Gas engines are 10:1. Diesels are 16:1, some as high as 22:1. My Unimog does not have glow plugs or air heater to get I started, I believe it is 18:1. Older army trucks like yours will be set up for crappy fuels, you can adjust your injector timing for better performance. Get a remote mounted turbo, not as efficient as one at a manifold but 10x easier to install.
So gas engine, wide open at best sucks in 1atm of air, compresses to 10atm, fuel ignited and burns and you have 40atm pressure driving the piston down
With turbo, wide open at 15psi boost or 1atm you have 2 ATM in cylinder. Compressed to 10:1 that is 20, x4 and 80atm pressure driving down. Stock old diesels don't like more than 1
But the above is for gas, need to know your compression ratio. At least 15:1, probably closer to 18, but it could be 20
With boost you get high compression when you need it. With a high cr ratio engine, like 100:1 you will neve start it. You will need a starter ten times more powerful than you have. The connecting rods will not take the constant extra load, neither will your pistons.
If the engine is similar, find a forum and see what mods te truckers use. I know my Benz unimog there is tons of stuff I could do to it, nozzles, turbo manifolds readily availible too
The reason why it is more efficient is you have more oxygen availible for the given fuel to ensure a complete burn, at lower rpm you make more power. at 1000rpm it takes 1/2 power to keep the engine turning then 2000rpm, 2000rpm is half power to turn than 4000rpm. if with a turbo you can make same power at 2000rpm as 4000rpm you have increased fuel economy, probably not 2 fold but I bet by at least half that as the mechanical losses are the same. either way a turbo is good, I wish I had one
your gear ratios are probably goin gto suck too, too low and your engine revs too high wasting power, too low gears and it struggles to get going.
my truck was geard for 75km/h top speed. I installed 15% larger tires (stock were 40"dia) and now at 75km/h the engine is not running full out.
picture of mine, 46inch tall tires, 15 inches wide, gets 15mpg
