b16bri

Hey guys quick question anytime you would change cams from stock to some type of aftermarket cam (I'll be doing this on a B16 but i mean on any motor in general) Like i will be doing in a few months on my b16 do you need to degree the cams and check v2v and p2v clearances or are there just certain times you have to. For example only if you get the head machined or after installing new valvetrain ??

b16bri

Anyone ? i'm just curious trying to learn

ashb82

I always check

IN VTEC

iTrader: (3)

only if youve got a big one going in.

EsotericImage

iTrader: (8)

Depends on how big your going.. which brings up another question..

How big is too big:

If your looking at stage 2-3 then you should be ok IF the head hasnt been decked too much. If its still OE, then the P2V clearance should be ok.

If your going to stage 4+ you should have your bottom end built anyways and a high CR to make use of the cams.. so If your doing all of that, then the Cams will be an important factor as well. Usually reliefs are a tad bigger.

ALWAYS degree cams when upgrading! If your just going to drop them in and eyeball it, then youll have issues really quick.

b16bri

Is this something a machne shop has to do or is this something i can do myself if i baught the tools. I'm a little confused on how this is done i saw someone wright a thread about it on here but it still confuses me. I understand clearances are everything ive built bottom ends befor but this confuses me.

b16bri

I'm really eager to learn so any info on how this is done would be really appreacated.

b16bri

Anyone ?? ivwe been doing a lot of reading and it still dosent make sence to me.

PyroProblem

12NV made a thread about degreeing cams and checking PTV/VTV clearance in the all motor thread...
Id assume more n/a guys do this than f/i guys due to them usually running larger cams and larger domes...
Its a good idea no matter what IMO...
Also search for the "mike belben" kit. It uses dial indicators and a fixture for helping to measure this stuff....

b16bri

Thank you for responding by the way I know ive seen the kit and have read the thread it just dosent really make since to me. I was looking to see if anyone else had any other way of explaning it ?

PyroProblem

Lock the rockers so vtec is engaged...
Replace 1 cylinders valvesprings with some light pressure springs so you can press open the valves with your hand. Some just use the inner valvespring only...
Set up a dial indicator on the valvestems axis, keeping it straight as possible.
At max valve lift,zero out your dial indicator. Press the valve open until you feel contact with the piston. Note the indicators measurement.
This is your piston to valve clearance at that particular cam gear setting. Adjust your cam gears to different settings and recheck the clearances. After a few different settings, you will know what you can adjust the gears to while still maintaining sufficient clearance. Do this for the intake and exhaust cams...
This is roughly the basics for checking piston to valve clearance...

Degreeing the cams in require the degree wheel to be setup on the crank pulley. You need to know the cam mfg's specs so you can set them to their recommended settings. The initial settings prob wont be the final settings, but its a good place to start. All your doing here is timing the cams perfectly to the crank.

Valve to valve clearance is done withthe head removed, but valves installed with the low pressure springs. Use an old timing belt and vicegrips to keep the tension tight. When you rotate the cams youll see when both valves open at the same time. Measure the distance between them with feeler guages. Then you can adjust the cam gears to see where your valve to valve clearance becomes too close. I think .030" is what most people use as a safe number.

Hope I explained that good enough...

b16bri

Ya it helps a lot man thank you.. I think what confuses me is making sure or finding max valve lift or making sure i'm reading the cam spec right.