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Motorcycles
Scale motorcycle modeling topics.
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Tamiya 1/12 Honda RC 166
rdt1953
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New Jersey, United States
Member Since: February 06, 2015
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Posted: Monday, November 05, 2018 - 11:13 AM UTC
Hi to all -
Hope to be starting this in a few weeks -Tamiya's 1/12 Honda
RC 166. This will be a bit of a discipline test for me . I have been a modeler all my life of all subjects and genres with most of my recent efforts 1/48 Japanese aircraft . While I have been involved with real motorcycles for over 50 years I have yet to complete a model of one . I don't know why but I have a few starts spanning many years that await completion. Perhaps with the Kitmaker family watching I will be compelled to finally finish one.



This seems to be another of Tamiya's wonders. I have purchased all four accessory detail sets . These include a tiny rivet set for the fairing and seat ,
a set for the forks that includes photo etch clutch basket and separate friction and drive plates, a wheel set with turned flanged alloy rims and individual wire spokes and nipples that must be laced just like the real thing on included fixtures and a photo etch final drive chain that must be assembled link by link and supposedly fully functional .

I have long considered the RC 166 to be the most amazing motorcycle ever built. Honda built this GP racer in the mid sixties to compete with the dominant 2 strokes of the era . Soichiro Honda was committed to 4 stroke technology - ( He later caved in a bit and built two stroke off road bikes ) - because he felt strongly about their cleaner emissions and lower fuel consumption. Because a 2 stroke produces power with every revolution and a 4 stroke every other , generally speaking the only way to make a 4 stroke competitive is to double the rpm. Honda sought to achieve this by reducing reciprocating mass and this means small components . The answer was and still is many tiny cylinders, valves and pistons.
So became the RC 166 - a 60 horsepower 250cc DOHC 4 valve per cylinder inline six that did 150 mph . In it's second season in the very capable hands of Mike Hailwood it won 10 of 10 GP's and also gave Mike one of his 14 titles at the Isle of Man TT. All of this in an era that predated computer aided design and machining. To think that Honda bashing is prevalent among a certain group is amusing to me.

If you have not done so , give yourself a treat and google this machine-
several videos demonstrate it running at 18,000 rpm ( yes that is correct 18 THOUSAND rpm) -it will make your ears bleed and there is even a clip of a complete tear down on a Japanese TV program !



Cheers ! Richard
Cosimodo
#335
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Auckland, New Zealand
Member Since: September 03, 2013
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Posted: Tuesday, November 06, 2018 - 06:43 PM UTC
I am looking forward to this Richard. The thought of a six cylinder 250 these days would be crazy but Honda were certainly innovative. Do you have the option in the box to build it as Mike the Bike's machine?

cheers
Michael
rdt1953
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New Jersey, United States
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Posted: Wednesday, November 07, 2018 - 12:56 AM UTC

Quoted Text

I am looking forward to this Richard. The thought of a six cylinder 250 these days would be crazy but Honda were certainly innovative. Do you have the option in the box to build it as Mike the Bike's machine?

cheers
Michael



Hi Michael - As you may be aware Honda only campaigned these exotic machines for one more season- 1967 - and then withdrew from GP racing because the governing body (FIM ?) changed the rules to limit the number of cylinders in an effort to keep it more affordable for privateers . Sadly we will likely never see these jewels again.
Markings are included for Mike Haiwoods mounts - numbers but somewhat disappointingly no rider name for the windscreen.
Thanks for the interest - I hope I can do it justice .
Richard
Joel_W
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Posted: Thursday, November 15, 2018 - 08:40 AM UTC
Richard,
I can't believe that I take a few days off from checking to see if you've posted your introduction post as yet, and here it is. So I'm officially late to the party once again. But I promise to stay extra late to make up the time

Without a single doubt, this is going to be a spectacular build to the highest degree Mr. Tamiya ever thought that his creation would reach. Your skills at the bench clearly dictate such a build.

I'm really looking forward to watching you lace though spoke wheels, as well as the rest of the AM, especially all that PE.

As for the FIM, which as to be the little brother of the FIA, changing the engine rules was really common back then. Usually the real reason was the other manufactures, or the most influential of them didn't want to loose to a 4 cyl 18k machine, nor did they want to invest in that direction.

Now I'm going to go Google the real deal and hear what a 18k rpm engine sounds like.

Joel
rdt1953
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Posted: Thursday, November 15, 2018 - 12:16 PM UTC
Joel -

Glad to have your interest as always ! Although I am extremely anxious to get started on this it will be a bit yet as I am still focusing my attention on some 1/1
scale motorcycle stuff.
In the meantime I thought my fellow gear heads might like some more fuel for thought . I never tire of preaching about this bike so I hope I can be forgiven for pontificating once again.
Let's see - 18k RPM . That's 333 revolutions per second ?
peak HP approx 62 - 250 cc . Thats 248 HP/liter. One cylinder of Chrysler's street hemi displaced 872cc. If it had the same specific output it would need to make better than 1,700 horses.
Bore - 41mm or 1 5/8" approx
Stroke - 31mm or 1 7/32 approx

A stroke of 1 7/32" means the crank throw was less than 3/4".
A built up crank of less than 14 '' in length made up of 13 individual pieces -
none of which were larger than a domino.The machined jigs for the assembly of the crank weighed more than the entire bike's 250 lbs.
The camshafts were barrel shaped rather than cylindrical to minimize whip.

Amazing - here are a couple of pics.





designed with slide rules and drafting tables - machined without the benefit of CNC -

Thanks for looking ! Richard
Joel_W
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Posted: Thursday, November 15, 2018 - 01:01 PM UTC
Ricard,
Talk about a small package.

In my Enduro Karting days I ran a 6.1 Komet 2 cycle engine and max rpms was 6,900! Not much more then what I turned in my B which Redlined at 6,000.

Just can't comprehend 18,000 and it stayed together.

Joel
RussellE
#306
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Victoria, Australia
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Posted: Thursday, November 15, 2018 - 09:00 PM UTC
watching with interest Richard!
rdt1953
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Posted: Friday, November 16, 2018 - 12:25 AM UTC
Glad to have another aboard from the land dan unduh !