit on the back that is definitely dexion. 
HowardB - 6/3/17 at 08:54 AM
quote:
Originally posted by benchmark51
There is a bit on the back that is definitely dexion.
nick205 - 6/3/17 at 09:30 AM
quote:
Originally posted by benchmark51
There is a bit on the back that is definitely dexion.
That's the bit that caught my eye too
As above there are Sierra bits on there, but then many cars of this type use Sierra bits.
Do you have any history on the car?
What background did the seller give on it etc?
super-ron - 6/3/17 at 10:17 AM
yes is indeed :lmao: like I said all the dodgy bits are getting cut off. I'm a welder fabricator so rest asured
I've spun the diff and it is a LSD, and was told it was a cosworth item, which I think the rear discs are too.
The only info I got with it was the first owner made the chassis, then the second owner built it up to this stage. it was labeled as a Locost but it
seems there are even different versions of them. the main difference if first they had a live axle and then independent rear suspension, this has
neither. but Google does show quite a few with de dion rear end. I was hoping there was some tell tail signs that people might spot to what I have
I can take any measurements required.
JAG - 6/3/17 at 10:22 AM
Does anyone recognise the De Dion rear axle?
Is it the MK axle?
wylliezx9r - 6/3/17 at 10:25 AM
I think it's an early MK based on the original Ron Champion Locost.
mookaloid - 6/3/17 at 10:45 AM
quote:
Originally posted by wylliezx9r
I think it's an early MK based on the original Ron Champion Locost.
Whatever anyone might think about MK, there was never anything wrong with the welding.
Whoever built that chassis wan't a professional welder so home built I would say.
super-ron - 6/3/17 at 11:17 AM
The welding of the main chassis isn't too bad, but the bits added on like radiator brackets, floor and bulkhead, roll cage, fuel tank mount,
extra panhard mount, steering coloum mount, is pretty bad and we'll all be coming off. 90% of the chassis I'm happy with but will be doing
some bits again.
So it's a possibility it's an older Ron Champion Locost and had the live axle swapped for a De Dion? or is that what the early MK's
were?
I did measure the wheelbase but forgot to jot it down, I think it was 93inches?
mcerd1 - 6/3/17 at 12:37 PM
quote:
Originally posted by super-ron
I've spun the diff and it is a LSD, and was told it was a cosworth item, which I think the rear discs are too.
as the rear discs are solid ones rather than vented they can only really be the 2WD sierra cossie
or the bog standard sierra ones (from an ABS car or an XR4i or any of the non-cossie 4x4's)
dead easy way to tell them apart - the cossie discs are 273mm dia - the normal sierra ones are 253mm dia.
if it was a 2wd cossie diff then it would be a 7.5" one with 108mm CV joints rather than a 7" one 100mm CV's used on all the other
sierra's including all the 4x4's.
But the one in the pic looks like a 7" diff to me - its seems to have one long threaded bar through the top mount
7" LSD's are standard on all the 4x4 cars...
the front hubs and brakes look like any bog standard 2wd sierra (not cossie or 4x4) which should make thing easier - the ordinary sierra's had
240mm dia discs (and drums on the back) and the ones with rear discs had 260mm discs (with slightly bigger calipers ~60mm pistons rather than
~54mm)
[Edited on 6/3/2017 by mcerd1]
super-ron - 6/3/17 at 01:26 PM
quote:
Originally posted by mcerd1
quote:
Originally posted by super-ron
I've spun the diff and it is a LSD, and was told it was a cosworth item, which I think the rear discs are too.
as the rear discs are solid ones rather than vented they can only really be the 2WD sierra cossie
or the bog standard sierra ones (from an ABS car or an XR4i or any of the non-cossie 4x4's)
dead easy way to tell them apart - the cossie discs are 273mm dia - the normal sierra ones are 253mm dia.
if it was a 2wd cossie diff then it would be a 7.5" one with 108mm CV joints rather than a 7" one 100mm CV's used on all the other
sierra's including all the 4x4's.
But the one in the pic looks like a 7" diff to me - its seems to have one long threaded bar through the top mount
7" LSD's are standard on all the 4x4 cars...
the front hubs and brakes look like any bog standard 2wd sierra (not cossie or 4x4) which should make thing easier - the ordinary sierra's had
240mm dia discs (and drums on the back) and the ones with rear discs had 260mm discs (with slightly bigger calipers ~60mm pistons rather than
~54mm)
[Edited on 6/3/2017 by mcerd1]
Great info.
That lines up with a few things as I roughly measured the rear discs at about 270mm and front discs at about 235mm with a tape measure. I'll see
if I can measure up the CVs to get an easy i.d on the diff.
nick205 - 6/3/17 at 02:11 PM
quote:
Originally posted by JAG
Does anyone recognise the De Dion rear axle?
Is it the MK axle?
Don't recognise the De Dion axle, but then I've not used one and never really looked at many either.
The front upper wishbones do have an MK look to them, but perhaps not the lower ones.
Some above have mentioned "home built". Some of the welding looks less than stunning so that could well be right.
mcerd1 - 6/3/17 at 02:22 PM
quote:
Originally posted by super-ron
That lines up with a few things as I roughly measured the rear discs at about 270mm and front discs at about 235mm with a tape measure. I'll see
if I can measure up the CVs to get an easy i.d on the diff.
if your rear discs are 273mm and the diff is a 7" (thats the size of the crown wheel vot the case btw - see here to help ID it properly:
linky )
then someone has being doing so interesting mixing and matching.....
the 7.5" cossie diff not only uses bigger CV's, but also bigger shafts and bigger bearings and I think even different stub axles - the rear
brake caliper is the same as the normal sierra one and the extra reach to get over the bigger discs is provided by longer lugs on the hub carrier /
bearing housing.
all these different sizes of CV, shaft, bearing make any mixing and matching quite difficult without some custom machining.... so most people stick
to all the rear axle parts from a single donor to make it easy...
MikeRJ - 6/3/17 at 04:34 PM
Looks very much like the original book chassis with mods to fit the De-dion axle and wishbones to suit the Sierra uprights. Note that lower wishbone
design is as per the original flawed book design; prone to bending due to the sudden change in cross section
DRM Black7 - 6/3/17 at 04:45 PM
That's not an MK Dedion there. Front wishbones are early MK tho, they crack where the round tube meets the flat plate on the lower wishbone.
jacko - 6/3/17 at 06:21 PM
quote:
Originally posted by wylliezx9r
I think it's an early MK based on the original Ron Champion Locost.
spot on that man
super-ron - 6/3/17 at 07:46 PM
hmmmm so that took a turn. so we're the early MK'S factory built versions of the haynes book?
loggyboy - 6/3/17 at 07:55 PM
quote:
Originally posted by super-ron
hmmmm so that took a turn. so we're the early MK'S factory built versions of the haynes book?
The haynes/Ron champion book?
Martin Keenan built a Ron champion chassis, then started selling them as prebuilt chassis, that's what started MK off as a kit builder. The later
Indy was the MKs development from a live axel to a IRS.
As above, It doesnt look like Martin Keenan built chassis as its just no neat enough - this chap teaches welding, he is a pro.
super-ron - 6/3/17 at 08:24 PM
quote:
Originally posted by loggyboy
quote:
Originally posted by super-ron
hmmmm so that took a turn. so we're the early MK'S factory built versions of the haynes book?
The haynes/Ron champion book?
Martin Keenan built a Ron champion chassis, then started selling them as prebuilt chassis, that's what started MK off as a kit builder. The later
Indy was the MKs development from a live axel to a IRS.
As above, It doesnt look like Martin Keenan built chassis as its just no neat enough - this chap teaches welding, he is a pro.
Ah I see that makes sense. The main chassis isn't bad but I wouldn't class it as professional.
So is it looking like the Ron Champion book spec chassis (home built), origionally fitted with a live axle, but then converted to DeDion rear setup
(of unknown origion?) and non 'book' spec (and flawed) front suspension?
So is this a thing then or a complete hybrid? I know there are lots of different 7 replicas but I was hoping there were certain things that would be
distinguishable.
nick205 - 7/3/17 at 09:16 AM
quote:
Originally posted by loggyboy
quote:
Originally posted by super-ron
hmmmm so that took a turn. so we're the early MK'S factory built versions of the haynes book?
The haynes/Ron champion book?
Martin Keenan built a Ron champion chassis, then started selling them as prebuilt chassis, that's what started MK off as a kit builder. The later
Indy was the MKs development from a live axel to a IRS.
As above, It doesnt look like Martin Keenan built chassis as its just no neat enough - this chap teaches welding, he is a pro.
Agreed. I built a Martin Keenan era MK Indy and the welding on it was first class - extremely neat and tidy. From the photos I don't think that
chassis was built by MK, it's simply not neat enough! Some elements (the rear De Dion mount) look very weak indeed. I'd be looking to cut
them off and do them again myself.
super-ron - 7/3/17 at 03:38 PM
quote:
Originally posted by nick205
quote:
Originally posted by loggyboy
quote:
Originally posted by super-ron
hmmmm so that took a turn. so we're the early MK'S factory built versions of the haynes book?
The haynes/Ron champion book?
Martin Keenan built a Ron champion chassis, then started selling them as prebuilt chassis, that's what started MK off as a kit builder. The later
Indy was the MKs development from a live axel to a IRS.
As above, It doesnt look like Martin Keenan built chassis as its just no neat enough - this chap teaches welding, he is a pro.
Agreed. I built a Martin Keenan era MK Indy and the welding on it was first class - extremely neat and tidy. From the photos I don't think that
chassis was built by MK, it's simply not neat enough! Some elements (the rear De Dion mount) look very weak indeed. I'd be looking to cut
them off and do them again myself.
Yes I certainly agree. I have been in contact with Sean from MK and he was very helpful indeed. He confirmed that none of this is of MK origin, and
added some useful pointers in which way to go.
Don't worry, everything that is slightly suspect will be chopped off and started again. The rear panhard mount on the chassis is one of these, I
don't think its even fully connected! I will be using the car very hard so nothing will be left as a 'maybe ok'.
super-ron - 7/3/17 at 04:05 PM
with the information provided I've been out with the tape measure again.
The diff does appear to be a sierra 4x4 LSD with 100mm inner CV's
but the rear discs are 273mm solid discs I'm led to believe are 2wd cosworth
its been mentioned the diff mounts are too thin, so measured them and the front ones are 6mm which looks fine but the rears are only 3mm
here are some more pics of the rear De Dion tube setup to see if it can raise any identity
and I also had a measure up to try and establish if this in fact a standard book chassis. I measured the track with the wheels off to the face on the
disc where the wheels sit. It was a solo effort so there might be the odd mm here and there
Front Track 58"
Rear Track 61"
Wheelbase 93"
The Chassis viewed from above is 38" wide and 118.5" long
The front panel end on is 63cm at the top, 34cm at the bottom and about 34cm tall
The side panels are about 13" tall
does this sound about right for a Ron Chapman Book chassis?
super-ron - 7/3/17 at 04:30 PM
Re: the DeDion beam, looks like there are plans online for them so could well be homemade as well. This one look very similar at the ends, although my
curved tube is more like a MK one than pointed like these
http://locost7.info/files/suspension/RortyDeDionAxleAssembly.pdf
mcerd1 - 8/3/17 at 10:01 AM
quote:
Originally posted by super-ron
with the information provided I've been out with the tape measure again.
The diff does appear to be a sierra 4x4 LSD with 100mm inner CV's
but the rear discs are 273mm solid discs I'm led to believe are 2wd cosworth
If the tag off the diff is correct (they can be swapped all too easily) then its a 3.92 ratio - the 'AAA' bit would also suggest it should
be an LSD (which I think you've already confirmed)
of course the only way to be sure of the ratio is to count the number of turns of the input to get 1 complete turn of the output...
the 7" 3.92 LSD was most commonly fitted to the fairly rare 2.0 XR4x4's (either pinto or DOHC), were as the V6 and cossie 4x4's got the
3.62 instead
273mm solid discs are the cossie 2wd items (google confirms the part no on them) these should use the same calipers as all the other sierra's
& granada's with solid rear discs (the pads are actually the same for all the solid and vented versions)
the only standard hub assembly I know with the longer caliper mount lugs for the 273mm discs that also has 100mm CV flanges is the one from a cossie
4x4 (escort or sierra)
the only way to know for certain would be to check the bearing sizes, but since that won't matter until you need to change the bearings it
shouldn't be too big a problem
for comparison here is the size of the lugs for the 253mm discs:
and these are the solid disc calipers:
[Edited on 8/3/2017 by mcerd1]
