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Author Topic: Team Go Dog, Go! Modified Partial Streamliners  (Read 865750 times)

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Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3435 on: October 17, 2019, 08:10:13 PM »
Another publication.  It looks like an SAE standard applies.  See 3.8 https://wenku.baidu.com/view/b024f568a98271fe910ef92a.html

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3436 on: October 22, 2019, 10:48:20 PM »
150 psi!  That tactic requires more gonadal volume than I have.

The rear tire is the critical one.  It has a 537# load capacity with the 25% reduction due to the 168 mph speed.  The static load is 410#.  537 - 410 = 127# This is probably enough extra to account for weight transfer.  The tire has 8 mph extra speed capacity and 127# reserve load capacity at 160 mph.  It should be OK at 160 mph.  Also, the tire manufacturer was consulted about how to do these calculations and they are aware of what I am doing.

The purpose of all of this is to give some documentation to justify the tire choice if the subject is discussed with the tech inspector.  These calculations should suffice for that. 

A 43 tooth rear sprocket will be used with a 19 tooth front sprocket.  The tire speed is 168 mph at the 9,500 rpm rev limit.  It will be impossible to spin the tire faster than the rated speed. 

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3437 on: October 22, 2019, 11:43:31 PM »
The documentation for the last post.  It will be in the notebook I bring to the race.  Next year if salt conditions are OK I will run in the BMST.  If the salt is bad I will stay in Wendover and run in the World of Speed.  WOS tech inspection is something I have not been through so I am making sure everything they may want will be available.   

Offline Old Scrambler

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3438 on: October 23, 2019, 09:24:03 PM »
Bo.........think about your bike weight at speed..........not on your foot :wink:
2011 AMA Record - 250cc M-PG TRIUMPH Tiger Cub - 82.5 mph
2013 AMA Record - 250cc MPS-PG TRIUMPH Tiger Cub - 88.7 mph
2018 AMA Record - 750cc M-CG HONDA CB750 sohc - 136.6 mph
2018 AMA Record - 750cc MPS-CG HONDA CB750 sohc - 143.005 mph
2018 AMA Record - 750cc M-CF HONDA CB750 sohc - 139.85 mph
2018 AMA Record - 750cc MPS-CF HONDA CB750 sohc - 144.2025 mph

Chassis Builder / Tuner: Dave Murre

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3439 on: November 07, 2019, 01:54:19 PM »
Folks are using those battleaxe tires on Hayabusas.  Those big bikes cannot unpeel them so they should work good on my turtle-speed wonder.  This is documentation to get through tech if I am asked about the tires.  I do include an allowance for weight transfer.

This is how my build is organized.  The Triumph shop manual has chapters on everything and exploded diagrams showing the parts covered in each.   

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3440 on: November 07, 2019, 01:58:05 PM »
The parts boxes are labeled as per the chapter headings and they contain parts shown in the exploded diagrams.  The notebook is also organized with this method.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3441 on: November 07, 2019, 02:27:31 PM »
This next series of posts deals with issues in the "Electrical & Ignition Systems" chapter.

The flywheel has the alternator rotor coils in it and it is on the crankshaft end.  The engine can be rebuilt with the alternator on the crank if no shaft work is needed.  Some work will be done on this engine's crank so the rotor must come off.  The factory rotor removal tool has a zero chance of success based on past experience.  This is the removal method I have developed.

A high-grade M22 x 1.5 bolt is purchased.  The end is turned down to a stub and a brass bushing is turned on a lathe to fit over the stub.  Anti-sieze is spread around the stub and bushing.  This tool is threaded into the rotor and it is tightened with an impact wrench.  The tightening compresses the tool and it pops the rotor off of the tapered crankshaft end.  Sometimes.

The impact wrench imparts energy to the tool.  Some of that energy is used to overcome friction between the tool and rotor threads.  More energy is lost to spin the tool end on the crank end.  The remaining energy compresses the tool against the crank by turning it in the rotor threads. 

Anti-sieze is used on the threads to reduce friction based energy loss.  The rotating tool pushes on the lubricated face of the brass bushing rather than the crank end and this reduces energy loss due to friction at the tool end.  This leaves more energy to compress the tool.  This home made tool will remove rotors that the factory tool cannot.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3442 on: November 07, 2019, 02:30:47 PM »
Tools to remove the rotor include a heat gun, impact wrench, strap wrench, and a strip of sheet aluminum.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3443 on: November 07, 2019, 02:40:23 PM »
The tool is threaded into the rotor and tightened with the air gun.  Sometimes this is all that is needed to remove the rotor.  The next step is done with the tool screwed into the rotor.

The sheet aluminum is bent and put inside the rotor.  It is a heat shield to keep the rotor coils from being overheated.  The center of the rotor is heated with the heat gun.  It is heated until the center is hot to the touch.  Sometimes the rotor pops off during the heating process.

Another burst from the impact gun is made when the rotor center is hot.  Usually this pops off the flywheel.  If not, the flywheel and crank are taken to a machine shop and an arbor press is used to separate the parts.   

Offline Jim Phelps

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3444 on: November 12, 2019, 01:35:50 PM »
150 psi!  That tactic requires more gonadal volume than I have.

The rear tire is the critical one.  It has a 537# load capacity with the 25% reduction due to the 168 mph speed.  The static load is 410#.  537 - 410 = 127# This is probably enough extra to account for weight transfer.  The tire has 8 mph extra speed capacity and 127# reserve load capacity at 160 mph.  It should be OK at 160 mph.  Also, the tire manufacturer was consulted about how to do these calculations and they are aware of what I am doing.

The purpose of all of this is to give some documentation to justify the tire choice if the subject is discussed with the tech inspector.  These calculations should suffice for that. 

A 43 tooth rear sprocket will be used with a 19 tooth front sprocket.  The tire speed is 168 mph at the 9,500 rpm rev limit.  It will be impossible to spin the tire faster than the rated speed.

From your wind tunnel test you can calculate the front and rear lift values at 160 mph and add that to your static measurements. You might find you have positive lift at the front wheel and additional down force at the rear. Also, torque has to be applied to the driven axle to match the forces of aerodynamic drag and rolling resistance. The reaction to that torque causes a load transfer from the front to rear, again causing additional load to the rear tire. I believe that it would be better to combine these forces and then show in your log book that you still have excess load capacity.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3445 on: November 15, 2019, 11:18:00 AM »
Thanks for the advice, Jim.  When I find where I put the wind tunnel data I will post it and then I need help with doing the calculations.  Traditionally weight transfer is not considered when inspectors evaluate tire speed rating vs potential motorcycle speeds.  I might be overthinking this issue.

Nuts and bolts on race engines are all tightened to specified values.  Disassembly is done by hand rather than an air wrench.  Fasteners that take much less torque to remove than to install are noted.  Problems might be occurring.

The eight large bolts holding the cases together around the crankshaft have been problematic.  They have loosened and there has been fretting at the joint between the crankcase halves.  This issue needs to be addressed before the engine is developed further.

The old crankshaft rod journals were at the same location on the crank, degree wise.  Both pistons went up and down together.  The inertial forces of this created large tugging forces at the crankcase joint.  The new crank has journals 90 degrees apart.  This spreads the inertial forces out over a longer duration of the rotational cycle and it reduces the peak tugging force.

The counterbalancers were used with the old crankshaft.  They were located in the upper case half and the pulled in the opposite direction of the crank inertia forces.  This increased tension stresses at the crankcase joint when the pistons were traveling through bottom dead center .  The counterbalancers are not used with the new crank.   

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3446 on: November 15, 2019, 11:31:17 AM »
Triumph made two changes to the big crankcase bolts and tightening procedures.  The latest bolts are used with a modified version of the most recent tightening procedure.  The newer bolts are more substantial due to some dimensional changes.

The bolts are tightened in stages as per the shop manual.  The bolts are tightened for each stage.  Then, each bolt is checked to make sure it is sufficiently tight before proceeding to the next stage.  Some may need a little bit more tightening.  This is an additional step that is not listed in the manual.

The standard Triumph bolt comes with a torx head that is easily striped during assembly and disassembly.  Stainless steel bolt heads are welded onto each bolt to replace the cheap and cheesy torx heads.  This is a big help.   

All of this works.  The crankcase bolts stayed tight after the most recent race.  Problem solved.   

Offline 4-barrel Mike

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3447 on: November 15, 2019, 11:45:34 AM »
A member of the Peanut Gallery asks: doesn't welding a stainless head to the crankcase bolts affect the strength and elasticity of  those bolts?

Mike
« Last Edit: November 15, 2019, 11:49:44 AM by 4-barrel Mike »
Mike Kelly - PROUD owner of the V4F that powered the #1931 VGC to a 82.803 mph record in 2008!

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3448 on: November 16, 2019, 12:27:13 AM »
The bolts are stainless along with the added heads.  Stainless steel is a poor conductor of heat.  One advantage to MIG is its speed.  The welds were zapped on so fast that there was not a lot of heat transfer to the adjacent bolt.  I saw no evidence that the bolts were annealed from weld heat. 

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3449 on: November 17, 2019, 12:23:03 AM »
As per the bolts, they were quenched after welding.  I did this so they would be cool and easier to handle.  That might have prevented annealing.  I do not remember very well.  That was in Spring 2018.

The crank, rods, and rod shells were sent to Marine Crankshafts in Santa Ana.  They work on the cranks for the Triumph flat track team.  Three sets of shells were sent.  One is the used 2018 set with wear from salt flat runs and dyno tests.  An evaluation of these is requested along with recommendations about any work needed on the crank.  Another set is four new shells intended for use in 2020.  Clearance measurements are requested for these.  I am not sure if my plastigage method is accurate.  Some professional measuring will be a big help.  The last set is two coated top shells.  There might be an advantage to using these.

An explanation was provided about how and why I removed 0.0002 inches diameter from the rod journals to get looser racing clearances in 2018.  This was done by hand using emery paper.  Is this mickey-mouse modification OK, I ask.

The graph shows dyno and computer model horsepower.  The rpm limit will be raised from 9,000 to 9,500 or 10,000 if the crank will withstand it.  I ask about this.  The engine should give more power if this is done.

The rod big end shells are the last reliability issue.  Once this is sorted the rev limit will be raised and the engine will be fully done in its naturally aspirated form.