View Single Post
Old 11-19-2013, 07:02 PM   #37
Tx Firefighter
Watch out for your cornhole !
 
Tx Firefighter's Avatar
 
Join Date: Jun 2003
Location: Azle, Texas
Posts: 14,162
Re: Where do the dots go for TDC

Quote:
Originally Posted by 78maliburat View Post
so do i ...but some dont understand tdc dot aligned balancer line 0 on tab motor at tdc both valves closed it starts
That is correct. Every time.

I think there's something getting lost in the discussion here though.

That picture of crank at 12 and cam at 6, is TDC, but it's the TDC valve open. You turn the crankshaft one complete turn until the crank dot is again pointing up at 12 o clock. Except now, the cam dot will also be pointing at 12 o clock. Now you're at TDC, compression both valves closed.

The crank sprocket is exactly half the size of the cam sprocket. Every complete turn of the crank only turns the cam half a turn.

To time the engine internally, ie crank to cam relationship, you can do either 12/12 method or 12/6 method. Both are right. Do one and turn the engine a complete turn and you'll have the other. It's only when you want to drop distributor into place that you need to either verify 12/12 positioning or check for compression at the number one hole, or line up balancer and watch both valves closed.

It's just so easy to line up crank and cam at 12/6 orientation and either drop distributor pointing at number 6 wire or turn the engine a complete turn and drop distributor pointing at number 1 wire. That way you don't have to watch valves, stick your thumb in plug hole for compression, or even have the harmonic balancer installed onto the engine yet.
__________________
I'm on the Instagram- @Gearhead_Kevin
Tx Firefighter is offline   Reply With Quote