True. If you look up any '40s to '50s mass-production car they were all, without exception, very lazy-revving by even mild standards of today. Even so, many of the engineers and engine-designers of those days weren’t really that experienced and many engines they made were very much “let’s bolt this together and see what happens!” as testing standards and measurements were not very refined at all.
Remember that the internal-combustion engine mounted in a vehicle was barely in it’s 50 years by then, so you would expect some really fragile designs.
The Soviet GAZ M20 Pobeda released in 1946 had a 2.1L side-valve straight 4 giving it’s max power at 50hp at 3600 RPM, and it’s maximum torque of ~125nm at 2200 RPM. It had a bore of 82 and a stroke of 100mm(!), compression was at 6,2.
As stated this was in a straight 4 mounted in a mass-production car. If i do remember correctly, engineers from Ford was involved in that design process too as they had a deal with GAZ to help the USSR get along with building cars, so they knew what they were building alright.
Look at France for a minute, just below the Eiffel-tpwer you would see a Renault 4CV, released in 1947 parked next to a Baguette-stand, it had a very uninspiring 750cc engine, a straight 4 actually! Bore vs stroke was 54.5 × 80 mm and a compression ratio of 7,25, and that was considered pretty hefty by that time. It produced it’s oak-barrel-matured 21 bhp at 4100 rpm, and that engine was practically revving itself to pieces by then. It’s maximum torque of 45Nm (mon Dieu!) was achieved at 2000 RPM, pretty much you average idling speed on a sports car these days!
And finally lets take a leap to the land of the rising sun, Japan, and take a look at Toyotas very first small cars produced after WW2, the Toyota SA. It’s rather miniscule 1.0L rice-boiler-engine called the Type S-engine located in the front was producing it’s peak power of 27hp at a mind-blowing 4000 RPM’s, that’s probably nice by today’s standard, but mind that this is a '40s era very small engine with tiny pushrods bouncing around like crazy in there when revving like that, redline was achieved at about 4500 RPM. It’s compression was at a rather dull 6,5 too with bore and stroke measuring at 56 x 75mm, respectively.
What do we learn from these three adorable collectors cars of the '40s? They all had a very uninspiring compression ratios, all of them had rather long strokes compared to their bore except for the Toyota, but then the Japanese were known for appreciating some new thinking even back then, and as such their engine were capable of some normalized RPM’s without blowing up and still, most of them ended up stranded by the side of the road with a big black pool of blood… sorry, OIL on the ground underneath.
So… Shorten your stroke, lower that RPM-limit, lower that compression and fill it up with something decent in the way of gasoline and pray to you most favorite deity that it will hold together, i am too bogged down in '40s to '60s engine hell in Automation trying to make something that actually works, but with some very small and gentle tweaks here and there one will eventually make a decent engine… Just like in real life! 
Great job guys!