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Author Topic: Team Go Dog, Go! Modified Partial Streamliners  (Read 774432 times)

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Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2385 on: April 10, 2016, 08:27:02 PM »
Neil, like you say, it seems to hold up to wear and use better than any modern "hardware store" paint.  Another good thing is that it does not peel up the prior applied undercoat or older paint.  This is much different than the modern xylene based paints.

Not much appears to be happening on this build.  In reality, a lot is being done.  It is the "basic hard work" type of stuff and nothing is notable or glamorous enough to post.  The machinist that designed and built the valve train is taking my PipeMax data and is entering it into EnginePro.  This way, he can analyze what needs to be done with consideration for altitude.  He is using 6,000 feet as an estimate.  He is the head guy in the research and development department at a performance parts company.  The best thing I can do now is to be quiet and let him do what he thinks best.   











 

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2386 on: April 20, 2016, 12:00:50 AM »
The static compression ratio is 11.9 to 1 and I cannot increase it and keep the piston dome height at a reasonable level.  These four valve engines depend on mixture tumble rather than swirl as used in a two valve chamber.  Tumble does not work with a piston dome in the way.  So... compression ratio is optimized.

Bigger valves require excavation of the combustion chamber to fit them and to clear around the peripheries to prevent shrouding.  This will drastically lower the compression ratio.  The head flows just great at low to medium cam lifts, and much better than PipeMax requires, according to the expert at Kibblewhite.  There is nothing to be gained by making them bigger.  Valve size is optimal as it is.

There might be some room for flow improvement at high lifts in the intake ports upstream from the valves.  Maybe bigger carbs.  They will be 42mm flat slides that are scrounged off of dirt bikes, if I need to do this.

The new cams, evidently, seem to be ground for a stroker engine.  These are 1088 cc monsters that cram the mixture into a combustion chamber that was originally designed for a 790cc twin.  The have extraordinarily long durations, 266 intake and 258 exhaust, at .050.  There is lots of spread with lobe centers at 112 and 111.

This combination makes for a very low compression duration, power duration, and dynamic compression.  The dynamic is in the low 8's at B'ville.  My thoughts are, backed up by some calculations, that the need to have a reasonable street able compression ratio on the stroker requires the inlet valve to be hung open a bit longer than normally required.

Regardless of the excellent logic used to develop these bump sticks for a stroker motor, they aren't what I need for a 995 cc engine.  Calculations from the Horsepower Chain book say a 234 intake duration is optimum with a 104 lobe separation angle.  This is a whole lot less than what these cams give.  The peak power rpm will be 1.04 times higher and the peak torque 90 percent of what it would be with optimal cams.

Johnson Cams up in Washington does some work with these engines and have developed adjustable cam gears so I can fine tune the timing, just like on the old Meriden Triumphs.  The expert at Kibblewhite told me about this.  Johnson also grinds cams.  This should not slow the build down.  The cams can be made at the same time the ceramics are applied to the head.

Basically, lots and lots of hours the last few weeks are going into calculations and other high powered figgering.  I wire down a few inches on my pencil and had to buy a new pad of graff paper! 

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2387 on: April 23, 2016, 10:58:46 AM »
The cams I was shipped are a pattern used to set a land speed record on a 995 cc engine, I learned recently.  Some figuring shows the long durations require a lot of rpm to work with some sacrifices in peak torque and volumetric efficiency.  This can be a winning combination.  It allows the engine to use numerically higher gear ratios and this gives more tractive force.  This can more than compensate for reduced peak torque and VE.  A few builders are taking the high rpm approach both here in the US and in AUS.

The downside if the high rpm method is a reduction in component life and good skills are needed to build the motor.  In my case, I do not have enough money to replace a lot of parts.  Also, the stuff is custom made and it takes a long time to get.  Too, there seems to be a history of catastrophic component failure with these highly tuned engines.  The lessons learned from this, as per engine setup, I will never know.  I am pretty far removed from the "inner circle."

The original engine as shipped from Triumph had the rev limiter set at 7,300 rpm.  The limit is raised to 9,000 rpm this year on my engine.  Stresses on engine parts are often the square and sometimes cube of rpm increase.  The 1,700 rpm increase increases stresses 1.5 to 1.9 times based on these ratios.  The cutting edge builders are revving these things over 10,000 rpm.  This increases the stresses 1.9 to 2.6 times over those at 7,300 rpm based on square and cube ratios.  As seen by this, ultra high rpm puts bigger stresses on an engine.  Did the Triumph engineers include enough factor of safety in their design and material selection to address this?

The 9,000 rpm limit requires some cams with shorter durations than the ones I have.  The pattern development costs for custom cams make them real expensive.  There is a cam shop that has been selling and working on bumpsticks for these motors and they have been doing it for years.  The expert that is helping me is figuring out the cam characteristics I need with consideration for the measured flow in the cylinder head, the measured compression ratio, air density at Bonneville, and the desired peak power rpm that is in the mid 8,000's.  Hopefully the cam shop has something close to what I need.

The approach is to use some serious thinking and work to develop a motor that will beat the big rats on a tiny mouse budget.   

   

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2388 on: May 04, 2016, 11:45:01 PM »
A few minutes ago I sent in the entry for FIM 1000 cc partial streamliner, 1000cc, 2 cyl, naturally aspirated.  The 2014 rules are on the  BMST website so I printed a copy.  First, I read 2.81.18.  These are the partial streamliner rules.  Then I read the rest of 2.81.  These are the other specifications for Bonneville bikes.

Now comes the tricky part.  2.14 and 2.15 are sound regulations.  The section 2.14 say these will be enforced when required by supplementary rules or at specific locations.  So far, the speed trials have not required sound control.  I will read the noise control section when the 2015 rules are distributed, to make sure "no mufflers" continues to be allowed.

The rules from 2.12 down to 2.1.1 also apply unless said otherwise in the 2.80's section.  It helps to understand, when reading these sections, that many FIM world records are set on road race tracks with road race type bikes, and they make no sense for an LSR bike.  Requirements for helmets, etc are in 2.13.

The BMST also has requirements and in some cases they are more stringent than the FIM.  So, I read the BMST regs and make sure I comply with the strictest of the two, BMST or FIM.

The AMA requirements are different than the FIM.  It is not unusual for an inspector to forget the subtle differences.  Just in case, I always have a set of the FIM rules handy.

All of this makes the most sense if the rules are read from back to front.


     

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2389 on: May 16, 2016, 10:33:47 PM »
The ports were done by South Bay Triumph many years ago.  The standard valve sizes were retained and they did a good job.  The intake valve sizes were increased 2 mm a few years ago.  They were not matched to the ports as wells they could be.  I was sorta low on $$ at the time.  Then, I did a little deshrouding in the combustion chamber and matched up a pair of racing inlet manifolds this fall.

This year the head was sent to Kibblewhite so they could check the valve train and verify that it would work with the higher lift cams.  Also, they could renew any parts.  They built the valve train so they are the best choice for that.  The valves were not enlarged.  The intakes will stay at 2mm larger than standard and the exhausts are standard size.  All sorts of calculating says this is the best choice.

The big task was to put it on the flow bench and try for perfection in the ports.  There were two goals.  One was to get better flow at high lifts.  The low lift flow was great.  The other was to get a better flow distribution around the valve periphery.  This is hard to do with this side draft head.  The pictures show the finished job.  Two will be on this post and one on the following.  Note the pits on the combustion chamber surface.  This bike has been raced every year since 2007 and it shows.

   

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2390 on: May 16, 2016, 10:35:09 PM »
Another photo.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2391 on: May 17, 2016, 09:44:48 PM »
Preliminary flow results at 28 inches came in today.  To keep things in perspective, the max flow during the last flow test a couple of years ago was 211 cfm with exhaust stub, manifold, carb boot, carbs, and oiled foam filter.

Max flow with bare head with clay radius around intake is 249 cfm
Max flow with manifold, and rubber carb boot with clay radius around boot end is the same.  The manifold and rubber boot don't hurt anything, flow wise.
Max flow with all of the above and carb and velocity stack = 227 cfm.  The carb and stack are costing me 22 cfm.
Max flow with all of the above and the oiled foam filter is 211 cfm.  A problem is identified.  The filter appeared to be over oiled and dirty.  He will clean it and test it again tomorrow.

Now I know what to do.  Bigger carbs are a project for next winter.  Some 42mm flat slide dirt bike carbs should be the ticket.  There are 39mm ones on the bike now.  I can figure out the filtration then, too.  "The Horsepower Chain" book gives me a lot of guidance on this.

 

 

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2392 on: May 18, 2016, 07:30:10 PM »
The oiled foam filters are costing me a lot of power.  Pleated oiled gauze filters do not filter good.  The filters are on the carb bell mouths and the pulsing intake flow pulls grit and salt through the gauze.

What I am looking for is a paper type clamp-on filter that will give good filtration.  I can toss it when it gets dirty.  Any recommendations?

Offline salt27

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2393 on: May 18, 2016, 09:08:48 PM »
Bo,
We have had very good luck with "pleated oiled gauze filters" in the sand and on the salt.
I do use the largest filters I can reasonably fit.

  Don

« Last Edit: May 18, 2016, 09:12:09 PM by salt27 »

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2394 on: May 24, 2016, 10:21:34 PM »
A few hours ago I got home from watching the Sacramento mile.  It is a two day ride south of here.  One of my riding buddies went down too on his Thruxton, I rode the Bonneville, and my middle son came up from camp pendleton on his Bonneville.  We had a mini-motorcycle gang.  There was a triumph rider, Jake Shoemaker, on a Bonneville.  He placed second in his heat race and did not do very well in the final.

There were a bunch of Harleys there from factory and private teams.  They were expected to win on their 750 twins.  Some other folks were racing other brands and mostly 650 Kawasaki Ninja powered bikes.  These have 650 cc engines and much smaller displacement than the Harleys.  A fellow riding one, Bryan Smith, led the race for almost all of its length on a 650 ninja.  The second ranked rider, nationally, shadowed him on his harley.  He drafted him till the very end and then made his move to pass at the last seconds.  The kawasaki rider held him off and won by a wheel length on his 650.

In the old days the guy drafting the leader had an advantage.  His engine was cooler 'cause it was not working as hard and it had reserve power for the final dash for the finish.  The 750 Harley is air cooled and that drafting probably helped it.  The ninja engine is water cooled and it produced consistent power even though it was the lead bike and it was working hard.  That is my theory.  It seems that water cooling might be a big advantage during long races.

The spectators were allowed into the pits before the race.  My problem with filtration was discussed with other tuners.  Most of them use pleated and oiled filters.  Their filters were much bigger than the oiled gauze ones I used.  This might be important.  The sucking force is decreased in proportion to filter size.  Sock style covers were used by one experienced tuner.  They covered the gauze filters and kept the bigger particles out.  He said the flow reduction from the filter and sock was minimal.

In the past I used the sock and gauze filter system and was not very impressed.  It might work a lot better with bigger filters.  I think I can increase the surface area three times over what I used before.
 

Offline Peter Jack

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2395 on: May 24, 2016, 10:29:24 PM »
Bo, often the problem with the oiled gauze filters is that people tend to over oil them. That definitely increases the restriction.

Pete

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2396 on: May 26, 2016, 08:51:57 PM »
How do you know if they are over oiled?

The data sheet is attached.  I was going to refine the cam profiles and leave the filters and carbs alone.  Now I will enlarge the filters and carbs.  This testing saved my butt.

Offline Peter Jack

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2397 on: May 26, 2016, 11:48:49 PM »
Bo, if you go to the K & N website they have a complete article on cleaning and reoiling your air filters. They're very specific on not over oiling the filters.

Pete

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2398 on: May 27, 2016, 12:12:59 AM »
Thanks, Pete.  The original equipment battery is a big lead/acid 12 volt one.  It sits crossways across the frame between the air filters.  Tonight I ordered an equivalent lithium ion one.  It is much smaller and I will make a new battery box so it will fit lengthwise.  This will provide a lot more room for large air filters.   

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2399 on: May 28, 2016, 12:27:00 AM »
This is a picture from the cylinder head in the Kibblewhite R and D lab.  It is looking into the cyl head.  The tube width is the "reference bore diameter" and it is recorded for use in future calculations.

Note the corrosion.  I sprayed Marvel Mystery Oil into the combustion chambers before the bike was packed in Wales for shipment home.  Is there a better corrosion protection oil than this?