(Note: LANDRACING.COM donations are not tax deductible)


This is a public forum. The opinions expressed here don't
necessarily reflect the feelings of The Folks That Run The Site (that's us)
unless we explicitly say so, ok?


Author Topic: Team Go Dog, Go! Modified Partial Streamliners  (Read 865501 times)

0 Members and 4 Guests are viewing this topic.

Offline wobblywalrus

  • Hero Member
  • *****
  • Posts: 5067
  • Age: 66
  • Location: backwoods Oregon
Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2310 on: February 16, 2016, 08:28:39 PM »
The Hot Rod magazine did a comparison test and showed the thermal barrier coatings to help horse power.  The other coatings had mixed results.  Most of the info I read was from aerospace applications.  The development of these thin coatings solved all sorts of problems and allowed rockets and jets to do things they could not do before.  Vizard recommends them for some uses and he has some numbers in his books.  I have the Hot Rod article around here somewhere and I have Vizard's books.  I can dig that info up if needed and when I get some spare time.  I never bothered to save the links to the aerospace stuff.  One big selling point is one of my racing buddies who is smarter than me and goes really fast uses the thermal barrier on his piston.  Monkey see, monkey do, is my rocket science type strategy.   


Offline wobblywalrus

  • Hero Member
  • *****
  • Posts: 5067
  • Age: 66
  • Location: backwoods Oregon
Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2311 on: February 16, 2016, 11:14:12 PM »
Mark, I read this carefully before I sent the head away.  The head was ported when I used standard size inlet valves.  Two millimeter bigger inlet valves and seats were installed.  The ports were not matched well to the bigger seats.  I did a tuft test and flow was very biased to the long side.  My worry was the velocities were getting too close to sonic in that area of concentrated flow at peak horsepower rpm.

"Get some better flow if you can, and pay attention to improving the velocity distribution around the margin.  Improving that will be a big help."  This is what I asked him to do.  He uses a flow bench when he does the work so I figure it will be better than when I do it using my imagination and no bench. 

 

Offline fordboy628

  • Hero Member
  • *****
  • Posts: 2263
  • Age: 3
  • Location: Koozebane
  • GONE FISHIN' . . .
Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2312 on: February 17, 2016, 06:18:28 AM »
Mark, I read this carefully before I sent the head away.  The head was ported when I used standard size inlet valves.  Two millimeter bigger inlet valves and seats were installed.  The ports were not matched well to the bigger seats.  I did a tuft test and flow was very biased to the long side.  My worry was the velocities were getting too close to sonic in that area of concentrated flow at peak horsepower rpm.

"Get some better flow if you can, and pay attention to improving the velocity distribution around the margin.  Improving that will be a big help."  This is what I asked him to do.  He uses a flow bench when he does the work so I figure it will be better than when I do it using my imagination and no bench. 
 

Bo,

Using a flow bench in conjunction with tufts, "flow balls" and pitot tubes is definitely the way to go.    I can't tell you how many times I have flow tested a head "ported" by some "seat of the pants" flow genius, only to find the measured cylinder head flow is below the "average" for that type of casting.   Your guy is a pro, I'm sure it will turn out well.

Having said all that, the engines themselves, DO NOT care about the numbers.    Be sure to read that twice to get my meaning.    :-D

What IS important, is to know some hard data regarding these "relationships".    Having that information gives me some "direction", if required, when performing the final dyno tune.    That information also helps to define the selection of "other important parts" in the engine's "Comprehensive Build Specification" ©   And when your "Build Spec" might be compromised by some factor, say small cam grind selection, sometimes you can "band aid" it somewhere else.

The end focus is to produce horsepower, as opposed to information.    But the information based approach works better.   Ask guys like Mike LeFevers, Ken Duttweiler or Jon Kaase.

 :cheers:
Fordboy
Science, NOT Magic . . . .

I used to be a people person.  But people changed that relationship.

"There is nothing permanent except change."    Heraclitus

"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."     Albert Einstein

Offline wobblywalrus

  • Hero Member
  • *****
  • Posts: 5067
  • Age: 66
  • Location: backwoods Oregon
Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2313 on: February 18, 2016, 08:29:23 AM »
The class I race in allows fuel and my blend has some oxygen bearing chemicals.  More fuel is used and the main jets are four sizes bigger.  Does this require larger exhaust valves?  Right now this is the limiting factor in the build.  The intake valves sonic choke at about 9,000 rpm and the exhausts at 8,400 rpm based on a PipeMax analysis.

One reason I am not using bigger exhaust valves is the target rpm for going through the mile is 8,300 and there is a 0.5 to 1.0 point drop in static compression due to the combustion chamber being opened up for the larger poppets.  The aspects of using oxygenated fuel might make me think different.  Each cylinder has a pair of 33mm intakes and 26 mm exhausts.

Offline wobblywalrus

  • Hero Member
  • *****
  • Posts: 5067
  • Age: 66
  • Location: backwoods Oregon
Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2314 on: February 21, 2016, 10:57:10 AM »
The engines weigh over 200 pounds and I am too weak and old to lift them out of the frame, carry them down the stairs, and put them on the work bench.  The last time I did it we had two old guys doing the job and it was a bit much for both of us.

This year the engine is stripped in the frame, lowered down to the bike bench using ratchet straps, and carried downstairs to the cellar.  It is the size of an, er, large turkey.  It is light enough to carry around.

The last pix shows the open crankcase mouths.  It is hard to hold the rod steady when the cap bolts are tightened for plastigage measurement.  I am always afraid that rod movement is smearing the gage plastic and making the indicated clearance larger than it really is.   

Offline wobblywalrus

  • Hero Member
  • *****
  • Posts: 5067
  • Age: 66
  • Location: backwoods Oregon
Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2315 on: February 21, 2016, 11:14:48 AM »
The oil is pumped up through these holes in the main shell, it goes into the crank journal, and then it passes out through the big end journal.  There is significant wear on the lower load bearing shell.  Oil bleeding through a sloppy main bearing can starve the rod bearing.  This is a common problem with the rod journal furthest from the oil pump on BSA twins.  Tuning those rascals was when I learned about this.

The second pix shows all of the lower journals.  The outer journal on the left also shows wear.  The eight large bolts clamping the crankcase together around the crank are tightened to 40 pounds-foot torque.  Typically they are hard to loosen when the engine is pulled apart.  The inner bolts were like this.  The outer four bolts took 5 or 10 pounds-foot to loosen.  They were almost finger tight.  I cannot explain this.  I tighten up these bolts, make a second pass through to make sure they are tight, and put dots of fingernail polish on the heads when I am done.  All of these bolts were marked.  I know they were tight upon assembly.

Offline WhizzbangK.C.

  • Full Member
  • ***
  • Posts: 227
  • Age: 58
  • Location: Kansas City, MO
  • Ed Bennett, Speed Team Doo Kansas City fab shop.
Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2316 on: February 21, 2016, 11:40:24 AM »
Ah, this is obviously some strange usage of the word 'safe' that I wasn't previously aware of.  Douglas Adams

Offline manta22

  • Hero Member
  • *****
  • Posts: 3494
  • Age: 81
  • Location: Tucson, AZ
  • What, me worry?
Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2317 on: February 21, 2016, 01:29:09 PM »
That's a good video illustrating how fasteners come loose under vibration. The Junkers machine is a good test but it only applies a sinusoidal shear force to the joint. It gets worse when they are subjected to different forces.
 
I watched a shake table test of an instrumentation package that was designed to be launched on a high-altitude sounding rocket at White Sands, NM-- by using a swept-frequency excitation to the table, all the tight screws and nuts twirled around and literally fell off! Random frequency drive also produced the same results. Sinusoidal excitation is not as severe as it gets in actual practice.

I think that at one time SPS also had a presentation on vibration testing of fasteners.

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

Offline wobblywalrus

  • Hero Member
  • *****
  • Posts: 5067
  • Age: 66
  • Location: backwoods Oregon
Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2318 on: February 21, 2016, 10:56:45 PM »
I am pretty sure the cases were moving in relation to each other and that loosened the fasteners.  The tightening torque for the eight 10 mm x 1.25 mm bolts around the crankshaft was 40 Nm in my old 2003 tech manual.  The newest manual says to tighten them to 10 Nm and then to add 75 degrees more turn to that.  Another 20 to 30 8 mm x 1.25 mm bolts hold the crankcase top to bottom halves together.  The old manual says to tighten them to 28 Nm.  The new manual says to tighten them to 32 Nm.  It appears that Triumph has recognized that some additional clamping force is needed.

Some parts of the crankcase are sealing oil in the engine and Yamabond #4, the grey stuff, is applied there.  Most of the mating surfaces are metal to metal with no sealer.  Is there a sealer or bonding agent that is designed to keep surfaces from sliding on each other and allow the engine to be taken apart?  Epoxy would work great for preventing the movement but I could not split the cases apart later.  I am looking for something not as extreme. 

Offline salt27

  • Hero Member
  • *****
  • Posts: 1405
  • Age: 62
  • Location: S.W. Orygun
Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2319 on: February 21, 2016, 11:43:09 PM »
Maybe machining some of the bolt holes for hollow dowels?
« Last Edit: February 22, 2016, 12:51:24 AM by salt27 »

Offline manta22

  • Hero Member
  • *****
  • Posts: 3494
  • Age: 81
  • Location: Tucson, AZ
  • What, me worry?
Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2320 on: February 22, 2016, 10:03:14 AM »
WW;

Loctite used to make a case sealer that was designed to prevent fretting. It had high shear strength but you could still peel the case halves apart. I don't remember what it was called; it was sort of a yellow gel that came in a tube. I used it to seal a Corvair race engine case.

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

Offline bones

  • Full Member
  • ***
  • Posts: 131
  • Age: 63
  • Location: sydney Australia
Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2321 on: February 23, 2016, 12:44:51 AM »
Hi Wobbly

   I've been using Locktite  515 for sealing my crank cases for a long time.
  Hayabusa  -   4 cylinder kawasakis  -   tz 750 yamaha  -   350 tz yamaha.
 
  Never had any sealing issues.

    cheers   Bones

Offline wobblywalrus

  • Hero Member
  • *****
  • Posts: 5067
  • Age: 66
  • Location: backwoods Oregon
Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2322 on: February 23, 2016, 09:31:03 PM »
Bones, that Loctite sealer is designed to flex when the joint moves.  The opposite is what I want.  I am trying to stop the movement.  Loctite probably makes what I want.  I will e-mail them.

This plastigage is available from Triumph and it works great.  The usual plastigage sold here is very thin and it is a challenge to read the thickness of the squashed thread.  The British stuff is much thicker and it is easier to read the clearance as shown by the cards.

The engine needs to be flipped a few times to tighten all of the bolts.  The crank can spin during this and smear the plastigage.  It is wired down so this will not happen.   

Offline wobblywalrus

  • Hero Member
  • *****
  • Posts: 5067
  • Age: 66
  • Location: backwoods Oregon
Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2323 on: February 23, 2016, 10:10:42 PM »
The shells had typical wear patterns for one of these engines.  There is a very heavy flywheel on the right side and the lower portion of the lower shell showed the most wear.  The flywheel pulls the crank end down.  The other mains showed the most wear on the rear halves of the lower shells.  Street engines show the wear more toward the bottoms of the shells.  Race motors show wear higher up on the backs of the lower shells.  The most wear was very high up and just below the parting line relief.  This is consistent with the wear pattern for an engine raced hard.

The clearance was measured at the top of the journal as shown and it was .015 for all four.  The clearances according to the expert's formula should be .0016 to .0020.  The clearances are on the tight side.  I was using blue coded shells.  I will try the next looser size, the red shells, and if it is still too tight, the loosest ones, the white shells.

All of this investigation is showing nothing drastically wrong.  I see no signs of detonation or erratic combustion after careful examination.  An 865 cc engine with 8.9 to 1 compression is no powerhouse on gasoline.  It put out only 80 horsepower on the dyno.  Brute power from jungle juice is pushing this engine to near its structural limits is my best guess.  The plan is to build the engine as carefully as I can, make one pass on gasoline to loosen up the engine, dump the gas and put in the juice, make the runs for the record, and hopefully the dang thing will hold together.  Two things I will NOT do are to make more runs than absolutely needed or to up the nitro content.     

 

Offline wobblywalrus

  • Hero Member
  • *****
  • Posts: 5067
  • Age: 66
  • Location: backwoods Oregon
Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #2324 on: February 25, 2016, 07:33:28 PM »
Has anyone measured the oil temperature in their motorcycle engine?  How hot does it get?