4 replies to this topic

[robbo]

hi all,

I have finally got round to plumbing in the cooling system and i do not have a bypass hose, now i understand that by drilling the thermostat it will allow for a little water to flow so i dont get hot spots before the thermostat opens up, my question is, how many holes and how big. i have tried searching but cannot find anything specifc,

thanks in advancve

[Sammy D]

6 or 8, about a 5mm or 6mm hole.

I did eight 5mm, works nicely

Edited by Sammy D, 19 August 2008 - 06:36 PM.

[robbo]

cheers for the reply - do i really need that many, ive read a couple will do?

[m1n1]

Ive not had much luck with holes in my thermostat. I drilled three at 4mm and it really did take an age to heat up; especially in the autumn, winter time. No doubt leading to increased engine wear and fuel use; so ive not got just one hole, and it heats up quite well.

[Ethel]

It's easier to add them than take them away. 4 x 5mm holes would be about the same as a 10mm hole, which I'd guess is about the bore the original bypass.