Pistons

[Em1Lifestyle]

Plan on putting type r pistons in my B18B1 block would they go in or would I need to get my block bored

 

[nd4sped]

They are the same diameter if you get the OE standard piston. Just beware that you are about to increase the the compression to about 11.1 depending on if you use US P73-A0 pistons or JDM P73-00 pistons. The JDM variants will result in a slightly higher compression of about 11.6

 

[Diana Nam]

They are the same diameter if you get the OE standard piston. Just beware that you are about to increase the the compression to about 11.1 depending on if you use US P73-A0 pistons or JDM P73-00 pistons. The JDM variants will result in a slightly higher compression of about 11.6

i'll say 10:1-11:1 is pretty good CR from most builds

 

[ShinsenTuner]

I'm running 11.5:1 in my B20VTEC setup... if I could go back I would have opted for 12.5+

ITR pistons in an LS block yields different compression ratios depending on the head used.

 

[Diana Nam]

b20 have slightly bigger bore then b16s and b18s, 84mm> 81mm

 

[ShinsenTuner]

Although bigger bore, they utilize the same stroke of 89mm. I was merely making a comparison in terms of deck height, it is obvious that the piston bores are different. Bores do not effect the static compression ratios.

 

[Diana Nam]

you need to look more at the dynamic compression. i've already had gone thru all this lol and also is because my build its sort off in the " uncharted territory" so i have to rely on parts spec and clearance specs. i'm running custom 85mm 11:1 compression pistons paired to set of K20a rod spec but with that combo i have a dynamic compression of 9.75:1

 

[ShinsenTuner]

That's cool.

We also have no information regarding his head choice, valve train, and cam shafts. Hell, we don't even know what this engine is being built for.

 

[Diana Nam]

That's cool.

We also have no information regarding his head choice, valve train, and cam shafts. Hell, we don't even know what this engine is being built for.

true but for b series its pretty easy also regardless of what head hes using the difference is ver minor b18 non vtec head has only 45.0 of cc while all other b series vtec head area ll 42.7 of cc only 2.7 difference
only other excpetion is the b20 head used in the preludes those had b20aX had 47.3cc and the b21aX at 51.0cc

 

[nd4sped]

i'll say 10:1-11:1 is pretty good CR from most builds

My last NA build was 11.72:1 on 93 all day every day. Never had any detonation, I still have the pistons for any future builds I do. Pulled that motor and parted out some of it to put in a freshly boosted motor I built about 3 years ago.

 

[Diana Nam]

My last NA build was 11.72:1 on 93 all day every day. Never had any detonation, I still have the pistons for any future builds I do. Pulled that motor and parted out some of it to put in a freshly boosted motor I built about 3 years ago.

yea i'm just surprise that the Honda starting to get on board with high compression turbo builds when domestic people been doing it for decals now... but my setup is custom cause there really not much of "off the shelf" parts like the b series it take all the math work out the initial stage of the build i have wiseco custom 85mm with skunk2 alpha k20a/k20z rod in my f22b1 block which also is paired with my built h22a head. lol so my motor is F/H/K series as one motor. 9.75:1 was the best i can do my actual target CR was 10:1 unless i bore my sleeves to 87mm and use h23 rods plus if i used stock rods my CR woulda been 11.75:1

 

[Diana Nam]

i went with k20 rods since is shorter which will help the motor have better stroke to rod ratio for high rev application... these of the things that typical b series build don't need to be thought off everything been tried and made. so you jsut assemble and adjust and tune.