Z's Charger and Recent Engine Troubles

[zhc]

I posted this up on my Facebook page but figure I'd post it here too for you guys who don't frequent the FB.

Finally, I found some time to work on an update. This won’t just be about my most recent failure, I’ll also go over previous ones too. Why would I openly talk about all this bad and potentially embarrassing stuff? Well, as per my usual self, I like to share and document what I can when I can and that includes my successes as well as my failures. I do it in hopes that it helps provide a fuller and more realistic picture of what to expect and what to prepare for should one try and take a similar journey. This is for the folks who have been waiting for me to post about any of it so if you’re curious about my recent motor mishaps, read on! Fair warning, it’s going to be long and somewhat technical, but I’ll try to keep it as simple as I can.

Here is what happened with each motor that I’ve had issues with over the last 6 months.

Up until late last year, I had been racing on a 441 Demon Performance / TKM built stroker motor for nearly 2 years. It was originally built in March 2021 where I picked it up in the middle of TX2K21 week, spent 40 straight hours getting it installed, slept for a couple hours, checked in for the event, and then spent time getting it tuned and ready to race. The engine did great and sounded insane! I was #1 qualifier with a blower only pass but then my transmission broke so that was that.

Over the next 20 months or so of racing on this motor, I went on to reset the Charger Hellcat quarter mile record multiple times with dozens of 7 second passes and a best 7.72 @ 178 with a 1.18 60’. The only real issue I had over this time span until the end was apparent cylinder pressure leakage. I had to chase this issue a few times which involved removing heads to send off for inspection, resurfaced, and head gaskets replaced. Besides that, all was well.

Then Oct/Nov of last year, I traveled to Maryland to try and hit 3 events spanning 4 weeks. The first event was MSHS Maryland 2022 and this motor continued to perform with no signs of trouble. I ran a pair of 7 second passes there, a 7.8 @ 180+ and 7.7 @ 183 in testing, had a couple major drivetrain failures but powered through and finished the race series with a Heavyweight class win. The next Maryland event was WCF Import vs Domestic where I made just one qualifier pass, was #2 after round 1 but developed a problem while on the return road that would prevent me from continuing to race. What happened there? The bolts holding my crank trigger reluctor wheel decided to back out, shear off after striking the back of the block, and then the wheel proceeded to cause all sorts of internal havoc as it loosely flopped around on the crank and grinded against the block. This was not a trackside repair job with the resources I had available, and a bit of material had unfortunately run through all the bearings so that was that and my trip ended with me heading to Demon Performance to swap in my freshly built back up motor. Just in time!

Before I go on to talk about my 2nd 441 stroker, one additional issue was found upon tear down for repair and refresh. One rod was slightly bent. The rods that were in it were Carillo Pro-H selected for being lighter in weight. This is important to note as I move on to the next motor to talk about. I was extremely happy with my 1st 441 motor and how it performed. Based on my experience with 441 #1, I wasn’t expecting any of the failures that occurred this year. Looking back, I made 27+ 7 second passes with it plus countless more 8 second passes over those 20 months. Interestingly, I didn’t start consistently trapping 180+ until I swapped to the new gen 5 Whipple 3.0L and 3.8L blowers with the new Nitrous Outlet intake plates and that’s when things started to become a bit more unreliable with the additional power I had at my disposal.

YouTube My Reluctor Wheel Fell Off

 

[zhc]

My next motor, 441 #2, lasted just 3 months. Before it decided to let go, I ran 6 seven second passes on it including record reset passes of 7.70 @ 182 with a 1.18 60’ and 7.62 @ 183 with a 1.16 60’. Shortly after those passes, I swapped my HP90 factory style transmission for a TH400 and started testing. Unfortunately, I had issues and mishaps that led to several unintentional over rev scenarios and limiter bouncing scenarios, all while wanting to try and progress as quickly as possible to get back to feeling competitive for TX2K. I ended up kicking a rod and windowing the block on a 400-450 nitrous shot test pass, same shot size I’ve been running on all of my deep 7 second passes prior. Upon tear down and inspection, #1 rod had twisted like a pretzel then broke, #1 piston made contact with the head and valves, and #6 rod was visibly bent as well. Besides that, spark plugs all looked great along with everything else up top, no signs of knock, detonation, or excessive heat. Possible cause for failure? Either too much unintentional RPM or I overpowered the rods or a combination of the two. These were the same model rods I had in the previous motor. Coincidence? Maybe, maybe not, it’s hard to say with such a small sample size and many uncontrolled variables. Still, I didn’t want to try them again knowing I would likely want to keep pushing harder so I decided to try Wiseco Boostline rods next.

 

[zhc]

And that brings me to my last motor. A couple weeks ago I posted that I experienced another failure and that was after just over 2 months time. Ok, I’ll admit, at this point it’s getting ridiculously expensive and unsustainable for me. I’m going to have to make major changes if I want to keep racing this car.

Here are my preliminary findings. Cylinder #7 and #1 cracked through the sleeve and block into a near-by water jacket. #1 rod was bent and twisted pretty bad from hydrolocking. #7 rod was bent in the same manner but not as bad. Eye balling #3 and #5 rods, I can’t tell that they’re bent even though those cylinders had water in them. At first, I wasn’t able to rotate the crank but after removing #1 and #7 rods and pistons, I was able to rotate the Winberg crank freely. I’ll get it checked and hopefully it’s good for reuse. #7 rod bearing shows a pattern that I think can be explained by the hydrolocking and bending rod scenario. Other than that, rod bearings look great. #1 rod bearing looks like a million bucks. Spark plugs all looked great and everything up top didn’t show any signs of distress, detonation, or excessive heat.

So what happened this time? For me to tell a story, we need more detail. Here’s everything else that I’m working with to help explain my conclusions. Keep in mind that some of these observations could just be coincidental. Over the course of those final few days of racing, I made 7 passes spraying 450 – 475 shots of nitrous making around 26.5 psi of boost plus a couple misc. passes with less power. My original 441 motor seemed to have taken it just fine and with the Boostline rods, I was building confidence these rods were going to hold up. The motor overall seemed to be taking it like a champ, that is until it didn’t.

And just like that, when you think everything’s going well, a catastrophic failure hits you to let you know, nothing is guaranteed. Towards the end of that last pass in the final moments of wide open throttle, the only thing that stuck out as being abnormal when comparing previous logs to the last one was a subtle change in knock sensor pattern. This doesn’t mean it was knocking, just that it was picking up a little more noise than normal and this is when I believe #7 cylinder and block cracked. The car felt perfectly normal, fueling was perfect for the whole pass and the only indication that something might be wrong was seeing an opaque white smoke form up behind the car after I let off with my parachute out. After a short time passed, it lessened to where I couldn’t really see it anymore as I continued to slow down. Then as an afterthought I clicked it into neutral and the motor rpm abruptly dropped and died while I was still moving at over 70 mph. In the data log, I could see a big change in o2 sensor patterns on the problem side. This was due to all the steam and water that was hitting it while I was slowing down. There was also a dramatic and distressing change in knock sensor patterns while slowing down indicating that the motor likely experienced some sort of catastrophic failure. Bending rods explain that. After I got the car stopped, I heard something boiling and thought it was my coolant reservoir bubbling over. It turned out to be water in my exhaust still dripping out of the pipe. The motor wouldn’t turn over either, it was completely seized.

Later when I came home, I scoped every hole. On bank 2, cylinder #2, there was a small amount of water pooled inside. Everything else on that side looked mint. Bank 1 with the cracks had water pooled in #3, #5, and #7. #1 piston was near its topmost position so it would have been hard to see any water in it. The blower intake runners on the problem side showed clear indication of a ton of water and steam that splashed up as high as the intercooler bricks. Besides plugs on the problem side coming out with water on them, they all looked great. My coolant reservoir was empty and my radiator nearly empty when I went to drain it. I also tested the Whipple intercooler bricks for leaks and found no issue with them. All the water came from the engine’s coolant system.

Taking all this in, I believe #7 cracked towards the end of my pass due to being repeatedly subjected to excessive cylinder pressure leading to an eventual stress related block/sleeve failure. After I let off and was decelerating in gear, the motor drew in a ton of water through the new crack that formed filling #7 to the point where it got pushed out of both intake and exhaust valves. Water started filling the rest of the cylinders on that side but since I was aggressively slowing down with parachute out, a lot more of it ended up in #1 causing that rod to bend and twist in a worse way eventually cracking that cylinder wall as the piston seized in the bore.

Some of you might wonder how does that much water get sucked in? Well consider this, each cylinder is like a pump that sucks in and then expels air through 4 strokes consisting of intake, compression, combustion, and exhaust. When you have a new source for the cylinder to draw in something, in this case water through crack, and it’s always open, it’s now going to suck water in every time the piston moves down during intake and combustion strokes then try to push it out during exhaust, and bend rods during compression. The crack however does provide some relief and I believe that’s why #7 rod isn’t bent as badly as #1. #1 is bent bad because all that water had nowhere to go at first during compression strokes. I think I got that all right but if not, perhaps someone can correct me.

YouTube My Cracked Sleeve and Block Initial Discovery

YouTube My Cracked Sleeves and Block

 

[zhc]

There was one error on my part as a driver that might have saved me from bending rods to the point of seizing up the motor. My TH400 has a safe neutral which I can click into from 3rd gear and I’m supposed to do that as I let off the gas after deploying my parachute. Instead of being high rpm and straining the motor with engine braking, being in neutral would have quickly brought rpm’s down with no load on the motor and I think would have limited the severity of the damage. Unfortunately, I barely spent any time coaching myself on how to operate everything that was new about my car. I didn’t spend any time building muscle memory with practice dry runs sitting in the car either. Most of my spare time was spent on trying to prepare the car to make race events over and over. I should have spent more time on getting myself familiar with the TH400 setup versus jumping in and getting after it right away.

So many hard lessons learned. I’m not giving up but I also can’t afford to keep doing the same thing over and over so some things are going to have to change.

Phew… that was a lot! Till next time, be safe all!

 

[DavidKFla]

Wow. It just seems that sometimes shit happens in a row.

These things always seems to test you right before you move to the next level. Hang in there!

 

[Unholy707]

Wow. It just seems that sometimes shit happens in a row.

These things always seems to test you right before you move to the next level. Hang in there!

Things always happen in 3s.

Hang in there Z! Not many pushing these as hard as you are.

 

[vortecd]

Thanks @zhc for sharing. Lots of info and insight

 

[jonx96]

Z your posts are always humbling. Makes someone really think about their goals and how fast you want to go. Also being one dude you really put in a lot of work to make all this happen

 

[Marc W]

@zhc Thanks for the time and willingness to share your stuff. Much appreciated 👍🏼 With a max effort build taking place for us right now, all of this is food for thought. Have you had any thoughts about the rod length with the 441 vs something a little shorter? If you don’t mind…. Have you been limiting your rpm in exchange for this displacement?

 

[zhc]

@zhc Thanks for the time and willingness to share your stuff. Much appreciated 👍🏼 With a max effort build taking place for us right now, all of this is food for thought. Have you had any thoughts about the rod length with the 441 vs something a little shorter? If you don’t mind…. Have you been limiting your rpm in exchange for this displacement?

My last motor was a 426 actually. I didn’t mention because I was trying to keep my write up from becoming too long with a bunch of detail that wasn’t that relevant.

When I had the 8 speed, I was generally shifting well under 7k rpm, like 6800ish. With the th400, I ended up shifting around 7400 and then later 7200 or at least that’s what I tried to aim for. My converters were too loose so the car ended up going significantly faster with more rpm. My next motor will be another 441, will see how it holds up. The boostline rods look like they’re going to hold up well. I probably won’t turn it up as much so I can move it to my Cuda when I have something better to replace it with.

 

[Marc W]

We have been putting a ton of prep into the block. It’s a early (hard) 6.2 BGE. We’ve been opening up the water and oil passage ways and are smoothing and polishing every sharp or ragged edge. Particularly the oil returns. They’re even being polished to increase return and reduce oil suspension as the crankcase is breathing through those returns. The difference in these early blocks is evident when doing the porting. The newer BGE’s cut like butter compared to the 15-16 blocks. This thing is like kryptonite compared to the current blocks. We’ll be using a Callies billet crank, but the big deal will be the rods. They are special forged Manley I-beams that they produce “on occasion”. The magic of forging at its highest level. Adam tried to get some more but they said they are not making any more of those at this time. We are also hard filling the block to the water pump.

 

[Jack_Toepfer]

Excellent write up. Thanks for sharing.
Sorry for your luck man, I can only imagine the cost of motors, but also your time and frustration, you’re a special kind of guy (like most drag racers) to endure that punishment and show up on race day with a smile - and then go out of your way to help other people.

 

[Marc W]

My last motor was a 426 actually. I didn’t mention because I was trying to keep my write up from becoming too long with a bunch of detail that wasn’t that relevant.

When I had the 8 speed, I was generally shifting well under 7k rpm, like 6800ish. With the th400, I ended up shifting around 7400 and then later 7200 or at least that’s what I tried to aim for. My converters were too loose so the car ended up going significantly faster with more rpm. My next motor will be another 441, will see how it holds up. The boostline rods look like they’re going to hold up well. I probably won’t turn it up as much so I can move it to my Cuda when I have something better to replace it with.

My new one will only be 401ci. This is where different ways to accomplish the same goals come in. With the shorter stroke we can spin it higher (8000) to reduce converter slip to pick up mph on the top end. At least that’s the plan 😬. Had a talk with Coan about this and they built the new converter to do that with what we’ve got. We’ll see lol

 

[Speedy!]

Great Info Z, always appreciate your insight.

 

[zhc]

My new one will only be 401ci. This is where different ways to accomplish the same goals come in. With the shorter stroke we can spin it higher (8000) to reduce converter slip to pick up mph on the top end. At least that’s the plan 😬. Had a talk with Coan about this and they built the new converter to do that with what we’ve got. We’ll see lol

You’re significantly lighter right? You’re not going to need as much power to match or go faster than I ever have which may put you below a lot of the limits a few of us have hit repeatedly pushing 2000+ crank.

 

[Marc W]

You’re significantly lighter right? You’re not going to need as much power to match or go faster than I ever have which may put you below a lot of the limits a few of us have hit repeatedly pushing 2000+ crank.

Right. The blue car is 3900 race weight and I’m still at 4050. I honestly don’t see getting one of these production cars much below that 3900 race weight without spending a fortune on light weight replacement stuff like doors, roof, etc. We’ve already done some of that with the suspension and ditching accessories, but it starts getting real expensive from this point.

 

[Magnified]

There was one error on my part as a driver that might have saved me from bending rods to the point of seizing up the motor. My TH400 has a safe neutral which I can click into from 3rd gear and I’m supposed to do that as I let off the gas after deploying my parachute. Instead of being high rpm and straining the motor with engine braking, being in neutral would have quickly brought rpm’s down with no load on the motor and I think would have limited the severity of the damage. Unfortunately, I barely spent any time coaching myself on how to operate everything that was new about my car. I didn’t spend any time building muscle memory with practice dry runs sitting in the car either. Most of my spare time was spent on trying to prepare the car to make race events over and over. I should have spent more time on getting myself familiar with the TH400 setup versus jumping in and getting after it right away.

So many hard lessons learned. I’m not giving up but I also can’t afford to keep doing the same thing over and over so some things are going to have to change.

Phew… that was a lot! Till next time, be safe all!

Thanks for sharing. Sorry that all happened as it did. Glad it wasn't worse.

 

[SilverBillet]

Horsepower is expensive!

 

[The Max]

Sorry to read all this mayhem with your Charger. You have certainly kicked ass with your car, earned a lot of respect and set a bunch of records. Nobody can take that away. Good luck with your next project!

 

[Boris]

There was one error on my part as a driver that might have saved me from bending rods to the point of seizing up the motor. My TH400 has a safe neutral which I can click into from 3rd gear and I’m supposed to do that as I let off the gas after deploying my parachute. Instead of being high rpm and straining the motor with engine braking, being in neutral would have quickly brought rpm’s down with no load on the motor and I think would have limited the severity of the damage. Unfortunately, I barely spent any time coaching myself on how to operate everything that was new about my car. I didn’t spend any time building muscle memory with practice dry runs sitting in the car either. Most of my spare time was spent on trying to prepare the car to make race events over and over. I should have spent more time on getting myself familiar with the TH400 setup versus jumping in and getting after it right away.

So many hard lessons learned. I’m not giving up but I also can’t afford to keep doing the same thing over and over so some things are going to have to change.

Phew… that was a lot! Till next time, be safe all!

Its been years but i thought you were not supposed to go into neutral in a 400, can overspin the trans and turn that into a grenade.

Again, its been years and I'm sure someone possibly came up with a solution by now. I'd double check with your trans guy.