inline6 Posted August 2, 2015 Share Posted August 2, 2015 (edited) My new engine expired during the last session of the day yesterday at Road Atlanta. It had run 3 prior sessions and was most of the way through the last. I was going down the long back straight. I'll be pulling it out and examining it when I can in the next few weeks to see if anything is salvageable. I have two small holes in the block on the passenger side - looks like rod #2 let go. Here are a couple of video clips. I apologize in advance for the horrible sound quality - my cell phone mic sucks. I was using a driving recorder app called "caroo free". It's not a good choice for track days because it chops the video up into 20 sec snippets, but it does record some gps related info, and if you have an obd-II car, I understand you can add some car specific data to the video also. Anyway, these first two are from the previous lap in the same area - the long back straight. https://www.youtube.com/watch?v=x2Pnqk9RMQ8 https://www.youtube.com/watch?v=ekXNkr2dgi0 And these three lead up to and include when it happened: https://www.youtube.com/watch?v=Q4SveDFs1jo https://www.youtube.com/watch?v=oUMRzc6TWgk https://www.youtube.com/watch?v=hvEFJtsWnek It was my first track day event in 5 years as the car was off the road for a very long time, mainly for the engine build and a move from VA to GA. I really don't want to wait very long again, because I'd prefer to drive the car rather than look at it. I want to keep the inline 6. I don't think the current engine was "all that crazy" of a build, so I don't think that the specs of my build are inherently a problem. The short block has the same parts as Rebello 3.0. The cylinder head featured a Kinetic Sunbelt cam and valve spring set up with titanium retainers (with stainless nissan comp valves). I'll hopefully be able to pinpoint the cause as I take it apart. Edited August 4, 2015 by inline6 Quote Link to comment Share on other sites More sharing options...
310z Posted August 2, 2015 Share Posted August 2, 2015 Wow, to bad on the motor, down time and money. The sound quality sounds just like mine using a Cannon sx200 although my videos are the full length of the event. 20 min. in some cases. Your RPMs sound similar to mine I am guessing up to 6500? Quote Link to comment Share on other sites More sharing options...
clarkspeed Posted August 3, 2015 Share Posted August 3, 2015 Did the oil pressure drop? Turns 6 and 7 will put the oil on 1 side of pan. Quote Link to comment Share on other sites More sharing options...
zack_280 Posted August 3, 2015 Share Posted August 3, 2015 Good luck getting it back together. My buddy was there and told me it was a V8 Z. I heard a guy in a mustang hit the wall pretty hard after he slid through the oil slick. Quote Link to comment Share on other sites More sharing options...
inline6 Posted August 4, 2015 Author Share Posted August 4, 2015 (edited) Did the oil pressure drop? Turns 6 and 7 will put the oil on 1 side of pan. It must have dropped, but I'm not sure why it would? I am running the DP Racing oil pan which is the same as the Nissan Competition pan. That one is pretty proven from my understanding. And I actually did check oil level before he last run - it was about 1/16th below the H mark on the stick. Also, my car handles ok, but the suspension is not dialed in (unless by accident) and I'm no Mario Andretti either. I was running on 4 year old VictoRacer V700s - so not street tires. Going down the back straight, I heard a "shhhhh" noise for a second or two. i glanced down at temp and oil (my car is a series I, so this is the same as my gauge). Temp needle was about a quarter inch passed the non-labeled mark in the middle, as it had been for the previous sessions. The oil pressure was a bit to the left of the middle mark. As soon as I looked back out the windshield, the engine let go. The problem, in my opinion, is my stock gauge reacts pretty slowly to oil pressure changes, at least judging by watching it at start up. This time around, it will be mandatory to upgrade all of the gauges, and to add an oil pressure light such as this: https://www.pegasusautoracing.com/productdetails.asp?RecID=1855. Good luck getting it back together. My buddy was there and told me it was a V8 Z. I heard a guy in a mustang hit the wall pretty hard after he slid through the oil slick. Jim Pantas, the director of NASA South East left a message for me to call him. On the call, I found out that the Mustang driver passed away. Jim told me that there wasn't much oil on the track. They went looking for it to put sta-dry down and there just wasn't that much. There was also some in car video from a car behind him and they had viewed it to try to determine what happened. They aren't sure, but he said it looked like something on the car broke because of how sharply it veered to the left. I dunno. I feel terrible. But, there were 12 or 13 cars that came through there before he did and they didn't have any problems... meh... this just sucks. Additional safety equipment beyond my harness and roll bar is on my ever growing list now. Probably looking at racing seats instead of the BMW seats I have now, and a Hans device at the least. Edited August 30, 2015 by inline6 Quote Link to comment Share on other sites More sharing options...
zack_280 Posted August 4, 2015 Share Posted August 4, 2015 Wow. I wasn't really sure what happened since my buddy didn't see it. He was just repeating what he heard. It's pretty scary to think about. Not sure what the actual cause was or if the Mustang driver had any safety equipment, but something like that definitely makes you think twice about safety. I don't think I would ever get on track again without a Hans. Quote Link to comment Share on other sites More sharing options...
inline6 Posted August 4, 2015 Author Share Posted August 4, 2015 Wow. I wasn't really sure what happened since my buddy didn't see it. He was just repeating what he heard. It's pretty scary to think about. Not sure what the actual cause was or if the Mustang driver had any safety equipment, but something like that definitely makes you think twice about safety. I don't think I would ever get on track again without a Hans. Jim said the there was no safety equipment in the car other than stock. As it is now, I only have a four point harness and roll bar. That's really not sufficient in my mind anymore for track day safety needs. Quote Link to comment Share on other sites More sharing options...
johnnyddn Posted August 4, 2015 Share Posted August 4, 2015 A little more info on the accident. http://oppositelock.kinja.com/fatal-accident-at-road-atlanta-1721931526 Quote Link to comment Share on other sites More sharing options...
30 ounce Posted August 5, 2015 Share Posted August 5, 2015 That really sucks about your engine! It's pretty much the same as mine. Let me know what you find out. Quote Link to comment Share on other sites More sharing options...
clarkspeed Posted August 6, 2015 Share Posted August 6, 2015 On the engine, I also have a Nissan comp pan but have noticed my Accusump working in 6 and 7 before. Seems 6 loads the oil up on left side and then throwing it into 7 really pulls it out of sump. Noticed it most when my oil pump was marginal. As far as incident, that is tragic. A little oil can make a big problem. On other hand, a couple years ago a guy left his drain plug out and oiled down entire back straight. We ran the race with no problems. BB corvette was running 180 there. My guess is something broke. Especially if he made it to the brake zone. When I started HPDE many years ago I stuck with the priority of safety, reliability, and then speed. Hans, 5 pt harness, roll bar, and a single pc firesuit are not overkill. Quote Link to comment Share on other sites More sharing options...
JMortensen Posted August 12, 2015 Share Posted August 12, 2015 FYI, the Mustang had its own mechanical issue and the oil apparently had nothing to do with the crash. That from the guy who has the car now. http://www.corner-carvers.com/forums/showthread.php?t=48979 Quote Link to comment Share on other sites More sharing options...
EvilC Posted August 12, 2015 Share Posted August 12, 2015 Jon nice work, inline6 hope this helps put your mind at ease. Quote Link to comment Share on other sites More sharing options...
inline6 Posted August 13, 2015 Author Share Posted August 13, 2015 FYI, the Mustang had its own mechanical issue and the oil apparently had nothing to do with the crash. That from the guy who has the car now. http://www.corner-carvers.com/forums/showthread.php?t=48979 Jon nice work, inline6 hope this helps put your mind at ease. I scoured the internet for 3 days looking for info. There wasn't much beyond a few posts about the oil from the blown engine causing this. At times over those days, I felt really bad. Then I came across a post from the same guy. Since he seemed to be close to the family and helped load the car the next day, and he was saying it was a mechanical failure, I wondered if he was privy to info that wasn't public. I have to admit, it did make me feel a lot better. No one wants to be the cause of someone losing control at the track and losing their life. The most important thing I learned from this is that anything can happen... What if at my next track day event, someone blows and engine and puts a bunch of oil on the track... and I am the next car to come through? The best way to minimize injury or death from "the anything" is to install as much high quality safety equipment as possible. Quote Link to comment Share on other sites More sharing options...
HowlerMonkey Posted August 22, 2015 Share Posted August 22, 2015 (edited) I've seen engines throw a rod once oil temperature reaches around 300 degrees.........that seems to be the magic number common in about 10 instances I have seen over the years of racing various nissan inline and V6 cars. Your water temperature might not give you a good indication of oil temperature. Edited August 22, 2015 by HowlerMonkey Quote Link to comment Share on other sites More sharing options...
inline6 Posted August 24, 2015 Author Share Posted August 24, 2015 (edited) I pulled the engine out and apart this weekend. When I started to unscrew the main bolts (I used stock ones) the number one main bolts had next to no torque. The number two had none - they were already loose and I removed them by unscrewing with my fingers. My guess is that the 7200-7300 rpm harmonic that is a known issue with these engines caused the number 1 and 2 main bolts to come loose... excessive clearance in the #2 main caused a loss of oil pressure to the number two rod. That bearing disintegrated, heat generated quickly and caused the #2 rod to fail. It looks to me like the cap and rod bolts failed first. The bolts both broke and the cap split into two pieces. I found one of them on top of the driver side frame rail. Then the middle section of rod #2 got caught up against the block, and sheared off near the piston pin. This chunk of #2 rod then found its way between the number #1 rod and the block instantly locking up the engine, not allowing even 1 degree of crank rotation in either direction until I freed it up today. The #1 rod broke also but not at the bolts. It broke in the I beam section. Ok, here are a bunch of pics of the carnage: Pass. side of block - 3 holes - one behind alt. bracket: Driver side of block: Section of rod #2 caught under rod #1: #2: #2: Main oil galley taken out by #1: #2 left, #1 right: Oil pan schrapnel: #2 and #1 - crank removed: #2 bore: #1 bore: #2 bore: #1 bore: #2 bore: #1 bore: #1 main bearing: #2 main bearing: What's left of rods: #2 rod section that ended up pinned by #1 rod journal to block: Other rod bearing starting to show problems: #1 main bearing: Crankshaft bolts friction welded? What the crank should look like: Crank damage: Oil pan damage: Edited August 25, 2015 by inline6 Quote Link to comment Share on other sites More sharing options...
michael wales Posted August 24, 2015 Share Posted August 24, 2015 Info like this is why i frequent this forum. A crappy situation for one leads to good info for the rest so we can keep more Zs on the road/track! Quote Link to comment Share on other sites More sharing options...
Leon Posted August 26, 2015 Share Posted August 26, 2015 Holy hell man! That is some serious destruction. Quote Link to comment Share on other sites More sharing options...
SleeperZ Posted August 26, 2015 Share Posted August 26, 2015 A bit of polish and that crank will be good as new. LOL, that's a pretty complete breakdown. Quote Link to comment Share on other sites More sharing options...
inline6 Posted August 26, 2015 Author Share Posted August 26, 2015 Bad car stuff always happens to me in twos or threes. I was telling this to my co-workers the Friday before I went to the track. The day before, a guy in a Ford Expedition that works in the same building didn't see my Honda S2000 parked next to him in the parking lot, cut hard and punched the throttle getting out of his space... hit the poor thing, shifting the front over a foot and a half to the side (I was backed in). He never stopped, just hit it and knocked it out of the way as he exited his space. He did come tell me... but jeeez. For a parking lot fender bender, it was innnnnsaaaaaannnnne. I told my coworkers that I fully expected a catastrophic engine failure that weekend. And this is certainly the worst I've ever seen. Quote Link to comment Share on other sites More sharing options...
Chickenman Posted October 19, 2015 Share Posted October 19, 2015 (edited) One thing that bothered me when I looked at the photo's of the damage was the chamfering done to the crank oil holes. I've never seen oil hole chamfers that deep nor that large in diameter. Oil chamfers should just break the hard edge and be as shallow and small as possible. Have a look at some crank shafts on modern day high revving production motors such as the V-TECH series by Honda It rang a bell, so I quickly started grabbing some of my SBC and Datsun Engine building books. Sure enough, there was a picture of excessive chamfering on a SBC crankshaft ( very similar to what was done on your Crank ) with a warning from Smokey Yunick that excessive chamferring would cause a reduction in the Hydrostatic wedge and that was something that you definitely do NOT want. John Ligenfelter had the same warning. Yunick stated this " old school "method of crank prep was 10 years old and used in days of 50 wt oils and relatively low revs. That advice was given way back in 1979!! All that's needed for de-burring oil holes is a very slight radius round the oil hole. Just break the sharp edge. Enlarging the hole or ovalising the hole to feed " More " oil just reduces journal area and reduces the hydrostatic wedge. And it does NOT feed more oil to the journal. Have a look at modern day Nascar engines, Pro Stock, GT1, or LMP. Absolutely minimal radius around the oil holes ( and tight, tight bearing clearances... but that depends on journal design and size ). You absolutely must maintain that Hydrostatic wedge at all costs. I don't know if that contributed to the failure, but it probably didn't help. It's an area of crank preparation that I would defiantly change.... IMHO Edit: Jeez...how many times can I say " Hydrostatic Wedge ".... LOL Edited October 22, 2015 by Chickenman Quote Link to comment Share on other sites More sharing options...
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