I'm trying to reduce surge in my baffled tank, and want to foam fill it. I'd rather do it in one block, so as to be able to carve a void in it to stop it blocking the fuel outlet (I presume fuel cannot travel too quickly through the media)
Would I be able to squash a 30x25x12 block through a 40mm dia hole?

Or should I just use the cubes?

James

I assume those dimensions are inches if so I'd say next to no chance I'm afraid. Blocks might be your only bet, even those maybe a little tricky unless very small.

They are in cm, its only a small area

You could always use "Explosafe" aluminium foil balls.
You can pour them in the filler

Demon Tweeks sells small blocks of foam ready to be stuffed into the fuel tank

James don't use it.
It's ok on a racecar that you strip down, but on a road car the foam gradually breaks up and gets sucked into the pipework.
You are better off with internal baffles

http://www.demon-tweeks.co.uk/Motorsport/Fuel_System/Fuel_Tank_Baffles/Demon_Tweeks_Easy_Pour_Fuel_Tank_Baffle_/1545/0/23019

or

http://cgi.ebay.co.uk/ALLOY-FUEL-SURGE-TANK-SWIRL-POT-RALLY-RACE_W0QQitemZ320521799574QQcmdZViewItem?rvr_id=&rvr_id=&cguid=4ea4516b11f0a0aad3a 6cba6fff3b6cd

Thanks guys, I don't like the idea of fixing fuel surge by adding weight, complexity and pumps to go wrong - so I might try those aluminium baffles...