What are people using M8 Riv-nuts for?
It just seems to me to be a large size for a car.
This size of fixing is getting into the range of beaning structural which I would think is not a good thing for a riv-nut.

Regards
Jason

Watch out, we'll be getting into the ridiculous argument of "is it OK to fix a roll bar on with Rivnuts" again if you're not careful!

I did wonder myself why on earth you would actualy need an M8 riv-nut when you posted about hiring out a riv-nut tool............

I have been asked for them by some people building cars and did not think to ask why they needed to be M8 and now curiosity has got the better of me.......

Perhaps they bought 20 bags of M8 bolts rather than 20 bolts and so they plan to use M8 bolts for absolutly everything.

what size clearance hole do you need to drill for an m8 rivnut? about 15-16mm?

i always worried about drilling a hole for an m6 rivnut in a tube!

on my new build, i've just tapped the chassis rail to hold the scuttle on since it really doesn't need rivnuts. same for the nose cone.

i doubt in most applications on a kit car you really need anything above m5 even.

i'd think most people would want m8 rivnuts because it 'looks' right, despite the fact it's only holding on a non structural glassfibre panel. i guess it comes down to understanding.

it's convincing them otherwise that's the hard bit
tom

10.9mm hole for M8 Riv-nuts.

I suppose for fiber glass parts you would also use a penny type washer ( or a plate ) as well to spread the load.

We bond plates on to the fiber glass parts if a fixing go's through it.

Jason

M6 is the biggest i'm going with rivnuts. well, except M8 for the scuttle, dont want to risk anything with that.

What about to hold the fuel tank down? That is the only place I am using the M8 size (but like you lot, I worry about the diameter of the hole - I worry putting a bolt through a chassis tube, let alone an even bigger hole for RivNuts!)

If you are bolting through a chassis tube are you welding in a crush tube?

You could always weld a tab on or a threaded boss to hold things like fuel tanks and scuttle panels on.

Jason

I hadn't welded in a crush tube - how critical is it? I have only bolted through a tube to attach earthing points , so the holes are small (M5). Am I likley to be dmaging the tube then? So would you recommend a crush tube for this sort of application?

Could you just weld an M5 nut to the tube or a small plate with a hole in for an earthing point ?

If you have drilled a hole through both sides of the tube you could weld a tube in it will have the advantage of stopping water getting in as well. The tube could have your thread in for your earthing point as well. Or a riv-nut?

Slightly off thread but I see you are using a Triumph engine. What diff ratio have you gone for?

I will look into the crush tube. I am sure I can find something which I can cut a thread into and weld into the hole.

I am using an RS2000 axle (3.54 ratio open live diff) for now. That should give a top speed of ~110mph. The engine has supposedly been tinkered with (I was told around 149bhp in the bike), so until I get a chance to get it on the road and remap, I don't know how it will drive. It sounds absolutely amazing!

I am using the older daytona engine ( pre fuel injection ) in a sylva R1ot. And I did have a T595 bike.

A good map and exhaust will give 147bhp at the flywheel. What size tyre's you using?

I have bought 205/60/13 for the rears and 185/60/13 for the fronts. Oh and they are the soft R888 tyres. Should be good fun. I am pleased to hear you appreciate the engine. I am surpised they are not used more often - it has been an easy engine to get going and they cost peanuts! The major downside is the lower power outputs compared with the Jap fours, but I think it will be a great engine to welcome me to the world of the BEC. You got any videos of your riot running?

No vid's yet not got that far.
And yes great engine for a Bec
Big clutch good torque and cheep the only draw back is suitable diff ratio's.

Jason