What is the major difference between r18 & r20 engine

Tak

Well-Known Member
638
403
New York City
Vehicle Model
LX
Body Style
Sedan (FB2)
As the title says, what's the difference between r18 & r20? i.e. piston, compression, etc.
Is it possible to swap the engine?
I have a couple of guys with r18 keep saying they can swap r20 engine.
I don't know and I have no idea. Hence I am here to ask.
Thanks,
 
Last edited:
what r20? some of this from wikipedia is bs, but still. The money you'd spend on a swap would be crazy. If you want more power, you'd be best to do a K series (si) motor. Even then, you'd be better trading your car in for the si if you're considering a swap. You'd lose less on trading/buying a new car versus labor/parts/install


R20A1
  • Found in:
    • 2007- Honda CR-V (RE1, RE2)
      2008- Honda Stream (RSZ)
      2013- Acura ILX (DE1)
      • Displacement: 1,997 cc (121.9 cu in)
      • Compression: 10.5:1
      • Bore & stroke: 81.0 mm × 96.9 mm (3.19 in × 3.81 in)
      • Power: 150 PS (110 kW; 148 bhp) @ 6,200 rpm
      • Torque: 19.4 kgf·m (190 N·m (140 ft·lbf)) @ 4,197 rpm
R20A2
  • Found in:
    • 2007- Honda CR-V (RE5)
      • Displacement: 1,997 cc (121.9 cu in)
      • Compression: 10.5:1
      • Bore & stroke: 81.0 mm × 96.9 mm (3.19 in × 3.81 in)
      • Power: 150 PS (110 kW; 148 bhp) @ 6,200 rpm
      • Torque: 19.4 kgf·m (190 N·m (140 ft·lbf)) @ 4,200 rpm
R20A3
  • Found in:
    • 2008- Honda Accord (CP1 and EU market CU1/CN1)
    • 2016 Proton Perdana
      • Displacement: 1,997 cc (121.9 cu in)
      • Compression: 10.5:1
      • Bore & stroke: 81.0 mm × 96.9 mm (3.19 in × 3.81 in)
      • Power: 156 PS (115 kW; 154 bhp) @ 6,300 rpm
      • Torque: 19.3 kgf·m (189 N·m (139 ft·lbf)) @ 4,300 rpm
      • Top speed: 215km/h
R20Z1
  • Found in:
    • 2012 - 2016 Honda Civic (FB2)
    • 2013 - Honda Accord (CR1)
      • Displacement: 1,997 cc (121.9 cu in)
      • Compression: 10.6:1
      • Bore & stroke: 81.0 mm × 96.9 mm (3.19 in × 3.81 in)
      • Power: 155 PS (114 kW; 153 bhp) @ 6,500 rpm
      • Torque: 19.4 kgf·m (190 N·m (140 ft·lbf)) @ 4,300 rpm
 
Thanks @webby
I will share this information to those folks who talk about this.
I really don't know much about this r20. I only know r18 haha
 
both engines are very similar, both engines share the same pistons and heads. the r20 block has different crank bearings and something else was relocated, different bearings because the stroke is longer. r20 uses a 3 stage intake manifold where as the r18 uses a 2 stage intake manifold.

If you look up the #s ratings, both have the same amount of torque but the r20 has 10 more hp. You can take the r20 block and bolt up the r18 heads and intake manifold... but might not gain all 10hp because the r18 intake manifold is different. Doing this route would allow to use flashpro, doing a whole r20 engine swap requires the ecu or maybe a piggy back ecu. You can get a used r20 for about $700, so its not too bad price to hp gain. Then add a skunk stage 2 cam for another 10-15hp w/ tune
 
both engines are very similar, both engines share the same pistons and heads. the r20 block has different crank bearings and something else was relocated, different bearings because the stroke is longer. r20 uses a 3 stage intake manifold where as the r18 uses a 2 stage intake manifold.

If you look up the #s ratings, both have the same amount of torque but the r20 has 10 more hp. You can take the r20 block and bolt up the r18 heads and intake manifold... but might not gain all 10hp because the r18 intake manifold is different. Doing this route would allow to use flashpro, doing a whole r20 engine swap requires the ecu or maybe a piggy back ecu. You can get a used r20 for about $700, so its not too bad price to hp gain. Then add a skunk stage 2 cam for another 10-15hp w/ tune
What r20 are you referring to?
 
What r20 are you referring to?

All r20, there may be some minor differences between the engines and correlation with the last 2 digits, but if he gets an r20 from a car that is sold in his country there should be no problems with a swap or hybrid build. Usually the last 2 digits means there are ecu tuning differences to be used in another country to comply with emissions.
 
It's a very interesting idea but... No one is going to swap an R20 into their Civic. The amount of work and cost just isn't worth it. Same with the huuuuge list of people who wanted 2012+ R18 flash pro. Lots of talk, no doing. Even with a "cheap" $700 R20 block available, thats a ton of work and money for ~10hp. You could gain much more than that just swapping the IM with a custom unit or trying to retrofit one of the 06-11 Weapon R intake manifolds. Those were showing a 20-30hp gain and better with the FI turbo/sc setups.

edit: last i knew the final 2 digit id code can also signify differences in the oil pan design. It's very likely you could run into serious clearance issues with the subframe or other places. We also don't know how the transmissions might bolt up. Especially if you get a CRV R20 block, that AT/MT could be completely different.
 
It's a very interesting idea but... No one is going to swap an R20 into their Civic. The amount of work and cost just isn't worth it. Same with the huuuuge list of people who wanted 2012+ R18 flash pro. Lots of talk, no doing. Even with a "cheap" $700 R20 block available, thats a ton of work and money for ~10hp. You could gain much more than that just swapping the IM with a custom unit or trying to retrofit one of the 06-11 Weapon R intake manifolds. Those were showing a 20-30hp gain and better with the FI turbo/sc setups.

edit: last i knew the final 2 digit id code can also signify differences in the oil pan design. It's very likely you could run into serious clearance issues with the subframe or other places. We also don't know how the transmissions might bolt up. Especially if you get a CRV R20 block, that AT/MT could be completely different.


what? no one bought a flashpro for their R18? for shame, i love my flashpro for my R18, my little civic definitely has more oomph and still gets great mileage. but the Weapon R intake manifold sounds quite interesting... but then its a injector swap too, plus plus plus... lol
 
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There are people who bought it for the r18. A lot of people who put themselves on a list to buy it didn't follow through.
 
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