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Discussion Starter · #1 ·
I'm looking to get a swap, and I'm thinking of starting with a B20 setup and eventually going to a CRVTEC build later on down the road. I know that the B20A is the lemon of the B20 series. As for the B20Z and B20B engines, what's the difference? Is there any?
 

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they differ in compression, and i believe the b20z was only jdm. i might be wrong about the jdm thing but they have different pistons. i think the b20z has higher compression.
 

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Discussion Starter · #3 ·
So the block is identical then? Higher compression might not be a bad thing. :D
 

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yea the B20b has a C.R. of 8.8 and is USDM. the B20z has a C.R. of 9.6 but i can't remember if it is an only JDM engine. when i bought mine a year ago. i bought it from a local junkyard. and i saw the engine in the CRV. so i knew the actual milage of the enigne. and my engine was a B20z.
actually now that i'm thinking of it. the junkyard owner. actually owns a few race tracks in Maine and in Canada. as well as junkyards in Both countries. so maybe the CRV i got my engine out of was a CDM and not an USDM. and maybe Canada got the B20z!?!
 

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Discussion Starter · #5 ·
If i'm looking to go VTEC later on down the road, would the higher compression engine be a better option? I have no plans for boost at this point.
 

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Discussion Starter · #7 ·
Ok...this is the info I have gathered about the USDM B20's

B20B- 1973 [email protected] [email protected] 8.8:1 84 89 dohc no 2 1997-1998 CRV
B20Z- 1973 [email protected] [email protected] 9.6:1 84 89 dohc no 2 1998-2001 CRV

As far as I understand, the only differences are the pistons, and the fact that the 98-2001 CRV engines have knock sensors due to the higher compression from the different pistons.

Any other differences?
 

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it looks like you have all the differences now.

on your question on which one to get. i would go with the B20z. here are my reasons why:

-more HP
-the C.R. isn't that high where it would be bad for a turbo setup. if you wanted to lower the C.R. then all you'ld need is a thicker cometic headgasket. but if you do go turbo. i would build the bottom end for sure. since thats the B20's weakness.
-and if you do plan to go N/A with a CR/VTEC then higher the C.R. the better.
-and if you plan to go turbo with a CR/VTEC then lower C.R. the better. but either B20 could get the job done for sure.
 

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if you are gonna rip out the internals, then get which ever is cheaper. 9.6:1 compression isnt that great for NA and the internals really arent strong enough for a lot of boost.
 

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If you change the pistons (and rod bolts) choosing between B20B or B20Z would be irrelivant. I would assume that the Bs would be cheaper to buy since they'd be older. I also believe that JDM B20Bs are the same CR as the B20Zs.
 

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Discussion Starter · #11 ·
OBD1 Kenobi said:
If you change the pistons (and rod bolts) choosing between B20B or B20Z would be irrelivant. I would assume that the Bs would be cheaper to buy since they'd be older. I also believe that JDM B20Bs are the same CR as the B20Zs.
Thanks for the info. Which VTEC head did you go with on your CRVTEC?
 

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I have an OBD0 B16A head from my first swap.

Upon the install onto the B20B block, I converted the engine to OBD1 as the only exhaust manifold I had was a DC Sports 4-1 header, unuseful for a two oxygen sensor system the PR3 (OBD1 B16A) ECU would be looking for. I used the P28 (D16Z6) ECU as a temporary measure before I got a chip burnt for the Hondata S200 I have. (I also have a JDM P30 ECU but will need to get the surface-mounted components desoldered carefully as it is very sensitive to severe heat.)

VTEC comes on at 4800 rpm and the redline is about 1000 rpm higher than I rev the engine. I didn't build the bottom end so I have to be wary of my rev-counter. The engine feels like VTEC should be set to come on 200 rpm lower and once I put in new higher-compression pistons and ARP rod bolts, I will be able to rev higher. This was my achillies heel at the track. The engine was on it's second "pull" but I had to choose a higher gear before the potential could be realised.

Prior to the car being written-off, the B20B VTEC OBD1 had an estimated flywheel horsepower of 220 and torque of 140 lb∙ft. It also passed AirCare (emissions) on the first attempt and had an average of 32 miles per imperial gallon, the best being 41 mi/gal and on a quite spirited run. I also got away with 87 octane gas but that'll change once the higher compression pistons are fitted.
 

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Discussion Starter · #13 ·
Thanks OBD1_Kenobi...wow, that just about answers all the question I can think of at the moment. :)
 
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