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Aftermarket BIG Valve Cylinder Head

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Copper Coated Custom Cometic Copper .005" base gasket....

High compression lightweight Takegawa 58mm/ 120cc piston...

66412347_IMG_20200822_1736483.thumb.jpg.03bb43377ddecc8ab038377b0d0a1fca.jpg

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4 hours ago, mixxer said:

How to make air cooling cooler ..

Shave the fins😎956052635_IMG_20200822_1753112.thumb.jpg.ce7a6500d5391a3141d77f521f96cedf.jpg

Looks great sir.

How/what is the deck height? 

Edited by adnohguy

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Details later.... 

Notice the powder coated and shaved fin valve cover.... Probably good for +1~1.5Hp

Don't hate it because it's so beautiful 😁

Screenshot_20200823-115547.thumb.png.6bc3b7c882d9a2abfc23c3f41191affc.png

Edited by mixxer
  • Haha 2

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Since Guy asked... 

Assembled clay checked squish = .036"

Stock compression = 9.7:1

130cc engine measured compression = 11.3:1

I would have liked more comp , but it's still a solid bump over stock...and it is still very safe for a non tempermental play bike....

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The squish measured in at .036"

Totally and utterly fine with that number...  Very glad to have ordered the .005" Cometic Copper base gasket(s)...

Using the Kitaco cam with the best overlap period had me concerned that I could be tight on piston to valve clearance... All of my experiences have led me to find happiness with .080" or more P to V clearance....

Intake valve clearance was .121"

And exhaust valve clearance was .146"...

I'm very happy with the clearances, but for a minute I was wondering why I would have so much clearance with a high overlap cam....

The design of the head has the valve seats more "sunken" into the head in order for the big valves to have enough clearance to not contact each other during overlap... Part of the reason the combustion chamber has so much more volume than stock also... And definitely the reason behind the extra safe margin of piston to valve clearance...

The total combustion chamber volume with the assembled chamber and piston at TDC came in at 12.6cc and a compression ratio of 11.3:1

Even with the bigger stroker crank offered ... And 145cc total displacement... Using the thin custom base base gasket and higher compression piston I used... Compression would have come in at exactly 12.5:1 ....

Still funny to me was all the praise I initially read about the Spartan big valve head from Shift Up...  Unless you tighten squish and find the highest compression 58mm big bore piston and add a 4mm stroker like I did.... You would be running with 9:1 compression with a 120cc bore kit set at 12:1 compression for the stock head....

 

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Edited by mixxer
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Stock carb is 22mm PD Keihin...

27mm Keihin PZ Pumper carb with choke hardware removed is what I'm going with...

Takegawa made a nicely shaped airbox boot to fit right up...

All direct bolt on ...spacer.png

IMG_20200830_132314.thumb.jpg.7c01992c91abc8f9e6c87b47880465c1.jpg

Edited by mixxer
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17 hours ago, mixxer said:

27mm Keihin PD Pumper carb

   Is that a for real, genuine, Keihin?

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14 minutes ago, Doogee57 said:

   Is that a for real, genuine, Keihin?

I wish....  It's a copy...

I had to work on it to get the pump shot to aim correctly ...instead of at the carb floor....

They have these in PZ27mm and PZ30mm copies for around $30 on eBay...

I had bought this one several years ago just in case I built another Honda 100...lol...

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1 hour ago, mixxer said:

I wish....  It's a copy...

   Yeah, that's what I figured. I've also got one of those (for my XR200) but I've been too busy to try it yet. It's still in the box.

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Sooooo close... Just waiting on a few parts....
Pumper carb needed a pipe space bracket to space the Pro-Circuit headpipe away from the accelerator pump diaphragm... Done...
The footpegs needed some mods for a perfect fit... Pain in the arse ...but done!  Check the pegs... Worth the pain...
True performance wizards will recognize the only true silicone waterproof plug cap in the NGK lineup... the venerable TB05EMA.... naturally... It's all in the details😎🤘

IMG_20200831_193626.thumb.jpg.79c825851e384680e0dda8df142165b6.jpg

Edited by mixxer
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I misspoke earlier in this thread when I said compression went from 9.7 to 11.3....

I was looking at the xr80 spec page in the 80/100 manual... The 80 comes with higher comp than the 100...

Compression is up from 9.4 to 11.3:1

That's even better...😎

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Fat Cat approved lightweightIRC IX-09w tire is in the house....  

New flywheel should be here by the weekend....

Shouldn't be too long before I get to hurt myself goofing around on this thing 👍

IMG_20200901_210732.thumb.jpg.2a92f4f8e3671b21817d9c06f54a9554.jpg

  • Haha 2

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93ish% Complete....

Have to true rear wheel, swap to IRC tire....

BBR chain guide doesn't accommodate the wide 420 o-ring I found... Gotta mod guide.....or drop o-ring chain

Front brake lining needs surface rust removal and actuator arm needs correct clocking....

....then I really hope it's test ride/ break-in time...

IMG_20200903_195243.thumb.jpg.be4a1467e371bb32476e4a1c88410838.jpg

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1 hour ago, mixxer said:

93ish% Complete....

Have to true rear wheel, swap to IRC tire....

BBR chain guide doesn't accommodate the wide 420 o-ring I found... Gotta mod guide.....or drop o-ring chain

Front brake lining needs surface rust removal and actuator arm needs correct clocking....

....then I really hope it's test ride/ break-in time...

IMG_20200903_195243.thumb.jpg.be4a1467e371bb32476e4a1c88410838.jpg

Look awsome great job!👌

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Done finally.... What a long strange trip it's been....

All the apprehension of parts and techniques combining to do what you want ....

"Hoot" is alive and lives up to it's name....

 Very happy with everything.... Hauls serious 100 ass ... mid-RAGE is fantastic ... Glad I stayed with. stock CDI box/stock rev limiter.... I like this thing pulling the plug on the rpm party instead of revving to the moon...

It's still pulling hard at the rev limit... You would totally run it higher to see where it flattened out and signed off in power.... so I'm glad the stock limiter puts a lid on things....

Easily the fastest of the 3 I have owned/built...

A 12 year old could put serious hurt on egos in the woods with this little beast 🤘💪

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Edited by mixxer
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16 minutes ago, mixxer said:

Done finally.... What a long strange trip it's been....

All the apprehension of parts and techniques combining to do what you want ....

"Hoot" is alive and lives up to it's name....

 Very happy with everything.... Hauls serious 100 ass ... mid-RAGE is fantastic ... Glad I stayed with. stock CDI box/stock rev limiter.... I like this thing pulling the plug on the rpm party instead of revving to the moon...

It's still pulling hard at the rev limit... You would totally run it higher to see where it flattened out and signed off in power.... so I'm glad the stock limiter puts a lid on things....

Easily the fastest of the 3 I have owned/built...

A 12 year old could put serious hurt on egos in the woods with this little beast 🤘💪

792735141_IMG_20200905_1354472.thumb.jpg.0fe69aee67c4a485a7f0b2463cfced5e.jpg

1782863944_IMG_20200905_1407392.thumb.jpg.0f0e3bf59c2dbeb93cbc6f6b6e5b1870.jpg

Friggin awesome build. Well done sir.

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1 hour ago, everlastneverfast said:

Friggin awesome build. Well done sir.

Many thanks, my friend!

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Forgot to mention... 

This little thumper got Bronze Swingarm Bushings!!

LOL.... Anyone remember when that was a hot handling upgrade in the 70's ?!?

The stock composite bushings, whatever they are made of, were crumbling on disassembly ....

I looked up on eBay and found somebody still machining bronze bushings for some old style swingarm setups...  Very Retro Cool😎😁

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