Optispark.......Again

John Nechiporchik · 07-08-2015, 07:43 PM

Some may recall that last year I had an optispark shatter in the shutdown area. After much discussion, I replaced the cap and rotor with MSD parts for this year.
Sunday, the car experienced another no start after a run.
We did a few quick checks at the track:
Checked for spark at #1 plug....OK
Checked for fuel delivery ....OK
Put timing light on and spun over with ignition on....Timing reading 100 degrees!
Took distributor cap off and rotor fell out. the rotor attaching screws were sheared clean off.
Since this was the second catastrophic failure with this base (Stock) distributor, I purchased a new MSD billet unit.
Installed the new unit.....same condition. Timing reading 100Degrees.
As this is the newer style LT1 distributor, it is driven by the cam pin. Therefore, it only installs one way.
I disassembled the car again to make sure there was no operator error. could not find any.
I called MSD to verify which terminal inside the cap actually fires #1.
I called twice , talked to two different "tech" reps, and got conflicting answers....after nearly begging them for help.
So, I'm unsure what to look for next.
FYI...the car has a FAST XFI 2.0 system. Since the winter rebuild and installation of the FAST System, we have around 15 passes on the car plus 10 chassis dyno runs.

Any help would be appreciated.

Thanks,
John

magnumv8 · 07-08-2015, 07:57 PM

according to the info I have.....

A - Cyl # 2

B _ Cyl # 4

C - Cyl # 6

D - Cyl # 8

E - Cyl # 1

F - Cyl # 3

G - Cyl # 5

H - Cyl # 7

hope this helps

D L Rambo......Stk 1300

joelster · 07-08-2015, 08:42 PM

You can install a vented optispark 3 ways. Only 1 is correct. The dowel pin has to go into the correct slot which looks a little different than the other 2.

This is the back of a vented Opti

Here is a comparison pic between the 2

Here is the correct place on the back of the vented opti which the dowel pin must go. His finger is pointing to the correct slot, it looks slightly different from the others:

You MUST loctite the screws onto the rotor, and tighten them hard. If you fail to do this, they will back out, then the rotor will wobble, shatter, or shear the bolt heads off. This happens a lot when people replace the cap and rotor.

joelster · 07-08-2015, 08:44 PM

Firing order on the outside:

John Nechiporchik · 07-08-2015, 09:02 PM

Thanks for the info.
I am specifically looking for which terminal on the inside of the distributor cap fires #1 cylinder. Because of the potted design of the cap, it does not line up like a conventional cap where the internal and external terminals line up.

The distributor was installed correctly to the cam dowel.
Let me clarify.... When the old distributor was in the car and the cap removed, the rotor was in approximately the 6 o'clock position with the damper set at 40 degrees BTDC. I was able to determine this even though the rotor screws were sheared off.
The new billet distributor , in the exact same crank/cam position, the rotor was in the 8 o'clock position. I assumed the old distributor suffered from getting re-phased during the breakage and as a result the new unit would drop in and solve the problem.no such luck.
So, I'm sure someone out there can help solve this .
Not sure if a bad crank trigger sensor would cause this.
BTW,the FAST timing map reads 34 degrees when cranking.

joelster · 07-08-2015, 09:24 PM

I see what you are saying now. You want to know what post on the inside of the cap is for cylinder number 1. Apply some current to each of the posts on the inside and attach a test light to the #1 output. When it lights up you'll have your answer.

John Nechiporchik · 07-08-2015, 09:54 PM

Great idea Joel. thanks for the idea.

John Nechiporchik · 07-08-2015, 10:27 PM

Joel, Test completed. The terminal that fires #1 cylinder is the one just between 6 and 7 o'clock if you are looking at the distributor cap from the front of the engine.
Science project complete!
Thanks again for the idea.
Now to solve the macro problem.

John Nechiporchik · 07-09-2015, 02:51 PM

Problem resolve and car is running.
The MSD Billet distributor can be improperly installed by allowing the cam dowel pin to drop into one of the cam bolt holes on the rear of the distributor instead of the designated dowel slot. Interestingly the cam bolts all cleared as the dist. bolted up without any interference. This caused the rotor to be out of phase resulting in the no start.
When I initially installed it , I grabbed the rotor and tried to turn it and it did not move. I failed to turn it in the other direction which would have indicated to me the dist. was improperly installed.
Live and learn....sometimes the hard way.

07-08-2015, 07:57 PM	#2
magnumv8 Member Join Date: Feb 2009 Location: Coraopolis, Pa. Posts: 172 Likes: 0 Liked 0 Times in 0 Posts	Re: Optispark.......Again according to the info I have..... A - Cyl # 2 B _ Cyl # 4 C - Cyl # 6 D - Cyl # 8 E - Cyl # 1 F - Cyl # 3 G - Cyl # 5 H - Cyl # 7 hope this helps D L Rambo......Stk 1300

07-08-2015, 08:42 PM	#3
joelster Member Join Date: Nov 2007 Location: Tonawanda, NY Posts: 106 Likes: 0 Liked 0 Times in 0 Posts	Re: Optispark.......Again You can install a vented optispark 3 ways. Only 1 is correct. The dowel pin has to go into the correct slot which looks a little different than the other 2. This is the back of a vented Opti Here is a comparison pic between the 2 Here is the correct place on the back of the vented opti which the dowel pin must go. His finger is pointing to the correct slot, it looks slightly different from the others: You MUST loctite the screws onto the rotor, and tighten them hard. If you fail to do this, they will back out, then the rotor will wobble, shatter, or shear the bolt heads off. This happens a lot when people replace the cap and rotor.

07-08-2015, 08:44 PM	#4
joelster Member Join Date: Nov 2007 Location: Tonawanda, NY Posts: 106 Likes: 0 Liked 0 Times in 0 Posts	Re: Optispark.......Again Firing order on the outside:

07-08-2015, 09:02 PM	#5
John Nechiporchik Member Join Date: Mar 2007 Location: Grosse Ile Mi. Posts: 316 Likes: 84 Liked 13 Times in 7 Posts	Re: Optispark.......Again Thanks for the info. I am specifically looking for which terminal on the inside of the distributor cap fires #1 cylinder. Because of the potted design of the cap, it does not line up like a conventional cap where the internal and external terminals line up. The distributor was installed correctly to the cam dowel. Let me clarify.... When the old distributor was in the car and the cap removed, the rotor was in approximately the 6 o'clock position with the damper set at 40 degrees BTDC. I was able to determine this even though the rotor screws were sheared off. The new billet distributor , in the exact same crank/cam position, the rotor was in the 8 o'clock position. I assumed the old distributor suffered from getting re-phased during the breakage and as a result the new unit would drop in and solve the problem.no such luck. So, I'm sure someone out there can help solve this . Not sure if a bad crank trigger sensor would cause this. BTW,the FAST timing map reads 34 degrees when cranking.

07-08-2015, 09:24 PM	#6
joelster Member Join Date: Nov 2007 Location: Tonawanda, NY Posts: 106 Likes: 0 Liked 0 Times in 0 Posts	Re: Optispark.......Again I see what you are saying now. You want to know what post on the inside of the cap is for cylinder number 1. Apply some current to each of the posts on the inside and attach a test light to the #1 output. When it lights up you'll have your answer.

07-08-2015, 07:43 PM	#1
John Nechiporchik Member Join Date: Mar 2007 Location: Grosse Ile Mi. Posts: 316 Likes: 84 Liked 13 Times in 7 Posts	Optispark.......Again Some may recall that last year I had an optispark shatter in the shutdown area. After much discussion, I replaced the cap and rotor with MSD parts for this year. Sunday, the car experienced another no start after a run. We did a few quick checks at the track: Checked for spark at #1 plug....OK Checked for fuel delivery ....OK Put timing light on and spun over with ignition on....Timing reading 100 degrees! Took distributor cap off and rotor fell out. the rotor attaching screws were sheared clean off. Since this was the second catastrophic failure with this base (Stock) distributor, I purchased a new MSD billet unit. Installed the new unit.....same condition. Timing reading 100Degrees. As this is the newer style LT1 distributor, it is driven by the cam pin. Therefore, it only installs one way. I disassembled the car again to make sure there was no operator error. could not find any. I called MSD to verify which terminal inside the cap actually fires #1. I called twice , talked to two different "tech" reps, and got conflicting answers....after nearly begging them for help. So, I'm unsure what to look for next. FYI...the car has a FAST XFI 2.0 system. Since the winter rebuild and installation of the FAST System, we have around 15 passes on the car plus 10 chassis dyno runs. Any help would be appreciated. Thanks, John

07-08-2015, 09:54 PM	#7
John Nechiporchik Member Join Date: Mar 2007 Location: Grosse Ile Mi. Posts: 316 Likes: 84 Liked 13 Times in 7 Posts	Re: Optispark.......Again Great idea Joel. thanks for the idea.

07-08-2015, 10:27 PM	#8
John Nechiporchik Member Join Date: Mar 2007 Location: Grosse Ile Mi. Posts: 316 Likes: 84 Liked 13 Times in 7 Posts	Re: Optispark.......Again Joel, Test completed. The terminal that fires #1 cylinder is the one just between 6 and 7 o'clock if you are looking at the distributor cap from the front of the engine. Science project complete! Thanks again for the idea. Now to solve the macro problem.

07-09-2015, 02:51 PM	#9
John Nechiporchik Member Join Date: Mar 2007 Location: Grosse Ile Mi. Posts: 316 Likes: 84 Liked 13 Times in 7 Posts	Re: Optispark.......Again Problem resolve and car is running. The MSD Billet distributor can be improperly installed by allowing the cam dowel pin to drop into one of the cam bolt holes on the rear of the distributor instead of the designated dowel slot. Interestingly the cam bolts all cleared as the dist. bolted up without any interference. This caused the rotor to be out of phase resulting in the no start. When I initially installed it , I grabbed the rotor and tried to turn it and it did not move. I failed to turn it in the other direction which would have indicated to me the dist. was improperly installed. Live and learn....sometimes the hard way.