The only differences between the b20b and the b20z are the

1. intake manifolds
2. knock sensor on b20z
3. pistons

On a b20b, if you use the b20z's intake manifold will that make up for most of the 20hp loss? Maybe headers too?

b20b = 126hp
b20z = 146hp

thanks


Modified by AGENT 99 at 5:13 AM 4/8/2008

 

I'm pretty sure the B20z (or the B20b, can't remember) intake manifold won't clear the hood when swapped into a car, so you'd need an LS or aftermarket one, but the big difference in power is the pistons, and the resulting compression ratio (8.8:1 vs. 9.6:1 I think).

 

The tall manifold on the b20b is what wont fit. People say the b20z's flat manifold will fit.

Question is, does a LS manifold give more hp than a flat-top z manifold?

 

If I'm not mistaken the cams are different as well. I think most of the power comes from the increased compression with slightly more agressive cams. The IM most likely has a minimal effect. Certainly not 20 hp.

 

We need a dyno chart of a b20b with

- LS manifold
- b20z manifold
- skunk or other manifold

I think the b can make up most of the hp with just a manifold. Just...which one?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AGENT 99 &raquo;</TD></TR><TR><TD CLASS="quote">
I think the b can make up most of the hp with just a manifold. Just...which one?</TD></TR></TABLE>

I doubt that just the intake manifold will make that much of a difference. It has more to do with the compression.
b20b=8.8:1
b20z=9.6:1

That's assuming it's the b20b engine with the lower compression pistons.

 

not for nothing but changing manifold on a stock motor will not do much for hp gains... in this case you have to change it because of the giraffe neck manifold so just go with the ls manifold u will have about a 4-5hp gain which will see about 2hp to the wheels the b20z has higher compression pistons so the b20b is not gonna have the same hp numbers and it will take a heck of a lot of bolt-ons to reach this number of the b20z... i have the b20b and was thinking about the b20z but since i was changing the pistons the b20z would have been a waste of money

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by KENetics1 &raquo;</TD></TR><TR><TD CLASS="quote">

I doubt that just the intake manifold will make that much of a difference. It has more to do with the compression.
b20b=8.8:1
b20z=9.6:1

That's assuming it's the b20b engine with the lower compression pistons.</TD></TR></TABLE>

I agree, the crv "giraffe style" intake manifold may contribute to better low to mid range torque numbers, however, you won't be able to use it without cutting a hole in your hood. Keep in mind the hp numbers the OP quoted are factory rated as well, not very accurate, imo.

I believe there were actually 3 different pistons used amongst the jdm b20b all which resulted in a different c/r.

Some of the jdm b20b motors also came with a different cylinder head, stamped "P8R" rather than the more commonly used P75 head. I actually bought a B20b long block years ago with the P8R head. The P8R head came with oversized intake valves and other advantages. Here's a link to the head to the P8R head that I had years ago, it lists all of the differences. https://honda-tech.com/zerothread?id=1130502

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Nisif &raquo;</TD></TR><TR><TD CLASS="quote">

I agree, the crv "giraffe style" intake manifold may contribute to better low to mid range torque numbers, however, you won't be able to use it without cutting a hole in your hood. Keep in mind the hp numbers the OP quoted are factory rated as well, not very accurate, imo.

I believe there were actually 3 different pistons used amongst the jdm b20b all which resulted in a different c/r.

Some of the jdm b20b motors also came with a different cylinder head, stamped "P8R" rather than the more commonly used P75 head. I actually bought a B20b long block years ago with the P8R head. The P8R head came with oversized intake valves and other advantages. Here's a link to the head to the P8R head that I had years ago, it lists all of the differences. https://honda-tech.com/zerothread?id=1130502</TD></TR></TABLE>

I wonder if that P8R head would be able to use the LS intake mani due to the wider intake ports.

One other big question. The crv isnt exactly known as a quick vehicle. So... why are people swapping it in? Maybe its the fact of mating it with a 5spd trans combined with a decent amount of torque and at least some upgrading potential?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by AGENT 99 &raquo;</TD></TR><TR><TD CLASS="quote">

I wonder if that P8R head would be able to use the LS intake mani due to the wider intake ports.

One other big question. The crv isnt exactly known as a quick vehicle. So... why are people swapping it in? Maybe its the fact of mating it with a 5spd trans combined with a decent amount of torque and at least some upgrading potential?</TD></TR></TABLE>

because of the torque numbers... and torque is harder to achieve than horsepower and the more displacement the more torque thats why people like to go with the b20 it has more torque than any other b series motor

 

Yep, and also I just looked it up and the 97-00 crv weighs 3200lbs and (my civic, 6th gen) weighs 2300lbs. While the crv is not a fast car, it does 0-60 in 9.9.

Now, with 900lbs less, a more aerodynamic body, and a manual trans, I'm starting to see the light here. I'm trying to buy a z engine but it seems hard to come by at the moment. I still cant get over that 900lb difference.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by IanB &raquo;</TD></TR><TR><TD CLASS="quote">I'm pretty sure the B20z (or the B20b, can't remember) intake manifold won't clear the hood when swapped into a car, so you'd need an LS or aftermarket one</TD></TR></TABLE>

Here is the B20Z installed in my 96 hatch, the intake manifold fits just fine

Ok, i'll clear up a few things:

The B20Z gets its 20hp from the higher compression. Mine came with a P75 head and P75 cams, just like late model Integra's.

Another cool thing is that the B20Z has the better flowing oil pump, same as the one found on vtec models like gsr and type r models.

It should also be noted that the B20Z was from 99 and 2000 model years. The JDM has the same specs but still called a B20B.

The intake manifold is a different design for sure. It doesn't make more power, but, it does increase low and mid range power with a slight decrease in the high end.

Rated power on all models of B20 is underated. The biggest reason for this is because the stock exhaust manifold is such a piece of ****. The addition of any header really helps free up power over the stock design.

The one thing that really suprised me when i swapped in this engine is how rev happy it was......i didn't expect that. My civic goes like hell, i love it!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Deetz &raquo;</TD></TR><TR><TD CLASS="quote">

Here is the B20Z installed in my 96 hatch, the intake manifold fits just fine
</TD></TR></TABLE>

Nice.

 

looks good..... engine looks like it belongs in that bay lol.....what tranny r u using?.... and what u do think it does in the 1/4? ( provided u haven't already run it)

 

Not really sure about the stock crv header being garbage? Check out a stock B20Z header vs aftermarket header.

 

I was happy to get rid of that oem mess of exhaust routing in favor of an Edelbrock unit

 

There is a thermal efficiency equation for compression ratio and power change. Power change = (CR new/CRold)^0.3 * old power. It's almost completely negligible. Going from 8.8 to 9.6:1 is like 2 HP. In general, a rule of thumb regarding horsepower and CR, a complete point increase will raise horsepower by 3-4%. So a max of 5 HP gained going from 8.8 to 9.8. The B20B low comp had 8.8. Somewhere they made a 9.2 as well. the High comp Z2 engine was 9.6.

So no. Power did not go up drastically because of the compression difference. Going from 8.8:1 to 12:1, you'd see approximately 16 HP increase max and that requires premium fuel and careful ignition timing and tuning. The heads have a more aggressive cam profile, the intakes are more free flowing, and the ECU was tuned accordingly. A z2 or high comp b20b paired with a aftermarket intake and a 1320 exhaust manifold is a very cheap method of adding 10-15 horsepower when tuned. Port/polish heads can make a heck of a difference and will also even the flow between each cylinder (ultimately resulting in max power and mitigating knock at worst case conditions, since knock happens first in the worst condition cylinder such as poor air flow).

To run regular gas and make more power, I would recommend aftermarket intake to replace the airbox (intake manifold is fine), aftermarket exhaust manifold (upgrade cat back later to 2.5" by 1320 or yonaka if they ever get back in stock), and a S300 OBD1 ECU with wideband oxygen sensor to best tune the map perfectly for car. Definitely need the newer head, whether it's the B20B P8R head, or the Z2 head. Another free but very effective upgrade is to port and polish the intake/exhaust or head depending on which port is larger. 5-10 HP right there and better worst case conditions to mitigate detonation/knocking.
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