Pablomg

Hi ! My name is paul and im from spain, i have b20z non vtec and I'm going to built the engine, I'm going to use fuel pump 98 (93) so I wanted to know if the b20 sleeves hold up better at high rpm (for 9000 rpm 12: 1 cr) or low rpm and a lot of compression (8000 rpm and 13: 1 cr) the cams are 405A.

Thanks.

turbociv910

no. stock b20 sleeves wont hold up to that rpm for very long. RPM is not their friend.

Pablomg

So, does it support a higher rc than the friction of a high rpm?

AllMtrRex

Is this going to be a daily, street/strip or drag car? Several guys have gotten away with stock sleeves/high compression and 9k+ rpms. It just depends on how often you will see 9,000 rpms. Yes, staying below 8k will keep things together longer. However, B series Vtec transmission (B16/ITR,GSR) was designed with high rpm combination in mind, as well as the Vtec B series (P72, PR3) cylinder heads. If you are going to keep things around 7500rpms, stay with the non Vtec route.

Pablomg

Yeah, its " fire wekeend car ( track, drag, all) " but I want reliability too. I like the powerband non vtec. So then you confirm me, that the sleeves are more capable of supporting high cr than high rpm? (mechanically speaking).

I have the motor opened, so all the answers are for choose nippon racing pistons 13:1 or 12:1. ( acl bearing)

Thanks

TheShodan

iTrader: (14)

The B20 can support high cr, but it won't make the engine a better platform. Lots of cylinder head work and camshaft must be done to get any benefit out of higher cr. Keep it at 12.5 and under. Going 13.0:1 will be tuned as though it is lower anyway to prevent engine knock.

Pablomg

I thought, if I'm not going to use e85, the ignition map will be very late and for that better to use 12: 1, however this doubt comes from a YouTube video where a b20 hits 263 whp with fuel pump and 9k rpm, but if what I do not want are dizziness really should run 12: 1 and 8k rpm..

ontariorider

spAdam

iTrader: (1)

Pablomg

definitely, b20 is a lottery, I know many non vtec / vtec setups that continue to last at 9000/9500 for years, and others have broken at 8000 rpm a months

Chance EG

You'd need to port the **** out of a non-VTEC head for it to produce power that high in the RPM band. I also have no idea what you'd do for bolt-ons, but something would be needed to be done for intake/throttle/manifold.

As with what Shodan and others are saying, going past a certain point on compression (~12.5 on 91-93 octane seems to be agreed) will start to yield opposite results of what people want because you have to retard the ignition map so much.

For the block itself, a stock B20 block with ARP rod bolts is good to ~8K RPM (mechanically speaking). Don't go beyond 84.5mm on the OEM sleeves, 84.25mm or even the stock 84mm bore is best if it can be built around that. "Built" with OEM sleeves is fine up to 9K as long as the walls haven't been bored way out.

Pablomg

Okei! Thats clear, but I had not found information on the reliability of CR, (in the USA for every 30 tuned civics in Spain there is 1) My Bolt On Are Ultra Street with 74mm TB, the cfm head is ported the same cfm that itr head, rmf v3 headers, the cams are 405A practically the same that crower stage 2 vtec, the only difference is 31mm valves, that's why it has a better volumetric charge from below to upper middle, so I like the powerband non vtec.

TheShodan

iTrader: (14)

Again, that powerband issurle can be solved with the camshafts in the VTEC Head of A B20VTEC, which I'm sure you don't have many of there. Trust me, its worth the swap.

Regardless, reliability is dependant on the assembly of the engine, and the ability of your timer. However, with higher completion comes higher risk of damage with less benefit as it increases. With that said, we must let live teach this lesson to you, as though seem pretty determined upon using your own logic vs. Those a bit more experienced in this area (which is why you don't find much info on this topic now, as its been done with mediocre results, compared to slightly lower compression (11.5-12.5.) , and better work on the cylinder head itself

But We of course wish you best successs.

K7-1Ktrevor

K7-1Ktrevor

Pablomg

with that compression and cams, I would leave stock degree, you will see the difference. at the end I decided for 11.1: 1 cr, following the same configuration that has an acquaintance with b20v and cams stage 2 crower (the same that 405A crower) and the car is very fast and reliable

spAdam

iTrader: (1)

This.

I have a spreadsheet around somewhere with all of the data for the Crower non vtec cams and it calculates for degreeing and bottom end geometry too. But you should read up on this and play around with the online calculators. Intake valve closing time is an important concept. Crower's cam cards are available online and the rest you can sort out from Zeal CR calculator or similar. The tools are available for free.

Example: My 84.5mm P8R/B20 with RS machine ITR clones and stock CRV cams was pretty close to knock on 93 in FL, but I couldn't pull enough timing to get it to not knock on 91 in CA. Even part throttle. It was shitty. With 403s I was able to put several degrees back into several spots in the curve. Drivability is better because I was able to shape the torque curve a bit with the extra knock margin. Honestly, people have this obsession with sky high static CR numbers and I feel I end up seeing more under-cammed engines than I see over-cammed engines. It's especially bad with the low quality E5-E10 blends we have to run these days. Might be different in Spain if you guys get non-ethanol gasoline. I don't know.

K7-1Ktrevor

Pablomg

Exactly, the feeling I have is that I have seen moving very well and doing very good times with a cr contained (11-11.5) and good work head. For example a k20a2 is 11:1 and with good work head is very very fast and high whp

2LEM1

iTrader: (1)

Cracking sleeves comes from detonation, not the compression ratio itself. As long as the motor is tuned correctly you can run as high of a C/R as you want and the sleeves will be fine.

RPMs is dictated by rod bolts, cams, and head flow, again sleeves are not part of the equation.

1HGEJ2

iTrader: (1)

Ive built a b20vtec with 84.5mm pctx nippon pistons, Eagle rods, stock crank, hx bearings, ported head, sk2 pro2 cams, skunk2 ultra street im and 70mm skunk2 tb. 4-1 rmf header with 200cpsi cat and 63mm catback..243hp. On 102 octane. Exhaust is to small. Revs no problem 8500rpm and tune wasnt with knock. Knock ears on dyno and street. Edit cr 14:1