just wondering how to find true tdc. I need it to adjust my roller rockers. Shoebox's website tells me but I need to know how to tell if #1 is the tdc or if #6 is at tdc. I think this is the only problem with my car right now after the cam swap. That and a few vacuum lines. Thanks in advance for all your help

 

Hard to tell true TDC so just get it close with the lifters on #1 on the base circle after the intake valve closes. Then do the EVOIC method, exhaust valve open, Intake closed method after you install everything.

 

Is the intake off? If it is, you can do a quick visual check of the lifters and spot which of them is at TDC.

If #1 is at TDC you will also be able to adjust #2, 5, and 7 intakes plus #3, 4, and 8 exhausts. If any of those valves are not at zero lift, start over assuming that #6 is at TDC.

 

pull #1 plug and you can place your thumb over spark plug hole as a friend rotates engine with ratchet. You will hear a "woosh" as it reached TDC. You will know this is "compression stroke" instead of "exhaust stroke".

This is close enough to adjust rockers as the lifters are definitely on base circle and not on lobes. I would not consider this EXACT TDSC for degreeing a cam but will work for the rockers.

Just rotate the engine 90* and go to #8 and so on and so on as you work through the firing order (1-8-4-3-6-5-7-2).

Good luck.

Lloyd

 

i no longer am a believer in the 1 and 6 method. when i used it on this last build i had 3 valves completely out of adjustment. one really tight and two really loose. might just be the size of cam but for me the extra 10 mins spinning the crank 90 at a time was worth getting the valves set right.

 

thats fine on a hyd. cam...but on a solid you have to do it one valve at a time....

to do a cyl. do the intake when the ex is first openind. do the ex when the intake starts to close.

A hyd. may need to be doen that way also if it is a big cam.

 

on shoebox's website it also has a chart telling you how to find TDC.. If your crank pully is keyed correctly, cylinders number 1 and 6 will be at TDC when the arrow is at twelve o clock. I just put new springs in and used this method so my valves would not fall in and it worked perfectly, valves hit the piston and do not fall in just as stated.

 

Thanks for all the help, I used Lloyd's method and it worked out pretty good I just lashed them a little tighter than last time. Yea the intake was on and when I put the crank pulley on I didnt index it. Ill let yall know how everything went when I get all the little stuff done. BTW for you guys using a scorpion rocker how tight do you set the rockers when your adjusting them.