B20A5 swap to b18b1

ok so i just recently purchased a 1990 prelude si with a B20A5 in it but when we started it the main rear bearing was out and i have taken the engine out and its been six months since i worked on it the motor is also knocking so i am rebuiling it. but recently i have come accross a B18b1 and was wondering if i could swap this for the moment until i rebuil my other engine or what would i half to do to swap it or if it is aplacable please help i am new  

Yeah you could possibly do that swap, just use all the B series stuff off your B20 block and put it on the B18 block.  

thank you also can i just hook the b18b1 motor to the original b20a5 transmission  or do i half to swap it to  

The b20 tranny will bolt up to the new block. All b series parts are interchangable except for a few things, but you should be ok swappin everything over  

ok thank you that helps alot  

will i half to change the tcu or will the original just reset  

It should work just fine, the b20 and the b18 have the same fuel maps and stuff so it'll be ok  

i have the b18b1 in my garage on a stand after i got it and was looking at all of the connections and they are different or look different than the ones i have in the car allready all of the electrical wiring that is do i half to replace all of the wire or can i just replace the end connectors  

gonna save you some time and effort cause ive owned a couple preludes myself.  and there really arent any engines you can swap into the 3rd gen.  because the b20a5 and b21a1 are not really related to the rest of the B series engines and it is different from the B20 found in the CR-V or whatever it comes in.  the only swap that has been done in a lude successfully is an H swap and motor mounts are made for that swap and everything.  I will say that i have seen one b18c in a lude and it was not pretty with everything that the guy had to go through.  so sorry to give you the bad news but ya...