Is it worth it?
 

I have a 90 civic si with 164,000 miles on it. How far do you think it would be smart to go with it? Turbo or super a good idea? sell it and get a newer civic? what problems will I run into with a high mileage engine? anyone have any experience with this kind of situation?

compression will be the first give away as to the condition of your engine, do you know the engine code on it? im not familiar with a 90 si engine.

it is an D16A6

Only got 1 line to say...
b16a pistons + rods + turbo = ;)

I suppose I'll hold onto it, as long as it has potential. Yesterday we were changing the pads on it and discovered a broken cv boot. Took us the entire day to finally figure out how to make a new 'spedi-boot' stay on (they suck), but I really do enjoy messing with this mechanical. If anything this car will be a good learning expereince for my second one.

There is potential with the engine...I would just think about putting some new pistons rods....actually rebuliding the whole bottom end of the engine to support boost on a high mileage engine.

the 4th gen (88-91 or ED chassis) cvics have huge potential. they weigh next to nothing and can be hybridized with almost anything. if you have good compression and are confident in your bottom end, you should be able to swap the d16z6 (sohc vtec, 125-130 hp) head fairly easily. if you were to add vtec, your best bet would probably be to get a zdyne ecu, or you could just use an rpm activated switch for the vtec, though your a/fr might lean out a bit once the vtec kicks in. from what i understand, you can pretty much mix and match parts from the d series engines.

I'll do some research on that. Those high miles still worry me, though.