first timer timing question, is OT what i want to see?

[1971Ginger]

I'm trying to get my car properly timed through the use of a timing light. I searched and tried to.understand the process (I think I got it) but I had a question.

do I want to see the " OT " when the strobe flashes? I should idle somewhere around a 1000 k?

pardon the dumb questions

[Kidasters]

I'm trying to get my car properly timed through the use of a timing light. I searched and tried to.understand the process (I think I got it) but I had a question.

do I want to see the " OT " when the strobe flashes? I should idle somewhere around a 1000 k?

pardon the dumb questions

If you don't know, it's not a dumb question.

I haven't looked at timing marks for awhile. I can't remember what's at TDC, and what's where.

But here's my question - are you using an adjustable timing light? If so, you can dial in the proper amount of advance, and you should see the TDC mark, either on the flywheel or crank pulley.

If you aren't, you should see the proper advance mark at the proper spot. I can't remember what either is right now, but it's in all of the manuals (haynes, shop manual, etc...).

Good Luck.

Ken

[Denis]

[BillWilliams]

You are looking for a BB for the timing mark

[1971Ginger]

this is what has me confused. I had it hitting the OT but if that's too late then do I need to back. it down?

I do have a timing light with an advanced feature.

[BillWilliams]

You may be ok, it looks like the OT was for late cars and the BB is for early cars.

[austinmf]

what do the OT marks signify?  the BB is zero TDC   what is the OT?  What other marks are on the flywheel?  I see the BB and a line or hash mark.

 

My pulley is custom and the point is long gone....

[Hans]

OT is German for TDC. There are two possible places where you will find this on the engine - either the front pulley and/or on the flywheel visible through a hole in the bell housing above the starter. On the flywheel, as shown in the pics, you will also see a "ball" pressed into the flywheel marked Z, which again is something German for "timing point". With a timing light, you want to see the ball on the flywheel through the hole at around 2200 rpm (I don't have the specs in front of me but that's close enough). On the front pulley, there may or may not be a Z mark, but you can paint one on.

 

To your question, by 1000 rpm, advance has already started, so if you set it on the OT, you do not have enough advance. You can use the OT to set what is known as static advance, which is done witht the engine off. Turning motor "by hand", the idea is to have # 1 fire as OT goes by. Harbor Freight sells a timing light that will allow you to set advance based on the OT mark. Do you have vacuum advance on your car? Someone else can advise on whether you set timing with that disconnected. I only know non-vacuum advance set-up.

 

If you're going to keep your 2002, might I suggest you ask Santa for a Haynes manual which shows how to do this and gives the correct specs for your model.

[M3M3]

what do the OT marks signify?  the BB is zero TDC   what is the OT?  What other marks are on the flywheel?  I see the BB and a line or hash mark.

 

My pulley is custom and the point is long gone....

the BB is not TDC, OT is TDC.   the BB represents the stock timing advance at the prescribed RPM for the engine.  if you have a "dumb" old style timing light, you use the BB.  if you have an adjustable timing light, you use the OT mark.

 

many threads already describing this found with a simple search on "timing mark".

Edited December 19, 2013 by mlytle

[70deluxe]

the BB is not TDC, OT is TDC.   the BB represents the stock timing advance at the prescribed RPM for the engine.  if you have a "dumb" old style timing light, you use the BB.  if you have an adjustable timing light, you use the OT mark.

 

many threads already describing this found with a simple search on "timing mark".

 

 

with authority!

[austinmf]

Thank you Hans and Marshall.   I do have an adjustable timing gun and the haynes shop manual.  

 

I also have EDIS and megasquirt.  

 

I am confused about how they interact (software running the car) but I think I just figured it out.... kind of miss the distributor... timing adjustments were so easy...

 

Motor still is not spot on but I am real close... megasquirt is definitely not plug and play!

[dbmw2002]

No worries mate, Marshall gets that way sometimes, I think he needs a walkabout

[eurotrash]

correct me if I'm totally wrong here, but...

 

If you want full advance (34 degrees in this example) at 2500, 3000,  or whatever rpm, set your light to 9 degrees advanced.  Hold the rpm to the desired number, and set timing to the ball. 

 

The ball is 25 degrees BTDC + the nine at the light = 34 @ X-RPM.

[Hans]

Good point, eurotrash, on setting for total advance. I though it best to get the basic setting done first as a benchmark. But yes, between 33 -36 deg total advance by about 3k rpm is the target. I just painted a line at 33 on my front pulley, but I got to get one of those new fangled timing lights. Are we dealing with a vacuum advance distributor here? You could also just add 34 deg to OT mark

[M3M3]

correct me if I'm totally wrong here, but...

 

If you want full advance (34 degrees in this example) at 2500, 3000,  or whatever rpm, set your light to 9 degrees advanced.  Hold the rpm to the desired number, and set timing to the ball. 

 

The ball is 25 degrees BTDC + the nine at the light = 34 @ X-RPM.

of course, since a digital timing light is needed for this method, you can skip all the math and just set the timing light for desired full advance (in this example 34deg)  and time off the OT mark on flywheel or crank pulley.  don't bother with the ball mark and eliminate the chance for math error/confusion.  keep it simple.

Edited December 19, 2013 by mlytle