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Author Topic: Team Go Dog, Go! Modified Partial Streamliners  (Read 867341 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
 a/k/a Seldom Seen Slim
 Skandia, Michigan
 (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: Today at 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.