Do the SS heat exchangers allow for a faster cabin warm up - from your experience.
About a year ago, I replaced the SS exchangers for OEMs on my ‘75 1.8
It seems like the cabin would heat up faster with the SS ?
Flappers are good, cables properly set, and fan operates
Anyone been down this road?

In my experience, yes SS heat exchangers transfer more heat faster.
The SS tubing has thinner wall and I believe SS transfers heat faster as well.

But real world experience, yes they heat the car faster.

Jim

Stainless is an extremely poor conductor of heat infact much worse then stock steel.. What you are likely experiencing is thinner materials as you mentioned..

I think its the design change of the back dated exchangers that make the difference

I had a side project to ceramic coat the inside of a stock HE and and the outside of the shells with entropic and insulating coatings. I sold them to Rob back East a while back for him to continue it since I sold my car.

I think what happens over time is that they.....yes......wait for it......rust, and then that is a inhibiting factor in the heat transfer and then air flow......from a previous thread, a poor conductor of heat.

Same thing on the cylinders...they rust and then conduct heat poorly.