Head Question

SuPrADr1Ft786

New Member
Apr 5, 2005
62
0
0
38
Davenport, Florida, United States
Hey whats up, hows the head suppose to be when set to Top Dead Center, the block is set to TDC but the head isn't, in other words how would the valves be like. I mean i put the cam gears in and I aligned it to the line thats on the rear timming belt cover and i look at the valves and it doesnt look right, i dont know if my camshafts are put on wrong or what. I know the guy that rebuilt my motor took my valves off to polish them and i dont know what else, so I'm lost as to what I have to do, i just want to try to time the motor while the motor is apart, or that isnt possible??? I know before I took the motor apart it was set at TDC, so I have no clue as to what it could be.

example. in TDC piston number 1 and 6 are in its highest point correct??? If so would the valves for piston 1 and 6 be open or closed and if so, is it the intake or exhaust side??? Hope I didnt lose anybody, hope u guys can help me out, thanks in advance

Also when you take out the stock head bolts and theres these spacer things would I still need it even if I go with ARP head studs??? If I do need them, what are the part numbers
 

Stretch

Tallest MK3 driver ever!!
Mar 30, 2005
1,275
0
36
37
Toronto, Ontario
OK, Take a deep breath :icon_bigg
The pistons 1 and 6 are up you say, so this means they are pushing the gasses out, so your exhaust valve would be open, the smaller one on the passenger side of block as it has to let the gasses out. Your intake valve is probably gona be open a bit too, because the piston is at the top of the stroke so it has to push down right after and needs more combustibles to do so and the intake valve lets those guys in. Those little spacer things are for the factory bolts, they're washers, most likely so the bolts don't mess up the aluminum or over time don't make it soft or otherweise ruin the holes. I'm sure your ARP bolts or studs, whichever you choose to buy will come with their own set of washers. If they don't then they will tell you i nthe instructions weither you should use your stock pieces. Most likely if they don't provide new ones you don't need them, but I'm just saying I always thought they did. So anything else?
eric
 
R

revolutionary

Guest
Remember that the cam turns at half the speed of the crank so when the crank is at TDC your #1 cylinder can be either at TDC compression OR TDS split overlap (both intake and ex valves are open) depending which cycle you are on. Don't worry about what is going on at any other cylinder than #1. About every engine is set so that when you set up the timing gears the engine is at TDC compression (both valves closed)

As a side note, when #1 is at TDC compression, then #6 is at TDC split overlap and vise-versa.