I have a 1990 Prelude SI. It's completely stock. I have low compression on number 3 cylinder. It has 130 lb versus 195 on the remaining three cylinders. If I squirt some oil into the bad cylinder the compression jumps up to 170 lbs or so.

Surprisingly, the car doesn't run too bad, but does lack power. I am getting some oil in the intake chamber from the hose that connects the valve cover breather to the intake. If I take the hose off the valve cover breather, I can feel pretty good pressure being forced out of the cover. This is 'blow by' I assume, from the bad cylinder.

Question is should I rebuild my B21A1 or replace it with a JDM. I don't want to have a big headache fitting a different motor in the car. If it doesn't 'drop right in' I don't want to mess with it. I got 200 kmiles out of my B21A1. My local mechanic says he would be very surprised if my motor needed to be rebored. He says he just doesn't Honda motors come in that need boring unless they have been abused.

If I rebuild mine, does anyone know where to get a quality engine rebuild kit? Should I get one from the Honda dealer and stick with OEM?

Thanks.

 

first, if you try to bore that block you will ruin the sleeves. that block must be resleeved if you do anything to it. as far as the jdm b21 motor i have heard a bunch of people that have done it and it is a direct bolt up. if you want to rebuild that motor just go to your local parts store and buy the head gasket set and lower conversion set and you will have pretty much all the gaskets you will need to rebuild that motor. then depending on how far you want to go get the main and rod bearing set and replace those too. oh, and don't forget to replace your timing belt and water pump while you are at it, unless you have just done those.