B20B VS B20Z... The truth told, lets end the rumors

[irev210]

Okay, lately... like wildfire, I see people misinformed about what the difference is between the USDM and JDM B20B and the "special" USDM B20Z This is the run down... okay, some of you guys got all your shit backwards about the JDM b20b and the USDM b20b and USDM b20z OK here it is 95.5-98 JDM B20B are 8.8:1 p3f compression pistons Rated at 126hp 99-00 JDM B20B are 9.6:1 PHK compresion pistons Rated at 146hp 97-98 USDM B20B are 8.8:1 p3f compression pistons Rated at 126hp 99-00 USDM B20Z are 9.6:1 PHK compression pistons Rated at 146hp Now, the difference between the JDM and USDM, NOTICE, ITS THE SAME!!! Now, how to tell the difference, so you dont need to take apart your b20 motor to see... Okay, all high comression motors w/ 9.6:1 compression pistons have a factory knock sensor. They need the knock sensor to safely run 87 octane gas. I question the cam profiles and I have no idea why honda rased the redline?. The older motors CAN have regular P75 intake manafolds from the factory, dont be fooled. They just are not as common as the p3f LONG intake manafolds. They are low compression aswell. The PHK intake manafold is a clear indication of a high compression motor. It has the air intake resinator chamber, its a silver box that is attached to the phk intake manafold, this is the dead giveaway that its a high compression block, it is used to create a chambering effect, ask the techs at honda, I dunno how usefull it is. HOWEVER I have seen 99-00 block with P3F(long intake manafold) w/ knock sensor. I am going to take the head off and update w/ pics. Notice the factory knock sensor. This knock sensor shares the same style plug as the 97+ honda prelude VTEC JDM B20B PHK XO pistons (9.6:1 compression) Modified by irev210 at 11:31 PM 4/13/2004

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[EKFerioHawaii]

copied and pasted. save as b20.doc. Thank you irev210.

[BERT-O]

Thanks for the write-up

[Jeff C]

Were did you get your information at regarding the JDM models?

[irev210]

i spent 700 dollars on a 97 JDM b20b and 850 on a 2000 JDM b20b... thats how i found out about the JDM ones... along with asking my supplier about them

As far as learning about the difference between the USDM B20B and USDM B20Z

http://hybrid2.honda-perf.org/tech/b20/b20tech.html

gave me the rest of the info i needed.

I kinda put 2+2 together...




[Modified by irev210, 7:14 PM 4/2/2003]

[Jeff C]

Just checkin'.

[irev210]

yah i know its hard believing people on honda-tech when so many people say so many different things, thats why i was sure to get the facts straight.

[lazy bum shaughn]

Man nice write up!

[b20guy]

Cool, but can we modify this? e.g. 99-01 USDM B20Z

[Tr0LL]

since no one read my thread that I posted like 1.5 weeks ago.... I'll post it here.....

First of all, according to the JAPANESE honda site, there are ALSO b20bs with a compression of 9.2. So.. I asked for some help from the crv ppl but got no answers.

http://honda-tech.com/zerothread?id=452440 or here it is again

I'm trying to figure out this whole compression theory crap.... Simple favor to ask of you guys....... Please post your year, which intake manifold it came with, and if it's a USDM or JDM b20b...... LASTLY, if it has a 3 layer or 2 layer head gasket.... if you don't know how to tell, it's really easy, just look at the gap right here:


or here:


I'm trying to figure out what the standard is. Especially from you USDM B20b owners. Mine LOOKS like a 2 layer to me.... My friend tells me the standard should be a 3 layer.... so this is what I am checking now...... If the standard is a 3 layer, then perhaps, some JDM B20Bs do have 9.2 compression because of the thinner head gasket. All 96-98 B20bs prolly do have P3f (lower compression) pistons (versus the higher compression PHK pistons), but with a 2 layer gasket (if it's not the standard), it should yield a higher compression.....

So far from my research on a bunch of boards, the going theory is.......

96-98 JDM B20B = 8.8 Compression
97-98 USDM B20B = 8.8 Compression

99+ JDM B20B = 9.6 Compression
USDM B20Z = 9.6 Compression...

And if your still stuck in the past..... NO, not all JDM b20b's have 9.6 compression. That was already been proven by many (pulling the head and looking at the pistons).

[illi Adik]

Good Info.

[eg6ajk]

Just to add there were some CRV - 97-98 spec motors (came with 5spd 4WD) tranny which were rated at 145ps, they had 9.2 c/r
http://www.honda.co.jp/HOT/ModelData.../shogen97.html

great info.

[SpeedVelocity.org]

heres a B20B.....Turbocharged!!!!!!!!!!!!!!!!!!!!!!!!

http://www.SpeedVelocity.org


[Modified by SpeedVelocity.org, 10:33 PM 4/5/2003]

[irev210]

dang thats pretty crazy, so the 9.2 compression one has like 140hp...

I wonder if those are the motors with the P75 intake manafold...

Basicly a LS motor with more torque???

I think it would have to be more then just the headgasket, switching from a 3 to 2 layer headgasket, wont rase your compression by .4, would it?

I guess Ill have to buy one of the motors with a p75 intake manafold to really find out, maybe it has a different model p3f piston

[daver]

blast, i just had the valve cover off my low rise mani jdm b. I shoulda checked the cams.

d

[The Rob]

I have a 98 JDM B20b with a giraffe manifold that hmotorsonline swears is a 9.6:1 compression motor.

[daver]

I have a 98 JDM B20b with a giraffe manifold that hmotorsonline swears is a 9.6:1 compression motor.

Did you do a compression test on it? There seems to be a wide range of results on these engines. Could be an indicator...

the z's seem to get 200-210's say some owners. Some jdm b people have claimed 160's. I got 180's on my b (which is what the ls is supposed to pull off), makes me think i got a 9.2:1 cr. But compression tests can be so skewed by people.

d
d

[irev210]

I have a 98 JDM B20b with a giraffe manifold that hmotorsonline swears is a 9.6:1 compression motor.

B20B JDM SPEC (9.6:1 compression) bare LONG BLOCK $699.00*

B20B JDM SPEC (9.6:1 compression) complete LONG BLOCK $799.00**

According to http://www.passwordjdm.com on their website, all jdm b20b's are 9:6 compression, which is obviously a bunch of garbage. I love how they try to sell their lies. Speaking of password, my buddy went to go buy a true 9.6:1 compression motor and he called 1 hour before he got there, and they told him that they had it in stock. He got there, and first he said, "you wanted the high compression one right? the one with a knock sensor" so he brought out a motor, and said that someone took the knock sensor out earlier that day thats why the treads were there but no knock sensor. Anyway, im sure that 95% of the people he tells that to believe him. Its sad they run such a shady business.

[teg92]

P8R

[Blaze45]

so what numbers can i expect with compression for a 9.2 and and an 8.8?

Thanks

Blaze

scratch the 9.2 what about the 8.8?


[Modified by Blaze45, 1:48 AM 4/8/2003]

[daver]

Well, the plot thickens. I was just too curious about my cams (1996 jdm b20b w/ls mani stock) so i popped off the valve cover and got this...


looks like i got the p75 g3 integra cams...


on a 1996 (with the p75-5 head stamp)


block stamp


and the p75 stamped intake mani with the ls 60mm tb, all stock

I'm thinking i may have that 145ps one listed on the jap site. maybe from the orthia...? Or whatever else may have had the low rise intake mani on it. The orthia is listed at a 9.2:1 cr. I'm sure i have the low cr pistons, but it really looks like only a 2 layer head gasket. Need to know if the USDM b's have 3 layer gaskets tho.

d

[M3tor2nR]

mmm~ boosted b20Vtec.

[irev210]

According to that, that gives really good support about it basicly being a LS motor w/ more torque. Just REALLY makes me curious as to what type of pistons it has.

Thanks for the good info, I think we are putting this all together...
It has to be the 142hp version




Modified by irev210 at 10:47 PM 4/11/2003

[irev210]

Originally Posted by teg92

P8R

What do you mean by that, is that the piston used to create the 9.2 compression?

12251-p8r-004 is the headgasket # for a b20...

[SpeedVelocity.org]

SPEED VELOCITY PERFORMANCE
DNR PROJECT
B20B