I have an Aero Classics 7 row cooler now……pn 8000075. This is a “standard” Aero Classics cooler, not one of their HE models.
My understanding is that the Niagara/NDM/Harrison coolers are comparable to the Aero Classic standards with respect to both price and performance…..they are both relatively cheap and relatively inefficient. So, I presently have a relatively inefficient 7 row. I have over 800 hrs on my YIO-390-EXP using this cooler and overall, it works….just a little marginal. The push to a 13 row high efficiency model for these engines seems to be overkill.
My understanding is that the Stewart Warner/Meggitt coolers are comparable to the Aero Classic HE series, with both being relatively highly efficient and high price. All literature and vendors state the HE series as being an FAA/PMA approved direct replacement for the SW and with the same or better performance.
The Airflow Systems X line also looks good. They are comparably priced, and I suspect comparable performance, to the SW and HE lines. Their performance plots show them superior to the Niagara and Aero standard line……but don’t show comparisons to the SW or HE.
Looking at the dimensions, the following are all about the same size.
10 row Airflow AS-2004X
8 row Aero Classics HE 8001599
8 row SW/Meggitt 10599R
9 row Aero Classics standard 8000074
9 row Niagara 20003a
I am going to try to get the 10 row AS to fit. It is a little bigger than the others so if it doesnt fit, maybe the 8 row HE or SW will fit. These are all of the high efficiency models. If none of these fit, I doubt the lower efficiency 9 row AC standard and Niagara will fit either. As far as baffle mounted is concerned, the only remaining option would be to replace my existing low efficiency 7 row with a high efficiency 7 row and remove the shuttle. Neither SW/Meggitt or AC HE make a 7 row. AS does make a 7 row in their X line. I may see if they have any performance data comparing it to my existing AC standard 7 row.
If none of this pans out, then I am going to have to go remote. If I have to do this, i will fit the largest, most efficient unit in than I can, preferably with a 5” duct.
A good link about Aero Classic standard vs HE is
https://www.kitplanes.com/cool-and-cooler/