Ed,

 

            You can put me down for series rads and Jim M as well.  Neither one of us could get the coolant to flow equally through parallel rads.  Jim went so far as to add ball valves on the hot core to try and limit it’s flow.  It worked to a degree but plumbing got very heavy and complicated.

 

            I’ve pondered about this issue and I think there may be a number of factors involved.  (Group input is highly desired)  We both used large hoses for our installations.  1.5” to the Y’s and 1” from the Y’s to the rads.  (Actually, one of us used Y’s and the other T’s).  I’m wondering if the large hoses after the Y was too little flow resistance thereby allowing most of the coolant to pass through one rad.  I notice Tracey uses smaller hoses which may increase flow resistance to each rad and provide more of a balance.  I think someone is using AN16 fittings which is 1” hose but by the time you get through the restrictive male coupling, the same factors may apply.

 

            Al G. may be able to help me with this one…  Assuming a perfect world…  what would the outlet temperature difference be between series rads vs, parallel.  My guess is…  if we had 215 degrees coolant entering the parallel rads and we get 180 degrees leaving the rads, there is a 35 degree drop, or about a 16.3% drop.  Series rads would give a similar % drop divided by 2 for each.  215 – 8% = 199.  Then the second rad sees 199 – 8% = 184  (I rounded off the numbers cuz 1 degree isn’t an issue)  By my calculation (which may be out in left field) the difference is negligible.  

 

Neil  (Giving Rusty something else to think about)