GSR_ITR_BOIB

I would like to start by saying that if this is the wrong section for this, could a moderator please move it to the correct section for me? Thank you.

I am building a high compression all motor B series and my camshafts of choice were the Skunk2 Pro 3s. Before I wrap this build up and go get tuned, I'd like to degree the cams in, and clay the valves. I'm having some trouble degreeing in my exhaust cam though.

Skunk2 sets the center line for the intake cam at 100 degrees ATDC, and the exhaust cam at 104 degrees BTDC. I understand that the intake valves open BTDC and close ABDC, and that the exhaust valves open BBDC and close ATDC.

Here's the steps that I'm taking to degree my cams. I have my valve lash set to zero for these valves. I have vtec locked in with the supplied 'BBs' that were included in my cam degree kit from Xenocron Tuning Solutions. I also already found 'true' top dead center, and I have my center dial indicator zero'd out for TDC. I'm degreeing my cams from the number 1 cylinder location. I also have the intake and exhaust indicators zero'd out at TDC too. I begin by rotating the crank in the normal CCW direction until the intake or exhaust indicator (depends on which cam that I'm degreeing) reads .050" lift. I record the degree wheel value (BTDC or BBDC, depending on whichever cam that I'm degreeing). I continue rotating the crank in the normal CCW direction until I reach 'true' TDC again, meaning that the valve is now fully closed. I reverse direction of the crank in the opposite, CW direction, until the dial indicator reads .100" lift (I only do this so that I can reverse direction back to normal CCW to find .050" lift before the valve closes). I reverse direction once again, to normal CCW, until the indicator reads .050" lift. Now I'm at .050" before the valve closes. I record the degree wheel value (ABDC or ATDC, depending on whichever cam I'm degreeing). Now that I have the 2 values, I add them together, add 180 to the total, divide that value by 2, then subtract the opening degree value. So, for instance, if I was degreeing the intake cam and I got the degree values of 37 degrees open BTDC and 53 degrees close ABDC, I would add 37 and 53 together to get 90, then I'd add 180 to get 270, then I'd divide by 2 to get 135, then subtract the opening degree value (37) and this would be my current centerline of 98. Then, I would adjust my cam gears accordingly, to put the centerline of the cam where it should be according to Skunk2.

This worked for my intake camshaft perfectly fine. It was 1.25 camshaft degrees off of where the centerline should be, so it was easy to adjust the intake cam. But, with the exhaust cam, I can't seem to get it degreed in. As far as i know, the math should be the same as the intake cam is, the only thing that should change is the location of where the valve opens and closes opposed to the intake cam, as well as the degree numbers. But I'm coming up with some funky numbers. I'm coming up with numbers as to where my exhaust cam is 10.5 camshaft degrees off of centerline! My cam gears do adjust as much as 10 degrees, so I went ahead and tried to adjust accordingly. Well, it ended up that the piston and the valve had contact, so I just set the exhaust cam gear back to zero for now until I find out how to properly get it degreed in.

What could be the cause of this? Is there maybe a chance that the BB that locks vtec in is 'off' by a little bit in the exhaust rocker arm assembly? Is there a different math equation that i should be using that I don't know about? These are the only options that I can think of, but I'm open to any suggestions. This one really has me picking my brain. I'm completely stumped. Any advice is truly appreciated.

Thanks in advance!

0xenocron

At Zero on the cam, what are your Exhaust Opening, Closing and current peak lift numbers?

OneBadTurboCRV

I haven't personally heard of doing it solely off degrees. I have been using the method below for a long time now (before it was ever posted) and everything always matches the cam cards.

https://honda-tech.com/all-motor-nat...edown-2003538/

GSR_ITR_BOIB

I'm at work for the night now. I'll have to let you know those numbers tomorrow. I disassbled everything today - took it out of time, took the cams and cam gears out, took the rocker shafts out as well as cylinder #1 rocker arms for both the intake and exhaust sides, took the BBs out that I was using to lock in vtec, substituted the longer rods for the rocker arms supplied by Xenocron Tuning Solutions to lock vtec in this way instead, wiped the cam lobes off, as well as the contact point on the rocker arms, and re-assembled everything, put it back in time, and re-zero'd the valve last out for cylinder #1 on both intake and exhaust sides.

This is as far as I got today before I had to get ready and go to work.

By the way, I love this degree kit.

TomCat39

Thank you for this. Will be quite helpful down the road. That makes total sense and is easy peasy.

Ethyopian

hi, sorry a little late to the thread but what did you find the issue to be? I’m currently having the same issue…