91SIR

Ok ive got an ls block that's .50 over that I was gonna push to 82mm for lsvtec. I've got almost all the parts except the pistons. Today at work I convinced my boss to give me a spare b20 block we had at the shop. Now I'm trying to decide 82mm or b20???? Help me decide!!!Here's what I've got.
Bottom end
Eagle rods arp bolts
Arp main and head studs
Pistons TBD but will be 12-1 or 12.5-1 compression
Block guard (for what it's worth)
Golden eagle vtec kit
Acl bearings
Everything balanced
Vtec oil and water pump

Head
Gsr head milled .015
Mild port and polish
Stainless valves
3 angle Valve job
Old style skunk2 intake
Crower stage 2 cams 63402-2
Crower dual springs and ti retainers
Toda rep or smsp rep header
68mm throttle body
2.5 exhaust
Hondata s300
450cc injectors
Pump 93 gas
I think that's it haha let me know what u think.

TheShodan

iTrader: (14)

B20.. no need to bore that much, unless you like risk.

91SIR

The motor won't be daily driven. from what I've seen 82mm isn't that bad if ur not boosting the crap out of it and ur tuned well not running ur buddies base map or eBay chip

TheShodan

iTrader: (14)

You asked...I'm simply answering with a suggestion. B20VTEC is easier to get gaskets and other equipment, easier for replacement pistons and parts with less risk for the cylinder walls. A true 2.0 litre..

Whether or not it is "daily driven" is an irrelevant point.

I think you're waiting for validation from the masses to say its "ok" to go ahead with your plan of 82 X 89.. If that's the case, why waste time? Just do it, and enjoy the car...

10psiLsEf2

As stated above. I wouldnt bore a block to 82 mm. The sleeves are thin already.

Ditch the b18a/b and just go b20.

Daily or not your still going to put the cylinder walls under the same stress when mashing on it.

Just my.02

10psiLsEf2

82mm or 84 mm uhhhhmmmmmmmm hold on lemne think.

THERE IS NO REPLACEMENT FOR DISPLACEMENT

Uncle Dave

82mm is just fine on a b16a/B18A-B or the B18c blocks its just the max you can go safely.

10psiLsEf2

Yes and its safe to buy a condom, try and make it thinner for more pleasure.

Or just buy trojan ULTRA THINS?

raverx3m

iTrader: (1)

what about 82mm with 87mm crank?

10psiLsEf2

The stroke has nothing to do with cylinderwall thickness.

raverx3m

iTrader: (1)

But it has to do with sidewall load

Uncle Dave

There is really no point even posting correct info in this forum anymore as the e-engineer's will just come in here and post up pure rubbish to make themself's look like they know what there talking about.

raverx3m

iTrader: (1)

Forgot to put a quesrion mark lol

From what i was reading the crank/rod ratio does help
Im in for correct info confirmation
I know ita been said a milliom times that 82mm is the limit on b18 blocks
But i forgot the details about the stroke and rod length

TheShodan

iTrader: (14)

The "rod stroke" ratio talk is about optimization, but changing the stroke won't make the difference you think on such a build. its been done quite a bit.

93egSLEEPER

84mm B20 > 82mm B18 in all aspects.

vtecmasta85

Go b20, the added tq and horsepower is worth it. I like the supertech 12:5:1 pistons as i have them in my b20 vtec right now. What brand injector you have? I have rdx 410's they're nice. I'd go toda rep by the way as for the header selection. Go with a golden eagle block guard. Really would do a 3 inch exhaust for this setup.I'm not sure if you like those cams but a better cam choice would be pro 2/3, m22KE, or m24xx. I love my m24xx they are extra responsive, even on conservative tune with little timing. The car feels like its being pushed and they idle probably better than stock cams IMO.

Head wise, what type of vj you have? Did the shop tell you what angles you have in your head? This is important and shouldn't be overlooked at all. With that manifold you have, just get a 65mm throttle body and full 2.5 inch cold air intake. I have the AEBS intake manifold and portmatched it to a 70mm throttle body. By the way, if you plan to stay with 93 octane only stay under 12 compression. But if not, go 12:5 and e85! I think the ability to run more timing is worth it.

91SIR

Ive been looking at the rs machine itr replicas. with the gsr head and the .015 off im looking at 12.3 to 1 with a stock 3 layer head gasket. Ill have to look at the thicker cometic gaskets to bring it down some. I was also hoping the cams overlap would help alittle even if my static compression was alittle high?? The injectors are dsm 450s.

Ive had the cams forever and ive never run them, I think they will make over 200whp. from what ive read and seen they should make awesome midrange. After I get it built and tuned If im not happy with it ill start cam shopping. The valve angles are 35\45\60 I think that's the standerd on a performance vj for a Honda. E85 isn't readily available in my area so that's a no go. The motor is going in an 89 crx that will see some street and some track day events.

jdmconcepts

How did you figure out your compression ratio 91sir?

93egSLEEPER

Give it a read
https://honda-tech.com/forums/all-motor-naturally-aspirated-44/diy-compression-ratio-calculation-2476094/

91SIR

well I used the zeal auto calculator. The rs pistons aren't real itr spec, after some looking they have a 1.7cc dome and a 30.00mm deck height. so I just used those numbers in the calculator. I know measuring everything would be the right way but estimating will do at the moment.

vtecmasta85

Yes if ethanol isn't available keep it under 12 compression sir. Overlap affects dynamic compression if that's what you're concerned about. The specs those cams seem a lil on the milder side but not sure how fast the ramps are either. Those valve angles are stock and IMO the only way they would be anything performance like is if they are in different lengths/widths. But hey, just put the motor together and run it then go from there.