Foam air filters, a word of warning.

[Tim Falce]

I just started my race car to move it out of the garage. I parked it in the drive and went to move my Land Rover, as I was reversing the LR I noticed quite a lot of smoke coming from the air vents and wheel arches of the race car. Luckily the bonnet wasn't fastened down and upon opening it my ITG foam filter was burning merrily away from the area of the front carb. The flames quickly started to spread but I managed to unclip it and throw it out of the way.
So apart from a £140 filter totally wrecked no other damage was done, just be aware that they aren't fire proof, burn readily (I suppose I already knew that) and give off toxic fumes when a bit of unburnt fuel ignites them.

[GORDON STREETER]

Tim I'm glad your car didn't end up like mine a couple of weeks back.
I have seen these filters catch alight on 4 stroke bikes a couple of times.
They get soaked in petrol from the valve overlap at slow running then away they go. You were lucky this time . Do the lottery this week !

[jonners]

We had a problem with a pipercross sock once - it's made up of 2 bits of foam formed into shape and then glued

"The glue degrades in the filter's hostile environment, sir" said pipercross when we told them that we'd lost a dead cert class win because the end had come off and blocked up one of the ram pipes.

Don't think foam filters are that clever, generally - but what's to do when there's no alternative - we're going to have to get an ally air box fabricated for our car (Mk 2 Lotus Cortina) so we can throw the socks out - rolling road operator told us that at high revs they deflect inwards very noticeably.

Sorry - just realsied this is a bit of a hijack - glad you and your racer are still intact.

[Tim Falce]

Originally Posted by jonners

"The glue degrades in the filter's hostile environment, sir" said pipercross when we told them that we'd lost a dead cert class win because the end had come off and blocked up one of the ram pipes.

I had the same thing happen once but couldn't trace the misfire it caused, I didn't think to look in the carb inlet. I gave up on a weekends racing thinking I had a serious problem only to find it when I started looking at it in the garage the next day.

Back to today, I have enough of the filter framework left to cover it with some steel mesh which should also regain some of the 8 bhp I lost by fitting it in the first place.

[terence]

There is available aero mesh from R.S,Had the same happen on a TR4 a few years ago,unfortunatly the car had been left ticking over by the owner for "2 min,s". He did,nt race that day!!!!