Imagine you live in a world where a push rod, oil burning, rattly engine will require full machine shop treatment and performance specs over a stanadrd refresh just to be able to extract the amount of power i person yearns for.
You will end up spending too much money and time for little unreliable results if the wrong choice is made.
The question should be put when asking or thinking about engine upgrades is what kind or HP or KW combined with torque is standard for the engine and then look at what is required to make 1000-1500kg move quicker.
Start researching 4AG motors and their applications, CA18DET and SR20DET, Rotary.
I like the 4AGE but only the 100kw 7 rib NON tvis and have driven a few 20v compared to the 16v and they have some more revs but your screaming its tits off so i havent come accross anything saying there is any REAL benifit to the 20V.
But i wont be messing about with low capacity 4 cylinder motors as its personal preference to myself.
This is the kind of discussion that has probably been discussed a thousand times before but too much misinformation can be confusing.
Do some real research and the answers will come, do a want list of what you want to acheive.
Quick edit just thought my post is getting offtopic, but just trying to guide you towards not wasting your time asking places what engines they have if you havent made a choice on what engine to use ?? yeh ?