Motor Swap

B20 Or B18

  • B20

    Votes: 18 66.7%

  • B18

    Votes: 9 33.3%
  • Total voters
    27
  • Poll closed .

Integraguy04

CORNER CARVER
well all i know is that the b20 sleeves are a lot thinner and not as strong as the b18 sleeves...if your going to do an all motor setup then i would go with the b20 and do b20/vtec...but for boost you should be a lot safer with the b18...yea i know its not as much displacement but there is a little bit better of an insurance factor
 

integra4life29

Im in a band DO ME!!!!!
arent b20z's hard to come across or am I thinkin of another one......


but yeah i say boosted b18

all motor b20 vtec, im sure both would be fun to drive.
 


TypeR?

New Member
Integraguy04 said:
well all i know is that the b20 sleeves are a lot thinner and not as strong as the b18 sleeves...if your going to do an all motor setup then i would go with the b20 and do b20/vtec...but for boost you should be a lot safer with the b18...yea i know its not as much displacement but there is a little bit better of an insurance factor
Click to expand...
sorry but this statement is false!
the reason b20's crack sleeves is because people short cut on their b20/vtec builds and do not upgrade pistons and rod bolts and then try to rev them to the moon.
stock b20 pistons large diameter is at fault for breaking and then cracking the sleeve but by no means are the sleeves any thinner, trust me ive checked.
for example- lets say you have two plates in your hand and one is big and one plate is small, now hold them at equal distances from the floor and drop them. now which on do you think would be most likely to break? see what im getting at?
to the OP, go with the b20, just remember there is no replacement for displacement(no matter what the turbo guys tell you, hehe). but if you decide to build it and rev it past the stock b20 redline make sure you do it right.
 
Last edited:

Aussie

Zoom-Zoom
TypeR? said:
sorry but this statement is false!
the reason b20's crack sleeves is because people short cut on their b20/vtec builds and do not upgrade pistons and rod bolts and then try to rev them to the moon.
stock b20 pistons large diameter is at fault for breaking and then cracking the sleeve but by no means are the sleeves any thinner, trust me ive checked.
for example- lets say you have two plates in your hand and one is big and one plate is small, now hold them at equal distances from the floor and drop them. now which on do you think would be most likely to break? see what im getting at?
to the OP, go with the b20, just remember there is no replacement for displacement(no matter what the turbo guys tell you, hehe). but if you decide to build it and rev it past the stock b20 redline make sure you do it right.
Click to expand...
To add to this, the LS sleeves are 2 piece sleeves, the B20 uses a solid one piece sleeve. They are equally as strong and will both hold up the same to boost.

Here is some extra info

How to identify your B20 Motor:

Let's first start off by saying that ALL USDM motors will have a number after the last letter in it's engine code. The Engine code stamp can be found where the transmission and block mate at the front of the motor. The JDM motors do not have this number after the last letter. For example, a B20B1 is a USDM motor, whereas a B20B is a JDM motor.This is important to understand in determining which motor you have.

Next, there weren't any B20Z's in Japan. All the JDM B20's were stamped B20B, regardless of the year. You can tell the year of the motor by checking the year/month the head was cast in. The year is located just above the fourth exhaust runner. It is in a circle with a slash through it. Disregard the slash as it means nothing. For example a circle with a 9/8 is a motor that was made in 1998. Be careful though, as this is not a 100% accurate based solely on the year. You must also look at the month it was made. Again, it is right next to the year and will have the month in a circle with a slash through it. Just like the year, if it says 1/1, that means it was made in november, the eleventh month. I'll show you why the year is not 100% accurate. If a motor was made in 98, but was made in november or december of that year, it is actually a 99 motor. That is because they start making the motors early for the next years vehicles. If the head was made in september/october though, that is a tossup as it may either be the year cast on the head, or the next year, because that is the crossover where they stop making the current years vehicles and start producing the next year's vehicles.

Believe it or not, almost all B20's, regardless of year, come with the 96+ Integra LS P75 head. They are 99% identical. They have the same valves, springs, valve covers, distributors, cam gears, etc. as 96+ USDM/JDM P75 Integra LS heads. The only differences are w/ the variances in camshafts. There is one exception however. The B20 motor was equipped in MANY vehicles in Japan, mainly the SM-X, Step Wagon, CRV, and Orthia. Of the many B20 powered vehicles, three of them came with the P8R head, and only in certain model years. The Orthia, which came out in 1996 was one. The other was the Step Wagon. The orthia came with the P8R head in it's 96-98 model years and the step wagon came with the P8R equipped B20B in it's 96-98 model years. The CRV also came with either the P8R head or P75 head in it's 96-98 model years. The P8R head is a completely different casting than P75 heads which were used on all other B20's. This head came with 84mm combustion chambers and 33mm vtec sized intake valves.



All 99-00 B20's have a knock sensor, regardless of where it comes from, which signifies the high compression 9.6:1 motor. If your B20 does NOT have a knock sensor, it is not the 9.6:1 compression motor. High compression B20's use "PHK" pistons which have a less of a dish them, as the "P3f" pistons found in the low compression B20's do. All B20's have an 84mm Bore and an 89mm stroke regardless of year. They are internally and externally identical to 96+ B18B's, with the exception of the Pistons, sleeves, and in some cases, the intake manifold and cams. They all have an 81mm combustion chamber diameter as well, except for the "P8R" head, which has an 84mm diameter and larger valves, as described above.

Here is a list of the different compression ratios and Power Ratings for B20's, in regards to the year and origin of the motor:

USDM:
96-98 Honda CRV
126 HP, 133 ft/lbs TQ
compression: 8.8:1

99-00 Honda CRV
146 HP, 133 Ft/lbs TQ
compression: 9.6:1

JDM (taken from Japan's Honda website):
96-98 Honda Orthia
143 HP, 132 ft/lbs TQ
9.2:1 compression

96-98 Honda Step Wagon
123 HP,133 ft/lbs TQ
9.2:1 compression

99-00 Honda Step Wagon
134 HP, 136 ft/lbs TQ
9.6:1 compression

96-98 Honda CRV (two variants)
128 HP, 136 ft/lbs TQ
8.8:1 compression
143 HP, 132 ft/lbs TQ
9.2:1 compression

99-00 Honda CRV
148 HP, 136 ft/lbs TQ
9.6:1 compression

96-98 Honda SM-X
128 HP, 135 ft/lbs TQ
8.8:1 compression

99-00 Honda SM-X
138 HP, 137 ft/lbs TQ
9.6:1 compression

These power figures are worthless for you and me, in the sense that these numbers are for these motors in their respective stock vehicles. Take into account that these numbers are with each specific vehicle's stock restrictive header/exhaust, extremely restrictive ECU with it's conservative fuel/ignition tables, restrictive intakes, etc. I've seen multiple B20's dyno in the 125-140 HP range with nothing more than an intake, header, and exhaust, with torque numbers in the 130-140 FT/LBS region. Which is more torque than they are rated at to the flywheel. Based on the factory numbers, these kind of gains shouldn't be made just with an intake and exhaust upgrade. This just goes to show you how underated these motors are from the factory. There is a Rule of thumb that says whp numbers should be about 15-20% lower than flywheel rated horsepower. By using that formula, High compression B20 motors should be rated closer to 160 Hp and low compression B20 motors should be rated closer to 145 horsepower.

BEWARE!! Do NOT let engine importers fool you. Many of them knowingly try to sell you a "JDM" B20B and tell you that ALL JDM B20B's are high compression. As many of you have just learned, this is not true. They tell you this because demand for the low compression motors is alot less than the higher compression B20's. Possibly, many importers just don't know the difference. But don't take that chance. The only REAL way to tell is if the motor has a knock sensor. Also if it is a USDM "B20Z", it is no doubt the 9.6:1 compression motor. So, it may be safer just to find a "B20Z".
 

Integraguy04

CORNER CARVER
TypeR? said:
sorry but this statement is false!
the reason b20's crack sleeves is because people short cut on their b20/vtec builds and do not upgrade pistons and rod bolts and then try to rev them to the moon.
stock b20 pistons large diameter is at fault for breaking and then cracking the sleeve but by no means are the sleeves any thinner, trust me ive checked.
for example- lets say you have two plates in your hand and one is big and one plate is small, now hold them at equal distances from the floor and drop them. now which on do you think would be most likely to break? see what im getting at?
to the OP, go with the b20, just remember there is no replacement for displacement(no matter what the turbo guys tell you, hehe). but if you decide to build it and rev it past the stock b20 redline make sure you do it right.
Click to expand...
ok good to know...all im saying is that ive talked to mike at kingmotorsports and he has told me instances where he has cracked b20 sleeves with forged pistons around 11:1...but i guess that would go hand in hand with the b20's large piston diameter
 

Apollo

New Member
I guess I would go with the B18. Seems easier to tune for less cash. And probably easier to find. But IDK, looks like there's better qualified people to be giving this kind of advice ^^^
 
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