Hi, I know this topic has been discussed to death, but at the same time there isn't an agreement even on older posts here - How reliable are the B20 sleeves on an N/A application, is the engine as a whole as reliable as a B16A on a close to stock setup?
Before you flame me, a quick story:
I have the original B16A on my EG6, but it's due for a rebuild and I have the opportunity to pick up a B20Z block for a good price. The problem is that B20 blocks are very rare around here, and if something goes wrong it will be quite hard to find a replacement, not to mention there's a lot of paperwork involved to register another block to the car. It will not see any boost, but my goal is reliability over power. The questions are:
- Does anyone have personal experience running those engines for YEARS without issue?
- Is it a time bomb as many say?
- What needs to be addressesd besides the usual ARP rod bolts and a meticulous assembly?
- Should I just forget it and rebuild my B16 because it's just a matter of time before the sleeves crack?
It's a street car as it's pretty stock down to the original fat five wheels, apart from some basic bolt ons and a suspension refresh. It will definitely be taken to the dragstrip and to the circuit, though. The goal is to reach 170whp with the stock B16 8200rpm rev limit and stock B16AX cams. I just want to enjoy the car and do the usual running maintenance. The setup is: Ported and sligthly milled B16 head with valve job, 3" short ram intake, DC JDM 4-1 2.5" header, stock 2" exhaust with no cat and freer flowing mufflers, ajustable cam gears, chipped P30. Not sure if that is enough for my goal, but it's what I have.

 

100k mile 7500 rpm B20Z build here. No idea what the original block & crank miles were before I got it. Everything is fine, no evidence of sleeve issues when I had the head off in 2019 or so.

Don't get so obsessed with rpm. If it makes the power you want at a lower rpm, even better. Revs cost money, exponentially. 170whp @ 7500-7800 is totally achievable with a B20/B16 hybrid. Do the usual hardening, rod bolts (as you mentioned), balance, detailed build. It will live fine in a street car. It will also have great drivability compared to a super high strung 1.6.

As far as track abuse, it's hard to say... the duty cycle is so different. If you did nothing but drag and got 1000 passes out of the engine, you'd call that pretty damn good survivability, even though that engine only had 250 miles of wot on it. You'll rack up about the same amount of engine damage in a weekend or two of track use.

 

Good to know! From what I've seen it does make power up to around 7500rpm, as it is with the B16, so it would probably benefit from revving as high to get as close to peak power at the next gear especially with the B16 transmission. My tach redlines at 8k so I would be frustrated if I couldn't take it up there. But I get what you're saying.

In my case the crank would be machined, re-hardened and re-balanced to be used with undersized bearings as the crank had a spun bearing. It's common practice around here with these engines due to a lack crankshaft availability. If clearances are ok after a hone, I would stay with the stock 84mm bore. Wouldn't run without ARP rod bolts for sure. I agree on the track abuse issue. It will mainly be a street car with occasional strip/track use.

 

Sleeves crack from detonation. Make sure you have a competent tuner and you'll be fine, there's plenty of us running 85mm unsleeved B20 Vtecs