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Old 05-06-2015, 12:44 AM   #1
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How to measure v2v and p2v

I'm currently going through this so I figured I'd copy and paste it here (not my work). I'll post my findings when i'm done.

alright, i havent posted much up lately but "use the search function" so i thought i might do something helpful.
im going to try to do a little writeup on properly checking V2V clearance and P2V clearance. if anyone that has more experience finds something wrong with my steps please post up.
to start things out i received my head on friday with all valvetrain installed minus cams.
1. pull the rockers out of cylinder #1

2. take out all 16 valve springs or just take out the #2,3,4 rocker arms (its easier)

3. install 2 "check springs" (1 IN 1 EX) using your retainers into cylinder #1 with them installed in the #2 valve position. should look like this:

4. take a regular BB and install it in the rocker arm behind the small VTEC pin to hold the 3 rockers in "VTEC". do this on both IN and EX

5. install rockers

6. lube journals and install cams as if the motor was in the car (i just snug the cam journals down)

7. set valve lash at 0

8. wrap old timing belt around cam gears and keep it held there with a set of vice grips should look like this:

9. secure cylinder head to bench with cylinder #1 hanging over the edge

10. set cam gears to 0,0 (watch closely so you dont run them into one another)and rotate over while looking underneath at the valves and when they get to their closest to touching one another stop there. should look like this:

11. take feeler guages and slide them between the valves to get your V2V clearance. (write this down on paper so you wont forget)

12. change 1 cam gear at a time and continue. i change my cam gears in 2* increments, you may want to do each and every degree its your choice (remember to write down all your findings)

13. so lets assume you did all your cam gear changes, what did you find out? on this particular head these cams need MINIMUM 3* more advancement on the exhaust cam gear compared to the intake cam gear. this is my chart i made for this cam install:

notice at cam gear settings of 0,0 i have about .005 clearance.
also note how at 0,+4 i have about .030 clearance. this is MINIMUM on a race motor IMO. some go as far as .040. this is the reason these particular cams need 3-4 degrees advancement on the exhaust cam compared to the intake cam.

heres another chart i did using JUN 3 cams:

14. next rotate the cams till they are at their maximum lift, set your dial indicator to 0 and push down on the rockers. let them up, re-zero the dial indicator, then push them back down again. note how much movement there was until the dial indicator stopped. this will be your retainer to valve seal measurement, note that and then do the same to the other cam.
in this particular head i had .040 R2VS on the EX and .021 R2VS on the IN side.
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