351w timing mark.

[MikeKC130J]

Had the machine shop deg my cam, when I installed the harmonic balancer at top dead center it was set at 8* what does this actually mean to me? Timing and setting it up for timing well I’m definitely not keeping up with the class.

 

[EPB72]

?CRANK turn a little during balancer install?? If marks are in question (aftermarket damper??) TDC #1 cylinder recheck marks,,,Machine shop have damper during work they preformed if so maybe they have your answer.....8 degrees id think the crank turned a little during damper install first thought,,

 

[DirtDonk]

Yep, between you and the machinist, and their shop and your house, the engine has had more than plenty of opportunities to rotate slightly.
And maybe they didn't even bother to put it at TDC once done with their work, since they did not have the damper it sounds like.

But just as likely, or maybe even MORE likely, your damper and pointer are not matched up.
Remember Ford used at least two, or three different timing mark locations, and at least three or four different timing pointer designs and locations over the years.
Your pointer's location (it's not a stock Bronco pointer) could be from any number of different setups, but presumably it came with the 351 from the donor?

What you really need to do first is to determine if the engine is still at TDC and your marks don't match the pointer, or if the engine has simply rotated.
But yes, it does make an important difference to you. That knowledge is critical to knowing just what ignition timing you're setting when you adjust it.
Without knowing TDC, you'll never know to trust your numbers.

Paul

 

[DirtDonk]

I guess I should correct myself on the dire prediction and add that since it's an aftermarket damper/balancer, likely the numbers line up with whatever it's made to be compatible with. So if it's compatible with the donor engine and it's original pointer, then one would hope that you could trust the markings and you're simply set at 8° currently.

But it's still good to verify...

Paul

 

[B RON CO]

Hi, my guess is that you are fine with the balancer, and the timing mark.
You degree a cam with the balancer and usually the timing cover off of the engine.
I think that is just where they left it after they put it back together.
You can try to find true top dead center with a drinking straw on the #1 spark plug hole by turning the engine gently a few degrees back and forth.
Good luck

 

[MikeKC130J]

?CRANK turn a little during balancer install?? If marks are in question (aftermarket damper??) TDC #1 cylinder recheck marks,,,Machine shop have damper during work they preformed if so maybe they have your answer.....8 degrees id think the crank turned a little during damper install first thought,,

Yes aftermarket Dampner.

 

[MikeKC130J]

Yep, between you and the machinist, and their shop and your house, the engine has had more than plenty of opportunities to rotate slightly.
And maybe they didn't even bother to put it at TDC once done with their work, since they did not have the damper it sounds like.

But just as likely, or maybe even MORE likely, your damper and pointer are not matched up.
Remember Ford used at least two, or three different timing mark locations, and at least three or four different timing pointer designs and locations over the years.
Your pointer's location (it's not a stock Bronco pointer) could be from any number of different setups, but presumably it came with the 351 from the donor?

What you really need to do first is to determine if the engine is still at TDC and your marks don't match the pointer, or if the engine has simply rotated.
But yes, it does make an important difference to you. That knowledge is critical to knowing just what ignition timing you're setting when you adjust it.
Without knowing TDC, you'll never know to trust your numbers.

Paul

I am on TDC, the machine shop did have my dampner, the time pointer is original to the motor. 89 E350
Before I put the timing cover and water pump on I made sure the timing marks were livens up and the #1 piston was at the top of the cylinder by looking through the spark plug hole.

 

[DirtDonk]

Ok, then you need to either move your pointer so that it lines up with the zero, or re-number the damper ring using some timing-tape for the appropriate size.

It can be as simple as making a new mark and remembering what it means 10 years from now, or re-doing them with the timing tape and not worrying about correct timing ever again.
Frankly I'm kind of surprised that the damper was that far off of the pointer. I guess Ford had even more pointer positions that I thought!

But getting it right now, while the cover is off and the marks lined up, means less headache and head scratching later.

Paul

 

[blubuckaroo]

Frankly I'm kind of surprised that the damper was that far off of the pointer. Paul

I agree.
It's pretty hard to verify TDC through a spark plug hole. 8 degrees can happen pretty quickly when turning the engine over with a wrench.
I'd rather trust the existing timing marks, as long as it's the same balancer the shop used.

 

[rmk57]

I'd use a piston stop to verify tdc. Clockwise until it stops, mark the balancer then counter clockwise until it stops, mark the balancer. In between the two marks will be true tdc.

My fancy $300 sfi balancer was off by over 2 degrees.

 

[MikeKC130J]

I agree.
It's pretty hard to verify TDC through a spark plug hole.
I'd rather trust the existing timing marks, as long as it's the same balancer the shop used.

I did use the timing marks and looked through the spark plug hole.
It’s the same dampner they used at the Machine shop.
I’m going to the shop later today and ask them.