Hey members, iam new too honda tech and i looked through and did not see this question asked. I'm looking for answers about weather i should do a k20a fd2 swap or if i should just rebuild my current k20 z3 motor. Here's the deal it has 140kmiles on it. The motor runs great still. I take care of it but i know its prob going to have major issues eventually and i want to start doing major mods but i don't want to do it for no reason. do you guys think i can rebuild and save 5grand for cost of the k20a and buff up the internals and keep her going strong?

 

K24 block. Cheap and effective.

 

First do compression test and leakdown, then think about rebuilding ...

 

I would look into getting the K24 bottom end and transfer your K20 head. You will have a fresh bottom end with a retarded amount of compression/torque and the vtec head that is variable timed on both cams instead of just the intake like the stock K24 head. Which in turn will allow you to rev higher. Just a thought depending on your money situation.

 

k24a2 head also has true vtec on intake and exhaust

just the head alone will not allow for higher revs. the bottom end is a major weak point in stock form with high revs.

 

When I said K24 I should have been more specific by saying K24Z7 which is what my 2012 SI has everything I have read about it the head is only vtec on the intake cam which prevents it from revving as high. Where as the K20 and from what you just said some of the early K24s have the vtec on both cams. But the head will and can make a difference on how high it can rev just as much as the bottom end due to the fact if the cams don't move at the same rate of speed the exhaust can't flow as fast as the fresh air coming in.

 

Great info guys much appreciate it. I has my mind set on k24/k20 previously then a friend persuaded me to rebuild my z3. Im.very glad u guys,r knowledgeable here thats great to know i should go with my gut :-)