Wednesday, December 29, 2010
12/30 Ross Reynolds from NH, two mountain motor Cats
1/3 Richie Meyers 518er looking for more HillDrag HP
1/4 Joe Shear XF1000
1/5 Tom Anthony IQR tuning
1/6 Jake Jenkins/ Dave Dillenbeck F7 big bore ]cancelled]
1/7 Kevin Atkins XF1000
1/8 Pat Paradiso trail mod Dragon 800 w/ various pipes
1/10 Jake Jenkins/ Dave Dillenbeck F7 big bore
1/11 Joe Shear F1200 lakeracer w/ boondocker n2o
updates coming 1/23
1/12 Rob Schooping/ John Clarey HTG1200 triple
1/14 Tim Winslow & Todd Hogan 800 promod hill drag sled cancelled
1/20 Dave Patrick F7 pm Steve Falmond F7/ Black Magic 800 for boondocker tuning
1/21 Koz Bros XF800 improver tuning
1/22 Jeff/ Vinny/ Danny Cerio Hooper TCat 1400 tune
1/22 PM Bill Swoyer cameras off
1/23 Casey Mulkins Dragon 800 tuning, trying new Aaen single pipe
1/24 Mach Z nano N2O tune, cameras off
1/25 Koz Bros tuning Sherlock Improved Crossfire 800
1/26 Tim Winslow and Todd Hogan promod hilldraggers
1/27 Carl Theriault Crossfire 1000 pipe shootout, Z1 tune delayed by new england snowstorm
1/28 Casey Mulkins back again with ProR 800, pipes, shim kit once more delayed by lack of pipes
1/29 HillBilly Howard, Etec 800 stage tuning with Bobby Donnatelle cams on delayed by possible lack of fuel to make extra hp at low temp high baro
2/2 Full Power RX1 extra large turbo tune cancelled due to Justin having the flu
2/3 Todd Hogan, more hilldrag sleds to tune cancelled due to weather
2/4-5 Carl Theriault Crossfire 1000 pipe shootout, Z1 tune cancelled
2/6 three flattrack bikes, tuning for Daytona
2/7 Ryan Kehl, Crossfire 1000 pipe shootout
2/8 AM Heath tuning a Jaws pipes 1080 triple, Nate McCoy, going for big HP on a XF800 mod
2/16 Boyesen Reed evaluation on stock XF800 w/ Todd Hogan, cams off
2/21 Turbo Dragon 800, attitude controller tune
2/23 ProR800 pipe test, cylinder shim test w/ Casey Mulkins
Monday, December 13, 2010
For the next few weeks or so, all 400 plus HP tuneups are on hold. The following photos show what is left of my $1000 big driveshaft.
In my blog schedule I facetiously suggested that last weekend after the Shootout, "OSP Jim and crew [were coming here] trying to break my dyno....". I won't be making jokes like that anymore!
Saturday afternoon, OSP Jim and madman driver R. Dustin came to demo the power of Shawn Burke's Adirondack Shootout record setting turbo Nytro (anyone who was at the Shootout knows it really didn't need much dyno tuning), but we never got to make any big power with the Nytro before the steel molecules in my big driveshaft got tired of holding hands. While loading the engine at 8500 RPM in preparation for our first dyno test, we felt a 1/2 second shudder followed by a loud pop and the engine was against the rev limiter for a fraction of a second before being shut down. The driveshat had separated at both ends--from the rubber vibration dampener at the engine, and the automotive ujoint coupler at the absorber end.
Fortunately, the orange colored driveshaft loop did it's job, and the roof of my building is dented by small parts but unpunctured. But there was a violent 360 degree spray of bolts, u-joint bearing caps and bearing needles that created many new holes in the ceiling tiles, walls, and light fixtures. And there are surely some IED-like steel shrapnel that I will find, rusted, in the parking lot next spring.
The taper end on Shawn's nytro is bent, but that working end, splined to the end of the three cylinder crank is replaceable from the side of the engine.
But most importantly no one got hurt. I will keep what's left of the driveshaft to explain to people that come come here why we never enter the dyno room with the engine under power.
Do I need a stronger driveshaft? Nope--it wasn't fatigue from too many high power sled engines (the shaft is designed for 500 lb/ft continuously), but operator error that created this havoc. Trying to assess this mess, like a forensic detective, I think this is what happened...
Torsional vibrations--impact gun-like forces that create havoc with crankshafts/ crank tapers/ clutches appear to be extremely violent on three cylinder four-strokes when boosted to many times their designed torque levels. Monsterous torque levels can cause those engines' cranks to wind up and unwind, creating torque spikes up to 10x higher than the engines' average torque. This can cause premature wear on clutch parts, and slippage of crank tapers creating wedging of clutch tapers or even worse fretting enough to melt and weld the steel on the crank tapers! Recently FPP Justin was here with a high-boost 4tec that after maybe five 400+ HP tuning runs, and spot welded it's crank to my SkiDoo dyno adaptor. I was able to remove the adaptor from Justin's crank, but there were some small chunks of his crank taper melted and welded into the female taper on my steel dyno adaptor. But I have had very little trouble like that with the many high boost four cylinder Yamahas and two cylinder Z1s tested with big torque. There just seems to be more torsional vibes with the big triples.
I was hoping not to do unintended taper welding with the OSP Nytro. So when R. Dustin showed me a light coating of moly lube on the crank taper (they do that to prevent stuck clutches), I decided to not clean it off, and see how that might help prevent taper galling during dyno testing. I installed the grade 8 dyno adaptor bolt with all the torque my IR 1/2" drive impact would put out, and attached the drive shaft. But when we began testing--loading the engine at 8500 there was some unhappiness with the dyno trying to control things. The SuperFlow dyno is completely automated--if you set the control to hold the engine at 8500 before beginning at test, it will try to do that regardless of whether it' 50 or 500 HP there. In this case, the dyno seemed to obtain the desired 8500, but then it would misfire like tuning was poor but Jim saw on his laptop monitoring the stand alone that it was against the rev limiter. But the dyno measures dyno speed, and Jim was measuring engine speed so that difference was probably my coupler slipping on the crankshaft taper! But that didn't register with me (never had that happen before), and it should have. Brain failure one is I should have removed my adaptor, cleaned the tapers and started over. But we tried again several more times befor the catostrophic failure, and this time I believe the torsional vibes/ slippage caused my tight crank bolt to begin backing out creating even worse slippage, and severe out of balance condition at the engine. And that perhaps created more strange, almost indescernable vibrations that were causing the four bolts on the dyno end to become loose, and eventually completely remove themselves from the adaptor and fly away. So my second brain failure was not going to check the condition of the driveshaft fasteners prior to each attempt to test. All four nuts flew, as did the lockwashers and bolts. Nothing broke, the fasters just loosened up and removed themselves in just a few seconds of operation, then flew in all directions like the square pieces of a pineapple hand grenade. I've done this so many 1000s of times without fastener issues, I ignored them at the worst possible time.
So OSP Jim will need to replace the Nytro crank end (hopefully only a few hundred bucks) and I will replace my big driveshaft. No need to redesign it, just build it again. But my cavalier assumption that what I tightened during setup will remain tight during the session is changed. And maybe now blue locktight on dyno shaft fasteners on these big engines will be part of the program for gonzo HP things.
And I must compliment the OSP guys on having the demeanor necessary for anyone who regularly races/ tests/ sells engines approaching 10hp/ cubic inch. Not everyone has that. Gaskets can squirm out, pistons can sieze, blocks can crack, rods can snap, and dyno drives can fail. I don't know who coined the calmly spoken southern drawl phrase "parts is parts", but it's appropriate.
This innocent looking small engine coupler is about $600 worth of stuff- the eight hole Lord torsional vibration damper is a key component necessary to protect the engines from their own harmonics. And that center self aligning bearing (what's left of it) is designed for the linkage of helicoptor rotor assemblies. The aluminum part is custom made on CNC machinery. New parts are on the way here.
Tuesday, December 07, 2010
“Blow Up” is a commonly used euphemism among performance sledders to describe a seized piston—stuck in the bore because it temporarily grew bigger than the hole due to lean operation or deto. That euphemism annoys me because a stuck piston is not a “blowup”—it’s very non-destructive, non terrifying like a “blowup” would imply. I have always thought that the term “blow up” should be reserved for something more serious than a crankshaft that no longer turns, with something awry, but easily fixable inside the engine that is preventing normal rotation.
When funnycar racer John Force says he “blew up”, you know something way more violent than a stuck piston occurred.
In November I had my first real, true sled “BlowUp” on the dyno.
Terry and Mike Queenan had the Queenan Brothers Racing Hayabusa powered asphalt sled here to tune. This was to be a fun session—the fellow who provides parts and tuning for the Motec EFI system for Queenans (as well as the Al Anabi drag cars and bikes) was remotely monitoring the DTR tuning session from his home office in California, making fuel/ timing tweaks after each run via internet and observing the dynocams.
Creeping up on revs and boost (I think we were only running 11 psi boost and 410 HP) this fellow noted, watching data during each dyno test, that oil pressure had dropped a bit—perhaps due to rising oil temp? We cooled the crankcase for a few minutes before the next run. But what we did not realize was that a rod bearing on the big end of one of the engine’s aftermarket connecting rods was beginning to seize on the crank journal—perhaps smearing rod bearing material into the crank oil journals preventing total loss of oil pressure. This friction would eventually create heat that would in the next six seconds of boosted operation cause the rod to try to friction- weld itself to the crankshaft, then turn blue and eventually grab and snap sending parts flying.
On dyno test 10, we ran the engine up to 11,500 RPM and a sudden, loud snap accompanied a 7’ diameter ball of fire that enveloped the expensive area of the sled all the way to the ceiling tiles in the equally expensive dyno room!
This fire was accelerated by the 80mph air from the dyno air supply ducts—making it look exactly like one of John Force’s Funny Car “blowups” where headgaskets squeeze out and spew oil onto the headers creating one of those nasty, terrifying oil fires and an out of control funnycar. But in this case it was the rod cap blowing out the front of the Hayabusa crankcase, showering the cherry red header/ turbo with engine oil and creating the first DTR fireball.
I bolted from the control console, grabbing one of the 25 year old, but previously unused Halon fire extinguishers, and ran into the dyno room and with two pounds of Halon completely extinguished the fire. Terry and Mike Queenan were duly impressed with the speed at which Jr. Fire Marshal Jim was able to run from the control console, grab the the extinguisher and reach and address their burning sled. Halon is great stuff—today banned by the greenies but still said to be available, at a premium, from suppliers who have a stash of this stuff.
But with the fire extinguished, there was still a substantial amount of oil left on the dyno table beneath the sled….what if this sled was running down the dragstrip at 180mph instead of sitting on my diamond plate steel table?
That unburned oil, instead would surely have been spewed and drizzled in front of the smooth rubber track with instant loss of traction and directional control! It’s one thing to have an engine explode (truly “blow up”) and shut a sled down, but the prospect of dumping oil directly in front of the smooth rubber track is terrifying considering what we all know might happen should a high speed sled/ rider encounter a guardrail or concrete barrier at 180 mph plus!
Fortunately, Queenan’s sled features a high tech multi-stage dry sump oiling system which minimizes unnecessary oil volume within the crank case and the sled also has a solid pan beneath the motor which trapped some of the oil from spilling out under the chassis. Without these features, the fire on the dyno table and the potential real-world scenario could have been much, much worse.
Why not add some sort of diaper-like oil catcher like the top fuel racers use? For them, dropping oil mostly between the two rear tires is not a huge control issue, but NHRA is mostly concerned with downtime necessitated by cleaning up the mess. But sled racers with boosted four stroke engines approaching 10 HP per cubic inch will surely occasionally “blow up” engines, inevitably dropping oil directly in front of the tracks. It would be wise to deal with the inevitable spewing oil ahead of time.
From now on, people bringing heavily boosted engines to DTR must endure a pre-test fire drill.