Which Coolant Hose Type?

[thermojac]

I am looking to replace the coolant hoses on my V12 and would be interested in members views/experience of whether to fit silicon or standard cloth reinforced as there is a significant difference in price.

[MarekH]

Silicon hoses are only of any interest when a custom shape is needed. There is no "performance" upgrade in this case and presumably the standard fitting silicon hoses are significantly lower value for money. I'd suggest that anyone who has fitted them and thinks otherwise hasn't read "The Emperor's New Clothes" - you don't need hoses with an eye popping bursting pressure spec or a temperature range of -60'c to 180'c in a standard application.

I have some silicon hoses on my car, but only where I have fitted some water flow meters to monitor thermostat opening and bypass flow. as these are a different diameter from standard. I'd say they are less forgiving of any diameter mismatch when compared to rubber and are less flexible to engine movement.

kind regards
Marek

[thermojac]

Thanks for your advice Marek and at 5 times the cost of silicon over standard it doesn't look too attractive.

John

[vee12eman]

Hi John,

I have no experience of silicone hoses for the V12, but I have fitted cotton reinforced units and the Kevlar reinforced type too. My advice is DO NOT buy the Kevlar ones. Utterly rubbish. However, one thing be aware of is that even the cotton reinforced type have difficulty sealing if the flanges to they fit are not in good shape. Poor quality castings, corrosion and pitted surfaces are common on older V12 engines so make sure that each flange is in good condition. Either replace badly corroded alloy castings or file/emery cloth the flanges smooth. Also check both new and old castings for casting marks which can be big enough to make sealing difficult. Also, silicone hoses are quite stiff, so hard to get them to conform to damaged/poor surfaces, not to mention simply being difficult to fit, remember there are over 20 hoses, some in difficult to access locations.

Good luck,

Simon

[thermojac]

Thanks very much Simon for the heads-up on Kevlar. Yes, I believe there are 26 in total so hopefully, the winter months will be enough time

Thanks again

John

[Neil Duke]

Silicon hoses are very soft,I use them on my Special Saloon Anglia.No need for them on the S3.

[PeterCrespin]

I have no experience of silicone hoses for the V12...

I wouldn’t have guessed it, Simon, since you’re the only one to spell the name right. Silicon is a brittle crystalline mineral similar to carbon. Your namesake and our pet chemist Simon Johnson will correct me if I’m wrong, but saying ‘silicon hose’ is like saying the standard ones are coal rubber (which black ones arguably are, due to carbon black filler I think..)

Very good points about dressing/sealing corroded hose spigots too.