CR-VTEC discussion

[madtownhonda]

Originally posted by Phatwhippin_CRX
The B20z/b is MUCH more turbo friendly.... the block is much stronger (cylinder sleeving) and has lower compression....

the B20 is a much better choice for turbo than a B18c.....

people have their reasons for turbocharging a b20 or b18b, I would rather turbo a vtec motor myself

[Phatwhippin_CRX]

Originally posted by madtownhonda


people have their reasons for turbocharging a b20 or b18b, I would rather turbo a vtec motor myself

True....... but you can't get a crazy set of cams, or there will be horrendous valve overlap, unless you severely retard your timing....

The VTEC motors, contrary to what alot of people say (mostly non-VTEC guys) are good with turbo, as long as overlap is controlled..

Hell, I saw a dyno where a 485hp civic lost 112hp when VTEC was disabled.. you can't deny it makes power.

But the reason I'd rather turbo a B20 over ANY other B series motor, is beacuse the cylinder sleeves are the strongest of them all...

Hell I plan on turboing my B16a rex in summer.... but I'll admit, the B20 is the best B series engine to turbo... without a doubt..

[madtownhonda]

Originally posted by Phatwhippin_CRX


True....... but you can't get a crazy set of cams, or there will be horrendous valve overlap, unless you severely retard your timing....

The VTEC motors, contrary to what alot of people say (mostly non-VTEC guys) are good with turbo, as long as overlap is controlled..

Hell, I saw a dyno where a 485hp civic lost 112hp when VTEC was disabled.. you can't deny it makes power.

But the reason I'd rather turbo a B20 over ANY other B series motor, is beacuse the cylinder sleeves are the strongest of them all...

Hell I plan on turboing my B16a rex in summer.... but I'll admit, the B20 is the best B series engine to turbo... without a doubt..

oh well...we have different opinions....the only advantage I see with the b20 is the 1 piece design of the cylinder casting and the slight edge in displacement....I still would rather turbo a b18c

[CivSiGuy]

personally, going turbo I'd do B18B just cuz doin' the whole setup w/ turbo is soooo cheap to do. Not as much hp, but much more friendly to your wallet.

[Phatwhippin_CRX]

Yes, defintely more wallet-friendly.... or a turbo on a B20z (not a CRVTEC).....

Less power? Possibly........ but that extra .2L of displacement, coupled with low compression pistons will most likely make up for the absence of VTEC. Those .2L may not make much of a difference to start... but add FI and watch a 1.8L non-VTEC DOHC motors' HP pull far away from a 1.6L DOHC non-VTEC.

If I didn't mind on not being quite as fast NA, then I would have gone B18a/b.... and then just built it for an eventual turbo. But I didn't want to drive around for a year or so with a b18a/b when I could get more power from a B16a and eventually turbo that...

[madtownhonda]

Originally posted by Phatwhippin_CRX
Yes, defintely more wallet-friendly.... or a turbo on a B20z (not a CRVTEC).....

Less power? Possibly........ but that extra .2L of displacement, coupled with low compression pistons will most likely make up for the absence of VTEC. Those .2L may not make much of a difference to start... but add FI and watch a 1.8L non-VTEC DOHC motors' HP pull far away from a 1.6L DOHC non-VTEC.

If I didn't mind on not being quite as fast NA, then I would have gone B18a/b.... and then just built it for an eventual turbo. But I didn't want to drive around for a year or so with a b18a/b when I could get more power from a B16a and eventually turbo that...

lower compression doesn't mean the engine is better...it means it can handle more boost...boost pressure is a byproduct of flow rate (CFM)

advantages to a high compression turbocharged motor:
1. the intake charge (A/F mixture is compressed moreso than it's low compression counterpart) is cooler than a low compression motor, therefore the turbo has a lower operating temp and doesn't have to work as hard

2. it doesn't need as much boost to obtain the same power numbers

3. full boost comes quicker and you remain at full boost for a longer period of time (especially with a high revving VTEC motor)

4. It makes power before the turbo spools up (a b20 will do this too)

A controlled amount of overlap is good.....the only reason overlap is bad is when boost pressure is lower than backpressure, thus causing the spent exhaust gases to be "pushed" back into the combustion camber diluting the fresh intake charge (reversion)...you couple the turbo with a free flowing turbo exhaust a larger DP and a 3" cat and you can come pretty close to 100% VE, depending on the size of the turbo...but seeing as you have some power down low from the higher CR and smaller amount of time to full boost, you can have a bigger turbo...the bigger the turbo, the lower the backpressure...your sacrifice is a little turbo lag, but more power up top where Honda motors make power (especially the VTEC motors)

so no doubt the b20 is a good motor, but I would rather have a b18c....my next choice would definetly be a b20...if I was on a controlled budget, I would get the b18b...If I had unlimited funds, I would build a turbo CRVTEC...so basically it all comes down to how much money you are willing to spend or have at your disposal

[SpoonManEK9]

HI, just to let you know i feel bad if anyone went out and bought all that stuff for a build. If you wanna do it right ask someone whose done it before. I know the headers for a b16 DEFINETLY WONT FIT.... the B18c's should fit BUT may require grinding of the block. The B16 block is shorter then the b18, and as far as i know the B20 is just about a inch or so taller then the b18. The LS/Vtec with 1.8 isnt the same as a cr-vtec with 1.9L of displacement. theres still a hell of alot more torque maybe 15 lb/tq. The cheapest to build is the Cr-Vtec, get a GSR head, stay N/A, get some CTR pistons and cams, port and polish the head. to match the bore of the b20 block. and get that sucker tuned with basic bolt ons, you wont put down 250 like that guy said... you probally will never see 250HP from a b series all motor without having to rebuild it every 10k miles. I dont think id go with a B16 or b17 crank you dont just lose displacement you also lower your CR, if your going to do something like that get some JDM CTR rods, they are the strongest B series rods availible.

Just read and ask questions, dont just jump into this kind of stuff. best thing to do is find someone whose built one and ask them for help and advice cause they know first hand.

JJ

[VTEC_boi]

Originally posted by SpoonManEK9
HI, just to let you know i feel bad if anyone went out and bought all that stuff for a build. If you wanna do it right ask someone whose done it before. I know the headers for a b16 DEFINETLY WONT FIT.... the B18c's should fit BUT may require grinding of the block. The B16 block is shorter then the b18, and as far as i know the B20 is just about a inch or so taller then the b18. The LS/Vtec with 1.8 isnt the same as a cr-vtec with 1.9L of displacement. theres still a hell of alot more torque maybe 15 lb/tq. The cheapest to build is the Cr-Vtec, get a GSR head, stay N/A, get some CTR pistons and cams, port and polish the head. to match the bore of the b20 block. and get that sucker tuned with basic bolt ons, you wont put down 250 like that guy said... you probally will never see 250HP from a b series all motor without having to rebuild it every 10k miles. I dont think id go with a B16 or b17 crank you dont just lose displacement you also lower your CR, if your going to do something like that get some JDM CTR rods, they are the strongest B series rods availible.

Just read and ask questions, dont just jump into this kind of stuff. best thing to do is find someone whose built one and ask them for help and advice cause they know first hand.

JJ

"Port and polish the head. to match the bore of the b20 block."
WHAT? Since when does the head have anything to do with the bore of a block?


Plus, you're telling whom to read? CivSiGuy...hmm...i wonder how he's jumping into it w/o asking questions when he STARTED A THREAD ON IT. :rollseyes:


JDM CTR rods are the strongest B series rods available? What about Crower FORGED rods and Eagle rods??? I have a feeling those are stronger than oem Civic R rods that won't even fit correctly w/o the use of a B16 crank and other such things (if even then)

__________________________________________________ __

Now, I would NOT destroke a CRVTEC...R/S ratio isn't everything and the B20 R/S ratio isn't all that bad.

Why would people stroke motors if the R/S ratio would be ruined that much? They wouldn't....ever heard of a 2.6L DOHC VTEC motor? Check out this month's SCC...2.6L of hardcore H22 power

Screw R/S ratio - it isn't that bad on the B20 and you'll make more power/torque if u leave it 2.0L.

[4bngr]

I picked up a bare b20b block for 50 bucks, yay.

If i were to use my b16a crank with my b16a head, what would the rod length need to be in order to preserve the "perfect" rod ratio?

Also, I would like to run 12:5:1 on the street with RC 310's and a hondata s200. people say that the sleeves are too weak to take this combo, any suggestions?

My cam choices are somewhat limited as i dont have the cash for JUN, I was thinking something like Skunk 2 stage 3's. or maybe a crower cam, once again any suggestions?

Everything from my b16a, with the exception of the rods, pistons, and head should bolt on to the b20b block right?

[94tegRS]

Originally Posted by 4bngr

I picked up a bare b20b block for 50 bucks, yay.

If i were to use my b16a crank with my b16a head, what would the rod length need to be in order to preserve the "perfect" rod ratio?

Also, I would like to run 12:5:1 on the street with RC 310's and a hondata s200. people say that the sleeves are too weak to take this combo, any suggestions?

My cam choices are somewhat limited as i dont have the cash for JUN, I was thinking something like Skunk 2 stage 3's. or maybe a crower cam, once again any suggestions?

Everything from my b16a, with the exception of the rods, pistons, and head should bolt on to the b20b block right?

this thread is quite old just so you know, like a year. anyways you need not just a crower cam, but cams. and if you are gonna have this as your daily driver I dont reccomend stage 3's

also on b20vtec.com hes cracked his sleeves a few times from 12.5:1.

just use your B16 cams, and I dont wanna try and figure oput the rod length you need but if you go to crower it will tell you the rod length of a B16, and knowing it is 1.74:1 and doing math you could figure the cranks stroke, then figure out what length rod would need to accompanie that stroke to get 1.75:1 or anythign close. but you are going to get forged pistons/rods anyways, and hondas cranks are good, so whatever r/s you come up with wont be too big of a deal unless you are trying to make TONS of power. stock is 1.54 and those B18 vtecs that rev like crazy are not much better, 1.58 they just have oil squirters to cool the pistons a bit.

[4bngr]

Im lookin to make at least 200whp daily driven, so, um yea.

Well, not really daily driven, maybe 3-4 days a week. I'll just roll on the stock head until i have money, i am really concerned about the bottom end tho, i want it to be reliable, but make gobs of power at the same time.
O, and 'd like to rev to at least 9k

[94tegRS]

you seriously dont need to rev that high, not even smart to do so on a stock B16 head, especially a stock B20 block.

you are gonna need a much stronger valvetrain, then with the block you are going to need all forged internals and a block guard or something or you are looking for problems,

what are you used to driving, you should get someone to give you a ride in their car that has some sort of basic LSVTEC or CRVTEC because my integra wasnt really FAST to me but I saw a dyno of one wiht bolt ons and I think it had like 113 to the wheels with bolt ons. but my car wasnt exactly slow either, you might be underestimating 200WHP, then again mayeb not but just something to think about.

[94tegRS]

oh yeah, and im not talking about my current one, i was talking about my old 94 hatch with I/H/E.

[Miataracer]

wow... i cant believe how much bs was flying around in this old post.

[4bngr]

I know that i will need forged internals, the block is bare so thats my starting point.

Im looking at 11:1, maybe more for compression using je pistons, an l2 or b20 crank

possibly toda b cams, oversized valves, valve springs, and titanium retainers. I have done my homework, just need a little more advice.