CivicOnBlades

Hey Guys.
Just wondering what type of numbers id be looking at with a pretty much stock B20vtec. Jdm b20b bottom end....b16 head....type r cams....and I/H/E....and probably a b16 or gsr tranny.
Im kind of hessitent about the whole idea just because its not a factory honda engine.
Reply with your success stories/builds.

zeeman

iTrader: (1)

170-190whp depending on the rest of the setup and if you tune it or not.

Tuning is key with ls/b20vtecs b/c there isn't a stock b20vtec ecu that you can use.
Keep the revs to 7500-8000rpms max and use the Golden Eagle conversion kit and you shouldn't have any problems.

Fr0z3N

Yes, don't neglect tuning, your car will run smooth, make more power, get better gas mileage and last longer.

CivicOnBlades

Ya a tune is definitly a must.
That seems like a pretty good number....and probably like 140tq?
They seem like a good motor to put together....ive just never done one so i dont want to **** it up...you know.

Fr0z3N

I might be doing an ls vtec soon

CivicOnBlades

^Oh ya.
Are you going to build it up?

zeeman

iTrader: (1)

b20vtecs can make anywhere from 140-160wtq

CivicOnBlades

Ya for the most part....if there stock....its usally closer to 140wtq.

zeeman

iTrader: (1)

yup.

If i ever pull the turbo stuff off my daily driver and put it on my CRX (race car), i'd build a b20vtec for the daily driver, or maybe even just a b20. Being able to use 87 octane gas is a good thing with the way gas prices are lately. Oh and I'd be able to have a/c again in the daily driver (stupid turbo is in the way...lol).

Tyson09

iTrader: (1)

i wish i could have my a/c back but now with the gt3076 im thinking im going to have use motor mounts to hold my turbo in, and just let my motor hang off the turbo haha

CivicOnBlades

Thats another reason why i will most likely do the B20vtec becasue lately you never know what gas prices are gonna be.
87 Octane FTW.

zeeman

iTrader: (1)

you should use 91 octane with any DOHC VTEC engine.....and 94 octane is only $0.04 more than premium (91)

CivicOnBlades

Really? I wasnt aware of that. I thought you only needed high octane fuel when you have a high compression engine.

zeeman

iTrader: (1)

all DOHC VTEC engines are "high compression"

The lowest would be the USDM GSR @ 10:1 CR.

LEITNER

you are correct. the highest compression you are going to get on a stock b20z piston is 11:1 if you whack .090 off the head...then there will be other issues you will have with piston to valve clearance. higher octane is for detonation resistance, thats it. a b20b piston has a 9cc dish so you wont even yeild 9.5:1 compression with a pr3 head so 94 octane is NOT needed.

zeeman

iTrader: (1)

you only really need 94 octane on a boosted car, or something with like 12:1 CR

Hell i've even done boosted cars that run on 91 octane and run well. There was a b20vtec that made 280whp @ 8psi on 91 octane, safely too.

CivicOnBlades

What type of compression raito am i looking at then?

zeeman

iTrader: (1)

roughly 9.5:1 like steve said (PR3 is the code for a b16 and ITR head.....its the same casting)

which you can safely run on 91 octane, you could probably even run on 89, my one good buddy (RIP dennis) had a stock as stock can be b20vtec in his beater and we tuned it using 89. This guy was brutal with cars too. He would beat the crap outta that car (92 hatch with a b20vtec) and it took the abuse without any issues.

All it literally had was a crappy 4-2-1 header that we had to re-weld the flange (for the cat) back on to, a cheap filter on a stick (short ram intake) and a crappy crush bent 2" exhaust that came with the car.

It started out as just a b20 with those bolt-ons, which was nice and torquey and pulled well until about 5500 or so. Had this for a year, then we put the b16 head on, with the golden eagle b20vtec conversion kit (which I recommend using) along with some golden eagle head studs and that was it. We never went to the dyno with it, b/c he didn't care, it was his beater. But it definately drastically improved performance from 5000-7500 and ran great on 89 octane for the year he drove it until his accident.

Moral of the story is b20vtecs are great engines. IMO the 84mm X 89mm makes a nice torquey engine and is a great platform for some serious numbers. I've done a few very mildly built ones that are in the 210whp 155wtq range, some with more torque than others depending on their intake manifold/throttle body/intake tube setup.

CivicOnBlades

I am definitly going to use the golden eagle kit.....it comes with everything you need and looks very straight forward. Im sorry to hear about your buddy.
Ive heard a lot of people saying that the vavle relfief is not good and you have to watch what kind of cams you put in. This true?

zeeman

iTrader: (1)

yup, the b20s use smaller valves, so the valve reliefs in the pistons are very very small. You can "notch" the pistons, but by the time you do that properly you could have bought yourself a set of the RS machines cast iron ITR style 84mm pistons that have bigger valve reliefs.