Page 1 of 1

Radiator cap PSI tolerance?

Posted: Sun Jan 18, 2015 3:23 pm
by JTY
What is the standard spec PSI tolerance for the 323i radiator cap? Having trouble looking it up. Nothing seems marked on the cap itself neither.

Say you wanted to upgrade to a Stant Racing cap (http://www.demon-tweeks.co.uk/motorspor ... er-release), what tolerance would be appropriate?

Many thanks

Jeroen T.

Re: Radiator cap PSI tolerance?

Posted: Sun Jan 18, 2015 7:08 pm
by Jeroen
1 bar afaik, but why would you want to increase pressure? Keep in mind that might break other parts. I remember issues with E30 rad caps opening too late ruining heater matrixes and heater valves.

Re: Radiator cap PSI tolerance?

Posted: Mon Jan 19, 2015 7:46 am
by JTY
1 bar equals abt 14.5 psi. Thanks, Jeroen. Need a new cap and just looking into the options.

Re: Radiator cap PSI tolerance?

Posted: Mon Jan 19, 2015 7:57 am
by Jeroen
Ah ok, thought you were looking into increasing pressure. Yup I think abt 15 psi is also a common value you find on the net. And they do fail on a regular basis indeed, either opening too soon or too late!

Re: Radiator cap PSI tolerance?

Posted: Mon Jan 19, 2015 1:34 pm
by TopCat
I like these Stant jobs very much and have them on most cars fm 22lbs on racecar

I think we run an 18lber on Herman- so far no probs

I will check if needed tonight?

Re: Radiator cap PSI tolerance?

Posted: Mon Jan 19, 2015 11:35 pm
by JTY
A check always welcome and useful information, Topcat! Thx.

Re: Radiator cap PSI tolerance?

Posted: Tue Jan 20, 2015 11:16 am
by TopCat
yes it is an 18-22lb Stant

Photo to follow

However please note that Herman has a Big block M30 Alpina engine with the standard 323I Radiator (with elec fan) as well as new hoses everywhere.
Herman is a genuine B6 28

Re: Radiator cap PSI tolerance?

Posted: Tue Jan 20, 2015 1:25 pm
by JTY
:thnx

Re: Radiator cap PSI tolerance?

Posted: Tue Jan 20, 2015 4:17 pm
by TopCat
Image

Image

Re: Radiator cap PSI tolerance?

Posted: Tue Jan 20, 2015 7:16 pm
by JTY
:thumbsup