I read in this forum that JUN is making a JUN type 4 cam for road racing ? Is this true ? I am looking for a cam upgrade for my JDM ITR use for road racing ? Any reccomendation ,thanks guys

 

JUN 4's have been out here in the states for a while. IIRC Tbone (cam king ) ran these for like a day and half. I dont have specs but i believe they are crazy huge, v2v and p2v clearance may be an issue.

 

EDIT: Sorry for the repost

 

i thought those were the BC4s he had?

 

titan motorsports used to sell the jun 4's i dunno if they can still get them or not.

 

I have a set...hopefully the motor will be done this week

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by iakona &raquo;</TD></TR><TR><TD CLASS="quote">i thought those were the BC4s he had?</TD></TR></TABLE>
I had Jun 4's like a year and a half before the buddy4's..
I never got to run the jun 4's because they were too big. I couldnt even run them with the cam gears at 0 0 since clearance was only .025
Here were my clerance #'s with the 4's with .5mm oversized valves.
JUN 4 info: with the cam gears zeroed.
intake c/l 103° .502" net lift
exhaust c/l 101° .505" net lift
valve-valve cl = .025"

intake gear/exhaust gear - valve/valve cl.


0/2° retard .008"
0/2° advance .034"

2° advance/0 less than zero (stopped rotating crank, reached zero early)
2° retard/0 .030"
3° retard/0 .040"

other combinations for reference

2° advance/4° advance .033"
2° retard/2° retard .020"
3° retard/2° retard .025"
4° retard/2° retard .030"
4° retard/1° retard .038"


Steve Sakai tried to run them and he said with stock valves in his head that he couldnt even run them at 0 0 as the valve to valve was to close.

 

i heard about the same thing,,, i hope they are,,,, and if they are,, is going to be sick..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tbone &raquo;</TD></TR><TR><TD CLASS="quote">

Steve Sakai tried to run them and he said with stock valves in his head that he couldnt even run them at 0 0 as the valve to valve was to close.</TD></TR></TABLE>

if he couldnt run the cams with stock valves, what were these cams made for? if i remember correctly, you have OS valves. so if both stock and OS valves wont work, how would anyone run them?

*scratching head*

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DOHCtorTHRUST &raquo;</TD></TR><TR><TD CLASS="quote"> so if both stock and OS valves wont work, how would anyone run them?</TD></TR></TABLE>
There are tricks that machine shops can perform to the head to increase valve to valve clearance.

 

pretty crazy cam spec , is it suitable for curcuit racing ?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DOHCtorTHRUST &raquo;</TD></TR><TR><TD CLASS="quote">

if he couldnt run the cams with stock valves, what were these cams made for? if i remember correctly, you have OS valves. so if both stock and OS valves wont work, how would anyone run them?

*scratching head*</TD></TR></TABLE>

I said he couldnt run them at 0 0 on the cam gears , I didnt say he couldnt run them at all..

 

Ok guys, JUN3 or TODA B/C ?for high speed circuit usage ??

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JUNEJ1 &raquo;</TD></TR><TR><TD CLASS="quote">I have a set...hopefully the motor will be done this week



</TD></TR></TABLE>

I also have a set.......and we will soon see if I have any valve 2 valve issues. let me know what happens with your motor. have you done anything to compensate for valve clearance?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tbone &raquo;</TD></TR><TR><TD CLASS="quote">
I had Jun 4's like a year and a half before the buddy4's..
I never got to run the jun 4's because they were too big. I couldnt even run them with the cam gears at 0 0 since clearance was only .025
Here were my clerance #'s with the 4's with .5mm oversized valves.
JUN 4 info: with the cam gears zeroed.
intake c/l 103° .502" net lift
exhaust c/l 101° .505" net lift
valve-valve cl = .025"

intake gear/exhaust gear - valve/valve cl.


0/2° retard .008"
0/2° advance .034"

2° advance/0 less than zero (stopped rotating crank, reached zero early)
2° retard/0 .030"
3° retard/0 .040"

other combinations for reference

2° advance/4° advance .033"
2° retard/2° retard .020"
3° retard/2° retard .025"
4° retard/2° retard .030"
4° retard/1° retard .038"


Steve Sakai tried to run them and he said with stock valves in his head that he couldnt even run them at 0 0 as the valve to valve was to close.

</TD></TR></TABLE>

so what are the tricks to increasing clearance and how far should clearance be in order to be considered practical/safe?..

can i use these cams in my b18c5 on stock valves.....what is your suggestions?

 

using any aftermarket cams on ur stock motor should have upgraded valves. just to be safe. and if ur running jun's 4 that deff get some aftermarket valves.

 

and how is this!?

i assumed that without a BUNCH of money, u cant change the
angle the valve opens to
the amount of space in between the valves


soo the only trick i can see is the machine shop reducing valve size even more than stock...

im confusssededd

 

they can raise the seat height, effectively reducing the amount the valve opens by having a shorter throw spring. i do believe you can also change the valve seat depth.

 

If they make stage 4 for H22 I'd jump on it.
Im currently running their only stage 3s for H22, loving it.

 

bump

 

aftermarket valves are not necessary per se
it is the issue of oversize valves that jun does not recommend
that is the same for the Jun 3s also
which i have and run
you also cant run more than 1.5 degrees separation for the 3s so I imagine the J4s are probably even less in separation...

 

what is the recommended minimum valve to valve clearance.? I have heard .030"
Also how do you conclude that you have enough or not enough clearance.?
Thanks,.

 

clearnaces are found by claying the motor
a tedious process as you assemble and disassemble the motor
mine has just under 30 thou but it worked

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by eg6hatch3 &raquo;</TD></TR><TR><TD CLASS="quote">i heard about the same thing,,, i hope they are,,,, and if they are,, is going to be sick.. </TD></TR></TABLE>

what did you hear? what are you talking about!?

 

got my Jun 4 now with Jun oversize valve and retainers but no specs ,need help