I have Jun3's and was wondering if you can run them on a stock bottom end? My head is milded and has welded chambers.

 

You can run them but you won't make much power with stock redline, the 3's make power past 9000rpm. You would be better off with Jun 2's or Toda A's for more midrange power.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by all motor b20b &raquo;</TD></TR><TR><TD CLASS="quote">I have Jun3's and was wondering if you can run them on a stock bottom end? My head is milded and has welded chambers. </TD></TR></TABLE>
i really dont think you can run them cause they will contact the piston. is it B20B or a B20Z piston? also the VTEC valves are bigger diameter and unless hte pistons have had the reliefs enlarged, u might be in a bit of trouble with JUN3..
johnzm-who has no first hand experience

 

You can't without enlarging the valve reliefs in the stock pistons.

As for not making much power. I have seen 190whp untuned @ 8,500 rpm's, a little above stock redline.

 

Thanks EK- I'm going to refer you doubters to my dyno. We were completely untuned and this was pretty much an improptu run. The chart compares my old B16 with JUN IIIs to the B20 with JUNIIIs both had stock bottom ends and the only thing done was the valvetrain. enjoy!

https://honda-tech.com/zerothread?id=595246

 

He has a set of stock b16 cams or the Jun 3's which should he run in this set up?

stock B20B bottom end
built b16 head

 

I'm not saying you won't make power, what I meant to say was you won't make as much power with a stock redline. With more aggressive cams you sacrifice midrange hp/tq for peak hp/tq at high rpms. Look at the graphs below for a visual, these aren't b20 blocks but if they were the numbers will be similar except higher. I can't seem to find any JUN2 or Toda A dyno charts right now, if anyone has a link or something please post.

http://www.importreview.com/re....html
http://www.importreview.com/re....html

And for kicks
http://www.importreview.com/re....html

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Maximus &raquo;</TD></TR><TR><TD CLASS="quote">You can run them but you won't make much power with stock redline, the 3's make power past 9000rpm. You would be better off with Jun 2's or Toda A's for more midrange power. </TD></TR></TABLE>

Yeah, I think you would be better off with a smaller cam.

 

i think idealy something along the lines of a skunk2 stage 1 but if i had to choose between stock b16 and jun3 i wouldnt hesitate to slap the jun cams in.

 

The JUN III cams will make power below the redline- yes they will... I know this.. how?

 

run the the jun 3's. i don't care what any one else says, run bigger even, but make sure to open up the valve reliefs on the intake side a little. i ran skunk2 stage 3 just fine on a stock b20b bottom end. it made tremendous power. i didn't gain much mid range compared to stock cams, but i didn't lose any power mid range either, top end was bannanas, ten times better than stock or some stage one cams