It lives

See cars and bikes being built for the salt

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Michael Riddell
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Joined: Sun Jul 15, 2012 9:50 am

Re: It lives

Post by Michael Riddell » Fri Mar 08, 2013 8:58 pm

I was the other Nitro bike and it was "fill it to about half way then add two cups of nitro, shake well and serve". Didn't blow up!

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RGV
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Location: Adelaide Hills

Re: It lives

Post by RGV » Sat Mar 09, 2013 9:30 pm

Michael Riddell wrote:I was the other Nitro bike and it was "fill it to about half way then add two cups of nitro, shake well and serve". Didn't blow up!
1/2 way in a postie bike is ?? 2 cups. Big or small? You running very fat jetting or is this an educated guess? Glad to hear its still running. I havnt messed with Meth before so am on a steep learning curve.

Dave

Last Minute Racing
DLRA #928

2010 MPS/G 250 118 MPH
2011 Washed Out
2012 Washed Out
2013 MPS/G 250 131 MPH (RECORD)
2014 MPS/G 250 140 MPH (RECORD)
2015 MPS/F 250 DNF
2016 MPS/F 250 114 MPH (RECORD)
2017 MPS/F 250 DNF

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gennyshovel
Posts: 834
Joined: Tue Mar 29, 2005 10:10 am
Location: Broken Hill

Re: It lives

Post by gennyshovel » Sun Mar 10, 2013 10:19 am

Michael Riddell wrote:I was the other Nitro bike and it was "fill it to about half way then add two cups of nitro, shake well and serve". Didn't blow up!
It's a pitty you didn't get an official "big" track time Michael
Tiny
Tiny DLRA# 484
Postiebike Racing , created & funded by TwoBob Engineering

Michael Riddell
Posts: 3
Joined: Sun Jul 15, 2012 9:50 am

Re: It lives

Post by Michael Riddell » Mon Mar 11, 2013 10:45 pm

The fuel mix wasn't quite hit and miss but Ross was involved. It worked out about right with 16%.The jetting was worked out and then we used what we had. Over geared it for some test runs so it wouldn't go bang. And the non-timing run was a bit disappointing but didn't want it to buggar up a bloody great week. There's always next year! (got to stop saying that)

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RGV
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Location: Adelaide Hills

Re: It lives

Post by RGV » Sat Mar 23, 2013 1:03 pm

Got my new rods, waiting for bearings and seals then its time to rebuild a crank for my new motor. New rods are 5mm longer so ive tracked down some pistons with a -3.5mm compression height, the rest of the height, 1.5mm, will be used to move the barrels up to create more of a top end port timing.

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Last Minute Racing
DLRA #928

2010 MPS/G 250 118 MPH
2011 Washed Out
2012 Washed Out
2013 MPS/G 250 131 MPH (RECORD)
2014 MPS/G 250 140 MPH (RECORD)
2015 MPS/F 250 DNF
2016 MPS/F 250 114 MPH (RECORD)
2017 MPS/F 250 DNF

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AuotonomousRX
Posts: 690
Joined: Wed Jan 06, 2010 10:05 pm
Location: Eyre Peninsula SA

Re: It lives

Post by AuotonomousRX » Sun Mar 24, 2013 12:02 pm

Dave

They certainly are a more substantial Con Rod. 8)

Pete
Metric Target 250 on a 250 on a Red Bike

Pete :shock:
DLRA #866
SATA #49

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ChrisACT
Posts: 111
Joined: Thu Nov 10, 2011 7:39 pm

Re: It lives

Post by ChrisACT » Sun Mar 24, 2013 9:51 pm

Is the new rod heavier? Will you have to re-balance the crank?

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RGV
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Location: Adelaide Hills

Re: It lives

Post by RGV » Sun Mar 24, 2013 10:17 pm

Piston is 16g lighter and rod is about 14g heavier, so saving of 2g.

Dave

Last Minute Racing
DLRA #928

2010 MPS/G 250 118 MPH
2011 Washed Out
2012 Washed Out
2013 MPS/G 250 131 MPH (RECORD)
2014 MPS/G 250 140 MPH (RECORD)
2015 MPS/F 250 DNF
2016 MPS/F 250 114 MPH (RECORD)
2017 MPS/F 250 DNF

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RGV
Posts: 688
Joined: Sun Feb 06, 2011 9:17 pm
Location: Adelaide Hills

Re: It lives

Post by RGV » Sun Apr 14, 2013 9:57 am

Bit happening out in the shed over the w/end.

New piston and rod V old.

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Some case flowing and port matching.

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Next is building the crank and a dummy assemble of the motor to see what the 5mm longer rod is going to do to the port timing.
Ive found a piston with a 3.5mm lower compression height so only have to make up 1.5mm under the barrels.

Dave

Last Minute Racing
DLRA #928

2010 MPS/G 250 118 MPH
2011 Washed Out
2012 Washed Out
2013 MPS/G 250 131 MPH (RECORD)
2014 MPS/G 250 140 MPH (RECORD)
2015 MPS/F 250 DNF
2016 MPS/F 250 114 MPH (RECORD)
2017 MPS/F 250 DNF

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AuotonomousRX
Posts: 690
Joined: Wed Jan 06, 2010 10:05 pm
Location: Eyre Peninsula SA

Re: It lives

Post by AuotonomousRX » Sun Apr 14, 2013 11:32 am

Nice work Dave :D

Pete
Metric Target 250 on a 250 on a Red Bike

Pete :shock:
DLRA #866
SATA #49

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RGV
Posts: 688
Joined: Sun Feb 06, 2011 9:17 pm
Location: Adelaide Hills

Re: It lives

Post by RGV » Sat Apr 20, 2013 8:26 pm

Got my carby's yesterday. Might have made a bit of a mistake when I ordered them. They turned out to be 40 mm not 38. Might be a touch too big.
Image

Could probably get them to work but I wanted to keep the same size so I dont have to alter my air box, and I would have to make a pretty big bracket to hold these suckers on. Anyone want a pair of 40mm VM Mikunies?

Dave

Last Minute Racing
DLRA #928

2010 MPS/G 250 118 MPH
2011 Washed Out
2012 Washed Out
2013 MPS/G 250 131 MPH (RECORD)
2014 MPS/G 250 140 MPH (RECORD)
2015 MPS/F 250 DNF
2016 MPS/F 250 114 MPH (RECORD)
2017 MPS/F 250 DNF

internetscooter
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Joined: Mon Nov 20, 2006 12:18 pm
Location: Melbourne
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Re: It lives

Post by internetscooter » Sat Apr 20, 2013 11:33 pm

How do you calculate the size of the carb required? I have seen on an online calculator somewhere (can't remember now) where they spat out the size of the carb required for a given Hp. I based my single 38mm on what was standard and then added some. Is there a formula that you are using?
Paul
---
DLRA #647
89.664 mph (aiming for 100mph+)
Vespa Labs [url]http://www.vespalabs.org[/url]

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RGV
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Joined: Sun Feb 06, 2011 9:17 pm
Location: Adelaide Hills

Re: It lives

Post by RGV » Sun Apr 21, 2013 1:03 am

Hey Paul, Ive got a excel worksheet, "useful 2 stroke tuning sheet 3" Its got a fair bit of stuff on it. There are some GP bikes running 40+ carbs so I will have a look at how much messing round it will be to fit them. They are quite a bit bigger than the 38's im running.

Dave

Last Minute Racing
DLRA #928

2010 MPS/G 250 118 MPH
2011 Washed Out
2012 Washed Out
2013 MPS/G 250 131 MPH (RECORD)
2014 MPS/G 250 140 MPH (RECORD)
2015 MPS/F 250 DNF
2016 MPS/F 250 114 MPH (RECORD)
2017 MPS/F 250 DNF

internetscooter
Posts: 474
Joined: Mon Nov 20, 2006 12:18 pm
Location: Melbourne
Contact:

Re: It lives

Post by internetscooter » Sun Apr 21, 2013 9:38 am

RGV wrote:Hey Paul, Ive got a excel worksheet, "useful 2 stroke tuning sheet 3" Its got a fair bit of stuff on it. There are some GP bikes running 40+ carbs so I will have a look at how much messing round it will be to fit them. They are quite a bit bigger than the 38's im running.

Dave
Yes they look big ;) You might be able to make a couple of different manifold types to produce different characteristics - I might be interested but I'd only need one and only towards the end of the year (pending other mods).

Is that spreadsheet available online anywhere?
Paul
---
DLRA #647
89.664 mph (aiming for 100mph+)
Vespa Labs [url]http://www.vespalabs.org[/url]

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RGV
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Joined: Sun Feb 06, 2011 9:17 pm
Location: Adelaide Hills

Re: It lives

Post by RGV » Sun Apr 21, 2013 11:03 am

Not sure where I got it from, send me ya email and ill shoot a copy off to ya. Ive got a heap of different ones for all sorts of things. Head calculations, chamber design, n stuff.

Dave

Last Minute Racing
DLRA #928

2010 MPS/G 250 118 MPH
2011 Washed Out
2012 Washed Out
2013 MPS/G 250 131 MPH (RECORD)
2014 MPS/G 250 140 MPH (RECORD)
2015 MPS/F 250 DNF
2016 MPS/F 250 114 MPH (RECORD)
2017 MPS/F 250 DNF

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