I found some new Isky 1600-series "Super Rad" springs that are a good match for my build. This particular Isky series doesn't appear to have been offered for very long, and the attached spec sheets I was able to locate date back maybe 10 years.
They appear to be a fairly high-end endurance spring w/ nitride treating. Isky's description says the are (were) "one step beyond our 9900 RAD Series" which they do still offer, IIRC. This also makes me wonder what the circumstances were that Isky dropped them, considering they still have multiple spring series.
Also, anyone know what spring company made this spring series? I've heard that PSI has made some of Isky's top-of-the-line springs, but don't know much else. Thanks - Brad
.
What can people tell me re Isky "Super Rad" valve springs?
Moderator: Team
What can people tell me re Isky "Super Rad" valve springs?
You do not have the required permissions to view the files attached to this post.
Re: What can people tell me re Isky "Super Rad" valve springs?
Almost 250 of the "Best and Brightest" have viewed this post and nobody knows anything about these springs? 
Re: What can people tell me re Isky "Super Rad" valve springs?
I’ve never used them....... and frankly don’t remember even hearing about them before.
Somewhat handy with a die grinder.
Re: What can people tell me re Isky "Super Rad" valve springs?
What an idea... I called Isky and asked about them. 
My take-away from the conversation w/ Ron Iskendarian:
The 1600-series weren't high-demand items, although they were top-of-the-line endurance springs made by PSI, along with the other Tool Room series springs. Isky had too many spring lines that overlapped, and the Super Rads didn't sell enough vs the rest of their Tool Room spring offerings to justify keeping them. He said they're an extremely good spring that simply didn't hold its own from a marketing perspective.
Even though I couldn't find any newer references to them, Ron said they'd been made (in small volumes, I assume) as recently as 3 years ago. The ones I got must have been a very limited production run because they weren't even listed on the regular Super Rad spring spec sheet.
Well, now I know...
My take-away from the conversation w/ Ron Iskendarian:The 1600-series weren't high-demand items, although they were top-of-the-line endurance springs made by PSI, along with the other Tool Room series springs. Isky had too many spring lines that overlapped, and the Super Rads didn't sell enough vs the rest of their Tool Room spring offerings to justify keeping them. He said they're an extremely good spring that simply didn't hold its own from a marketing perspective.
Even though I couldn't find any newer references to them, Ron said they'd been made (in small volumes, I assume) as recently as 3 years ago. The ones I got must have been a very limited production run because they weren't even listed on the regular Super Rad spring spec sheet.
Well, now I know...
Re: What can people tell me re Isky "Super Rad" valve springs?
Isky historically has been very good at advertising..maybe not so much anymore, possibly the well is running dry?BradH wrote: ↑Tue Jul 16, 2019 7:06 pm What an idea... I called Isky and asked about them.
The 1600-series weren't high-demand items, although they were top-of-the-line endurance springs made by PSI, along with the other Tool Room series springs. Isky had too many spring lines that overlapped, and the Super Rads didn't sell enough vs the rest of their Tool Room spring offerings to justify keeping them. He said they're an extremely good spring that simply didn't hold its own from a marketing perspective.
Even though I couldn't find any newer references to them, Ron said they'd been made (in small volumes, I assume) as recently as 3 years ago. The ones I got must have been a very limited production run because they weren't even listed on the regular Super Rad spring spec sheet.
Well, now I know...