"bob and john" (bobandjohn)
11/17/2018 at 11:16 • Filed to: None
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"bob and john" (bobandjohn)
11/17/2018 at 11:16 • Filed to: None | 5
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Ari henning took 2 CBR 300 motors and went to town.
possibly one of the BEST videos they have ever done. I need to find someway to support him and Zack, because they are
by far the best 2 moto journalists there are. (Our former Sean McDonald comes in a very close 2nd, but these guys do more informative videos and I have learned a LOT from them)
My bird IS the word
> bob and john
11/17/2018 at 12:15 |
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Highly relevant, thanks for sharing
Nom De Plume
> bob and john
11/17/2018 at 12:30 |
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I highly agree with everything you said. One does not expect this quality of content from a magazine anymore.
One of my favorite videos from them.
DipodomysDeserti
> bob and john
11/17/2018 at 12:57 |
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Love it.
Tekamul
> bob and john
11/17/2018 at 12:58 |
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I had no idea Ari got blown up by a fire rwork. I always like his stuff, and this might be one of the best. Only two data points is limited, but of course those are very pricey and Labor intensive data points. I'm not that surprised because Honda. They make amazing small displacement motors.
jminer
> bob and john
11/17/2018 at 13:28 |
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They are awesome, enjoyed them for years. They’re moving to motor trend I believe. May be enough for be to get a subscription there.
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bob and john
> jminer
11/17/2018 at 13:58 |
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I already had one for Roadkill garage. so this is icing on the cake for me
Urambo Tauro
> bob and john
11/17/2018 at 19:30 |
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This is a great topic, and I’m glad to see someone go to all this trouble. It’s too bad the sample size is so small, but testing more engines would have been a massive undertaking indeed.
It still kinda bugs me how he leaves out any details after noting that there was one measurable difference (in ring end gap). I would have liked to have heard how big the difference was, and if there were any overlooked measurements that might explain the difference.
But hey I guess you can’t please everyone, especially with a test like this. There are always going to be some lingering questions, until someone really commits to a much more comprehensive test.
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bob and john
> Urambo Tauro
11/17/2018 at 19:48 |
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if you listen carefully, he says that he posted all the data in the description./ here it is
Engine 1, “By The Book Break-In”
Installed at 1,828 miles, removed at 2,861 miles
Break-In Notes: Ridden gently. Didn’t exceed 50% throttle or 5,000 rpm for the first 600 miles, and didn’t exceed 75% throttle or 7,000 rpm until 1,000 miles. Didn’t experience WOT until 1,000 miles was accumulated. Ridden with constantly varying engine speed and load, no easy task on a slow bike in a busy, urban environment!
Oil and filter changed at 600 miles.
Piston OD: 2.9910” at install, 2.9910” after 1,000 miles
Cylinder ID: 2.9925” at install, 2.9930” after 1,000 miles
Top Ring End Gap: 0.0130” at install, 0.0145” after 1,000 miles
Compression: 235 psi hot after 1,000 miles
Leak Down: 4% hot after 1,000 miles
Engine 2, “Brutal Break-In”
Installed at 2,861 miles, removed at 3,890 miles
Break-In Notes: Went to WOT within moments of first starting up, and was ridden hard for 1,000 miles.
Did everything we’re told not to—lots of throttle and high-speed droning at steady throttle. Oil and filter changed at 600 miles.
Piston OD: 2.9910” at install, 2.9910” after 1,000 miles
Cylinder ID: 2.9925” at install, 2.9930” after 1,000 miles
Top Ring End Gap: 0.0130” at install, 0.0150” after 1,000 miles
Compression: 235 psi hot after 1,000 miles
Leak Down: 4% hot after 1,000 miles
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Urambo Tauro
> bob and john
11/17/2018 at 20:18 |
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Good catch, I missed that . F igured it would be the “brutal” one. Man, t hat sure is close though .
You can tell a Finn but you can't tell him much
> bob and john
11/20/2018 at 14:15 |
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It would be much more interesting to see what the Ra values for the pin, pin bores, piston skirt, cylinder walls, conrods, conrod bearings, main bearings and crankshaft look like between the two engines, as well as before and after break in . The piston ring gap, compression and leak down tests give some information, but the piston and cylinder bore diameters are not dimensions that would be expected to change significantly.
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bob and john
> You can tell a Finn but you can't tell him much
11/20/2018 at 18:49 |
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I woudl have liked to see some bearing information as well, but practically, the ring end gap and bore/piston disameter would see the most wear and tear and it is traveling by far the most distance in the motor and subjected to the highest loads.