For those still in the dark...(sorry!) I'm opting to replace the polypropylene barb, with a nylon one.
In the mean time, OC forums killed an idea to sponsor DIY blockmakers, for a round of tests by Bill Adams, but in the middle of it all, there was some info about Radius that I thought I'd repost here:
1-My pump may only deliver a pressure equivalent to 9 feet of head, at 250 gph. There seems to be many versions of the 2-MDQ-SC, I guess I hoped that mine was one of the best, at 10.5 feet.
2-I estimated the flow/pressure at 4 gpm, and 11 feet of head (through the block): if you've been following this thread, you know that this only referred to the inlet (still incorrectly), and not the flow inside the block, past the nozzle, so the block is actually a lot more restrictive. Les estimates a head of 35 to 50 feet, at 4 gpm.
Total heads loss (at 4 gpm):
3/4 ID tubing: 0.62" of head, per foot of tubing
rad: n/a (when it goes to a chiller)
res: about 2" of head
3-That nozzle (above) was to be 3/16. I've since decided/recalculated to go with 3/8. Either way, I'll be ordering a polycarbonate rod, 5/8 ID (to fit the inner res tube) so that I can try different nozzles.
4-More importantly, Bill pointed out that viscosity changes significantly at a lower temp, to which I replied that using the Windshield Wiper fluid will make little to no difference, at least according to Scott Gamble (corrections notwithstanding).
5-Bill has pointed out (correclty) that I have no modelling software. I do plan to use one, when I can find it (free CFD anywhere?) and have the time to mess with it.
Now all this started when I called Radius a high flow/high pressure block, which was of course objected to.
