when measuring for cooling hoses, do you measure the narrowest part on the radiator (not the bead itself) and go with that?

whenever i've bought hoses in the past they never seem to be quite the right size... so thought it was worth checking.

Yes, you want the bead to stretch the hose slightly so it doesn't slip and gives a nice tight seal. I've not been afraid to go a mm or two undersize if needs be on the hoses

cool, coz i'm sure once i ordered a temp sender adapter, measure the thermostat housing on the engine so it would be the same, and it was quite different when it arrived. thought i'd done it wrong lol

how much can silicone normally stretch?
my radiator's 38mm i think, and the engine is 35mm. would be good if i didn't need reducers at £7 each

3mm stretch may well be pushing the limits of the elasticity but guess someone may have the answer you need with a hose of that size. You cant compress the hoses though so you need 34-35mm hose for the engine end - cant fit a hose in between sizes and then clamp it down - not without expecting a leak anyway

[Edited on 2/4/10 by Paul TigerB6]

thanks Paul
i'll go out and double check everything tonite, then go and add up the cost of all the bits i'll need

it'll have to be a reducer then. i guess i can deal with that if i have to.
i'd need to put a T in the bottom hose for the header tank, so i'd have a reducer, aluminium joiner with take off welded on, then the 35mm hose i guess

No problem mate. Can you use a silicone reducing elbow / straight reducer off the radiator to then allow a 35mm aluminium t-piece to be used??

Isnt there someone on here who can make up the ali parts to spec?? I know Merlin Motorsport do 38mm ali t-pieces

like this

mrsilone on ebay sells all sorts of bits, and joiners. need some stuff welded up in the coming weeks, so i'll get them to do that too

silicone at those sort of diameters will stretch 3mm without issue - WD40 works well for lubrication (as it evaporates after the event too).

Silicone stretches, rubber or whatever it really is, doesn't, and can seriously HURT the hands after a while!

good stuff gents
silicone's what i'm going to use, so you think 35mm should go on the radiator easy enough?
mrsilicone has free delivery by the looks of it, so i'll get the 35mm stuff, if it doesn't go on the radiator, i'll look to get some reducers later then