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Sierra based chasis
mathew - 12/10/02 at 11:27 PM

Can any body tell me where i can find dimensions for a sierra based chassis or get a plan from
Thanks
Mathew

locost7-online.com - 13/10/02 at 08:38 AM

if you look xxxxxxxxxxxxx you can buy a book, called build you own tiger sportscar.

www.xxxxxxxxxxx.com/xxxxxxxx.htm

---------

Ahem! Try www.locostbuilders.co.uk/books --Chris

mathew - 13/10/02 at 05:26 PM

Thanks for the reply.
At a last resort I could build the tiger sportscar mentioned on your site but is there anyone out there that has the suitable plans to modify the plans given in the book (build your own sportscar for under £250)that I could use as mk1 and mk2 escorts are hard to come by
thanks

Dunc - 13/10/02 at 05:32 PM

The main difference from 'the book' will be the rear suspension setup. A good start would be to look at the McSorley Plans. The 442, larger chassis, would be a good start. Leave the transmission tunnel until you've got and measured your donor gearbox and trial fitted it.

mathew - 13/10/02 at 05:55 PM

Where can i find the Mcsorley plans and is it the same style as the the locost
thanks

bob - 13/10/02 at 06:02 PM

quote:
Where can i find the Mcsorley plans and is it the same style as the the locost
thanks



http://mcsorley.net/locost

Findlay234 - 13/10/02 at 07:32 PM

ive got a CAD plan for a sierra based chassis it's 2 inches wider than the book chassis and its mildly longer as well, i think i remember about 4inches longer. i can email it to you if you want it. i dont know how much help it will give you.

cheers

ludsonline - 14/10/02 at 05:28 AM

I found plans for the Sierra IRS Rear on the net last night might be of some help picture with dimensions in the photo archive

rallyslag - 14/10/02 at 12:56 PM

where from?

john_s - 14/10/02 at 05:12 PM

I've built my chassis for a sierra donor from the McSorley +4 plans. Am currently working out the rear suspension. It's going to be loosely based on the tiger avon book.

John

Gremlin - 15/10/02 at 12:40 PM

This is really for McSorley but have you any plans of adding a irs version to your McSorley collection?

I would try to model one but no idea where to start or how to use autocad. Im a computer tech and fix the software if users have problems with it but dont really use the software i support.

Dunc - 15/10/02 at 04:11 PM

John S,

What are you using to work out your rear suspension?

Dunc

James - 15/10/02 at 05:10 PM

Gremlin wrote:

quote:

I would try to model one but no idea where to start or how to use autocad.


Although I'd always recommend CAD if people start messing with the chassis- particularly if changing the front end you don't really need it for the rear as it's far less complex. Have a look at the MK website to get an idea of how MK do it. Then study the pictures on this site- Bass has put up pictures of the Tiger book. Then look around for other pictures on websites.
Also, there is an IRS picture in the fuel tank section of The Book which I'm sure you've spotted.

If all this fails buy the Tiger Avon book: http://www.amazon.co.uk/exec/obidos/ASIN/1903706092/locostbuilder-21

and translate their plans onto your Locost!

With all these it's not that hard to get the basics of how to do it!

HTH,

James

john_s - 15/10/02 at 05:43 PM

quote:
What are you using to work out your rear suspension?


A rather low-tech approach... some lumps of metal and a hacksaw!

The plan is to make wishbones to the tiger book dimensions (in terms of distance between inner and outer mountings), and position rails as close as possible to the tiger positions to fit into the McSorley +4 chassis.

I'm making hub carriers from a piece of channel cut from a length of 120 x 120 x 5mm RHS, and will have to modify the wishbones slightly to connect to this.

John.

fastenuff - 15/10/02 at 06:05 PM

james you must have a 2nd edition book.

Gremlin - 15/10/02 at 11:05 PM

James

Thanks for that. I already have the tiger book but was not that happy with the back half of the chassis. The front was nice and well thought out but the back looks like it has been thrown together and i was just trying to make things a bit easier for me as im limited on cash and cant be remakeing bits.

I will deffinatly look on the photo section but i was hopeing buy producing the cad drawing i would get a few dimensions.

Oh well! Off to the garage with a bit of paper and a ruler.

James - 18/10/02 at 11:16 AM

Fastenuff,

Yes I do- I've looked at both and I definately prefer the 2nd. Saying that though, a lot of people have had trouble with the bit of the chassis where the rear shock mounts (the 102mm*102mm*3mm plate) because of the lack of clarity in the 2nd book. Looking at the 1st book this area is much clearer in several pictures.

It's page 95 and you can practically build IRS off that alone.


Gremlin,

You're right, trial and error fitting definately gets through more metal- my pile of RHS that's now too short to be used is growing rapidly!
I planned mine out and used trigonometry to calculate what I could in advance but some data is impossible to find as what's needed to calculate it is missing from The Book.

I agree the Tiger plan doesn't look ideal but if you can't/don't want to/don't trust yourself to design it yourself then I guess it'd be a big help.

Looking at the Stoneleigh photo archive here (when it works again) and The Book it's not that hard to come up with something that fits the original style of the rest of the chassis.

Cheers,
James

Hallsy - 18/10/02 at 04:04 PM

There is a lot of talk of using the +4 or +442 plans if using a Sierra rear suspension set up. Is this necessary or just a preference as i am looking at building the standard "book" chassis as per the McSorley drawings and will be using a Sierra donor?

john_s - 18/10/02 at 05:48 PM

quote:

There is a lot of talk of using the +4 or +442 plans if using a Sierra rear suspension set up. Is this necessary or just a preference as i am looking at building the standard "book" chassis as per the McSorley drawings and will be using a Sierra donor?


The extra 4 inch of width suits the sierra donor better as it has a wider track than the escort.

The extra height of the +442 could be useful due to how tall the pinto engine is. I'm just using the +4 plans; am going to find out the hard way if a pinto goes in without too much bother!

Hallsy - 19/10/02 at 05:35 PM

So if using the Sierra steering rack (i'm presuming it can be used) and the Sierra drivetrain it is advisable to use the +4 drawings?
As for the rear suspension arms would you just replicate the front ones and position them to suit the position of the rear driveshafts and hubs?

locodude - 19/10/02 at 06:23 PM

Why use + anything plans. The MK Indy chassis is basically a locost with an IRS back end and extended front wishbones. It even uses the donor driveshafts. The rack is modded to prevent bump steer. The only reasons for + something chassis is really being a bit lardy/ ease of engine install. Don't forget that the bodywork will be harder to source if going bigger! Just a few peneth of thoughts!

Hallsy - 19/10/02 at 06:34 PM

Right, so if using the standard chassis plans the Sierra front track and rear 'shafts can be used as long as the front wishbones are extended ( can these be bought to meet this requirement?) ensuring that the geometry is still the same and that rear wishbones are made up to suit the position of the rear hub/'shaft assembly?
I would like to stick with the standard chassis plans (McSorley) but use a Sierra as donor and so irs rear, will i survive!!?? I am an engineer by trade so i should be able to!!

ludsonline - 19/10/02 at 06:49 PM

Hi Hallsy,
I have ordered the Tiger book from Sudbury Library and will scan the chassis pages when I get it and e-mail them to you if you want

James - 19/10/02 at 07:14 PM

Hallsy,

yes, you can buy the wishbones from MK to suit the Sierra track with a standard chassis. I asked about this at Donnington and it's not cheap but possibly a good idea.

Remember if using Sierra you'll also need to enter the great balljoint search or get your Sierra hubs' lower hole bored wider to suit a Cortina balljoint.

I also asked at Donnington about the modified rack. There's an additional reason aswell as for bump steer that it's chopped: the fact the with the standard rack the mounts end up outside the car! MK chop it so as to get the rack mounts where they would be on an escort.

For both rack and hubs you can get them from MK on an exchange basis.

With Sierra you'll also need to make/buy rear uprights. These are about £30 each from MK. You'll also need hub insert bushes for the front hub so it can take the Sierra top mount. You can make these (not too hard but need a tapered hole for the BJ) or buy from MK. (£20 each!!!).

Basically my advice would be only use a Sierra if you really can't find/don't want a MK2 because it is a lot more expense and hassle...

I'm doing it so I should know!!!

Cheers,

James

[Edited on 19/10/02 by James]

Hallsy - 20/10/02 at 11:34 AM

ludsonline, cheers mate, that would be much appreciated.

James, i could machine the hubs easily enough at work, to accept a cortina ball joint. As for rack, if u were to chop it and shorten it (is this just a case of cutting and welding back together?) then surely you could just use standard wishbones as the track could be made to be as the escort.
I see what u mean about exta cost, its just that o thought it would be alot easier to find a sierra than an escort, i s'pose i haven't actually tried looking for an escort yet though, i'll have to see what happens i guess.

interestedparty - 20/10/02 at 12:42 PM

Correct me if I'm wrong, but I believe that it's actually the Maxi balljoint that is used with the modified Sierra hub.

John

James - 20/10/02 at 01:41 PM

Hallsy wrote:
James, i could machine the hubs easily enough at work, to accept a cortina ball joint. As for rack, if u were to chop it and shorten it (is this just a case of cutting and welding back together?) then surely you could just use standard wishbones as the track could be made to be as the escort.
I see what u mean about exta cost, its just that o thought it would be alot easier to find a sierra than an escort, i s'pose i haven't actually tried looking for an escort yet though, i'll have to see what happens i guess.



Where do you live- fancy doing mine for me at the same time?

The front track *can* be the same as the escort but remember the rear track is 7"(!) greater on the Sierra. I don't know how this 'go-kart' affect would affect the handling (for all I know it might be better) but you're taking a risk.

Yes it is much, much easier to get a Sierra- you need to be lucky to get a £50 Escort whilst the Sierra owner has to be lucky to get someone to take it away! My point is that rushing out and buying a Sierra is a fun idea (I couldn't wait) but in the long run fitting it will take much longer (and probably cost more) than waiting till an Escort comes along. Bear in mind you can build the chassis in the mean time!

Anyway, don't get me wrong I don't want to put you off the idea- if you can do it and want to then good for you I just don't want you going into it blind!


HTH,

James

[Edited on 20/10/02 by James]

bob - 20/10/02 at 01:42 PM

John
Yep its the maxi ball joints used on bottom wishbone to sieera hub,hub is machined to accept balljoint.

If the photo archive gets working this i'll bung some pics of it all an there with the shortened MK rack in situ.

James - 20/10/02 at 01:44 PM

quote:
Originally posted by interestedparty
Correct me if I'm wrong, but I believe that it's actually the Maxi balljoint that is used with the modified Sierra hub.

John


Yeah, sorry you're right.

Cheers,

James

Hallsy - 20/10/02 at 04:07 PM

Cheers for advice guys, i overlooked the fact that the rear track would remain much wider!!
I think i will just build up the chassis as you say and see what donor crops up as time goes by.

jbmcsorley - 21/10/02 at 05:57 PM

Hi Gremlin,
Sorry it's taken so long to get back to your question about IRS plans...
The Sierra doesn't exist over here so it's kind of difficult to measure the donor.
If someone in the UK sends me a Sierra, I'd be glad to design an IRS version of the 442! There are similiar donors here, but they are super hard to find.

Side note... the +4 chassis design on my website calls for a +4 nosecone and will (most likely) better suit the Sierra rack. The 442 design uses a standard nosecone and will (again, most likely) call for custom lower wishbones to get the front and rear track lined up.

Gremlin - 22/10/02 at 02:31 PM

Can get you a sierra for nothing but pp may bankrupt me

You could get some mesurement from Avon Tiger and work form the mk picture. I think Ron C is releasing a new book in the new year with all the irs dimensions and dimensions for different engines and gear boxes. Not sure if the chassis will be the standard size or changes?