Re: Honda Motocompo NCZ50 - The build log!

Toby B /
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OK, so another update.

I’ve continued struggling for revs and power with the Puch head, so after translating the work of some trailblazers in Japan with these bikes, I went back and gave the factory head a shot. Then viola, - back past 10k rpm again with a bit more speed. It then became clear that all I needed was some more compression.

However, I was surprised that the custom 46mm cut NU50 head (like this one: https://www.treatland.tv/honda-nu50-46mm-custom-cut-head-p/46mm-cut-head-urban.htm), would affect compression so much. It wasn’t until I decided to fill all three heads with liquid did I realise the difference in volume. From left to right, oem head -> custom 46mm cut NU50 head -> 46mm Puch head.

headcomparobottom.jpg

The oem head came in at 7.5ml, and the other two were around 10ml. The real question for me was how the custom NU50 head gained so much volume when the only expected change was machining the outer rim to 46mm. Well… it looks like the reason owes to the bowl being machined too! For whatever reason, the bowl section has a lot less meat than the factory head.

motocompohead.jpg
nu50customhead.jpg

As standard (49cc), I calculate that the CR would have been something like 6.5:1.

Once I went to 70cc and the bigger heads, CR would have gone to something like 7:1, but for whatever reason still ran shit up top.

With the current oem head paired with the 70cc kit, CR is probably 9.3:1 ! Maybe that’s why the bowl is machined out of the NU50 custom cut head, - to keep something similar to a factory compression ratio?

Either way, for the moment I will continue to run the oem head, until such time that I can machine down the Puch head to give the double benefit of extra cooling and more compression.

Part 2 of my experiments to follow next…

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Subject Written By Posted
  Honda Motocompo NCZ50 - The build log!Topic by: Toby B Toby B 08/24/17 08:30PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 08/24/17 09:40PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Overpriced Parts Overpriced Parts 08/27/17 12:23PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Responsible Jon Responsible Jon 08/24/17 09:42PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 08/24/17 09:56PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 08/24/17 11:06PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Stephen Keller Stephen Keller 08/24/17 10:40PM
  Re: Honda Motocompo NCZ50 - The build log!Re: jayson sumpter jayson sumpter 08/24/17 11:15PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Jonathan R Jonathan R 08/24/17 11:45PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 08/29/17 10:06PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Mike Boyd Mike Boyd 08/29/17 10:09PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 08/29/17 11:32PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Ryan Graeme Ryan Graeme 08/30/17 01:09AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Paul Boyer (OFMC) Paul Boyer (OFMC) 08/25/17 12:05PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Graham Motzing Graham Motzing 08/25/17 01:00PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 08/31/17 05:24AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Mike Boyd Mike Boyd 08/25/17 06:22PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Korean Fried Chicken Korean Fried Chicken 08/25/17 06:32PM
  Re: Honda Motocompo NCZ50 - The build log!Re: will warn will warn 08/25/17 09:48PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Dan (LandLordsMG/PSVMC) Dan (LandLordsMG/PSVMC) 08/26/17 02:22PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Dave Brzezicki Dave Brzezicki 08/27/17 07:29AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 08/28/17 12:51AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Wild Card Wild Card 08/27/17 08:19AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Born to be WillD Born to be WillD 08/28/17 10:06AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Tobias Doesn't Care (ง •̀_•́)ง Tobias Doesn't Care (ง •̀_•́)ง 08/28/17 12:16PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Born to be WillD Born to be WillD 08/30/17 09:50AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 08/31/17 12:22AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 08/29/17 11:36PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 08/31/17 09:25PM
  Re: Honda Motocompo NCZ50 - The build log!Re: will warn will warn 08/31/17 10:55PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Graham Motzing Graham Motzing 09/29/17 06:10PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 08/31/17 10:08PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Jawanna Blaist Jawanna Blaist 11/01/17 04:34PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Siezed Again Siezed Again 11/06/17 02:28PM
  Re: Honda Motocompo NCZ50 - The build log!Re: todd amundson todd amundson 12/17/17 05:56PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 08/31/17 11:08PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Dave & Bummerzz Dave & Bummerzz 09/06/17 10:29AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 09/06/17 06:45PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Kansas John Kansas John 08/31/17 11:50PM
  Re: Honda Motocompo NCZ50 - The build log!Re: buzzy mode buzzy mode 09/01/17 11:52AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Mike Boyd Mike Boyd 09/01/17 02:56PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Full Tuck Full Tuck 02/08/18 08:04AM
  Re: Honda Motocompo NCZ50 - The build log!Re: jayson sumpter jayson sumpter 09/01/17 08:46PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 09/04/17 01:36AM
  Re: Honda Motocompo NCZ50 - The build log!Re: ᴛᴇʀʀʏ ᴅᴇᴀɴ ᴛᴇʀʀʏ ᴅᴇᴀɴ 09/04/17 04:18AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 09/04/17 08:46PM
  Re: Honda Motocompo NCZ50 - The build log!Re: ᴛᴇʀʀʏ ᴅᴇᴀɴ ᴛᴇʀʀʏ ᴅᴇᴀɴ 09/04/17 08:50PM
  Re: Honda Motocompo NCZ50 - The build log!Re: will warn will warn 09/04/17 08:51PM
  Re: Honda Motocompo NCZ50 - The build log!Re: will warn will warn 09/04/17 09:00PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 09/04/17 09:05PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Brandon Weiss (Detective brandon to you) Brandon Weiss (Detective brandon to you) 09/06/17 10:08AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Nobody likes a bully. * Nobody likes a bully. * 09/06/17 10:46PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 09/06/17 11:25PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 09/12/17 08:22PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Huy Tran Huy Tran 09/12/17 09:31PM
  Re: Honda Motocompo NCZ50 - The build log!Re: buzzy mode buzzy mode 09/26/17 02:21PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Downhill Harvey (OFMC) Downhill Harvey (OFMC) 10/01/17 12:04AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 10/03/17 11:17PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Downhill Harvey (OFMC) Downhill Harvey (OFMC) 10/19/17 07:56PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Hepatitis J [OFMC] Hepatitis J [OFMC] 10/25/17 12:01PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Charlie BUZZARD Charlie BUZZARD 10/04/17 07:18PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 10/19/17 02:48AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 10/22/17 08:05PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Mike Boyd Mike Boyd 10/23/17 08:01PM
  Re: Honda Motocompo NCZ50 - The build log!Re: will warn will warn 10/22/17 09:19PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 10/22/17 10:16PM
  Re: Honda Motocompo NCZ50 - The build log!Re: will warn will warn 10/22/17 10:56PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Bas Autowas Bas Autowas 10/23/17 05:37AM
  Re: Honda Motocompo NCZ50 - The build log!Re: MPB Andyrew MPB Andyrew 10/23/17 10:21AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 10/23/17 05:38PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Mike Boyd Mike Boyd 10/23/17 02:09PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Glenn Kuehn Glenn Kuehn 10/24/17 04:47PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Dave & Bummerzz Dave & Bummerzz 12/18/17 10:17AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 01/08/18 05:15PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Cooper Liu Cooper Liu 01/15/18 07:56AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 01/15/18 04:56PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 02/04/18 11:37PM
  Re: Honda Motocompo NCZ50 - The build log!Re: David Cox David Cox 02/05/18 10:29AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 05/21/18 12:15AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Cooper Liu Cooper Liu 02/07/18 10:02PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 02/07/18 10:08PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Cooper Liu Cooper Liu 02/07/18 11:29PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 02/07/18 11:39PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 02/07/18 11:42PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 02/21/18 07:12PM
  Re: Honda Motocompo NCZ50 - The build log!Re: David Cox David Cox 02/21/18 07:26PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 02/22/18 09:52PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Cooper Liu Cooper Liu 03/18/18 12:42PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Derek Cox Derek Cox 05/20/18 08:07PM
  Re: Honda Motocompo NCZ50 - The build log!Re: David Cox David Cox 05/20/18 08:10PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 05/21/18 12:01AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Cooper Liu Cooper Liu 02/25/18 04:16AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 02/27/18 06:01PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Brandon Weiss (Detective brandon to you) Brandon Weiss (Detective brandon to you) 02/27/18 06:41PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 02/27/18 06:45PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Emil Kniemel Emil Kniemel 02/27/18 06:51PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Jeroen H Jeroen H 08/07/20 05:22AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 08/07/20 05:41AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Jeroen H Jeroen H 08/14/20 11:53AM
  Re: Honda Motocompo NCZ50 - The build log!Re: Ryan Graeme Ryan Graeme 08/08/20 03:42AM
  Re: Honda Motocompo NCZ50 - The build log!Re: max barsby max barsby 08/07/20 05:07PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Stephen Keller Stephen Keller 08/09/20 10:00PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Toby B Toby B 08/09/20 08:58PM
  Re: Honda Motocompo NCZ50 - The build log!Re: Stephen Keller Stephen Keller 08/09/20 10:03PM

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