Comitaus' Engine Failure
07-06-2006, 05:44 PM
#1
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Join Date: Jun 2003
Location: Grand Prairie, TX
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http://bdc.cyberosity.com/v/Tuning/Ohio_June06/
This link shows pictures and a couple videos of Luke's car from a tuning trip I just got back from a few days ago up in central Ohio. I did a few cars there; Luke's being the heaviest-load one. Today, he called me and told me it had popped while driving a relative of his around the neighbourhood. He had done a 12/13psi run (low boost setting for pump gas) here and there and then went up to the high boost setting (18.5psi). He said it stuttered once then sounded like a Harley at the top of 2nd gear in the 7k-8krpm range. Here's the specs:
- Half-bridgeport motor I built two years ago. Pictures of the assembly and porting work for reference can be found here http://bdc.cyberosity.com/v/Assembly/LukeWeber/ and here http://bdc.cyberosity.com/v/Porting/LukeWeber/ -- Series 5 motor w/ the smaller rear dowel pin land, 9.0:1 rotors, Rotary Aviation apex seals (2mm), etc.
- HKS TO4R w/ a custom divided manifold, twin Tial 38mm WG's, 3.5" exhaust, 1.32 A/R P-Trim turbine housing
- Plugs used were BUR9EQ's all around but am unsure if they were platinums or not
Luke's car is very well built considering the time and effort he has taken into constructing it. Good parts were used and there were no short-cuts taken.
We had the same kind of stuttering occur on the dyno at both low and high loads. On low loads, I had him setup to run about 12-13psi on 93octane pump gas and nothing higher. On higher loads, the sky was pretty much the limit as I knew the next limiting factor would be the fuel pump. As was found, we were in the 18psi range when his duty cycles are edging towards 90% on 720's and 1680's with a base pressure of 40psi. Everything else working correctly. The fuel pump is a Supra pump and the EFI system is a Haltech E6X. The stutter was intermittent yet, when it was consistent, would only happen at high RPM's, say right at 7krpm and above. The stutter was usually a fairly nasty jolt which felt identical to what would happen when running too hot of a spark plug for the given heavier loads. While we were on the dyno, it occurred three, perhaps four times and was enough to have me concerned. We were pretty much wrapping up by the time I was concerned enough to stop things as he was beginning to run out of pump. On the way back to his house (a good 20-30min drive), it didn't stutter or pop a single time. I had figured that perhaps there was an issue with a hot plug causing a misfire with the car being on the dyno and concluded that since it was on the dyno compared to being on the road that overall the vehicle would be hotter -- hotter water temps, air temps, oil temps, that kind of thing that's not experienced as much while on the road in normal driving conditions. Today that same stutter came back and as best as I know it only happened once. It was a hard enough knock to deflect the rear rotor housing and resultantly crack the upper rear iron dowel land, sending oil all over the engine bay, emptying the system out in about 10-15 seconds of running.
I have seen this one other time before and it was on another Turbo II about three years ago under much lesser loads. The vehicle was being tach'd out in 2nd gear at higher RPM's, similar to Luke's, when it encountered one, single, hard stutter, then it cracked the same dowel land, dumping the oil out. Other than that, I've only encountered odd misfires three times and I believe all three of them were plug related where the leadings still had 7's in them instead of 9's (being the stock plug configuration).
I've spoken to GMON about it some today and he's mentioned the possibility of problems w/ the plug wires that are in use. As best as I can tell from the pictures I've taken of Luke's engine bay, he's using some high quality MSD wires but am not sure exactly what kind.
Any thoughts?
B
This link shows pictures and a couple videos of Luke's car from a tuning trip I just got back from a few days ago up in central Ohio. I did a few cars there; Luke's being the heaviest-load one. Today, he called me and told me it had popped while driving a relative of his around the neighbourhood. He had done a 12/13psi run (low boost setting for pump gas) here and there and then went up to the high boost setting (18.5psi). He said it stuttered once then sounded like a Harley at the top of 2nd gear in the 7k-8krpm range. Here's the specs:
- Half-bridgeport motor I built two years ago. Pictures of the assembly and porting work for reference can be found here http://bdc.cyberosity.com/v/Assembly/LukeWeber/ and here http://bdc.cyberosity.com/v/Porting/LukeWeber/ -- Series 5 motor w/ the smaller rear dowel pin land, 9.0:1 rotors, Rotary Aviation apex seals (2mm), etc.
- HKS TO4R w/ a custom divided manifold, twin Tial 38mm WG's, 3.5" exhaust, 1.32 A/R P-Trim turbine housing
- Plugs used were BUR9EQ's all around but am unsure if they were platinums or not
Luke's car is very well built considering the time and effort he has taken into constructing it. Good parts were used and there were no short-cuts taken.
We had the same kind of stuttering occur on the dyno at both low and high loads. On low loads, I had him setup to run about 12-13psi on 93octane pump gas and nothing higher. On higher loads, the sky was pretty much the limit as I knew the next limiting factor would be the fuel pump. As was found, we were in the 18psi range when his duty cycles are edging towards 90% on 720's and 1680's with a base pressure of 40psi. Everything else working correctly. The fuel pump is a Supra pump and the EFI system is a Haltech E6X. The stutter was intermittent yet, when it was consistent, would only happen at high RPM's, say right at 7krpm and above. The stutter was usually a fairly nasty jolt which felt identical to what would happen when running too hot of a spark plug for the given heavier loads. While we were on the dyno, it occurred three, perhaps four times and was enough to have me concerned. We were pretty much wrapping up by the time I was concerned enough to stop things as he was beginning to run out of pump. On the way back to his house (a good 20-30min drive), it didn't stutter or pop a single time. I had figured that perhaps there was an issue with a hot plug causing a misfire with the car being on the dyno and concluded that since it was on the dyno compared to being on the road that overall the vehicle would be hotter -- hotter water temps, air temps, oil temps, that kind of thing that's not experienced as much while on the road in normal driving conditions. Today that same stutter came back and as best as I know it only happened once. It was a hard enough knock to deflect the rear rotor housing and resultantly crack the upper rear iron dowel land, sending oil all over the engine bay, emptying the system out in about 10-15 seconds of running.
I have seen this one other time before and it was on another Turbo II about three years ago under much lesser loads. The vehicle was being tach'd out in 2nd gear at higher RPM's, similar to Luke's, when it encountered one, single, hard stutter, then it cracked the same dowel land, dumping the oil out. Other than that, I've only encountered odd misfires three times and I believe all three of them were plug related where the leadings still had 7's in them instead of 9's (being the stock plug configuration).
I've spoken to GMON about it some today and he's mentioned the possibility of problems w/ the plug wires that are in use. As best as I can tell from the pictures I've taken of Luke's engine bay, he's using some high quality MSD wires but am not sure exactly what kind.
Any thoughts?
B
07-06-2006, 05:47 PM
#2
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Join Date: Jun 2003
Location: Grand Prairie, TX
Posts: 917
A couple of things I forgot to mention:
The race fuel he was using was 110 Leaded and was barely diluted with any pump fuel. The amount of spark advance I had him setup to run on this was 16* advance on the leadings with a 6* trail-split past about 15psi of boost. It was left on the conservative end purposefully. I also took 13 datalogs of the car on the dyno and not once did I ever see any indication of a trigger problem in terms of not having smooth, sequential RPM's going up and down.
B
The race fuel he was using was 110 Leaded and was barely diluted with any pump fuel. The amount of spark advance I had him setup to run on this was 16* advance on the leadings with a 6* trail-split past about 15psi of boost. It was left on the conservative end purposefully. I also took 13 datalogs of the car on the dyno and not once did I ever see any indication of a trigger problem in terms of not having smooth, sequential RPM's going up and down.
B
07-06-2006, 07:23 PM
#3
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Join Date: Jan 2003
Location: London, Ontario
Posts: 2,871
I've been told you can actually SEE arcing on the outside of MSD wires. This was on my car, but I wasn't there at the time. Whether that would cause a motor problem other than poor running I don't know.
07-07-2006, 01:11 AM
#5
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Location: CT
Posts: 1,345
Originally Posted by TYSON' post='827144' date='Jul 6 2006, 08:23 PM
I've been told you can actually SEE arcing on the outside of MSD wires. This was on my car, but I wasn't there at the time. Whether that would cause a motor problem other than poor running I don't know.
one of the cars on the dyno would have the msd wire arc onto the IC pipe.
07-07-2006, 01:37 AM
#6
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Originally Posted by kahren' post='827209' date='Jul 6 2006, 10:11 PM
one of the cars on the dyno would have the msd wire arc onto the IC pipe.
There were a few people watching us dyno but they were a good 6-10 feet away. The engine bay was also facing the sun at that time of day so I am not sure if they would've seen a spark at the end of the plug wire or not. In any event, I know I didn't because I was in the car tuning.
Anybody else have any information about these MSD wires? Is this something bonafiable that others have experienced or is it more a heresay kinda thing? The problem here on Luke's car is definitely in the world of ignition to the tune of a random misfire causing seriously advanced pre-ignition.
B
07-07-2006, 02:08 AM
#7
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Join Date: Dec 2003
Location: Minneapolis,MN
Posts: 500
Very interested to hear ohms per foot on those wires as well as what plugs he was running.
I was on the dyno last friday and heard 3 nasty bangs. Scared me shitless, turned down the boost and all was good. Couldnt imagine how nervous Id be with that kinda power.
On two of my buddies cars I can hold the home key down on at 6k and watch the map change from 10k to 0k maps all while the engine runs relatively well. Both are E6X's and both have been turned upside down trying to find the problem. We have made it better but arround 6k it still happens.
I personally think the X has issues with reluctor type pickup.
Id love to hear from others what they find while doing the above experiment. Do it in vac of course
I was on the dyno last friday and heard 3 nasty bangs. Scared me shitless, turned down the boost and all was good. Couldnt imagine how nervous Id be with that kinda power.
On two of my buddies cars I can hold the home key down on at 6k and watch the map change from 10k to 0k maps all while the engine runs relatively well. Both are E6X's and both have been turned upside down trying to find the problem. We have made it better but arround 6k it still happens.
I personally think the X has issues with reluctor type pickup.
Id love to hear from others what they find while doing the above experiment. Do it in vac of course
07-07-2006, 03:07 AM
#8
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Join Date: Jan 2002
Location: CT
Posts: 1,345
if you are usign msd wires, make sure the trailings dont run next to each other, ive seen a lot of peopel zip tie the trailing and leading plugs together. this is a no no, esp with the msd wires or whichever other ones that may arc. i like to use only stock wires, as it seems they work best against arching.
it seems that when runing way conservative timing you can also start detonating, or burning of the fuel is not as smooth when the spark goes off too late, preignition can occur even with high octane and low boost, this is almost the same thing as having the spark ignite too late, and having detonation, both of these can feel similar. ive also noticed that varing split timing can reduce the chance of this happening, too little split and the engine doesnt run smooth too much split and not smooth again. NAs seem to be happy with around 5-8 deg and turbo 8-15.
it seems that when runing way conservative timing you can also start detonating, or burning of the fuel is not as smooth when the spark goes off too late, preignition can occur even with high octane and low boost, this is almost the same thing as having the spark ignite too late, and having detonation, both of these can feel similar. ive also noticed that varing split timing can reduce the chance of this happening, too little split and the engine doesnt run smooth too much split and not smooth again. NAs seem to be happy with around 5-8 deg and turbo 8-15.
07-07-2006, 09:24 AM
#9
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Originally Posted by BDC' post='827210' date='Jul 6 2006, 11:37 PM
Anybody else have any information about these MSD wires? Is this something bonafiable that others have experienced or is it more a heresay kinda thing? The problem here on Luke's car is definitely in the world of ignition to the tune of a random misfire causing seriously advanced pre-ignition.
B
i had a 1st gen years ago, with racing beat wires. it was kinda so/so uptop, and it would burn up coils, i checked literally everything on the motor, and it was all fine.
what fixed it was a set of $6 kragen wires, i hadnt checked the RB wires, cause they are RB wires.
i'd have a hard look at the wires.....
07-08-2006, 11:28 PM
#10
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Ok B, Thanks for posting this up. The wires that I'm using are the MSD 8.5 Super Conductor Wires.
They are a very nice quality wire, and I was very impressed by them when I received them in the mail. They came with a sleeve over the wire to help with conducting the spark directly to the plug (to prevent arcing) and to help insulate against the heat.
I have a picture of them somewhere, and I'll have to find it and post it up.
My wires are zip tied together...so maybe that was the problem?
I am very disappointed that this happened, but i've been trying to keep a positive attitude about it, and have my motor come back stronger and better than ever.
I do still need to figure out what caused this in the first place...
I definitely think that we have it narrowed to ignition, whether it was the wires or the plugs, or maybe a combination of both...
They are a very nice quality wire, and I was very impressed by them when I received them in the mail. They came with a sleeve over the wire to help with conducting the spark directly to the plug (to prevent arcing) and to help insulate against the heat.
I have a picture of them somewhere, and I'll have to find it and post it up.
My wires are zip tied together...so maybe that was the problem?
I am very disappointed that this happened, but i've been trying to keep a positive attitude about it, and have my motor come back stronger and better than ever.
I do still need to figure out what caused this in the first place...
I definitely think that we have it narrowed to ignition, whether it was the wires or the plugs, or maybe a combination of both...