Mr Gasket timing tape problems!!!

[k5ren]

I bought the Mr. Gasket #1593 timing tape for the 383's 7.25" balancer and discovered a huge discrepancy in the marks and length around the circumference!
First thing I noticed was that the 0° and 360° marks did not meet at TDC. 180° did not meet the centerline of the balancer.
So I got online and found a site to "print your own" timing tapes and found that I could also print out a 7.25" 360° protractor to lay on top of the balancer so that I could double check the marks.
@ 90°, the tape is short by 10°.
In the fourth photo, the mark on the right is the 360° mark and should meet at the TDC mark on the left.
Last pic shows that when I set my TOTAL timing at 36° it falls short of that by 4°!!

Please tell me that I haven't lost my mind already!
HUGE Issue!!

.

 

[Daves69]

I believe it works like this for a 7-1/4" diameter balancer.

1/16" = 1°

Set up and find true TDC for #1 cylinder.

Carefully scribe the balancer OD for TDC and ALSO the inner ring to use as a visual aid for outer ring slippage.

2-3/8" from TDC should be 38°

2-1/4" from TDC should be 36°

 

[33 IMP]

I believe it works like this for a 7-1/4" diameter balancer.

1/16" = 1°

Set up and find true TDC for #1 cylinder.

Carefully scribe the balancer OD for TDC and ALSO the inner ring to use as a visual aid for outer ring slippage.

2-3/8" from TDC should be 38°

2-1/4" from TDC should be 36°

That's close enough. I get .003 short of 2 9/32 for 36°.
NOT saying this is what you did, but lots of people stretch those tapes to try to get them on tight, so they dont fall off.
Circumfrence of balancer equals pi x dia. Single degree is that result ÷ 360. Then take that number x whatever degree # you want.
3.14159x7.25=22.7765...etc
22 7765etc÷360 = .063268etc. times 36° =2.277etc, .004 short of 2.281, 2 9/32.

 

[pnora]

You would think the tape should be 22.765 inches long. Did you measure the circumference of your balancer.

 

[k5ren]

You would think the tape should be 22.765 inches long. Did you measure the circumference of your balancer.

Circumference measures just over 22.75"
As should the tape ....

 

[Fran Blacker]

If you had one that goes around the OD and it was to long make a copy reducing the size. Reduce to say 95% to long try 90% to short 93% etc.

 

[k5ren]

NOT saying this is what you did, but lots of people stretch those tapes to try to get them on tight, so they dont fall off.

33. Definitely not stretched. it's short

 

[k5ren]

"Make your Own" timing Tape link...

https://www.blocklayer.com/timing-tapeeng.aspx

 

[k5ren]

If you had one that goes around the OD and it was to long make a copy reducing the size. Reduce to say 95% to long try 90% to short 93% etc.

Here is an actual size PDF file to take to the print shop for a 7.25" tape.
I'll have a friend print this off for me.

 

[69Bee]

Arc Length = S
Angle = Theta in radians
Radians = (pi * deg)/180
r = radius

S = r * theta
= 3.625" * ((pi * 38 deg) / 180)
= 2.4042"

S = 3.625" * ((pi * 36 deg) / 180)
= 2.2777"

 

[k5ren]

Set up and find true TDC for #1 cylinder.

Carefully scribe the balancer OD for TDC and ALSO the inner ring to use as a visual aid for outer ring slippage.

That's good info Dave. Thanks
Yes, I used a piston stop and confirmed that line on balancer was, in fact, true TDC

 

[Runcharger]

36 degrees is 10% of the total circumference. Hard to do in inches but you could figure it in metric in about 3 seconds.

 

[440 Charger]

I bought the Mr. Gasket #1593 timing tape for the 383's 7.25" balancer and discovered a huge discrepancy in the marks and length around the circumference!
First thing I noticed was that the 0° and 360° marks did not meet at TDC. 180° did not meet the centerline of the balancer.
So I got online and found a site to "print your own" timing tapes and found that I could also print out a 7.25" 360° protractor to lay on top of the balancer so that I could double check the marks.
@ 90°, the tape is short by 10°.
In the fourth photo, the mark on the right is the 360° mark and should meet at the TDC mark on the left.
Last pic shows that when I set my TOTAL timing at 36° it falls short of that by 4°!!

Please tell me that I haven't lost my mind already!
HUGE Issue!!View attachment 1134668 View attachment 1134669 View attachment 1134670 View attachment 1134671 View attachment 1134672 View attachment 1134673



.

Time it by the feel and sound. Most like around 34 I have seen them run at 50 just do what you feel and hear these motors are ment for that .

 

[1967coronet]

Dial back timing light.

 

[68Dart470]

Yep, good timing light and be done with it. Those tapes fall off after first start typically anyways. Too much bs just to fall off.

 

[451Mopar]

Dial-back timing light:

https://www.summitracing.com/parts/ino-5568?rrec=true

 

[BSB67]

I would not use a dial back timing light unless you have a means to check its accuracy. I've only used two different dial-backs. But they were both wrong.

 

[beanhead]

Don't hate me for saying this...but you really need to consider a new balancer. The ones with marks out to 50°BTDC make setting timing a cinch. Your engine will thank you!

See this missing chunk? Good indication that the rubber is failing, which they all do after awhile. It's likely not doing it's job very well anymore, if at all...