GSR_ITR_BOIB

Ok, so I'm building an all motor, high compression B series. I understand what P2V clearance is, and why it needs checked, but I want to make sure that I'm doing it correctly.

I do not prefer to check the clearance using clay because number 1, being a CNC machinist, I don't feel that measuring something that's squishy is going to give you an accurate measurement, and number 2, everybody says to measure the clay with a set of calipers, and calipers aren't that accurate - at least not as accurate as a set of micrometers would be.

I've decided that I would like to check my P2V clearance using the 'check springs' that came with my Xenocron Tuning Solutions cam degree kit (great kit by the way - I highly recommend it). I want to make sure that I'm doing this the right way though, and here's how I'd be doing it:

The cam degree kit supplied me with 2 check springs, so first I would replace one intake valve spring and one exhaust valve spring with these 2 check springs. I'm doing this all based off of cylinder 1, and I already have VTEC locked in, my valve lash for cylinder 1 is set to zero, and I degreed in both cams as well. I would secure the check springs in place with my retainers and keepers, just as a normal valve spring would be. I would set my dial indicators up for both intake and exhaust side, and I would turn the motor over, and for whatever side of the motor (intake or exhaust) that I'm checking clearance on, I would watch that cam lobe/dial indicator to see when it has reached its peak lift/dwell, take note of the dial indicator number, and write it down. Next, I would take whether one of my fingers, or some kind of a tool with a flat end on it, and push the valve the rest of the way in until it was touching the piston. From there, I would take note again of the dial indicator number and write that number down as well. I would subtract the first number from the second number, and that would give me my P2V clearance for the current cam gear settings. I would repeat this process for the opposite side cam, and I would make a chart to record different clearances at different degree settings for each cam gear.

Does this sound right? If not, could I please get some constructive criticism on what I'm doing wrong and how I would correct it?

Thank you so much in advance!

0xenocron

Email me your order # and I have a write-up I can send your way to help you out!

chrisharris@xenocron.com

ojasia

I just degreed the cams and then measured how much clearance there was 15* BTDC and every 2* keep measuring until your at 15* ATDC I had .100"+ on every one. Stock H22 stroke, Wiseco 11.5.1 shelf cr slugs with Pro 1 Cams.

I dont think you have to do all that. Just because Once there degreed thats where they'll be at those Crank *'ees so once its coming to that proximity of TDC I started pushing down from where they were and counted how many 1000th's they were until it touched. Just take note at every crank angle of what the dial is at then push valve down and count. I dont know what your building with what cams but I asked a very respectable engine builder and he said .015" was safe for P2V but this guy makes big 4's with very high lift cams so If they can do that and rev to the moon my pro 1's with recommended springs with .100"+ will be more then happy. Hope this helps and you can understand it, with it all there in front of you I'm sure your starting to get an idea. GL

Also once lash is set it will actually be more clearance. So with VTEC locked and 0 lash you are creating less space then it will ever see.

I also bought the full kit from Xeno.

Pro-SeriesFab

Using clay and dial calipers works fine if you give yourself enough clearance . . .

You don't need +/-.001 when you are setting a gap 100x larger than that. And really for most engines that method will work fine.

The alternate way you described is the only real way to check it as accurately as you want. Setup a dial indicator on the tip of the valve and measure the amount of travel the valve has before hitting the valve relief in the piston.

The only concern with the dial indicator only method is it will not give you an idea on radial clearance the valve has, just axial clearance.