Author Topic: One for the 250cc folk  (Read 101339 times)

0 Members and 1 Guest are viewing this topic.

Offline generatorshovel

  • Sr. Member
  • ****
  • Posts: 412
    • http://www.dlra.org.au/forum/viewtopic.php?t=556
One for the 250cc folk
« on: November 17, 2012, 02:57:50 AM »
I thought Id share the build the easy way, hopefully I'll get a positive reward for the previous 20 months in hibernation in  Feb 2013 at Lake Gairdner

http://s1195.beta.photobucket.com/user/Blowncbr/story/3099

Tiny
Tiny (in OZ)
I would prefer to make horsepower, rather than buy, or hya it, regardless of the difficulties involved , as it would then be MINE

Offline Rex Schimmer

  • Hero Member
  • *****
  • Posts: 2625
  • Only time and money prevent completion!
Re: One for the 250cc folk
« Reply #1 on: November 17, 2012, 06:14:16 PM »
Tiny,
Not being a "bike" guy I did not realize that Honda made a 4 cylinder 250. What are the specs, bore and stroke etc.  What is the red line?? what was the rated horse power before blower? what is it now?

Great looking bike! hope you have some luck at Gairdner.

Rex
Rex

Not much matters and the rest doesn't matter at all.

Offline Old Scrambler

  • Sr. Member
  • ****
  • Posts: 721
  • Going Fast - Slowly
Re: One for the 250cc folk
« Reply #2 on: November 17, 2012, 07:15:00 PM »
I use photobucket......but could not view your pics.........Interested......I know of a builder looking to turbo a CB350F and run it on the salt.....
2011 AMA Record - 250cc M-PG TRIUMPH Tiger Cub - 82.5 mph
2013 AMA Record - 250cc MPS-PG TRIUMPH Tiger Cub - 88.7 mph
2018 AMA Record - 750cc M-CG HONDA CB750 sohc - 136.6 mph
2018 AMA Record - 750cc MPS-CG HONDA CB750 sohc - 143.005 mph
2018 AMA Record - 750cc M-CF HONDA CB750 sohc - 139.85 mph
2018 AMA Record - 750cc MPS-CF HONDA CB750 sohc - 144.2025 mph

Chassis Builder / Tuner: Dave Murre

Offline generatorshovel

  • Sr. Member
  • ****
  • Posts: 412
    • http://www.dlra.org.au/forum/viewtopic.php?t=556
Re: One for the 250cc folk
« Reply #3 on: November 17, 2012, 07:43:03 PM »
 The little fours were made in,
Honda CBR250  1986 (I want a head & cams from this model)
CBR250R '87-'89
DOHC (gear driven) 4 valves per cylinder, oval cross section valve springs, titanium ex valves
Bore x Stroke    48.5 x 33.8 mm
 Compression Ratio    11.5:1
45 BHP at 15,000rpm (R)
 
CBR250 RR '90 to '93
40 BHP at 14500 RR from '94 (Jap Government restrictions)
All models redline @ 18.000 rpm (tach lies though, it's actually 17,200rpm)
A "good" stocker will do about 108 mph (the RR's are speed limited)

They were exported to Australia by Honda one year only ('88 ?), most were for the Japanese domestic market.
They have been imported to a few countries by entrerpreneurs after they reach a certain age, and the Jap Gov tax the insurance making them far too costly to keep on the road.
The learner rider regulations here were once limited to 250cc, that's how they became so popular.
I have no idea how much extra power my supercharger gives it Rex, but a guestimate would be in the range of 70 BHP, minus the power needed to drive it, maybe 60 or so ?
Old Scrambler, I don't know why your having trouble viewing the link?
Tiny
« Last Edit: November 17, 2012, 07:50:21 PM by generatorshovel »
Tiny (in OZ)
I would prefer to make horsepower, rather than buy, or hya it, regardless of the difficulties involved , as it would then be MINE

Offline wobblywalrus

  • Hero Member
  • *****
  • Posts: 5503
Re: One for the 250cc folk
« Reply #4 on: November 19, 2012, 02:16:17 AM »
There are some pictures of them on the Australian e-bay.  They are very pretty little bikes.  The ones I saw had full body work.  Its odd.  All of that technology went into a learner bike. 

That bike looks good, Tiny.  Now you need to get someone to make a u-tube movie.  No one has heard a 17,000 rpm 250 four with a blower on it.     

Offline generatorshovel

  • Sr. Member
  • ****
  • Posts: 412
    • http://www.dlra.org.au/forum/viewtopic.php?t=556
Re: One for the 250cc folk
« Reply #5 on: November 19, 2012, 07:11:13 AM »
I have a GoPro (it's my data logging system) :-D , too bad I hit the wrong button during the last test run though  :?
There's one word that discribes the sound of a blown 250 four @ 17000 rpm
PAIN

Here's a teaser , this is part throttle only while I was sorting carb/jetting out a few months back.

http://youtu.be/TVr_gdo52so

Tiny
« Last Edit: November 19, 2012, 07:46:15 AM by generatorshovel »
Tiny (in OZ)
I would prefer to make horsepower, rather than buy, or hya it, regardless of the difficulties involved , as it would then be MINE

Offline Old Scrambler

  • Sr. Member
  • ****
  • Posts: 721
  • Going Fast - Slowly
Re: One for the 250cc folk
« Reply #6 on: November 19, 2012, 11:05:52 AM »
VERY NICE vid.......Today I see the photos without a problem.  Nice work on the intake plenum 8-)

I'm still looking for that 'test' road :lol: :lol: :lol:
2011 AMA Record - 250cc M-PG TRIUMPH Tiger Cub - 82.5 mph
2013 AMA Record - 250cc MPS-PG TRIUMPH Tiger Cub - 88.7 mph
2018 AMA Record - 750cc M-CG HONDA CB750 sohc - 136.6 mph
2018 AMA Record - 750cc MPS-CG HONDA CB750 sohc - 143.005 mph
2018 AMA Record - 750cc M-CF HONDA CB750 sohc - 139.85 mph
2018 AMA Record - 750cc MPS-CF HONDA CB750 sohc - 144.2025 mph

Chassis Builder / Tuner: Dave Murre

Offline wobblywalrus

  • Hero Member
  • *****
  • Posts: 5503
Re: One for the 250cc folk
« Reply #7 on: November 19, 2012, 10:41:59 PM »
That looks just like bootleg LSR in Oregon using GPS.  We would be driving on the other side and our tach needles start to move at 0 rpm, not at 6,000.  Nice.

Offline dr j

  • Full Member
  • ***
  • Posts: 143
  • Honda CRF250 & RS125 & 1954 Moto Parilla 175
Re: One for the 250cc folk
« Reply #8 on: November 24, 2012, 10:42:45 AM »
Tiny,
Bike looks great!  Sounds even better!  You have made lots of progress since I last saw photos.  Let me know when, not if, you break my 250cc 4stroke LSR mark of 131.8mph.  At least it will then stay with the Honda marque.
Jarl- Moto Madcap
Sharpsburg MD
BUB2012- Morini 350- 4 Mod Pushrod records, Parilla 175- M-VG rec
250cc 4stroke Nitrous Motorcycle- 131.8mph
250/4 Naked Motorcycle-115.6mph
APS/F-125/2 115.2mph
P/PV-175/4 Moto Parilla-59.7mph
29 Retired Maxton Class Records on 3 bikes and 4 engines

Offline bak189

  • Sr. Member
  • ****
  • Posts: 761
Re: One for the 250cc folk
« Reply #9 on: November 24, 2012, 11:08:47 AM »
Great bike....great video....just think how fast it would go on the proper side of the roadway...................................(I build a small sidecar outfit a while back using the 250.c.c four for a guys childeren to play with.. great little engine hard to find here in the States)
Question authority.....always

Offline generatorshovel

  • Sr. Member
  • ****
  • Posts: 412
    • http://www.dlra.org.au/forum/viewtopic.php?t=556
Re: One for the 250cc folk
« Reply #10 on: November 24, 2012, 05:16:30 PM »
Tiny,  Let me know when, not if, you break my 250cc 4stroke LSR mark of 131.8mph.  
Your record is safe Jahl , at least for another year.
I need to do some serious work on my tuck 1st (Jenny craig?)



It looked a LOT better before donning 2 cows, and 2 roos which were made into my leathers.



Maybe a making fairing would be easier than loosing the gut Iv'e had for 40 yrs ?
Tiny
« Last Edit: November 24, 2012, 05:31:22 PM by generatorshovel »
Tiny (in OZ)
I would prefer to make horsepower, rather than buy, or hya it, regardless of the difficulties involved , as it would then be MINE

Offline SaltPeter

  • Full Member
  • ***
  • Posts: 171
  • Can't you just be Serious for once in your Life!
Re: One for the 250cc folk
« Reply #11 on: November 24, 2012, 05:40:39 PM »
Making a Fairing vs Loosing weight

Six of one half dozen of the other for mine and my personal Belly Tank

I think I lost 5kgs in sweat making that fairing of mine Tiny :-D.

So go for it and knock both of the Birds down with one throw.

Pete the Croc Wrestler  :cheers:
The Mission is to go as fast as possible along on that old Road Less Traveled.

Offline wobblywalrus

  • Hero Member
  • *****
  • Posts: 5503
Re: One for the 250cc folk
« Reply #12 on: January 12, 2013, 11:59:23 PM »
People say is is hot where you are.  Here is a picture to look at to cool you down.  A "tit stiffener of a day" as we say here.  Stay safe.

Offline generatorshovel

  • Sr. Member
  • ****
  • Posts: 412
    • http://www.dlra.org.au/forum/viewtopic.php?t=556
Re: One for the 250cc folk
« Reply #13 on: January 13, 2013, 03:20:00 AM »
THANKS Wobbly, that worked a treat !
Although the worst of the heat is over for a while, while working in the shed making a scatter shield to protect my innards,,a nice cool change blew in, with a bit of rain.
There's more 110 degree days coming, but with some cooler days thrown in to make it bearable, but,,,the change is a sling off from a tropical cyclone that just missed the west coast, these are the mongrels that have washed out Speedweek the last 2 years,,,,,,,,,,,,,,,,,,,,,,,,,,,,, :?



She'll be apples.
Tiny
Tiny (in OZ)
I would prefer to make horsepower, rather than buy, or hya it, regardless of the difficulties involved , as it would then be MINE

Offline Sam Green

  • Full Member
  • ***
  • Posts: 88
Re: One for the 250cc folk
« Reply #14 on: January 18, 2013, 06:11:09 PM »
Good luck from England Tiny, keep us informed here. http://forums.sohc4.net/index.php?topic=115527.0

Sam. :cheers:
175cc Woodbridge Mile record holder 118.3mph