how do they compare?

 

well aside from the obvious that the 1 will have Vtec. which if you dont know what that is, check around on some forums for variable valve timing,
Code Specs Displ. Year(s) Model Origin HP Torque CR


D16A1 1.6L 16V DOHC PGM-FI 1590 '86-'89 Integra (DA) USDM 113@6250 99@5500 9.5:1

D16A3 1.6L 16V DOHC PGM-FI 1590 '88-'89 Integra (DA) USDM 118@6500 103@5500 9.5:1

D16A6 1.6L 16V SOHC PGM-FI 1590 '88-'91 Civic Si/CRX Si USDM 108@6000 100@5000 9.1:1

D16A6 1.6L 16V SOHC PGM-FI 1590 '89-'91 Civic EX USDM 113@6200 -------- ------

D16A8/9 1.6L 16V DOCH PGM-FI 1595 '88-'91 Civic/CRX Si JDM 137@6800 108@5700 ------

'90-'93 Integra LS/RS USDM -------- -------- ------

D16Y5 1.6L 16V SOHC VTEC-E PGM-FI 1590 '96-'00 Civic HX USDM 115@6200 104@5400 9.4:1 D16Y7 1.6L 16V SOHC PGM-FI



'96-'00 Civic CX/DX/LX USDM 106@6200 103@4600 9.4:1 D16Y8 1.6L 16V SOHC VTEC-II PGM-FI



'96-'00 Civic EX (EJ) USDM 127@6600 107@5500 9.6:1

D16Z6 1.6L 16V SOHC VTEC PGM-FI 1590 '92-'95 Civic EX/Si (EG/EH) USDM 125@6600 106@5200 9.2:1
I copied that from CLUBCIVIC.COM, that shows ya the differences in most of the more common 1.6 SOHC engines

sorry thats so hard to read, it came up better before i posted it...

 

it other words, the head (including the cams, valves etc etc)