I installed a ASP IO-375 M1SC with 9.0:1 pistons, counter-weighted crank, Superior Cold Sump. System32 EFII. MTV-9 prop.
80 hours flown since new in the last year.
The Vetterman Trombone exhaust fits perfectly with no issues.
Straight finned cylinders, no baffle or cooling issues. (Do the #3 cylinder baffle mod by adding a few washers).
If you choose a B&C starter, you'll have to trim and re-glass the Van's snorkel to fit around the larger than standard starter. I also enlaged the snorkel's opening that mates to the EFII throttle body so their sizes matched.
To attach the Throttle Cable, I used a bracket sold by
ShowPlanes (that I custom trimmed to fit) mounted to the bottom of the Superior cold air sump.
One thing to know is that I chose to use a 13 row oil cooler fitted with the
ShowPlanes Thirteen Row Oil Cooler Mount with its Air Control Valve. 13 rows is more than enough oil cooling. At typical cruise speeds in canadian summer temps, the air valve is typically open only 1/2 - 3/4 inch to have oil temps in the 180-190F range. It's open about half-way for extended 130KTAS cruise climbs. These days, flying at below freezing with the cowling inlets almost half blocked, it's fully closed to get 180F.
So out
side of the snorkel and the Throttle bracket modifications the installation was very straightforward as the weight and size is similar to a IO-360.
Compared to a 360, I arguably have a 15 - 20 extra HP on hand (maybe a bit more due to EFII). Needless to say that the acceleration and climb rates are stellar (they are already awesome with 180 HP).
Normal cruise speeds at 8K are north of 160KTAS with ~ 7.5 GPH, 50°LOP.
Break-in was a non-event, running 75% or above until the cylinder temps and oil consumption stabilized. About 8 hours for cylinders and 20 for oil.
Today, on average the engine burns about 1 quart/15 hours.
What would I change if I needed another engine?
Probably "normal" compression pistons to eliminate the 100LL only restriction.
I'm not tempted to test MOGAS before further, indepth considerations or even know if it's reasonable to consider.
The extra horses are always fun to have but are they a must??
I'm very happy with my engine and prop choices.
ASP and its staff are awesome.
I could'nt attend the build school in spring of 2020 because of COVID.
I may attend a future build of a similar engine, for education and personal interest.