I was comparing a b16a with a b16b type r and the only difference was the horsepower of course and the Compression Ratio the b16a was 10.2.1 and the b16b type r was 10.8.1.

How is that are the valves angled different?

What causes the compression ratio to jump for 10.2.1 to 10.8.1???

I'm lost

 

O yea and the type r has 2 obd's and the b16a has none...

Whats a obd?

 

the valves are not angled any different, the B16B is just a B18C with a B16 head and crank. so you have the IDEAL rod to stroke ratio, capable of spinning very high rpms with less stress. this is a very good road race motor, very well prepped from the factory including fully balanced bottom end, and of course, the civic type r cams.

obd means ON BOARD DIAGNOSTICS. it is a version of engine management and troubleshooting. obd2 has 2 o2 sensors, as well as more sensors on the motor overall. ( i believe there is a sensor related to the oil pump, if not crankshaft positioning) the B16A is OBD0, which means it runs 2 single wire o2 sensors. the first generation B16A has the weakest cams of all, being that they are the first production vtec cam that honda ever made. i replaced my B16A cams with B16A3 (usdm del sol) cams, and the improvement was very noticeable. diflucan.

 

the compression difference is in the pistons. that is why many b16a owners rebuild with ctr pistons.

there are many other differences between b16a and b16b...

 

I'm suprised you noticed it. Is it just a straight drop in, or is there modifications you have to do for these cams to work?

 

The B16A 1st gen cams are very weak, when I installed my ctr intake cam I noticed a reasonable difference from 7-8k without any tuning.

 

what's even weaker is the cams out of the JDM 1st gen B16 from an automatic Integra XSi/RSi. I swapped in some JDM 1st gen B16 cams from an SiR (only came in 5 speed manual) and i noticed a big difference. We compared the intake cams (auto vs 5 speed 1st gen b16)...and the VTEC lobe was noticably larger on the SiR one. So, of course the automatic B16 are detuned versions of their 5 speed bretheren. they are said to make between 150 and 155 crank hp....due to the previously mentioned cams, and the ECU.

 

The differences between the B16A and B16B are actually quite significant. The B16B is not merely a 'hot' B16A. Rather, it is a completely different motor. For starters, the B16B has a different bottom end. Rather than the B16A block, it is based on the B18C block. It does have the same bore and stroke as the B16A. But the taller deck height allows for longer rods and an even better rod ratio than the B16A (~1.85:1). So it is even more revvable than the B16A. Although the head casting is the same as the B16A, it has received the same mild port work as the ITR. It also uses the same valves, valve springs, and exhaust cam as the ITR. And it has a slightly more aggressive intake cam.

The B16B actually does not have OBDII electronics. OBDII is strictly a USDM thing. And although it has an ECU of similar plug type, it is non-OBD (not to be confused with 1988-1991 USDM ECUs, which are actually OBDI).