ATI Dampener Degrees (was Dumb Question number 455)

[DuckRyder]

I really do have to start writing stuff down.

ATI Dampner - consensus seems to be it is about 7 degrees off and i did verify this when i assembled the engine but i don't remember exactly which way....

So assuming 7 degrees off and i want 36 total actual do i want to align 29 or 43 with the pointer using my dial back light?

[blykins]

I'd adjust your pointer so that you never have to try and remember it. 

[JimNolan]

I spent over $200 with Damper Doctors in California to get my Balancer rebuilt. They sent me the wrong on and then said they threw my old one away. They finally got me the right style and I couldn't make the car run right. I checked the timing mark and it was 10 degrees retarded at TDC. I bought a new one made in Taiwan from AutoKrafters for $100 and it was perfect. Remember that name "Damper Doctor" and avoid it.

[DuckRyder]

I've got a new damper (professional products) to go on it when i change the cam.

[blykins]

I've got a new damper (professional products) to go on it when i change the cam.

That would be a significant downgrade.  You just need a pointer change.  I even have adjustable pointers where you could do it quickly.

[mike7570]

I have no idea if my ATI balancer is off or not nor which direction. Just take the time on any replacement to make a piston stop and find top dead center and go from there and like Brent said make a new pointer.
I wouldn’t rely on any 50-60 yr old engine parts mixed with some new items to come up with accurate markings to set the timing to.

[Rory428]

I ran ATI FE dampers on my 427 and 428 FEs for about 35 years, and yes they are about 7-8 degrees off, but all I did was to find true TDC, and ground away the factory steel timing pointer, until I had a new "point" at the correct position. No cost, and took a couple of minutes with the bench grinder.

[DuckRyder]

I've got a new damper (professional products) to go on it when i change the cam.

That would be a significant downgrade.  You just need a pointer change.  I even have adjustable pointers where you could do it quickly.

If i said the ATI is 20 years old would you still feel the same?

Ive gotta get some rocker shims anyhow, i'll get a pointer too.

I found my notes stuffed in a Christ book, looks like i determined true TDC was about the missile on my factory pointer, not very precise but it'll work for now.

[blykins]

I've got a new damper (professional products) to go on it when i change the cam.

That would be a significant downgrade.  You just need a pointer change.  I even have adjustable pointers where you could do it quickly.

If i said the ATI is 20 years old would you still feel the same?

Ive gotta get some rocker shims anyhow, i'll get a pointer too.

I found my notes stuffed in a Christ book, looks like i determined true TDC was about the missile on my factory pointer, not very precise but it'll work for now.

Yeah, I still think it would be a downgrade.  Not a Pro Products fan.  If you got a hankering for a new balancer, snag a Powerbond.

[DuckRyder]

Yeah, I still think it would be a downgrade.  Not a Pro Products fan.  If you got a hankering for a new balancer, snag a Powerbond.

OH wait, that's what i have... PB1111ST

I did say i need to write stuff down... 

[Falcon67]

On most of my 351Cs I've just painted a rebuilt damper semi-flat blank, installed, verified TDC, cleaned the damper surface and installed a Moroso timing tape. Removed the damper, gave 'em about 3 coats of clear spray and done.

It's been easy 20 years, but I used these guys to rebuild one - https://www.damperdudes.net/  It's still in good condition, even after being raced.  I switch to SFI type dampers if I'm going to be approaching 6500 or better on the track.  I've been around a cast iron ring separating from the center crank drive and it ain't pretty.  Been really close and damn lucky on two occasions. 

[1968galaxie]

Speaking of using old dampers.
I was sitting not far away in 1985 (I recall) an 1/8 mile drag race set up in the industrial section of a small southern Alberta city.
SBC powered rail, at the start line, brother had his hand on the engine to check temperature. His brother in the car revs the engine. The guy with his hand on the engine dropped like a rock. Dead as a door nail. Unbelievable! The damper came apart and ended up in this poor guys chest..... Was not a pretty sight.
Don't reuse old dampers - please.

[DuckRyder]

I really do have to start writing stuff down.

ATI Dampner - consensus seems to be it is about 7 degrees off and i did verify this when i assembled the engine but i don't remember exactly which way....

So assuming 7 degrees off and i want 36 total actual do i want to align 29 or 43 with the pointer using my dial back light?

Can we revisit this?

I don't have tools here to verify.

Lets assume its 7 degrees off, but which way are they usually off?

[blykins]

You can buy a piston stop for $5.   I'm not trying to be a smart aleck or crass, but the best way to know is to measure it yourself. 

[DuckRyder]

OK, Piston stop ordered - not 5 bucks....
 

[DuckRyder]

Im coming up with more like 17.5 degrees off vs the generally accepted about 7 degrees...

Can that be right? I don't see how i could mess this up but i seem to have an above average capacity for that recently...



Thanks Brent for pushing me to actually check it.

[blykins]

Adjustable pointer?  I've never seen one 17° off. 

Can you outline your procedure for checking where TDC is?

[DuckRyder]

Adjustable pointer?  I've never seen one 17° off. 

Can you outline your procedure for checking where TDC is?

Factory pointer from 1972 Truck. ( think you sent me an adjustable one, have to look.. but it definatly is not on the truck. )

I set it at 30 before on the compression stroke of number one... put piston stop in and turned it clockwise until it stopped and maked the first mark (i just used the edge of the pointer) so we can give them credit for a sharpie width)

Turned it counter clockwise until it stopped again - marked second mark again using the edge of the pointer.

Measured distance between two marks and placed mark halfway between at 0.



Added photo of pointer.

Also note there is a picture in prior post, they are taking a minute to load for me.

[blykins]

Are the hub/shell indexed correctly?

[DuckRyder]

I want to say it came assembled, but i'll have to pull the pulleys off and check i guess.

[cjshaker]

I've used 2 ATI balancers, and both were exactly 7* off, as seems to be the case with everyone who uses them (because they're actually made for BBC engines, IIRC). Your TDC method seems sound, and even giving a little leeway for chain slack, that number definitely seems to be off. Do you have a stock balancer to throw on to compare to?

[CaptCobrajet]

95% chance that TDC is at 353 on an ATI if you just bolt a stock pointer  on a stock timing cover.  Best to check for sure as others have said.   That being said, the answer to your question is your 36 you want will most likely be at 29 if you don't adjust it.

[DuckRyder]

I've used 2 ATI balancers, and both were exactly 7* off, as seems to be the case with everyone who uses them (because they're actually made for BBC engines, IIRC). Your TDC method seems sound, and even giving a little leeway for chain slack, that number definitely seems to be off. Do you have a stock balancer to throw on to compare to?

That seems more inline with what I remember that I saw when I checked before putting the heads on with a degree wheel. TDC landed somewhere in the aTi Logo.

I don't have a stock balancer on hand, but i do have a Powerbond. It appears the keyway is straight down at TDC or about 225 degrees. so if i put my keyway straight down i come up with TDC in the aTi Logo and the keyway seems to be at slightly less than 220 (218?) on the balancer.

Which if my math is right coincides with the 7 degrees we think it "should be".

I guess the question is how did I mess the numbers up with the piston stop?

95% chance that TDC is at 353 on an ATI if you just bolt a stock pointer  on a stock timing cover.  Best to check for sure as others have said.   That being said, the answer to your question is your 36 you want will most likely be at 29 if you don't adjust it.

Thank You

I think i'm going mark it as 353 = 0 and see how it runs.

I don't want to just throw the powerbond on because i think the spacer was shortened for the ATi and it is probably a better balancer anyway, degree marking not withstanding.

[My427stang]

Your procedure sounds good, the only thing I don't like is one side being dictated by screwing the stop in.

Now that it's together, bring the piston down, tighten the stop in a little bit more, and recreate your test by turning the engine one way until it stops, then the other.

I assume you may have already did that, but the way it was written concerns be that one side of it may be off.

The next thing would be to pull the balancer and see if the numbers come together with the new balancer., if you are still off it's likely you. 

One last comment, I see no benefit for that ATI for your application, if the second balancer lined up, I'd be done

[DuckRyder]

Thanks everyone:

I did it again and came up with 7 degrees.

I'm fairly confident in conjunction with the checking i did on the keyway that this is right, but cant explain why it came up different (i did it essentially the same way aside from starting earlier.)

<shrug>

Another picture: