JDM B20- B20B vs B20Z?

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stmotorsports

Senior Member
alright so I just received my B20 from jdm-online.com. It's supposed to be 99+ spec and has the correct intake mani (box plenum not giraffe), so at 1st glance I assumed it was the right one. Then I noticed it has year codes of 98 everywhere. It also has no crank sensor although I was under the impression that all 99+ spec motors had one, including JDM versions. Is this definitely 99+ spec or do I need to pull the head to check the pistons?
 
think about something real quick here..... do you think they assembled all 99's in '99? well, they dont.. first ones come out towards the end of '98..
 
yes, obviously. I'm more concerned with the crank sensor than the dates. Just trying to verify that it is indeed the B20Z spec before it ends up in the car later this week. I'd hate to find out afterwards cause then I'll be super pissed.
 
did the JDM b20s come w/ a crank sensor?? might wanna find out, it'd explain a lot too..
 
Just check the compression on it damn it! :mad:

Also I think the b20z was a USDM engine. JDM are still B20b but just the 99+ modles came with a higher compression.
 
I see people misinformed about what the difference is between the USDM and JDM B20B and the "special" USDM B20Z

95.5-98 JDM B20B are 8.8:1 p3f compression pistons
Rated at 126hp

99-00 JDM B20B are 9.6:1 PHK compression 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 don't need to take apart your b20 motor to see...

All high compression 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 raised the redline?.

The older motors CAN have regular P75 intake manifolds from the factory, don't be fooled. They just are not as common as the p3f LONG intake manifolds. They are low compression as well.

The PHK intake manifold is a clear indication of a high compression motor. It has the air intake resonator chamber, its a silver box that is attached to the phk intake manifold, 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 useful it is. HOWEVER I have seen 99-00 block with P3F(long intake manifold) w/ knock sensor.
 
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I don't mean to thread-jack but, How about this.. I just picked up a 99(?) B20b long block from an old friend who stated that he helped one of his friends replace his CRV engine that was smoking slightly, with a JDM one.
There must have been a difference with the valve cover since he left the JDM one aside with the extra parts (timing belt/tensioner, belt cover)from the swap.

It shows "B20B4" on the stamping. Are there more Variants of the B20's?
I've searched B20b on here and that's all it states in all the threads.. NO suffix after the last "B". This block does have a VIN coded, green tag, stamped on the pan-rail on the front of the motor though. Of which I can't give at this time since I'm at work.

E
 
thanx for all the replies guys. I understand all the rules of thumb with these motors, especially since I've helped install a few over the years. I'm just worried that maybe I have come across one of the oddball ones. Even in the info in AHHVTEC's post it says that regular P75 manifolds have been found in place of the normal giraffe version, and "...HOWEVER I have seen 99-00 block with P3F(long intake manifold) w/ knock sensor". The fact that the resonator manifold is installed on a 98 model could mean mine is a late-98 meaning 99+ spec, or just a 98 spec. I have to admit I did forget about the knock sensor, I'll check when I'm over there later
 
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I don't mean to thread-jack but, How about this.. I just picked up a 99(?) B20b long block from an old friend who stated that he helped one of his friends replace his CRV engine that was smoking slightly, with a JDM one.
There must have been a difference with the valve cover since he left the JDM one aside with the extra parts (timing belt/tensioner, belt cover)from the swap.

It shows "B20B4" on the stamping. Are there more Variants of the B20's?
I've searched B20b on here and that's all it states in all the threads.. NO suffix after the last "B". This block does have a VIN coded, green tag, stamped on the pan-rail on the front of the motor though. Of which I can't give at this time since I'm at work.

E

Well sorry to tell you but a B20b4 isnt a JDM engine, JDM engines dont have the last number stamped on the block nor do they have Vin numbers.
 
^^ true about the last #. No model designation suffixes. No vin tho? I didnt know that

EDIT: I just re-read 78civic's op and I think he means the usdm B20B4 is the usdm one that his friend replaced that he now has. So to somewhat answer the question, the only usdm versions came in crvs exclusively, where in other world markets B20s came in several different models. the only usdm versions I've ever seen are the pre-99 B20B4 and 99+ B20Z2. If I had to guess there is probably different suffixes for CDM and/or possibly california?
 
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There is no diffrence in california engines, they are all stamped the same accross the U.S.

how many psi are you holding in each cyl btw?
 
Thanks for the good info. I'm NOT worried about not having a JDM engine, I can make it as powerful as I need to. I even found a dual carb intake that I had laying around and IT FITS!!! I'd doubt that I'm gonna use it though.

On the static comp. Just hook a trans with starter to it (if you have one out to use), and you can jump the starter from a car or battery charger. Just have all spark plugs out and manifolds off, and let it spin for about 10-15sec for each cyl. To check for worn rings, squirt a little oil in the cyl and test again. Depending on the weight of the oil, it will raise the compression either slightly or alot.

For a leakdown test, you get that particular cyl on TDC and pressurize it with said tester, around 180-200psi and watch the pressure gauge to see if it starts depleting. Again, you will have slight loss but if it goes down rapidly you may need a valve job or more headwork. You can also squirt some oil in the intake/exhaust ports to aid in sealing temporarily..

See if this helps..

BTW, What do 8.4-5 and 9.5 compression come out to be staticly?
Apprx. 130 to 150psi?? (respectively)

E
 
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