Hi, i currently have a b20b b16a or b18c head (idk which head i have) vtec on my civic si 2000.
The reason of this post is because i need advice of what to do

First I wan to tell you some things or a few of my story with the car.

The car initially had a b18c1 forged pistons and rods, turbo with a gsr trans obd2 p72 (i believe, details is where i definetly need to check) the car felt like a rocket and felt strong. But then one day a friend presented me a guy from another city who was a tuner and he said that with a tune and bigger inyectors the engine would gian much more power, so he convinced me and one day he came, tune my car, rev it till 10krpm and said that it was safe (i had no previous experience in any way with the motor world and it was my first car ) and so I continue to use it (i did not abuse it because i was learning how to drive and that) then the problems started, one dya the engine got hot because of an cooling issue and later on it needed to be opened. The guy who tune it, also rebuild it and told me that i needed to drive 7500 kms to settle the sleeves and after that i could break in the engine. But one day, once again the engine failed, but this time it was the 3rd cylinder that wasnt working (one day 3k kms after) the car felt extremely weak and then i went to a mechanic and he told me that the car needed to be opened. I took the car to a new mechanic (prevoius) and started to show me the poor and bad work the tuner did (he was an engineer so thats why i trusted him but later he acted like a total ****, and he charged like 3500-4000dls it could be more because i spend gas, because he had to move and come form his city and he only came 1 day etc etc, and once again the engine was rebuild, everything was going fine and ok but sensors and cooling issues started afte the engine was finished and tune started (still on mechanics hand) after that i decided to remove the turbo and keep it N/A, but after te car was being tested, it blew and didnt work, he offered me to rebuild or choose between a ls vtec or b20vtec (because the only thing that failed was the short block) and i choose the b20b because of displacement. And after 4k kms the car overheated because of bad hoses and cooling issues and got filled with antifreeze on the inside, once again i needed to do something and the cheapier option was to rebuild it. I've spent over 12k on fixing this fu***** car and nothing on improving it, well just the paint job (total cost of 20k aprox).

Right now my transmission also blew (i guess the car has witchcraft or maybe i'm forsaken by god) but i just bought a type r lsd 4.7, and a bronze clutch with light flywheel and the engine is feeling pretty solid, the new guy who is fixing my car is actually very good and honest yet.

But thinking of the future i want 200-250 whp reliable and dd on pump gas 93 octane IF POSSIBLE if not, then just want to feel strong and reliable.

Any advice on how the f can i make my engine overheat and bulletproof, i have an aluminium radiator, new fan, the stock? hoses, and the thermostat is not working or something like that so the fan is always on (because there was an issue that couldnt be fixed)

And should i improve my b20vtec (cometick gasket and arp bolts it what i have on it) or rebuild the b18c1 with new sleeves(should i bore it?), eagle rods and wiseco pistons (this is not in the near future)

Again thanks for anything, i've reads tons of threads and videos and i will study and learn how to build an engine and that because im now interested in honda engines and want to properly take care of the car, but this will take time and in the meantime i want to improve the engine safety.

 

If you can wait, I'd just rebuild the B18c
There are strength issues with B20vtec that would need to be addressed with machining and/or parts. The rods (end caps and their bolts) aren't designed for high RPM. To make power on a VTEC head you need the revs for the flow. You could toss new stronger rods in to circumvent this but if it were me I'd take a B18c over a B20vtec any day.