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Author Topic: Team Go Dog, Go! Modified Partial Streamliners  (Read 904418 times)

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Offline RidgeRunner

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3450 on: November 17, 2019, 07:23:21 AM »
        ".......the engine will be fully done in its naturally aspirated form."   An indication of long range plans beyond 2020?   :wink:

                       Ed

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3451 on: November 17, 2019, 03:10:27 PM »
Forced induction.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3452 on: November 23, 2019, 11:00:07 AM »
Various flow tests of different complete intake systems were done in the recent past.  Flow through the head, alone, was of no interest.  The engine would not be used without some form of induction.

That was a mistake.  Most computer programs use bare head flow values and add the induction system restriction to this by calculation.  Using complete induction system flow values in the programs often double-counts intake losses when this is done.

The design of other intake systems is also an issue.  Evaluating a blower, for example, requires bare head flow data.

This are bare head corrected flow data for the Triumph intake at 28 inches with the addition of a radius made from clay at the entrance to the inlet.  The cylinder size is just under 500 cc.

The flow data I use is done on the same flow bench by the same person over a period of many years.  This helps a lot when comparing port and valve modifications from year-to-year.  The flow differences are often subtle and it is good to have that consistency in operator and equipment.  This way, the differences can be attributed to physical changes in the intake rather than changes in operator procedure or test equipment.

The cam lift is just under 0.400 inches and the flow curve flattens out at that value.  The cam lift and port flow are a good match.

 .   

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3453 on: November 26, 2019, 10:43:20 PM »
The table and graph have the corrected flow data for the intake tract at 28 inches based on Kibblewhite's flow bench.  The valves are 2mm oversize.  Test 1 is the bare head with clay shaped in a radius around the entry.   Test 2 is the head with carb and a long K and N filter with sock bolted directly onto the carb end.  Test 3 is the head, carb, a bellmouth, a plenum 1.2 times the cylinder volume, and a shorter K and N air filter with a sock.  Test 4 is the same as Test 3 except the walrus valve, a sort of anti-reversion valve, is between the filter and the plenum.

The two intake arrangements in Test 2 and 3 will be tested on the dyno.  The walrus valve goes into the recycle metal bin.

As per the equations in Harold Bettes' Engine Airflow book on pp 82 and 83, with an 8 percent HP loss between the engine and rear wheel added to the formula, the engine is estimated to make 114 HP at the rear wheel at 9,350 rpm.  This is a very reasonable estimate based on past experience.

 

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3454 on: November 28, 2019, 01:50:59 PM »
Happy Thanksgiving to everyone.  Turkey time here is 5 hours away.  It is on the stove.  Stay safe when driving around. 

Offline Seldom Seen Slim

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3455 on: November 28, 2019, 06:37:34 PM »
We cooked our holiday meal using the waste heat from the generator*.  The power is out over lots of the U P thanks to the 2 feet of heavy snow we got overnight Tuesday and we've been running the generator since.  I guess we'll be w/o commercial elect. 'til this weekend.

* Not really, but it sounded cool.

Happy Thanksgiving, everyone.
Jon E. Wennerberg
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 (that's way up north)
2 Club member x2
Owner of landracing.com

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3456 on: December 11, 2019, 11:02:26 AM »
The original OEM rev limit was 7,400 rpm when racing started in 2007.  The engine was ran near that rpm on the salt and taken apart.  Attempts were made to correct all seen problems.  That rev limit was used in subsequent years until I was confident all issues were fixed.  Then the rev limit was raised to 8,000 and the process was repeated.  This was done again with a 9,000 rpm limit in 2018.  This was the last year the engine was run and it went through many miles at 9,000 rpm.

Race tuners tell me these engines will go up to 10,500 rpm.  Folks have blown these motors to bits while doing this.  Some caution is warranted on my part.  An amateur builder, I am.

The Carillo rods recommended for the bike and sold to me in 2008 were "top loaders."  The bolt heads face up so the big end shells can be replaced when the top end is removed.  There is no need to take the engine out and to split the cases.  The rod big end shell problem was a known issue at that time, is my guess.

The staggered firing order crank used in 2018 was scrounged from a wrecked engine.  It was sent to Marine Crankshafts in Santa Anna, California for inspection and recommended modifications.  They have experience with these cranks in race use.  It was magnafluxed and deemed to be showing signs of use but still serviceable.  The journals were polished and the champhers on the oil holes were reshaped.

The big end rod bearing shells were inspected.  They were distressed.  "Too much rpm" was the verdict.  This is problematic.  More rpm is needed to be competitive.  The plan is to boost the rev limit to only 9,500 this year and see how the shells wear.  It appears that annual shell replacement will be the only viable solution to the issue.         

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3457 on: December 12, 2019, 09:49:38 PM »
A pair of one-piece wheels will replace the spoked ones.  Some internal spacers are needed between the wheel bearings and the wheel and sprocket carrier bearings.  They are internal parts so exposure to chlorides is less than with an external part.

Usually 304 stainless alloy is what I use for this.  It is a pain in the arse to machine on my primitive equipment.  These round bars are annealed 303 stainless.  It does not have as much corrosion resistance as 304 but it should be easier to machine based on the literature.  Does anyone have advice about this alloy?  A lathe will be he only tool used.     

Offline manta22

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3458 on: December 13, 2019, 12:20:22 PM »
WW, the only advice I have for machining 303 is the same for any stainless or titanium alloy is  "slow speed, heavy feed".
Regards, Neil  Tucson, AZ

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3459 on: December 17, 2019, 01:13:09 PM »
The 303 annealed stainless is a lot easier to machine.  The carbide inserts used were Dorian CCGT-21.51-UEU-DUP35RT for all but the finish cuts.  The finish bits were Dorian CCGT-21.51-UEU-DUP35VT.  Both types can be used dry.  Some Joe Gibbs oil was used and it helped a little.  The Dorian catalog gives feed and speed info.  A faster turning rpm was used for the finish cuts.  This bit combination is very versatile and I use it for all sorts of different metals.     

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3460 on: December 20, 2019, 08:55:24 PM »
The rods are sent to Carrillo for reconditioning.  These attached are some calculations to figure out rod bolt loading.  The tech experts at Carillo are helping me with this issue.  The general rule is that the stress should not be higher than 80 percent of the bolt steel yield strength.  That would be yield strengths of 62 and 69 ksi at 9,500 and 10,000 rpm respectively.  It takes some strong metal and lots of bolt preload to handle those loads.

Piston acceleration is another issue.  A maximum of 150,000 feet per second squared is mentioned in John Baechtel's "Engine Math" book.  The 162,000 value at 10,000 rpm is well above this.  CP Pistons is part of the same company as Carrillo and I have asked for help with this matter, too.

Math is a good thing.  It shows me what I need to worry about.  Any comments on these two values, bolt stress and piston acceleration, are welcome.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3461 on: December 23, 2019, 01:44:42 PM »
This series of posts give background info so the ones that follow will make sense. 

The wheel alignment jig was shown a few months ago.  Now it is on a couple of saw horses in the cellar.  The rear wheel is clamped in.  The front wheel is also there with four plywood spacers.  They make the front wheel wider so it matches the rear and the rails are parallel.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3462 on: December 23, 2019, 01:49:58 PM »
The swingarm is attached to the wheel using the rear axle.  The bottom engine case is attached to the swinging arm by way of its spindle.  The spindle is a close clearance fit in its holes in the case.  There is not a lot of slop there.

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3463 on: December 23, 2019, 02:12:42 PM »
The screwdriver points to where the spindle goes through needle bearings in the swingarm.  There is no slop here.  It is essential for purposes of frame alignment to realize that the rear wheel, swingarm, and engine are a single rigid unit.  Everything else comprises the other unit.  Chassis alignment is done at the interface between the two.   

Offline wobblywalrus

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Re: Team Go Dog, Go! Modified Partial Streamliners
« Reply #3464 on: December 23, 2019, 02:22:05 PM »
These pictures show the bushings at the spindle ends.  In one picture I am pushing up on the bushing.  In the other foto the bushing is dropped down.  There is a lot of clearance between the inner diameters of these bushings and the spindle.  These bushings are not part of the rear wheel-swingarm-engine rigid assembly.  They are part of the "everything else" unit.  Chassis alignment is done by loosening the swingarm spindle and all engine mount bolts.  The two assemblies are forced into alignment.  The swingarm spindle and engine mounting bolts are tightened.  Now the chassis is aligned.