I have a 1995 Integra LS with (stock) B20Z swap already installed. I plan to do a VTEC conversion and have studied and researched quite a bit on the subject. I plan to use the stock B20Z bottom end, GSR head/cams, and don't plan to rev over 8K. What I need to know is if I need to worry about the pistons smacking the valves.
I have read (in my search) both ways (that it will and that will not). Perhaps it is because the lower compression B20B engine has shorter pistons and the (higher compression) B20Z has taller pistons. Maybe the B20Z smack and the B20B does not? Can anyone give me a definate answer, from personal experience?

 

Well the comp doesn't really matter it's the valve reliefs that you have to worry about. Cuz the LS head has a completely different valve angle, opposed to a GSR head, or PR3 head. As you said I've seen people use the stock pistons, and the **** worked fine, and then again I've seen people that have completely destroy their motors do to piston to valve issues. So if you were to ask me I wouldn't take that chance, I would cough up some loot, and get a set of after market pistons.
It's better to be safe than sorry

 

well i just had this problem and i built a b20b with z pistons and i didnt notch the pistons and its runnin good. but its with oem type r cams and at perfect timing. i was told aslong as you use oem cams and 0,0 timing youll be all set.
ill let you know if anything happens

 

someone here on another post said they used a set of S2 stg2 cams on a stock B20b block with out notching the pistons. is that possible in a B20b 8.8 compression block???

 

I pulled apart a customer's CRVTEC due to him complaining about a loud ticking sound. It was a stock GSR head on a stock B20B block and all of the pistons had slight grooves knocked into them from the valves. The next week another customer brought his car in to be dyno'd and he was running a stock B20B block with a GSR head and CTR cams and never had a problem.

I personally don't think it's worth the risk.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eg6cusco10pt &raquo;</TD></TR><TR><TD CLASS="quote">someone here on another post said they used a set of S2 stg2 cams on a stock B20b block with out notching the pistons. is that possible in a B20b 8.8 compression block???</TD></TR></TABLE>
Nope, those cams would do nothing.