I have owned four Type I's and a couple of VW Vans. I've subscribed to, and read, Hot VW's for about six years. When I have had my VW's serviced I talk to the mechanics and I solicit opinions.
When I had my Thunder Ranch Speedster built I requested a fresh (Brazilian) full flowed 1915cc case with high performance components and a 3:88 Freeway Flyer, Type 4 oil cooler in the dog house, an oil filter, and a 1.5 quart "deep sump". I told Tom McBurnie I wanted a CB or a SCAT. He said he has a good relationship with SCAT and they build a good zero mile 1915cc engine. . . so I did it!
The bore of the 1915cc leaves enough case material (magnesium and or aluminum alloy) to withstand, and transfer, the heat and pressure produced by the engine. I have been told larger bores jeopardize the integrity of the case. Larger bores have a tendency to crack around the case studs. When the cylinders are bored to larger sizes these studs are very near to the opening where the piston sleeve is inserted in the case. I have been told as you reduce the amount of case "material" you reduce the case's ability to transfer heat and pressure away from combustion, under severe conditions, Heat and pressure can cause the alloy of the case to "granulate" (severely weakening the structure of the case). As a result, the extreme heat and the pressure causes the case to fail.
I am very happy with my 1915cc. I drove it today in stop-and-go traffic in ambient temperatures around 102 degrees for about two hours. The needle on my temperature gauge never went beyond mid-range.
Many owners of high performance Type I engines laughingly call them oil cooled engines (rather than air cooled engines). They may laugh, but there is an elephant of truth in the phrase. Also, there is a reason why engine builders do not provide warranties for larger builds - they know better.
If you are unhappy with the power of the 1915cc engine, next time build a quarter miler. You may have a 30 cent a gallon of gas complex (it's a Detroit thang).
Just my humble opinion!