Fireblade Nova Mounting

[7Nut]

Rob,

Is that a BEC only blat or with specially invited guests eg. other 7's 😬

By the way, we already have a BEC club in Essex on Sunday mornings

[Ray Gamma]

The BEC-Blat suggestion was only because I'd like to hear what we'd all sound like together 😬, and of course it would be good to put faces to names.

 

Of course all 7s would be invited - I would be concerned however that all those car-engined 7 owners would have a mass epiphany and the second-hand caterham market would be flooded; driving down residual values - I wouldn't want to be responsible for that

 

Edited by - Ray Gamma on 7 Feb 2008 16:23:53

[blade_runner]

Rob, I dont think its a matter of tightening the bolts in any sequence, I think the geometry of the mounts is not quite right, between top and bottom mounts, or the angle of the Nova box in the tunnel, and as the top bracket is the weaker of the mounts thats the one thats failing. the ideal thing would be to get your car on a proper ramp so you could stand underneath the car and fit the box and brackets loosly to try and see if everything is alining, which is very difficult to do when the cars just on axle stands!!

I'm convinced that something doesnt line up quite right, like the plate on the top mount maybe being a couple of degrees out of alinement then when its bolted up its put under strain. and i'd imagine that all the top mounting brackets have been made from the same jig.

 

'Pinky Pics' here

[Ray Gamma]

My own amateurish thoughts run along the lines of;

 

1. The short prop shaft from the engine to the Nova doesn't have a universal joint at at the engine end (just the rubber doughnut). This in my mind means that the input flange of the nova box needs to be carefully lined up with the short prop shaft first and attached. If this alignment isn't correct the prop shaft will be trying to move the Nova box elsewhere - straining the system.

 

2. In order to get this alignment correct some spacing washers may be required to then attach the Nova to it's chassis mountings.

 

3. Finally attach the long prop shaft (UJ at each end and some movement fore and aft meaning that Nova box position isn't vital).

 

This is just my numpty theory - any other thoughts?

[blade_runner]

I always bolt the box in first then attach both props. but my set up is slightly different as my top bracket for the nova also mounts the gear lever too and is rather large compared to the small triangular bracket used now.

I think the there is something wrong with the geometry on the newer type smaller triangle top bracket, which is putting it under stress when bolted to the chassis and nova box. its under strain even before the load of the engine is applied. when I looked at Stew's bracket it looked like the strain was trying to pull it apart as if the top of the nova box was leaning back and trying to enlongate the bracket, if any spacing or shins need to be applied then I would prob try between the top of the nova box and the flat plate on the bracket. but thats was after looking at stews failed bracket, yours may be different.

 

'Pinky Pics' here

[fozzybear63]

Rob

YHM

but count me in too please

 

Fozzy

Crockey Hill

[Blade Runner]

After pulling out my reverser box ouy today for replacement of the chain ,I to have found the flat top plate snapped off. I havnt had a chance to see if there are any other fractures to the mounts( called in for dinner) as it is covered in dirt. a clean up tomorrow might show up any signs.

After reading the above my thoughts are that misalignment is to blame so I think it will be a reinforced and repaired plate, bolt in front prop straight and then use packing washers to the bracket/mounts.

How have the modified brackets from Arch stood up, did you weld them in yourselves?

 

 

Trevor

 

PINK LOUD and PROUD

[Blade Runner]

Following on from the above, no other fractures found but problem with removing the main retaing nut to the flange plate, a socket and two foot leaver havent shifted it so before resorting to a chisel and hammer, two questions 1) is it common that it is so tight and 2) am I missing somthing?

 

Trevor

 

PINK LOUD and PROUD

[STEVE GILBERT]

Yes, you are missing something, simply use a nut gun on an air line, the shocking action will undo it easily.

Also use 12.9mt SOCKET HEAD bolts on the prop flanges (and I like Aerotight nuts but not critical) then you can use a small air ratchet and a long socket allen key to easily spin in (or out) the prop flange bolts after you have cracked them.

This will literally save hours particularly if doing on yer todd.

 

Steve

 

See My Caterham Fireblade Here.

[blade_runner]

I second what Mr G says about the 12.9 bolts and Aerotight nuts

 

'Pinky Pics' here

 

incar vids

[Blade Runner]

I have no air spanner but the shock of a lump hammer seemed to work 😬.

Once the chain was off i found about a dozen rollers broken up or badly pitted.

 

No proplems with flange nuts even being hex heads.

 

Just got to repair the bracket tomorrow.

 

Trevor

 

PINK LOUD and PROUD

[7Nut]

And a third recommendation 😬

 

Following on with the broken bracket theme (as you can read my woe's earlier in the thread ).

 

After various chats with bladey, he suggested instead of mounting the reverser box first followed by the prop's etc etc, I should just place the reverser box on the chassis plate, then secure the triangular mounting bracket and prop's. Guess what, the three holes to secure the reverser box to the chassis plate didn't line up

 

So with the three holes adjusted, I've had two years of bracket failure free sevening .

 

Stew

[blade_runner]

Trevor, with regards to the prop flange bolts steve G was refering to, myself, 7 nut and Steve Gilbert have all replaced ours with new longer 12.9 mt bolts, our new bolts are long enough to pass through the reverser box flange and then an Aerotight (shakeproof) placed on the thread on the back of the prop flange, its a Belt and braces thing, and a worth while mod I think after seeing the mess a flailing propshaft can do to a transmission tunnel or your leg!

I think the bolts and nuts cost under £30 from a good fastner supplier.

I makes it a little more fiddly to fit the prop shafts, but as Steve g says I have a micro 3/8 air wrench using that and extension and a wobbly hex socket it buzzes them in really quickly.

7 nut seems to have sorted out his alignment issues, he unbolted the reverser lower bracket from the chassis plate (i think this is the gearbox mount on a normal caterham) he then bolted the top trianglular bracket in place then bolted the reverser to this. fitted the props, then got under the car and looked at the alignment holes in the lower bracket and the chassis, and I think they were about half a hole out. then I think he filed the holes in the chassis flat plate out to match the lower reverser mount.

 

'Pinky Pics' here

 

incar vids

[Manxseven]

Oh Trevor, just the time for the axle upgrade 😬

 

Simon.

 

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Caterham BEC here