New Optispark fails after 50 miles
11-13-2018, 01:06 PM
#21
Race Director
Hello from the Optidoctor on ebay,
I offer to rebuild/refurbish any of my optisparks at no cost to the buyer. I do this for two reasons:
1. I believe it is excellent customer service.
2. We can both learn what created the failure and address it.
I offer the free rebuild service for as long as you own your LT-1. As a result, I have learned a lot about these distributors over the past 2 years. For example: A few Optispark II's have come back full of oil. I noted that they were all AC Delco rebuilds and that they leaked air through the bearing area. I evolved my rebuild process to address this issue. Interestingly, the problem was created by Cardone/AC Delco when the base plate is rebuilt.. They inadvertently create an opportunity for a large air leak. Then, the bearing area becomes an easier path for air flow compared to the intake hose and you end up breathing air from the timing chain cover area instead of the clean air from the engine air duct.
I offer to rebuild/refurbish any of my optisparks at no cost to the buyer. I do this for two reasons:
1. I believe it is excellent customer service.
2. We can both learn what created the failure and address it.
I offer the free rebuild service for as long as you own your LT-1. As a result, I have learned a lot about these distributors over the past 2 years. For example: A few Optispark II's have come back full of oil. I noted that they were all AC Delco rebuilds and that they leaked air through the bearing area. I evolved my rebuild process to address this issue. Interestingly, the problem was created by Cardone/AC Delco when the base plate is rebuilt.. They inadvertently create an opportunity for a large air leak. Then, the bearing area becomes an easier path for air flow compared to the intake hose and you end up breathing air from the timing chain cover area instead of the clean air from the engine air duct.
11-13-2018, 01:07 PM
#22
Race Director
Hello from the Optidoctor on ebay,
I offer to rebuild/refurbish any of my optisparks at no cost to the buyer. I do this for two reasons:
1. I believe it is excellent customer service.
2. We can both learn what created the failure and address it.
I offer the free rebuild service for as long as you own your LT-1. As a result, I have learned a lot about these distributors over the past 2 years. For example: A few Optispark II's have come back full of oil. I noted that they were all AC Delco rebuilds and that they leaked air through the bearing area. I evolved my rebuild process to address this issue. Interestingly, the problem was created by Cardone/AC Delco when the base plate is rebuilt.. They inadvertently create an opportunity for a large air leak. Then, the bearing area becomes an easier path for air flow compared to the intake hose and you end up breathing air from the timing chain cover area instead of the clean air from the engine air duct.
I offer to rebuild/refurbish any of my optisparks at no cost to the buyer. I do this for two reasons:
1. I believe it is excellent customer service.
2. We can both learn what created the failure and address it.
I offer the free rebuild service for as long as you own your LT-1. As a result, I have learned a lot about these distributors over the past 2 years. For example: A few Optispark II's have come back full of oil. I noted that they were all AC Delco rebuilds and that they leaked air through the bearing area. I evolved my rebuild process to address this issue. Interestingly, the problem was created by Cardone/AC Delco when the base plate is rebuilt.. They inadvertently create an opportunity for a large air leak. Then, the bearing area becomes an easier path for air flow compared to the intake hose and you end up breathing air from the timing chain cover area instead of the clean air from the engine air duct.
I typically smear rtv silicone around the bearing shoulders - from the back side, to avoid oil coming in from around any gap between the bearing and machined housing that may exist.
11-13-2018, 01:21 PM
#23
Some one asked about the bearing. Luckily, the Optispark I uses a single shouldered bearing. Unfortunately, the Optispark II uses the double shouldered construction.
The double shouldered bearing is not available. I spent a significant amount of time looking for it. It is possible to use the single shouldered bearing on an Optispark II, but it's difficult to get it assembled without the wobble characteristic that you encountered. A jig that presses the assembly together helps significantly. A jig is also useful for retaining the timing which is critical. I created a construction that works perfectly. Another problem that you run into with the single shouldered bearing is during install. If the Optispark is installed with the cloverleaf slot mis-aligned with the cam pin, the cloverleaf drive is pushed into the Optical disk mount. The gap that is created by the missing shoulder allows this movement. Then, the drive now has a new position relative to the optical disk. After correcting the install alignment issue, the Optispark is doomed as the optical disk will rub on the sensor.
The double shouldered bearing is not available. I spent a significant amount of time looking for it. It is possible to use the single shouldered bearing on an Optispark II, but it's difficult to get it assembled without the wobble characteristic that you encountered. A jig that presses the assembly together helps significantly. A jig is also useful for retaining the timing which is critical. I created a construction that works perfectly. Another problem that you run into with the single shouldered bearing is during install. If the Optispark is installed with the cloverleaf slot mis-aligned with the cam pin, the cloverleaf drive is pushed into the Optical disk mount. The gap that is created by the missing shoulder allows this movement. Then, the drive now has a new position relative to the optical disk. After correcting the install alignment issue, the Optispark is doomed as the optical disk will rub on the sensor.
Last edited by Optidoctor; 11-13-2018 at 01:32 PM. Reason: Clarification
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11-13-2018, 02:16 PM
#24
Safety Car
Does anyone have a picture (or one to take a pic of ) the double shouldered bearing ? I would like to see what they look like and how they go into the unit.
11-13-2018, 07:57 PM
#26
Here is how you gain some confidence: Take the fresh air supply hose (to the optispark II) out of the engine air duct. Place a small piece of paper over the end of the hose (size of a pencil eraser). With the engine at idle, see if the paper is held onto the end of the hose by the slight pull of the ventilation system. If it is, you're in good shape. If the paper easily falls off the hose, your optispark II is not sealed and it is freely drawing air from other places. Don't spend much time with the supply hose plugged and don't use your finger to test it. The slight vacuum will accumulate over time and become quite a force. You wouldn't want to pull on it hard and create a leak while testing it.
This test will show that your optical sensor is probably clean and dry because your ventilation system is drawing clean, dry air into it from the engine air duct. The high voltage side could develop an issue (like the OP encountered), but I notice the common failure is an optical sensor that can not see the optical disk.
I hope this helps.
Brad
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11-13-2018, 08:21 PM
#27
Melting Slicks
Here is a tip (along with some background) that should give you some confidence in your optispark II: The 1st generation optispark suffers from poor ventilation which leads to corrosion. I frequently get optispark I cores that look like a science experiment inside. The corrosion creates a very dirty environment that eventually prevents the optical sensor from being able to see the disk. The optispark II in your 96 will not have that problem. I rarely see significant corrosion in the optispark II cores. If your optispark II fails, it's most likely going to be full of oil or antifreeze. So, here we are: Oil or antifreeze inside an optispark I is rare, while it's common in the II. Corrosion is common in the I and rarely exists in the II. The reason for the difference is the forced air ventilation system on the optispark II. The slight vacuum that is pulled on the optispark II forces it to seek fresh air. The supplied inlet hose is the design intention to supply this fresh air, but it will take it from the easiest place it can find. Keep in mind that the pressure inside the engine air supply duct is below ambient pressure. This makes ambient air more appealing as a source to supply air. As the optispark gets older, it will lose its sealed status and the forced air ventilation system will start to draw from other places. One popular place is the bearing area. It sits right on the timing chain cover where all the leaking oil is hanging out. Another weak area is the seal between the base plate and plastic center section just below the water pump drive shaft. MSD addressed this area by adding another bolt to secure the base plate firmly to the center section and cap.
Here is how you gain some confidence: Take the fresh air supply hose (to the optispark II) out of the engine air duct. Place a small piece of paper over the end of the hose (size of a pencil eraser). With the engine at idle, see if the paper is held onto the end of the hose by the slight pull of the ventilation system. If it is, you're in good shape. If the paper easily falls off the hose, your optispark II is not sealed and it is freely drawing air from other places. Don't spend much time with the supply hose plugged and don't use your finger to test it. The slight vacuum will accumulate over time and become quite a force. You wouldn't want to pull on it hard and create a leak while testing it.
This test will show that your optical sensor is probably clean and dry because your ventilation system is drawing clean, dry air into it from the engine air duct. The high voltage side could develop an issue (like the OP encountered), but I notice the common failure is an optical sensor that can not see the optical disk.
I hope this helps.
Brad
Here is how you gain some confidence: Take the fresh air supply hose (to the optispark II) out of the engine air duct. Place a small piece of paper over the end of the hose (size of a pencil eraser). With the engine at idle, see if the paper is held onto the end of the hose by the slight pull of the ventilation system. If it is, you're in good shape. If the paper easily falls off the hose, your optispark II is not sealed and it is freely drawing air from other places. Don't spend much time with the supply hose plugged and don't use your finger to test it. The slight vacuum will accumulate over time and become quite a force. You wouldn't want to pull on it hard and create a leak while testing it.
This test will show that your optical sensor is probably clean and dry because your ventilation system is drawing clean, dry air into it from the engine air duct. The high voltage side could develop an issue (like the OP encountered), but I notice the common failure is an optical sensor that can not see the optical disk.
I hope this helps.
Brad
What also is nice about the MSD Cap is that it converts the Opti I to a vented system. Just took apart my 2 year AIP with MSD cap (converting to pin drive) and it looked brand new inside.
Steve
11-13-2018, 09:01 PM
#28
Race Director
Here is a tip (along with some background) that should give you some confidence in your optispark II: The 1st generation optispark suffers from poor ventilation which leads to corrosion. I frequently get optispark I cores that look like a science experiment inside. The corrosion creates a very dirty environment that eventually prevents the optical sensor from being able to see the disk. The optispark II in your 96 will not have that problem. I rarely see significant corrosion in the optispark II cores. If your optispark II fails, it's most likely going to be full of oil or antifreeze. So, here we are: Oil or antifreeze inside an optispark I is rare, while it's common in the II. Corrosion is common in the I and rarely exists in the II. The reason for the difference is the forced air ventilation system on the optispark II. The slight vacuum that is pulled on the optispark II forces it to seek fresh air. The supplied inlet hose is the design intention to supply this fresh air, but it will take it from the easiest place it can find. Keep in mind that the pressure inside the engine air supply duct is below ambient pressure. This makes ambient air more appealing as a source to supply air. As the optispark gets older, it will lose its sealed status and the forced air ventilation system will start to draw from other places. One popular place is the bearing area. It sits right on the timing chain cover where all the leaking oil is hanging out. Another weak area is the seal between the base plate and plastic center section just below the water pump drive shaft. MSD addressed this area by adding another bolt to secure the base plate firmly to the center section and cap.
Here is how you gain some confidence: Take the fresh air supply hose (to the optispark II) out of the engine air duct. Place a small piece of paper over the end of the hose (size of a pencil eraser). With the engine at idle, see if the paper is held onto the end of the hose by the slight pull of the ventilation system. If it is, you're in good shape. If the paper easily falls off the hose, your optispark II is not sealed and it is freely drawing air from other places. Don't spend much time with the supply hose plugged and don't use your finger to test it. The slight vacuum will accumulate over time and become quite a force. You wouldn't want to pull on it hard and create a leak while testing it.
This test will show that your optical sensor is probably clean and dry because your ventilation system is drawing clean, dry air into it from the engine air duct. The high voltage side could develop an issue (like the OP encountered), but I notice the common failure is an optical sensor that can not see the optical disk.
I hope this helps.
Brad
Here is how you gain some confidence: Take the fresh air supply hose (to the optispark II) out of the engine air duct. Place a small piece of paper over the end of the hose (size of a pencil eraser). With the engine at idle, see if the paper is held onto the end of the hose by the slight pull of the ventilation system. If it is, you're in good shape. If the paper easily falls off the hose, your optispark II is not sealed and it is freely drawing air from other places. Don't spend much time with the supply hose plugged and don't use your finger to test it. The slight vacuum will accumulate over time and become quite a force. You wouldn't want to pull on it hard and create a leak while testing it.
This test will show that your optical sensor is probably clean and dry because your ventilation system is drawing clean, dry air into it from the engine air duct. The high voltage side could develop an issue (like the OP encountered), but I notice the common failure is an optical sensor that can not see the optical disk.
I hope this helps.
Brad
and this confirms what i have long said.
the gen 2 optispark doesnt fail unless its ventilation system fails.
The only real maintenance is replacement of the cap/rotor - which suitable replacements are readily available
sure theres freak bearing issues, but i guess you can get hit by a meteor, have a hole open up and swallow you up, and also have a tiny chance of winning the lottery.
Last edited by dizwiz24; 11-13-2018 at 09:02 PM.
11-13-2018, 10:29 PM
#29
Le Mans Master
Member Since: Oct 2002
Location: Las Vegas - Just stop perpetuating myths please.
Posts: 7,098
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Here is a tip (along with some background) that should give you some confidence in your optispark II: The 1st generation optispark suffers from poor ventilation which leads to corrosion. I frequently get optispark I cores that look like a science experiment inside. The corrosion creates a very dirty environment that eventually prevents the optical sensor from being able to see the disk. The optispark II in your 96 will not have that problem. I rarely see significant corrosion in the optispark II cores. If your optispark II fails, it's most likely going to be full of oil or antifreeze. So, here we are: Oil or antifreeze inside an optispark I is rare, while it's common in the II. Corrosion is common in the I and rarely exists in the II. The reason for the difference is the forced air ventilation system on the optispark II. The slight vacuum that is pulled on the optispark II forces it to seek fresh air. The supplied inlet hose is the design intention to supply this fresh air, but it will take it from the easiest place it can find. Keep in mind that the pressure inside the engine air supply duct is below ambient pressure. This makes ambient air more appealing as a source to supply air. As the optispark gets older, it will lose its sealed status and the forced air ventilation system will start to draw from other places. One popular place is the bearing area. It sits right on the timing chain cover where all the leaking oil is hanging out. Another weak area is the seal between the base plate and plastic center section just below the water pump drive shaft. MSD addressed this area by adding another bolt to secure the base plate firmly to the center section and cap.
Here is how you gain some confidence: Take the fresh air supply hose (to the optispark II) out of the engine air duct. Place a small piece of paper over the end of the hose (size of a pencil eraser). With the engine at idle, see if the paper is held onto the end of the hose by the slight pull of the ventilation system. If it is, you're in good shape. If the paper easily falls off the hose, your optispark II is not sealed and it is freely drawing air from other places. Don't spend much time with the supply hose plugged and don't use your finger to test it. The slight vacuum will accumulate over time and become quite a force. You wouldn't want to pull on it hard and create a leak while testing it.
This test will show that your optical sensor is probably clean and dry because your ventilation system is drawing clean, dry air into it from the engine air duct. The high voltage side could develop an issue (like the OP encountered), but I notice the common failure is an optical sensor that can not see the optical disk.
I hope this helps.
Brad
Here is how you gain some confidence: Take the fresh air supply hose (to the optispark II) out of the engine air duct. Place a small piece of paper over the end of the hose (size of a pencil eraser). With the engine at idle, see if the paper is held onto the end of the hose by the slight pull of the ventilation system. If it is, you're in good shape. If the paper easily falls off the hose, your optispark II is not sealed and it is freely drawing air from other places. Don't spend much time with the supply hose plugged and don't use your finger to test it. The slight vacuum will accumulate over time and become quite a force. You wouldn't want to pull on it hard and create a leak while testing it.
This test will show that your optical sensor is probably clean and dry because your ventilation system is drawing clean, dry air into it from the engine air duct. The high voltage side could develop an issue (like the OP encountered), but I notice the common failure is an optical sensor that can not see the optical disk.
I hope this helps.
Brad
Funny you describe the vacuum inside the Opti as I'm planning to measure that vacuum amount by tee'ing into the vacuum line between the Opti and the orifice restriction. I've got the idea a small positive pressure would be more reliable.
11-14-2018, 08:21 AM
#30
Drifting
Here is a tip (along with some background) that should give you some confidence in your optispark II: The 1st generation optispark suffers from poor ventilation which leads to corrosion. I frequently get optispark I cores that look like a science experiment inside. The corrosion creates a very dirty environment that eventually prevents the optical sensor from being able to see the disk. The optispark II in your 96 will not have that problem. I rarely see significant corrosion in the optispark II cores. If your optispark II fails, it's most likely going to be full of oil or antifreeze. So, here we are: Oil or antifreeze inside an optispark I is rare, while it's common in the II. Corrosion is common in the I and rarely exists in the II. The reason for the difference is the forced air ventilation system on the optispark II. The slight vacuum that is pulled on the optispark II forces it to seek fresh air. The supplied inlet hose is the design intention to supply this fresh air, but it will take it from the easiest place it can find. Keep in mind that the pressure inside the engine air supply duct is below ambient pressure. This makes ambient air more appealing as a source to supply air. As the optispark gets older, it will lose its sealed status and the forced air ventilation system will start to draw from other places. One popular place is the bearing area. It sits right on the timing chain cover where all the leaking oil is hanging out. Another weak area is the seal between the base plate and plastic center section just below the water pump drive shaft. MSD addressed this area by adding another bolt to secure the base plate firmly to the center section and cap.
Here is how you gain some confidence: Take the fresh air supply hose (to the optispark II) out of the engine air duct. Place a small piece of paper over the end of the hose (size of a pencil eraser). With the engine at idle, see if the paper is held onto the end of the hose by the slight pull of the ventilation system. If it is, you're in good shape. If the paper easily falls off the hose, your optispark II is not sealed and it is freely drawing air from other places. Don't spend much time with the supply hose plugged and don't use your finger to test it. The slight vacuum will accumulate over time and become quite a force. You wouldn't want to pull on it hard and create a leak while testing it.
This test will show that your optical sensor is probably clean and dry because your ventilation system is drawing clean, dry air into it from the engine air duct. The high voltage side could develop an issue (like the OP encountered), but I notice the common failure is an optical sensor that can not see the optical disk.
I hope this helps.
Brad
Here is how you gain some confidence: Take the fresh air supply hose (to the optispark II) out of the engine air duct. Place a small piece of paper over the end of the hose (size of a pencil eraser). With the engine at idle, see if the paper is held onto the end of the hose by the slight pull of the ventilation system. If it is, you're in good shape. If the paper easily falls off the hose, your optispark II is not sealed and it is freely drawing air from other places. Don't spend much time with the supply hose plugged and don't use your finger to test it. The slight vacuum will accumulate over time and become quite a force. You wouldn't want to pull on it hard and create a leak while testing it.
This test will show that your optical sensor is probably clean and dry because your ventilation system is drawing clean, dry air into it from the engine air duct. The high voltage side could develop an issue (like the OP encountered), but I notice the common failure is an optical sensor that can not see the optical disk.
I hope this helps.
Brad
Given the significance of the Optispark vacuum, I would prefer to read that data on the dash more than oil temp.
Having suffered not one, but TWO bearing failures, I am less concerned with the sensor than some.
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cardo0 (11-14-2018)
11-14-2018, 08:04 PM
#32
Yes, I see that too. It’s a slow process and the oil stains the plastic as it makes its way to the center of the Optispark and the rotating assembly that will eventually sling it into the optical sensor and shut everything down. I’d say 20% of the failures come through the connector.
11-14-2018, 08:22 PM
#33
Race Director
Here is a tip (along with some background) that should give you some confidence in your optispark II: The 1st generation optispark suffers from poor ventilation which leads to corrosion. I frequently get optispark I cores that look like a science experiment inside. The corrosion creates a very dirty environment that eventually prevents the optical sensor from being able to see the disk. The optispark II in your 96 will not have that problem. I rarely see significant corrosion in the optispark II cores. If your optispark II fails, it's most likely going to be full of oil or antifreeze. So, here we are: Oil or antifreeze inside an optispark I is rare, while it's common in the II. Corrosion is common in the I and rarely exists in the II. The reason for the difference is the forced air ventilation system on the optispark II. The slight vacuum that is pulled on the optispark II forces it to seek fresh air. The supplied inlet hose is the design intention to supply this fresh air, but it will take it from the easiest place it can find. Keep in mind that the pressure inside the engine air supply duct is below ambient pressure. This makes ambient air more appealing as a source to supply air. As the optispark gets older, it will lose its sealed status and the forced air ventilation system will start to draw from other places. One popular place is the bearing area. It sits right on the timing chain cover where all the leaking oil is hanging out. Another weak area is the seal between the base plate and plastic center section just below the water pump drive shaft. MSD addressed this area by adding another bolt to secure the base plate firmly to the center section and cap.
Here is how you gain some confidence: Take the fresh air supply hose (to the optispark II) out of the engine air duct. Place a small piece of paper over the end of the hose (size of a pencil eraser). With the engine at idle, see if the paper is held onto the end of the hose by the slight pull of the ventilation system. If it is, you're in good shape. If the paper easily falls off the hose, your optispark II is not sealed and it is freely drawing air from other places. Don't spend much time with the supply hose plugged and don't use your finger to test it. The slight vacuum will accumulate over time and become quite a force. You wouldn't want to pull on it hard and create a leak while testing it.
This test will show that your optical sensor is probably clean and dry because your ventilation system is drawing clean, dry air into it from the engine air duct. The high voltage side could develop an issue (like the OP encountered), but I notice the common failure is an optical sensor that can not see the optical disk.
I hope this helps.
Brad
Here is how you gain some confidence: Take the fresh air supply hose (to the optispark II) out of the engine air duct. Place a small piece of paper over the end of the hose (size of a pencil eraser). With the engine at idle, see if the paper is held onto the end of the hose by the slight pull of the ventilation system. If it is, you're in good shape. If the paper easily falls off the hose, your optispark II is not sealed and it is freely drawing air from other places. Don't spend much time with the supply hose plugged and don't use your finger to test it. The slight vacuum will accumulate over time and become quite a force. You wouldn't want to pull on it hard and create a leak while testing it.
This test will show that your optical sensor is probably clean and dry because your ventilation system is drawing clean, dry air into it from the engine air duct. The high voltage side could develop an issue (like the OP encountered), but I notice the common failure is an optical sensor that can not see the optical disk.
I hope this helps.
Brad
11-15-2018, 08:01 PM
#36
Melting Slicks
My optidoctor opti works perfect and has for thousands of miles. I also had him rebuild my original 1996 as a spare. I suspect I will never need it. I will do his test on the vent system with the small piece of paper.
11-18-2018, 11:49 AM
#37
Drifting
People who report that they had bearing failures were likely fooled by a bad coil.
11-18-2018, 06:46 PM
#38
Le Mans Master
I don't think that's true. It may be true for an OE opti being driven around on the street and rarely, if ever, seeing high-rpm running. But in an engine that sees lots of time high revs, the OE bearings do develop wear (like road course lapping sessions). Also, I think it's likely that replacement optis with made-in-China bearings will be far more likely to have a bearing fail, even from just normal street driving.
11-19-2018, 08:27 AM
#39
Safety Car
Lets cut to the chase OK guys and say what we the owners of the OPTI Corvette are really thinking ( What in the hell was GM thinking when they came up with this crap ) Just saying.. For all the time I have been left on side of the road for an OPTI failure and one was in a 95 with 37,000 miles on it .. I need a drink .. and I just brought another one and is a pretty Corvette and will look pretty sitting on side of the road when this OPTI decides to stop working .. Get the best OPTI you can buy and hope for the best .. Having AAA helps..
11-19-2018, 11:09 AM
#40
Pro
Thread Starter
What would be great is if the software can be reprogrammed so that when the high and/or low resolution signal is lost the engine will still continue to run in a "limp home mode". At least this will avoid a non-operational condition in a dangerous location. I'm sure that someone with the knowledge of the GM program language can make this happen and then sell the patch. These cars should be old enough so that most States will allow an exemption to the emissions laws (well except for California) that the patch will conflict with.
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radwebster (07-25-2020)