Roll cage

[gavingraysonr300]

Just wondering how easy it is to swap out a roll bar for a roll cage no holes at the front at the moment any advice is appreciated thanks.

[Paul Deslandes]

If series 3 then not too difficult but requires removal of the rear shocks to get at the bolts which have thin hex heads.  Modified socket required to get these out if you have FIA bar with them fitted (not all do).  Socket requires its face grinding or turning down to remove the radiused end of the socket 'tube' so that there is maximum engagement with the bolt head.  Otherwise it's easy to damage the head.

You also have to expose the threaded bosses that take the through bolts at the front.

All up not a quick job but doable with a bit of care and preparation.

Paul

[Drumster]

As Paul says not a quick job, but to give you an idea it takes me about 2-3 leisurely hours to go from this:

to this:

which, in addition to changing the bar for the cage, also includes swapping aeros, wheels and front cycle wings.

Generally the cage stays on all year apart from the summer tour abroad.

[gavingraysonr300]

Thanks Paul for the good advice Gavin.

[gavingraysonr300]

Thanks for the advise car looks great by the way in both road and track.

[gavingraysonr300]

what size is the bolt going through at the front and i presume you need a locking nut on the inside ? also how easy is it to get the rear shocks out ? thanks Gavin.

[Paul Deslandes]

From memory they're 7/16" x 2" UNF and yes they should have a nylock nut on the inside. I also have a plastic nut cap on the inside of mine to avoid catching clothing on the end of the bolt.  I can't remember whether they chassis bushes are threaded or plain but if threaded you will need set screws, rather than bolts with a partially plain shank.

My cage also has triangular plates that have three cap head bolts + nuts onto the corresponding plate adjacent to the front large bolts.  The chassis plate will likely need to be drilled through.

Removing the shocks is the time consuming part and involves jacking up the rear end of the car, removing the bolts securing the shocks to the de Dion tube and unscrewing the top caphead bolts with a 3/8" allen key or hex driver.  If you don't have one you can make a driver from a 3/8" AF socket and a short length of hex bar cut off an Allen key with an angle grinder.

If your FIA roll over bar is bolted down at the top you will need a 3/4"AF socket modified as described above, and a long extension and wrench.

Don't expect it all to fit perfectly, especially the two rear end bars that go to the upper rear chassis cross member at the top of the boot.  They may need to be 'persuaded' to cooperate with ratchet straps. 

Others may hopefully have further advice.

Best of luck

Paul

[Drumster]

The threaded bosses at the front on my '93 chassis are 7/16" and you'll need 2 bolts per front leg, these being 7/16" x 3/4"

The rear bolts on my FIA bar are 3/8" x 3/4" and on the roll cage they are 1/2" x 1" both have thin hex heads as Paul says. Please note that my cage is a roadsport cage which is different from a superlight cage.

The above information may be different for metric chassis

Have a look at the following articles from the archives which provide a comprehensive guide.

Article 1

Article 2

 

[Paul Deslandes]

There you go!

[Wrightpayne]

The thin headed bolts are better attacked with a socket thats had the chamfer ground off the face - less likely to slip / round off the bolt. If you look closely at a socket its obvious how much to grind off.

Rear dedion brakes have the thin headed bolts holding the discs on too.

[gavingraysonr300]

Thanks so much for the information noticed in the article it said there is an important difference with the torque settings between metric and imperial my car is imperial would you know what the settings are ? thanks Gavin.

[gavingraysonr300]

Thanks for the advise would you know what the torque settings are for a imperial car ? thanks Gavin.

 

[Paul Deslandes]

They just need to be tight enough.  It's not like a cylinder head that needs a specific torque, although I would check them from time to time.

If you have the stainless steel door sill caps you may need to shorten them to clear the front mount.  I bought a second set that I shortened and can change over when I revert to the FIA bar.  If riveted in, replace with black self tapper screws

Paul