I can't say about those brands of rust converter paint,
but I can for sure say about Zero Rust brand rust converter paint.

I have used it on diesel engine blocks,
and newly rebuilt transmissions ( and steel wheels too  ) ..

I thought 'maybe' heat and fuel/oil would get to it ..
but nope.
   Since VW rebuilt 1.6 diesels are green, I painted a 1.6 rebuilt
engine that I did in green .. after two years it looked like I painted
it last week.

it goes on thin.
Might take at least 4 applications ..
but man ...this is the BEST spray paint I have EVER found ..

it doesn't run ..
it's tough as could be ...
just love it.
well worth the 10 bucks per can.
On 7/6/2014 11:32 AM, Neil N wrote:
> Hi all.
>
> Will a typical rust converter paint (RustCheck, Plastikote, etc.)
> withstand temperatures seen at the small coolant pipes on the WBX
> engine?
>
> Am searching to no avail and have searched the manufacture websites.
>
> The only POR-15 I can find locally "off the shelf, is "Clear" POR-15.
> Shipping time aside for the correct POR product, would like to use up
> what I have on hand  (Plastikote) on two small coolant pipes on my 2.1
> WBX. These pipes have *very* minor rust pitting.
>
> Please and thanks,
>
> Neil.
>
> --
> Neil n
>
> Blog: tubaneil.blogspot.ca
>
> '88 Westy http://tinyurl.com/c8rlw6p
>
> '81 VanaJetta 2.0 "Jaco"  http://tubaneil.googlepages.com/
>
> Vanagon VAG *Gas* inline-VR Engine Swap Group:
>
> http://tinyurl.com/d7gd5ej
>