500+HP and the big BANG!

[Scott231]

However, I do need funds for the new motor! As such, watch the Parts for Sale section for stuff from me. I always sell stuff on the cheap and then feel bad (for myself) cuz I know I could have asked for more.

But yeah, I am going to use the exploded parts as some sort of "art exhibit" in my garage. If nothing else, to remind me of what can happen.

I decided to dis-assemble the motor myself. I've been told that there will not be any easy way to detect what broke first. Three or 4 oil pan studs (that thread into the bock through the girdle) snapped off and I have 7 of them that do not want to come out. So I am off to the parts store to get a 1/4" drive 1/2" deep socket to add to my toolbox.

 

[Rollin]

Scott

... at ~5,700 the engine stumbled, made a Bang! and died...then bolts started falling out of the engine compartment...and then a much-larger-than-usual oil leak started dripping.

Scott been there got the shirt. However, to be a bonified member of the club I think ya actually have to drive over the crank in a rapid forward like motion lol. In my case try to understand my motor let go on the 3-4 shift @ 24 lbs of boost. Out of the corners of my eyes, I got to see sparkling items whizzing off curbs. NOT to mention what looked like a fireball that was following me as the car slowed from triple digits, or was it the red and blue lights of the local law enforcement (who by the way witnessed the whole incident). Oh yeah, that dreaded sound of metal sliding across concrete... it's been 4 years now, and if conditions are just right I can still hear it.

The "Powermaster" rules!

Pix's can be seen here courtsey of Mr URL:
http://www.geocities.com/rad87gn/dotcc.html

 

[tes87gn]

3 PIECE CRANK

I just remove a engine from an 87 GN and the same identical thing happened the crank split in three pieces. And get this, this customers car was on the emission station DYNO when it went also. Apparenly buicks don't like to be run hard while sitting still they would much rather be beating the pants off some unsuspecting victim while having the tard run out of them.

 

[quickt]

Originally posted by Bmason
Scott, that's quite a gain from tuning alone (60hp and 15hp). On both your car and the car that gained 60hp, what were the initial and final targets?

-Bobby

That car started at like 321 RWHP (uncorrected) and after several pulls and tuning alone we quit for the day with the best of 397 RWHP (uncorrected) and still had plenty of room for more. We also learned that EGT temp is not as good of a tuning tool as we thought. All 3 cars were tuned to around 1600 EGT before hand all 3 cars were in the 13.5 AFR on the first pull with mine being in the 14 afr. All 3 cars were about the same combo and the EGT temps were all over the map as we started getting them tuned. Including Scotts even though we only got 2 pulls on it. Steves car was making its best pull of the day in the 1480 range and an afr in the 11.8 range. My best pull was 1620 and an afr of 11.4. Scotts best pull was like 1500 and was in the 12.8 afr range. 2 of the cars had the same timing of 24 deg. mine was 18 the strange part was the huge changes in afr and the small changes in EGT. If you would have asked any one uf us at the beginning of the day. we all would have said our cars tune was close. Our tune was way off.

 

[quickt]

The point I was tring to make was this. Scott thought his car was in tune based on the fact that his EGT was in the 1500-1600 range. Before this day I would have also said his tune must be close. The fact is the tune was not even close. Again all based on EGT temp. This info we would have never learned without a wide band O2 and dyno time. The fact was the EGT was of very little use to us. I personally will never solely rely on EGT temps when tuning. I still think EGT is a helpful tuning tool as your tune gets close but EGT can be misleading as there are other factors that affect the EGT temps. The dyno might not be the place to set your car on kill I will agree. It is a great place to verify that your tune is close and to experiment with shift points timing and many other things. IMO its the safest place if you do not have a fuel management system with WBO2 to tune your car close before you start putting that hard top end 120+ MPH pull on the motor. 2 cars had a 218 cams one peaked at 5800 the other peaked at 5500. One car dropped 15 hp from 5800-6000 the other dropped 40hp from 5500 to 6000. These things we would have never known without the dyno.

 

[Mr URL]

I've been there and done that right down to splitting my transmission case too! Sorry to hear that Scott!!!

 

[TurboJim]

Originally posted by quickt
All 3 cars were tuned to around 1600 EGT before hand all 3 cars were in the 13.5 AFR on the first pull with mine being in the 14 afr.

Why would you start so lean? Why didnyt you start at say 10:1 and LEAN it as you went to achieve your goal? I'd think that would be much safer?!? You would have gone up to maybe 12.5, and stopped seeing a gain and still have been safer than a 14:1 AFR?

To each his own I guess, but there are so many people going 10.teen that I just cant believe fatigue was an issue when you've been blowing head gaskets more often than you fill the gas tank. Adding the special head gaskets removed the safety fuse and despite the girdle being installed, the next weakest link was the crank out the pan or a rod out the block.

I'm just curious why you guys chose to start so lean?

 

[re-evaluating]

WOW that sucks Scott

Jim I wasn't there but I would guess that it was the base line pull and the 14:1 was just where the tune was when they pulled the car on the dyno. Scott doesn't have a wide band on the car to set a target like a FAST system.

Scott that sucks.. I can relate though mine broke the crank nearly the same place. I would look closely and see if the piston failure happened first. I didn't have piston failure but I have seen a lot of stock pistons reach there limit. I also know it can take a while to recover when you are on a serious buget. I am finally getting mine back together and may have mine ready for the Midwest challenge, it will be close but I am hopeful. Let me know if I can help. Dave

 

[RobV6]

VERY SORRY

Scott several times you have given me great advice...........Wish I could help you now. Crank in that girdle must have been fatigued.
Sems to have shattered by photos. My dad was a machinest.
Maybe getting a collection is not such a bad idea??

But you are not pysically hurt. Trust me means a lot. Was in a 17,000 dollar accident . Guy cut me off. Still healing form that .
Materials can be replaced.....You can't... Fell awful...Stay well...

Rob

 

[Jack Evers]

Originally posted by 2 QK 4 U
Scott.... did your motor have Steel Caps along with the Girdle?

Images show what appear to be steel caps.

 

[quickt]

Re: WOW that sucks Scott

Originally posted by re-evaluating
Jim I wasn't there but I would guess that it was the base line pull and the 14:1 was just where the tune was when they pulled the car on the dyno. Scott doesn't have a wide band on the car to set a target like a FAST system.

Thats exactly what happened. The baseline pull was at 14.0 AFR Scott did not have a Wideband so we had no idea where he was starting at. We all aSSumed with EGT temps that Scott had tuned to he would probably be in the 11 AFR range somewhere. Even Scott thought before the first pull te car was going to be on the FAT side. After the first pull we added fuel with the intention of getting the afr in the 11.3-11.5 range. The 2nd pull the car picked up hp and kaboom it was all over. I never thought that the crank broke. The motor made a hell of a noise. I looked at Scott and said what the hell was that and Scott said I just lost the motor. Let me tell you there was lots of drama all at the same time oil leaking on the ground bolts falling to the ground the sound of parts flying under the hood. I finally have my 109 motor in the car and I will tell you. I am not comfortable pushing this motor after seeing this. I still have the stock caps with 4140 cap girdles and all I can think of is that crank snapping at 130 mph going down the track oiling down the tires. I made 515 rwhp at 19 psi and 18 deg timing. I was not even pushing the motor hard as it had only been running about a week. I put my car on the dyno next and at this point I wanted nothing to do with the dyno. I did want to know where I was at so I forced myself to do it anyway. The first pull was clean and that made me feel a little better. The 4th pull at about 6100 POW black smoke flew out the exhaust smoke under the hood and the smell of antifreeze and the engine died. I was like F**k. When I looked at the other fellas they all had the look like that was not good. I thought to myself where is that antifreeze smell coming from I only have water in this thing. We checked it out did not see anything wrong I started the car right back up good oil psi and made one more pull and that was it. This car is coming off the dyno as I needed to drive it home. I held it at 40 mph for like 3 minutes before I opened it up because I just knew it was going to blow up. We put a total of like 15 pulls on Steves car. I asked Steve you think we should put this many pulls on your car. He says " I would rather blow it up here than at the track the mess will be easier to clean up" I taked to Scott the next day. We decided that the t-chain had broke and I started rounding up the parts we thought he would need. He calls me back 3 days later and said the back 2 cyls valves are moving the rest of the valves are not. We determined from that phone call that the cam must have broke. Now keep in mind that 5 of us looked at this motor and not one has even noticed that pulleys are not moving when the engine was cranked over. Hell I dont think anyone of us thought the the crank was a possibility. Then Scott e-mails me that mess.

 

[86brick]

I guess this kind of shows the need and/or importance of a WBO2.........

I still say it's better to start out pig rich and slowly lean the car out, but that's just my theory of tuning with these cars from what I've heard from talking to the faster guys down here like Orlando.......

 

[TurboJim]

Re: Re: WOW that sucks Scott

Originally posted by quickt
Thats exactly what happened. The baseline pull was at 14.0 AFR Scott did not have a Wideband so we had no idea where he was starting at.

Did you guys not have a wb on the dyno? You must have to know you were at 14:1.

Surprized no one said "its too lean..get off it!!"

I got mine ready to pull, (My jack and stands are at work so I couldnt get under it to unbolt the converter and bellhousing) so in a week or so I'll be tuning my car all over again. Hopefully I dont have the same fate as Scott....

 

[Bmason]

Lonnie:

My initial questions on leaness and what the target/actual numbers were, were based on using FAST systems. I target the 11.0:1 range and start going up numerically from there. I saw where the TEC-II system was mentioned and assumed that it had a WBO2 and AFR targets could be set. Based on your reply, that's not the case and I didn't know that.

Additionally, I agree with the 1600 EGT. I used to tune my car to 1600 and it actually ran pretty well there. After getting the FelPro and actually playing with the AFR, basing my tune solely on the fact that the car ran 1600 wasn't correct. Some kind of a way the motor survived it, but now I'm wondering if I'm not a WOT pass or two away from the same fate?

-Bobby

 

[quickt]

Re: Re: Re: WOW that sucks Scott

Originally posted by TurboJim
Did you guys not have a wb on the dyno? You must have to know you were at 14:1.

Surprized no one said "its too lean..get off it!!"

Simply because the only thing the comp shows is recording while the run is in progress. Yes the dyno had a wideband. We had no way of knowing till after the first pull. The EGT in the 1500 range we would have thought we were closer to 11 than 14.

 

[V6 Beast]

I am most interested in why the EGT wasn't 1700+ for that lean a condition. I have mine just below DS header connector in crossover pipe and I have seen 1700+ when it got lean. I think it likes 1620 best but I am going to dyno to verify. I wonder if the variation is different types of EGT probes and gauges or a true difference in temp. Where was Scott's prob located?

I know when you get too rich, you can get rise in EGT from burning fuel in manifolds, but I can't think of condition where it gets too lean and then EGT goes down.

Sully

 

[The Swede]

Hi Scott!

Makes me sad to hear such things......
I remember the feeling when i blew up my heavaly tuned Chrysler 340" back in the 80's.

Must check all the reciepts i got with the GN what is in the bottom of it......

PS: Does your mail work?
haven't got any answer on the chip order.
The emission for 50's was just perfect! 0.0 CO!

 

[Scott231]

DOTC=Dyno'd Over The Crank

Just to address a few things that you guys discussed over the weekend -

My car was running on the dyno with 23 psi and 21* of timing during the dyno pulls. On the first pull, I recorded a max EGT of 1648. On the second pass I datalogged the EGTs (never looked at the gauge during the pull) and haven't reviewed the file yet. My EGT sensor is mounted in the PS header before the turbo.

I have the DynoJet information from my two dyno pulls graphed and saved to an Excel file. I also have the TEC-II data for both runs and the EGT data on the "fateful pass". I can add those graphics and some more pictures to the website when I get the time.

Interestingly, when I went back and re-reviewed the dyno pull where the motor blew, there was a big drop in RPMs at 4,150 RPMs, 9.5psi and 24* advance, a lull for a 1.5 seconds and then an "uncharacterically low-sloped" RPM line up to 5,650 where it snapped the crank. BTW, with the valvetrain spinning freely, the MAP sensor registed about 32psi the instant after the crank broke...prolly just a backfire.

Nobody yelled "Get off it your too lean" as our procedure was to set the dyno to record when the driver pushed "the Green button" and the the rest of us would stand back for fear of flying rocks, black smoke, pieces of tires etc...to the point that you cannot watch the screen. PLUS, I had proved earlier in the day with Steve's car that the laptop display during the run was nowhere near the actual readings that we saw later when reviewing the datalog.

And finally, my car did not have a wide-band O2 correcting system on it. My first pull was my first ever reading of A:F ratios. The motor did get richer and richer as the RPMs (and boost) came up. Since I had recently changed to 72pph injectors, we were expecting the fuel to be too fat. However, I now recall that at the Norwalk T&T 2 weeks prior, no one said my car was blowing black smoke...its always blown brown smoke at the launch.

BTW, the reason Lonnie's car barfed black smoke on his next to last pull was that he hit the rev limiter...which he did not verify until he re-reviewed the data later that night.

 

[Scott231]

That would be kewl Gene and I agree that more data is better for better tuning.

I know that David Bamford runs a probe on each header tube - data is collected through a RacePak. But that's like a $3,000 setup! Not a likely option for most TR Buick owners.

There are enough variables that one cannot rely on EGT temps alone, be it from the average (via one probe) or individual cylinder readings. Proper A:F ratios are necessary along the way. And what some people may not realize is that the fatter the engine is operating, the less effecient the volumetric effeceincy. Maybe the Ungineers on this list will chime in.

 

[bruce]

Just a few ideas.

I think Knock Detectors do more damage long term then not having them, in so far as people are putting too much faith in them. As far as the oem GN setup, they are too easily overwhelmed. The racing buicks push the envelope of even the basic range they work at, and with the ODD to OEM spec AFRs the acoustic signature is just enough different that at TIMES the K/S just totally misses seeing any detonation.

If you go to the expense of building a hot rod GN, then everyone should be running a WB, and AN EASY TO SEE DISPLAY. There's just no reason not too. If this isn't a clear case of justifing the $200 or $400 for one, I'm at a lose to understand why.

And relying on EGT is just as bad as relying on just a WB.
Why?.
According to some sources can EGT drop while in detonation. Now having that happen will really ruin ones day.

If someone comes up with an affordable in cylinder peak pressure position sensor that would be neat. Lacking that, it's back to plug reading. And lots of it.

IMO, there's no controversy about what's best, best is gathering all you can. For the price of an engine, EGT monitoring and a WB are just cheap insurance. Heck even an investment since you can usually get your money about back on them anyway.

Get both, if you can't afford the data logging, who cares?. While it's a neat feature, not having any indicators because you don't have the best out there is missing the point.

Oh, and even reading the plugs can bite you.
Even with that, you can miss the tune, and run well and puke a motor.
But, when you read them, and use EGT, and WB info you min the possibility of being wrong.