hey guys, im new to the B series game.
over a year, i was asking if i should throw an sir-g auto trans onto a b20v, but you know what happened

anyway- i bought a b20b high compression, rebuilt block, 12:1 arias pistons, a vtec conversion kit,
and a pr3-3 (89) CRX si head- its got gsc stage 2 cams, aem cam gears, supertech valves, and retainers- stock valves

so-----

im going to be new to manual, and im new to this kind of power- the rebuilt LS trans has a welded dif, too---

i was told that i should avoid putting 12:1 pistons in, from the guy who sold it to me, because he doesnt want me going into a wall.

what do you guys think?
i can get used to driving the car, but i was told if i want them in, the b20 stock rods need to be swapped to run the 12:1 pistons.

this is my daily-

 

i was also given a set of GSR cams incase i wanted to swap out the GSC stage 2 b16 NA cams

 

Is there e85 available? also, i wouldnt swap the cams to gsr cams thered be no benefit there. I sold my gsc cams to a friend and had them degreed and they are good to say the least. theres been people using aftermarket pistons with oem rods. take the car to a reputable tuner before beating on it. the LS trans will have very long gears so they may not be optimal but i dont know what gear ratios you like. hope you work it all out and have fun man!

 

That welded diff is going to cause you a lot of grief. As vtecmaster also said, the LS gear ratios are far from ideal for an N/A application. However, on the plus side this gives you a perfect "learner" manual transmission to become accustomed to before putting your money in a GSR/B16/ITR transmission (I'd personally recommend the B16 or ITR trans along with a proper LSD).

Take the car out to a big empty parking lot and just practice letting the clutch out and rolling into 1st gear. Once you're moving going through 2, 3, 4, 5 isn't as difficult. Practice starting on hills/inclines after that too.

And yes, I'd recommend upgrading both your rods and your rod bolts. Any forged rods (even Eagle) should be OK, and throw some ARP rod bolts in there too. Make sure you get that car tuned properly right away, even on 91-93 octane it should be fine but with that CR and those cams you definitely don't want to be driving around untuned, at all.

Edit: Also yes, keep the GSC cams. They'll outperform any OEM, especially with the other mods you have.

 

Thanks for the reply, guys. So to get back to your questions,

No, there's no e85, and it's like 3.30 a gal 20 mins away- not worth.

Also, im going to buy a stock, open diff for my rebuilt LS. Idk why there's even a welded diff in it anyway.

Next- the 12-1 pistons... I think I may have to keep the stock high compression pistons in the b20. I can't afford a good tune for a paycheck or two.
Would I still need a tune asap on a stock b20b hc block with that head?
The guy who sold me the ecus said one is spoon chipped, which he used in his type r. Im unsure though.

Regardless, im nervous and excited. I've driven a stick one time in a sti wrx that had a fresh stage 3 clutch. It wasn't easy for me. But i Understand how it works now, and luckily, my car isn't a (edit -BOOSTED- 300hp, and AWD.. nor will MINE have a lwfw for a while.

I was told that a stage 2 clutch is the most I should go for right now. Thoughts?
I have a competition pressure plate and oem flywheel. The clutch is bad, but it was included. Tossing it.

I have a build post. I'll link it soon!

 

A stage 2 clutch would be fine, and friendly for daily street driving. Both ACT and Comp clutch make good products. Exedy as well.

Run a stock Integra Type-R map on the ECU for the time being. If you have one available to you, hook up an O2 wideband monitor so you can make sure the car isn't running too lean or insanely rich. If you have the B16 cams on hand go ahead and use those for the time being as well, but otherwise with either those or the GSC just get them timed to OEM specs, don't use any advance on them.

 

A 12:1 B20VTEC with a mildly build top end usually ends up in the high 200's. It's not really out of this world power, you will get used to driving it very quickly. I would steer away from a very light flywheel though, I have an 8lb in mine and I prefer driving around with a heavier one.

 

Perfect!

So I decided that I will not be running 12:1 Aria's pistons in my block.
I spoke with the gentleman who swapped out my welded diff yesterday and he advised against. He said I definitely can, and could, however the stock block sleeves aren't that great for higher than stock compression. Granted, he was advising against it, if I was building over 300hp- mine won't come to that for quite a while, but I think the stock high compression pistons will do fine with the built pr3 head. Maybe 200 hp with the stock Pistons and tune?

 

i like spec stage 3+ clutch. feels stock-ish on engagement but bites pretty hard.

 

Yeah, this person putting in the welded diff in the first place is now advising as to what compression works, when there are countless ones done reliably, even in the comfort of one's own garage build. .

I'm sorry, I'm not buying it. time to find some other sources to "tap" for advice. As you won't go anywhere with welded-diff-man.

 

Check my build .. am running 13:5:1 compression . And made good power. Hope my post helps you in any way

 

Despite what ShinsenTuner said, "high 200's" is not really that common for a 12:1 B20VTEC. We've got a few that are above 250whp but IME you're more likely looking at low 200's: 220 whp or so. It depends on supporting mods, whether you're going e85 or not, and what cams you use, etc. But it's much more common to get a little over 200whp than close to 300whp.

 

I phrased it incorrectly, high 200s mean like actually into the 200's not almost 300 LOL.

 

hey guys, thanks so much for the replies.
so, im really on the fence about putting the upgraded pistons in still...(12.1:1) it may be excessive for me, being that im a new manual driver (havent driven more than 30 mins with a manual)

i mean, the question i now have is, how big of a difference would the stock 9.4:1 b20 pistons be to the 12.1:1 arias pistons, besides needing a good tune, and expensive gas??

honestly, im still trying to budget the rest of my parts, so im thinking about saving or selling them for later... still need (clutch master cyl, lines, pedals, exhaust and a clutch) -if anyone have parts let me know-

 

Just save up and wait. There is a huge difference between 9.4:1 and 12.5:1 when it's all said and done. The Tune and all that are worth the wait and the materials.
Don't be an impatient man.. just chill.

 

so, the topic now is the cams, with my mechanic, which is.... put stock GSR cams in and wait to use the GSC cams

GSC NA stage 2.
@1
int-266 dur. / 12mm lift
Exh-258 dur. / 11.5mm

GSR
@1
Int-230 dur. / 10.6mm lift
Exh-227 dur. / 9.4mm lift

also, i have a p72 ecu, but i really want to run the cams..... what should i do to run these cams in the b20v?
i have the 12:1 pistons too

 

the GSC when degreed came out to be 12.3mm lift and 264* INTAKE and 11.8mm lift and 260* EXHAUST. so a bit fewer duration on the intake but more lift and more lift and duration on the exhaust side. not to mention they have aggressive opening ramps. i sold mine to a friend and he's gonna use them on a high-revving, high-compression 1.8L setup. to run these cams, the 12:1 pistons should be enough.

 

Would I be able to safely run those cams on a stock 9.4:1 hc b20b motor with a VTEC si head??

 

The guy above you JUST SAID to use the 12:1 compression pistons for those cams. I have no idea why you seem to be purposely trying to "underbuild" your engine. 12:1 compression is nothing to be afraid of, it's not like you're buying a Hayabusa for your first bike. You're gonna make 200whp or so, it's going to be fun, and if you feel like it's too much car for you, there's this thing under your right foot called a gas pedal and you can ease up on that whenever you want.

 

Sure, you'd be safe, but it wouldn't benefit you to do it at all with that compression. They'd be a worthless/valueless purchase.

 

Hey guys big update-

I told myself I wasn't going to bother spending more money to run the 12:1 pistons, and that I'd use the gsr cams, but .....
For a price of 350, I got a set of GSR eagle rods, A polished GSR crank assembly, ACL bearings and got my jdm p72 chipped and tuned to run 12:1, the GSC N2 cams with a rev limiter of 8000.

Anyone see any problems with this, have concerns or opinions?

 

Check my build link in my signature for more details, and skip the long read if you wanna see everything

 

What are the specs on these 12:1 pistons?
What are they supposed to be 12:1 in, a b16/gsr/ls/b20??
We need the compression height and dome volume of these pistons, in order to calculate actual compression of the engine you are building and to tell if this Frankenstein of random parts is going to have a piston sticking out above the hole....
GSR's (b18c#) have a taller deck height than the b20 and LS, so using gsr crank/rods in an ls/b20 block, may give you some piston to deck clearance issues.
Also, just slapping in standard aftermarket bearings, instead of properly mic'ing out your bearing clearances and selecting the proper size bearings is a big no no, don't do that.
Mic your clearances and select the proper size oem bearings if you actually want this engine to last.

 

i hope the chipped ecu is just for initial startup..this kind of setup you will want a proper dyno tune.

very curious how the gsc n2 cams do. I wasn't even aware of them until last week when my engine builder suggested those over skunk pro series..
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There's what I have calculated.