I’m going to build a ls or lsvtec with 84mm bore, but I was curious to what kind of #'s people are getting from 84mm set-ups. I currently have a ls block that will have 84mm in the future or I’ll get out the game like Jay-Z. I have a gsr head, but after I sleeve the block I’ll decide whether to use it or just build a ls head. $ issues might make that decision for me. I think that’s what it boils down too. Vtec = more money and great power and nonvtec = more power per dollar. I like the idea of a nonvtec, but wouldn’t you have to run higher boost to reach the same goals?
lots of people are. i quote ferris bueller…
I was researching this 'cause I was considering doing it for my next engine. It seems the gains are negligible. Also if you bore to 84mm it limits your ability to re-bore if you should ever have to.
I’ve decided against it for my next motor.
Why not use LS/CRV rods and crank to stroke a GSR block. Save the headache of leaking oil lines.
because, depending on rod/piston combo, you have to remove the oil squirters and plug the galley, and possibly notch the block, which if you don’t know what you’re doing is more possibility for disaster than ls/vtec. 
besides, GSR blocks are much more expensive and tougher to come by than LS blocks. 
I don’t think you need to do all of that. It’s not that much comparing to a 94-95mm stroke. 89mm is pretty safe to do. Have you actually tried it though?
not for my own car, but i tried building a gsr block for a friend with LS crank and rods. at the extreme least you have to bend the oil squirters out of the way, and depending on rods you have to notch the block. i personally only know of one brand of rod that doesn’t require it, but it’s way too far out of 99% of enthusiasts’ price range (over $1k) so i’m not going to mention the name.
when all is said and done, more mechanics are familiar with doing the work on the head and block for a “normal” ls/vtec setup (tapping/plugging the head, drilling for dowels if you don’t want to spring the $20 for GE’s custom dowels) than for putting LS crank and rods in a GSR block.
I already have the LS/VTEC oil & dowel pin kit. Though I’m not going with an LS/VTEC setup. Gonna go with a B20A!!! block and B16A head.
b20a? dont you mean b20b? or b20a…thats a prelude engine right?
Keep it simple is what I always tell our customers.
No need to complicate things when you know a basic setup will already make good power.
You can build an 81.5mm bore LS block for turbo and still make good power with the LS head. 300-350HP isnt that difficult to do.
We also do many 84mm bore turbo blocks as well. your choices are either a low compression 9:1 dished piston or you can go with a flat top piston which will yield about 10.5:1 compression
I personally like the flat top better with a good matching turbo. You do have less room for error with this and tuning has to be much more precise with a higher compression turbo setup.
yep… B20A the old prelude engine. I know some of ya think… " wtf this guy is thinking!!! " I heard all the stories about thy bastard child of honda. But I believe it can be done. I mean I’m pretty much registered on Preludepower.com and have been gathering information about the motor for about 6 months already.
nice man. i hope it goes good man… good luck 
hey, what do you guys think about the difference with having 84mm? My boy has a b16 84mm and it pulls good without the turbo. I have to mash the gas hard to get my car to pull like his. There’s just no lag when he hits the gas and he doesn’t have his vtec working yet. I like it so I wanted to do this too, but I would have to sleeve the block. jaberdasher, besides the downside of having less room for reboring is there anything else you found that you didn’t agree with for this setup? I want lsvtec cause you have to run high boost to get the #'s of a vtec with the ls right? I’m still deciding, but that’s where I think this is going. I just like the idea of having 2.0L.
I forgot to ask about that lsvtec kit, it’s kind of expensive, but there’s no major machine work needed right. I’ve heard the claims, but I’d rather hear some people that have had experiences with them.
Keep in mind that an 84mm B16 and a B18A 84mm isnt the same.
the b18a 84mm will yield about 2.0L while the 84mm B16 is only about 1.8L.
84 on a b16 only yields 1.7 so all the comp calculators are telling me?
yeah I know, but I definently won’t be building a b16 
…I just don’t like em’. It pulls hard though, so I have to give props to my homie.
mah bad… ya it’l only be a bit over1.7L for b16s