SoCal Jet Boats

Tech Talk => Engine Mechanical / Electrical => Topic started by: el mojado on March 24, 2016, 11:13:39 PM

Title: Checking TDC
Post by: el mojado on March 24, 2016, 11:13:39 PM
I installed a brand new Summit balancer. I wanted to check TDC. I used a piston stop. Started at one end then turned the crank by hand the other way til it stopped. Then noted the half way point. I used a piece of small wire just above the 20° mark then turned and ended up at exactly the 40°mark. Turned the engine over to point the wire at 30° mark. My 0° mark lands at 2° ATDC. Does this sound normal? Is this any concern? Or do I just use that 2°ATDC as my 0° from now on?
Title: Re: Checking TDC
Post by: GT Jets on March 24, 2016, 11:34:14 PM
I installed a brand new Summit balancer. I wanted to check TDC. I used a piston stop. Started at one end then turned the crank by hand the other way til it stopped. Then noted the half way point. I used a piece of small wire just above the 20° mark then turned and ended up at exactly the 40°mark. Turned the engine over to point the wire at 30° mark. My 0° mark lands at 2° ATDC. Does this sound normal? Is this any concern? Or do I just use that 2°ATDC as my 0° from now on?


What timing tab?

GT
Title: Re: Checking TDC
Post by: el mojado on March 24, 2016, 11:34:44 PM
Oem timing cover
Title: Re: Checking TDC
Post by: el mojado on March 24, 2016, 11:49:45 PM

What timing tab?

GT
OEM cover and tab
Title: Re: Checking TDC
Post by: GT Jets on March 24, 2016, 11:56:00 PM
OEM cover and tab
Use White Out or a wrecking yard pen to make a new mark on the balancer...

You're going to think I'm an idiot, but I time off of cylinder 8 (on a Chevy, that is the cylinder after number one) and time it to that... Basically all the cylinders are 45 degrees apart, so for 36 degrees, you would use 9 degrees AFTC....
I know...Genius.

GT
Title: Re: Checking TDC
Post by: el mojado on March 25, 2016, 12:00:17 AM
I'm a little confused. I was thinking I would mark the tab where I measured actual TDC. Where 0°is on the balancer, I mark on the tab for actual TDC, and that would be where i measure with timing light. What am I missing?
Title: Re: Checking TDC
Post by: el mojado on March 25, 2016, 12:08:02 AM
I guess marking tab or balancer is the same, now that I think about it.
Title: Re: Checking TDC
Post by: aquaholic72 on March 25, 2016, 01:02:27 AM
This is how its done..O0

Your Friendly local v-drive owner

Title: Re: Checking TDC
Post by: el mojado on March 25, 2016, 01:08:19 AM
Got a video? I wanna be sure I do it right!
Title: Re: Checking TDC
Post by: aquaholic72 on March 25, 2016, 01:22:00 AM
Lol.. i was told you have to shotgun all the beers then give it hell.. O0

Your Friendly local v-drive owner

Title: Re: Checking TDC
Post by: aquaholic72 on March 25, 2016, 01:33:28 AM
On a serious note tho.. i always mark the timing tab. Your situation is exactly why they make adjustable timing tabs so you can set the tab at 0 to your balancer.. just my worthless 2 pennys..

Your Friendly local v-drive owner

Title: Re: Checking TDC
Post by: GT Jets on March 25, 2016, 08:48:20 AM
I doubt seriously it matters if you mark the tab versus the balancer, I just always mark the balancer anyway.

If you have available advance timing light, i expect it really don't matter. Maybe just pick up a timing tape for the balancer?

GT

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