My B20b needs a crank. I have been looking at other options for cranks and have a B16a crank available.
Pros and cons?

 

you lose a **** ton of displacement

no real pros

 

i might be wrong but i dont even think that would work. the stroke are way different..

 

Would require custom rods.

 

As Natural stated, you would need custom rods.

However, if I were you I would bore the B20B block out to 85mm, use the B16A crank and get the custom rods.

By doing this you would have more displacement than a B16A, a really good rod ratio and a very nice high RPM power band.

I have seen this combo EASILY make 145 lb-ft of torque. That is MORE than a lot of LS VTECs.

 

Thanks guys I think I have found a B18c crank from a GSR I am going to pick up.

The only reason I asked is because I have a B16a crank that is good and my B20b just spun a main bearing.

 

if you use a b18c crank, you will have to find matching rods.

 

B20 is. 2.0 b16 is 1.6 u dnt wanna down grade. Gsr block with LS crank thats a good mixture

 

My stock B20 with P8R head with only IHE made 143ftlbs with LS trans.

 

If you get the gsr crank I have a ls crank I could trade you. b20 and b18a/b cranks are exactly the same, the gsr one is different. Let me know Im in the market for a gsr cranks.

 

OK....

Your two liter is SUPPOSED to produce torque. That is what it was designed to do.

At 1756cc, this configuration (85mm X 77.4mm) is producing the same torque as your two liter.... with MUCH better reliability.

Besides that, in Tokyo you cant just put a B20 in your car without having to go through an extreme Shaken (Japanese car registration) paperwork nightmare!!!

 

sure, reliability after spending money on rods, bearings, boring ,honing, balancing, and everything else that might be needed to get it working.

All for the similar torque specs as a stock B20. thats all im sayin. Its a major project.

 

If you got money to blow do it, slap on a gsr/itr/aftermarket girdle, have rotating assembly balanced & sleeve the block high rev safe b20b lol really tho you'll spend less money to make more with an 89mm crank, would require custom rods as stated.

 

So here is what I have now, ITR style dome top B20 pistons, GSR rods and crank going into my B20b block. The crank and rods came out of a 96 GSR a buddy of mine to replace with a stroker kit. Now I get to start putting it back together.

 

wont u have a shorter stroke?

 

Hence the displacement/torque/power loss.
see reply #2

 

Marginally with the GSR crank, but it's still 0.2L larger than a normal GSR and now a point or 2 higher in compression than a B20. If I was given the option of a 9:1 89x84mm motor or a 10:1 87.2x84mm motor, I'd go with the later.

 

REALLY!?
How many threads have you seen thus far on "How To Build a Reliable B16A"?? Not one.... and you never will!! The redline for the B20B is 6500 RPM. I am assured that you and every other LS/CR VTEC, B20 and LS owner rev your engines well past that, which renders them unreliable.

However, there is still the ever present 7 year old thread on "how to build a "reliable" ls/b20 vtec" with 676,710 views and 2036 replies that consists of 82 pages!! The presumption of an outsider like myself should naturally be that at this stage in its development that the mystery would have been solved. The mystery on how to construct a non-grenading motor that Honda NEVER intended to exist.

Yes of course, it costs more than a simple B20 with I-H-E. The OP didn’t mention money as being an object. You could (should) do all the same things (rods, bearings, boring, honing and balancing) to your B20 also for the sake of optimizing it. These are all fundamental areas of interest for EVERY tuner of VTEC engines. Which, by that standpoint, declares it as NOT being a major project by any definition of the word.

 

oh boy.