Landracing Forum Home
November 20, 2017, 04:15:57 PM *
Welcome, Guest. Please login or register.
Did you miss your activation email?

Login with username, password and session length
News:
BACK TO LANDRACING.COM HOMEPAGE
 
   Home   Help Search Calendar Login Register  


(Note: Donations are not tax deductible)







Live Audio Streaming and Archives of Past Events
Next Live Event: TBD
Pages: 1 ... 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 [194] 195 196 197   Go Down
  Print  
Author Topic: Team Go Dog, Go! Modified Partial Streamliners  (Read 519132 times)
stay`tee and 1 Guest are viewing this topic.
Interested Observer
Sr. Member
****
Offline Offline

Posts: 330




Ignore
« Reply #2895 on: October 18, 2017, 07:46:35 AM »

Wobbly,
At the end of a long and frustrating day with only a short time available to consider use of the program is probably not the best way to approach it.  Although I havenít seen it, the program offered by Neels Vannik is apparently a derivation of, and extension of, the Blair technology (which I have seen) and is likely as good as you are going to find at modelling gas dynamics.  It may not be easy to digest at first but you need to sit back with an open mind and spend some time absorbing the overall approach that it uses.  Come to grips with what it offers and how to use it.  It is much more sophisticated and capable than Dynomation.
And do not expect to get instant, simply obtained, answers.  There is a reason that Dynomation doesnít do a good job of gas dynamics analysis.

There are any number of testimonials for the successful use of the program, including rddreams (just above, #2893) which, if you read through it, uses the Vannik program.
Logged
JimL
Sr. Member
****
Offline Offline

Age: 71
Location: Sutherlin, Oregon
Posts: 739





Ignore
« Reply #2896 on: October 18, 2017, 11:31:09 PM »

Bo....your reply 2892 sparked a funny memory.  I will post the little story in the jokes section, since you brought the actual event to mind. wink
Logged
wobblywalrus
Hero Member
*****
Offline Offline

Age: 64
Location: backwoods Oregon
Posts: 4442





Ignore
« Reply #2897 on: October 19, 2017, 09:27:15 PM »

Some shopping around shows me that the only other programs that do this type of modeling are real expensive, available to corporations, only, or both.  I am very thankful to have this program.  It is essential to get the power I need to be less slow.

The problem is toggling back in the screens to change things that were previously input.  Once I figure this out the big user related problems are solved.  Rose is on vacation so I moved the computer onto the kitchen table.  Some serious effort will be made in the next week to get some useful results.
Logged
wobblywalrus
Hero Member
*****
Offline Offline

Age: 64
Location: backwoods Oregon
Posts: 4442





Ignore
« Reply #2898 on: October 21, 2017, 11:11:02 PM »

My problem is being tired when I work with the program.  Last night I had 8 hours of sleep.  This morning I woke up, had two cups of coffee, and started to model the exhaust system.  It took about a half hour to figure out solutions to the problems I was having.  Now the exhaust, intake, and engine are modeled.  Tomorrow I will take the head off and measure the parts and model the cams and valves.  Progress is happening. 
Logged
WhizzbangK.C.
Full Member
***
Offline Offline

Age: 56
Location: Kansas City, MO
Posts: 196


Ed Bennett, Speed Team Doo Kansas City fab shop.




Ignore
« Reply #2899 on: October 21, 2017, 11:47:46 PM »

Don't you just love the feeling of the "ah-ha moment" when everything just clicks into place and becomes clear?  cheers
Logged

Ah, this is obviously some strange usage of the word 'safe' that I wasn't previously aware of.  Douglas Adams
wobblywalrus
Hero Member
*****
Offline Offline

Age: 64
Location: backwoods Oregon
Posts: 4442





Ignore
« Reply #2900 on: October 22, 2017, 07:06:49 PM »

Clarity of thought is a rare occurrence around here.  More enlightenment happened today.  Timing was measured for both cams to get data to put into the program.  The lobe centers are both retarded around 4 degrees.  This might be due to cam chain wear.  Advancing them back to the settings on the cam card should help to move the torque peak to lower rpm where it will be much more useful.
Logged
RansomT
Sr. Member
****
Offline Offline

Age: 58
Location: Georgetown, KY
Posts: 472





Ignore
« Reply #2901 on: October 23, 2017, 09:35:40 AM »

Clarity of thought is a rare occurrence around here.  More enlightenment happened today.  Timing was measured for both cams to get data to put into the program.  The lobe centers are both retarded around 4 degrees.  This might be due to cam chain wear.  Advancing them back to the settings on the cam card should help to move the torque peak to lower rpm where it will be much more useful.

I went back and looked but couldn't find it..with those 4 degrees what was the actual timing?
Logged
wobblywalrus
Hero Member
*****
Offline Offline

Age: 64
Location: backwoods Oregon
Posts: 4442





Ignore
« Reply #2902 on: October 23, 2017, 09:35:54 PM »

The cam grinder gets agitated when the specs are posted on line.  The RB Racing dynamic compression calculator is used with a 4,100 foot elevation and intake valve closing as per the cam card.  Dynamic comp is 8.69 to 1.  Actual cam timing lags 4 degrees and it gives a dynamic of 8.41 to 1.  The can grinder says I can advance the intake cam as much as six degrees from the card value.  This gives dynamic comp to 9.09 to 1. 
Logged
RansomT
Sr. Member
****
Offline Offline

Age: 58
Location: Georgetown, KY
Posts: 472





Ignore
« Reply #2903 on: October 24, 2017, 05:58:23 AM »

Those 4 degrees could be "scruffing" off a lot of TQ.  Went back and looked at your last dyno sheet, you definitely could take advantage of moving those 4 degrees.  You would gain TQ and increase power over the curve high in the RPM range and might even pickup peak HP.  Lobe separation would remain the same. Where the cams are now, you really don't know where peak HP occurs.  I know you will, but if you move them make sure you check PTV clearances.
Logged
wobblywalrus
Hero Member
*****
Offline Offline

Age: 64
Location: backwoods Oregon
Posts: 4442





Ignore
« Reply #2904 on: October 24, 2017, 11:10:27 PM »

Hopefully this new program will help me to figure out the lobe center angles.

Cam and bucket wear was a big problem last year.  The cams I had were proven race grinds that set land speed records.  They pitted and scored the buckets and the lobe tips.  High dollar race teams use valve train packages that last for a race, I was told.  These cams did not seem to be too excessive when this is considered.

My program is low to no budget so this would not do.  That is one big reason for the computer modeling.  It was to emphasize lower RPM, higher volumetric efficiency, and lighter parts to get power instead of lots of revs, low efficiency, and big valves and cams.  Power in an affordable engine is the goal.  Plus, in the UK the bike will be my transportation when I am not racing it.

Cams with lift that matches the flow capacity of the head were selected.  The head flows good to .4 lift so cams with .4 lift were selected.  These are webcam #208.  This is much less lift than those old race cams.  This reduces stresses on the oil film at the lobe tips.

The 208 cams might have worked with the old 28 mm tappet buckets.  Maybe.  30mm buckets were installed to be safe.  Kibblewhite did this work.  This is a big deal.  The cams need to stay on the buckets to give long life.

I was using a generic race spring package from a reputable source.  Most folks use valves 4 to 5mm larger than standard and rev the engines past 10 grand.  These springs were stiff to do this.  The valves are 1 to 2 mm larger and the red line is 9 grand.  Softer springs could be used.  A special set was made by kibblewhite for this engine and cams.  They looked at spring harmonics and other critical things.  The result is much lighter springs that do the lob.  This reduces valve train stress.

The cams were broken in using the outer springs, only, with no spring seat shims.  This advice came from land racing.com.

Real good quality synthetic race oil with a zinc-phosphorous package was used for the break in.  It is the oil I normally use.  I would not use it for piston ring seating.  Mineral oil is used for that.

The cams and buckets polished in primo.  They look better than any Honda cams or standard Triumph cams I have seen and are nice and shiny like Yamaha cam lobes.  This part of the build is working great.   

       
Logged
wobblywalrus
Hero Member
*****
Offline Offline

Age: 64
Location: backwoods Oregon
Posts: 4442





Ignore
« Reply #2905 on: October 27, 2017, 12:36:02 AM »

That latest computer program and the walrus do not get along.  It takes a nuclear rocket scientist to figure it out.  That excludes me.  The earlier program gives me no trouble.  It models a large diameter tapered header with a collector and a generic muffler without a catalytic converter.  Three intake and exhaust lobe center combinations were tried.  107-116 is what it is now.  112-111 is recommended on the cam card.  106-108 was a tightened lobe center setting the cam grinder says might work.

Based on the 11.7 to 1 compression ratio the bike has now, the 112-111 combo puts out 1 to 2 pound-feet more torque in the 6 to 9 grand range than the current settings.  The 106-108 combo puts out 3 to -1 more or less torque than the current settings with the torque addition at the lower rpm ranges.  The 112-111 combination works best with the 11.7 to 1 comp ratio.

Using a 13:1 ratio, things change.  The 107-116 combo puts out 2 to 5 more pound feet than the current settings and comp ratio, with the greatest increases in the lower rpm.  The 112-111 combo puts out 3 to 5 more pound feet than the current settings.  It is almost identical to the 112-111 combo.  The 106-108 mix puts out 5  to 1 more pound feet than the current setup with the greatest help in the lower rpm.  The 107-116 or 112-111 combos work well with the higher compression.

Pistons with 13:1 static comp ratio will be installed.  It appears these along with the 112-111 lobe center combo will restore the lost torque. 

,   
Logged
Interested Observer
Sr. Member
****
Offline Offline

Posts: 330




Ignore
« Reply #2906 on: October 27, 2017, 06:59:31 AM »

Wobbly, are the results you discuss in #2905 coming from Dynomation or Vannik? 
Logged
RansomT
Sr. Member
****
Offline Offline

Age: 58
Location: Georgetown, KY
Posts: 472





Ignore
« Reply #2907 on: October 27, 2017, 08:06:32 AM »

I always like my intake higher numerically than the exhaust and separation of at least 2 degrees but no more than 5. I would recommend as a starting point, 108-112 or 110-114.  108-112 should bring the peak down and increase the TQ across the curve.  But of course this depends on the center line of the ground.  I'm actually having a mental disconnect: usually, when you move the timing down on the intake side you gain TQ at the cost of higher peak HP.  So, moving the cams to 106-108 shouldn't cause a loss of TQ down low like you are seeing with the 11.7:1 pistons.
« Last Edit: October 28, 2017, 07:18:58 AM by RansomT » Logged
wobblywalrus
Hero Member
*****
Offline Offline

Age: 64
Location: backwoods Oregon
Posts: 4442





Ignore
« Reply #2908 on: October 27, 2017, 11:34:20 PM »

The results are from the "D" program.  The "V" software is not functioning at this time.

All of the combinations mentioned in the last post, plus the 108-112 and 110-114 mentioned, were run in the program.   That 108-112 works best.  It puts the torque where I need it.  That is what I will use.  Thanks for the big help.  Life is looking good.
    
Logged
wobblywalrus
Hero Member
*****
Offline Offline

Age: 64
Location: backwoods Oregon
Posts: 4442





Ignore
« Reply #2909 on: October 29, 2017, 11:31:28 AM »

The "V" program needs a smarter guy than me to get results.  I could not get past problems with data entry.  Everything except the exhaust system could be designed using the "D" program.  Engine data will be sent to Burns if this motor works good.  One of their services is pipe design.  They will send me back the specs and I will make the pipe.  That is in 2019.  This year I will try both of my existing exhaust systems and choose the best one.

The cams need to be retimed.  Light springs are used for the outer left valves.  I can push them down with my finger.  The shims under the other valve's buckets are removed.  This way, only the outer left valves will get close to the pistons.


* 2018 Build 002.JPG (123.37 KB, 800x600 - viewed 17 times.)

* 2018 Build 003.JPG (126.01 KB, 800x600 - viewed 21 times.)
Logged
Pages: 1 ... 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 [194] 195 196 197   Go Up
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.21 | SMF © 2015, Simple Machines
Simple Audio Video Embedder
Valid XHTML 1.0! Valid CSS!


Google visited last this page October 29, 2017, 03:44:17 PM