I started my turbocharging days with this motor, after it continued to blow head gaskets and piss me off i ditched it for an H22..
Well years later i decided to try it again, except this time cheaper, not pushing it as hard and leaving the motor fairly stock.
I found a pretty clean chassis with a blown up, already in pieces B21A1 for 650 bucks towed it home and started tearing it apart.
got the motor out and cleaned up the bay a bit
Bought a different block, the b21 is FRM. B20a5 is normal iron, bought the b20a5 short block in pieces for 100 bucks threw down a sick hone job and bought an Ebay evergreen rebuild kit.
H23 rods are a direct swap for these engines, and there much stronger looking then stock, scored a set for free
instead of cleaning the stock pistons and risk breaking them upon removal i bought a set of B series cast nippon turbo pistons, for the price why not.. had the wrist pin bores honed to fit. Combined with the b21a1 head we now have a really low compression b20a5 ( about 7.9) spent more than i wanted on that but got the rods, turbo, and injectors for free so i spent money else where.
decided to do a quick cleanup job on the head, lapped all the valves replaced stem seals, and cleaned up the valve bowls, got the head resurfaced for free, Thanks Kyle!
motor going together
Being this is a bastard child of a motor there is no cheap cast iron china turbo manifolds out there, so i bought one for an H22a and made it work... drilled/hogged out a few holes, nigger rigged the gasket and WALA
Got an old Garrett T3 turbo off a mustang/tbird for free, had tons of shaft play but in otherwise decent shape, got a rebuild kit for it off ebay, took it to work and sandblasted it all up.. 75 bucks into the turbo
modified the compressor outlet for a normal coupler, and built a gay little flange for the air filter
Pretty much no way to fit internal wastegate with the H22a manifold which sucks so i niggered a external setup with a really chinese wastegate and recirced it back into the downpipe, thanks Columbia River Mandrel Bending for the quick shipping and awesome prices/RHMT discount!
intercoolers are a pain in the ass and somewhat of a nigger to install on these old preludes, so i stole a meth kit for 150 bucks and used the ECU to control it..
Got the BOV for free thanks NOL!
Got a steal on S300 ,already installed in a P75 Vtec and boost control ready! i know Hondata is hated around here but for 350 bucks..
Finished product, daily driving it on 10psi
All in all i have about 2400 bucks into the entire setup including the cost of the car and a new Comp Clutch