Author Topic: Team Go Dog, Go! Modified Partial Streamliners  (Read 1435978 times)

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Offline manta22

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3015 on: January 13, 2018, 10:37:59 AM »
Monza? Maranello?

Regards, Neil  Tucson, AZ
Regards, Neil  Tucson, AZ

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3016 on: January 13, 2018, 09:19:32 PM »
Roma, Sorrento, Florenzia, Como, Bolzano, then Venezia.  Side trips to Lucca and Pisa.  In Como we will be near Monza.  Maybe another side trip?

The bolts might be stretching, in which case some stronger ones can help.  Or, the aluminum case might be compressing and less clamping force might be optimal.  Or, the bolts might be rotating out.  The solutions to these problems are completely different so more data collection is needed.

Doweling might help.  Who does this?

 

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3017 on: January 14, 2018, 12:46:47 AM »
The 2015 trip to Wales to race at Pendine was my first overseas trip besides going to Hawaii.  Working, learning a trade, engineering skool, and raising children used all of my time and money.  Summer vacations were spent helping my parents with projects too big for them to do.  It is nice to get the time to go somewhere. 

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3018 on: January 21, 2018, 07:21:31 PM »
The crank is shown in the upper case and the empty places in front and behind the crank are for the counterbalancers.  The balancers are shown in the other foto.  The crank crank and balancers tug against each other through the bolts I am having problems with.

The Triumph flat track race bikes use dynamically balanced 270-450 firing order cranks without the counterbalancers.  My bike will not use the counterbalancers this year to reduce stress on the case fasteners.  The crank was dynamically balanced a couple of months ago so that task does not need to be done.     

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3019 on: January 26, 2018, 01:48:05 AM »
The rod big end shell to journal clearances recommended by Mahle are 0.00075 to 0.001 inch clearance per inch journal diameter plus 0.0005 for a race motor.  This is 0.0017 to 0.0021 for the Triumph.  The journal lapping with toothpaste makes the clearances right in the middle of this range.  The rod big ends are not too tight.

The recommended crank main shell to journal clearances are 0.0016 to 0.0020 using the same formula.  The measured clearances are 0.0015.  This is a bit tight although it is within Triumph manufacturing tolerance.

The crank shell housing is aluminum alloy and it expands almost twice as much as steel crank per degree of temperature increase.  Some calculations are made.  It is assumed the recommended clearance is measured at the typically specified 68 degrees F.  Heating both the cases and the crank 30 degrees F expands both.  The crank main journal diameter increases 0.00029 inches.  The housing for the main bearing shells expands 0.00062 inches.  This increases the crank to shell clearance to 0.0018 inches which is OK.  It appears, clearance wise, that starting with a warm engine is all I need to do to get the correct main bearing clearances.

My question is this.  How is main bearing clearance set up in an aluminum block engine?  It seems there must be a way to account for the differences in expansion for the materials.

Offline WhizzbangK.C.

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3020 on: January 26, 2018, 08:44:35 AM »
My understanding has always been that assembly clearances are specified as measured under standard room temperature conditions, and that those tolerances are calculated by the engineers to provide proper running clearances at operating temperatures.
Ah, this is obviously some strange usage of the word 'safe' that I wasn't previously aware of.  Douglas Adams

Offline CNC-Dude

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3021 on: January 26, 2018, 04:10:38 PM »
The rod big end shell to journal clearances recommended by Mahle are 0.00075 to 0.001 inch clearance per inch journal diameter plus 0.0005 for a race motor.  This is 0.0017 to 0.0021 for the Triumph.  The journal lapping with toothpaste makes the clearances right in the middle of this range.  The rod big ends are not too tight.

The recommended crank main shell to journal clearances are 0.0016 to 0.0020 using the same formula.  The measured clearances are 0.0015.  This is a bit tight although it is within Triumph manufacturing tolerance.

The crank shell housing is aluminum alloy and it expands almost twice as much as steel crank per degree of temperature increase.  Some calculations are made.  It is assumed the recommended clearance is measured at the typically specified 68 degrees F.  Heating both the cases and the crank 30 degrees F expands both.  The crank main journal diameter increases 0.00029 inches.  The housing for the main bearing shells expands 0.00062 inches.  This increases the crank to shell clearance to 0.0018 inches which is OK.  It appears, clearance wise, that starting with a warm engine is all I need to do to get the correct main bearing clearances.

My question is this.  How is main bearing clearance set up in an aluminum block engine?  It seems there must be a way to account for the differences in expansion for the materials.
Different alloys of aluminum expand more/less than others at the same temp. It seems most motorcycle engines are the die cast variety, while most automotive race blocks are cast or even billet, and have different expansion rates than a die cast block does. Many racers with aluminum engines also use block and oil heaters before they crank an engine at a race to allow everything to expand and be race ready. But as with your extra clearance recommendation for the rods, you also would follow suit and increase the main bearing clearances the same. Keep in mind that extra bearing clearances sometimes means lower oil pressure, so prepare ahead and see what changes in your oil pump can compensate for that so you can maintain a good pressure.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3022 on: January 26, 2018, 05:55:04 PM »
Thanks for the help on this.  The rods and crank have similar thermal expansion coefficients so the clearances are not expected to change much between 68 degrees F measuring temperature and operating temperature.  The die cast aluminum cases and the iron or steel crank have vastly different thermal expansion coefficients with the cases expanding more than the crank.  It seems to get correct operating temperature clearances the clearances must be tight at 68 degrees F.  Maybe I should be happy with 0.0015 clearance at 68 degrees F.  I am not sure about this.  There is very little info available on the finer points of bike engine tuning

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3023 on: January 27, 2018, 12:54:32 AM »
The new version crankcase bolts arrived.  They are the same diameter as the old ones.  They are longer and they engage the threads 5 mm further down in the crankcase.

The crank bearing shells are made by NDC Bearing Co. in Japan.  The older shells have F-780 stamped on them.  The NDC website says these are lead-bronze on steel and they are "High load half bearings."  Triumph made a change to the part number.  The newer shells are stamped with FC170 and the website says these are "Half bearings with higher load capacity, compared to F-780."  It was a no-brainer decision to upgrade to the newer main bearing shells.  Eight are on order.

The rod bearing shells are stamped with F-780, too.  An upgrade seems like a good idea.  The Rocket III engine uses the same rod bearing shells that I do according to Triumph part numbers. They use Rocket III engines in the Triumph streamliner.  The folks that build these engines might know about an upgrade.

Research continues.   

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3024 on: January 27, 2018, 11:25:55 AM »
The search for a team rider is over.  The major qualifications are to not argue with the team owner, tuck in well, and stay out of the beer stash.  This little guy does all of that and more.  www.bbc.com/future/story/20180126-meet-the-motorbike-racing-robot

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3025 on: February 10, 2018, 12:39:09 AM »
The class I took and the reference material I have give me all sorts of information to set the wire feed welder feeds and speeds for full penetration welding.  All I need to do here is to build up a bead on this aluminum casting so it can be machined down to fill in the gap.  Full penetration would be for a 7/16 piece which seems like far too much wire feed and amps.  Any help with this is appreciated.

This is the rear hub for my desert race bike.  It is so old that they do not make a new hub for it.

Offline Peter Jack

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3026 on: February 10, 2018, 01:16:36 AM »
You're walking on seriously shaky ground here Bo. Without seeing what you're attempting to weld but mentioning a hub, I would say safety rates high with this project. First be sure you know what alloy you're dealing with and match it as closely as possible. Second, remember that generally aluminum softens under the heat of welding and must be properly treated to regain its strength. Thirdly, this sound like a precision job and mig definitely is not a precision process. It's not something I'd approach with mig. Tig would be by far the preferred process.

That being said, be careful to keep everything super clean and use preheat if you decide to go ahead.

Pete

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3027 on: February 11, 2018, 12:34:08 AM »
Some off season entertainment...

"The One" is the big bike show in Portland.  The sun was out.  It was sunglasses in February for Rose.  The line was a quarter mile long to get in.  It was hard to snap pix.  Butts and legs everywhere.  It took patience to get photos.  The venue is an old factory.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3028 on: February 11, 2018, 12:38:08 AM »
This is a really old honda.  From the mid or early 50s.  Note the perimeter frame.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3029 on: February 11, 2018, 12:43:37 AM »
This Benly honda is four or five years younger.  Look at how much the casting and metal work advanced in a few years.