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millwoodva

Xr 170

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Takegawa Kit - pn: 01-05-2716

136cc Stage III S-CUT, Takegawa Super Head. Incoporates the same STAGE III head used in the other top end performance bore kits but now employees the S-CUT technology to allow larger displacement with out the use of a crankshaft. This kit can be installed with your stock crankshaft and no need for splitting your cases and complete motor tear down.

1) 62mm S-CUT High Compression Piston

2) 13.1:1 Compression Ratio

3) Nicasil Cylinder design for tighter tolerances and lower friction and less parasitic losses.

4) Roller Bearing design on the cam supports

5) 28.5mm Intake Valve

6) 23.5mm Exhaust Valve

7) 4.5mm Valve Stem diameter

8) Higher rate valve springs, for higher lift cams and more over-Rev.

9) S35 Cam Shaft, Higher lift, more duration for high end performance.

http://japan.webike.net/products/1639704.html

Mated with a Kitaco 56.5 mm Stroker crank.. By my calculator.. equates to 170 cc 👍

http://japan.webike.net/products/375963.html

Edited by millwoodva

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Remember SCUT kits have a piston that is larger than the hole in the cases so increased stroke would have to be past TDC not BDC. That would require taller cylinder, longer timing chain, ect, I dont think the two kits are compatable.

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This has been brought up before...If- it is possible to get the 62mm piston into the engine cases because of the increased stroke, by my calculation the piston pin would be just about out of the cylinder at bdc. I don't believe the assembly will mock up

Wishfull thinking tho

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This has been brought up before...If- it is possible to get the 62mm piston into the engine cases because of the increased stroke, by my calculation the piston pin would be just about out of the cylinder at bdc. I don't believe the assembly will mock up

Wishfull thinking tho

Possibly a case/cyl. spacer plate? .. 👍

I believe the cam chain length could be dealt with..

I used a 10mm spacer to stroke my YZF750... YZF1000 crank in 750 cases

result.. 912cc

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👍 These XR100 stroker kits use a shorter rod. The cylinder deck hight remains the same as stock. Rod/piston plunges deeper into the engine case.

A long rod stroker (aka stock length rod) will require a cylinder spacer. Piston plunge/rise is 1/2 the stroke over stock depth/height. 1/2 of 56.5mm = 5.75mm

The SCUT kits eliminates the need for the cylinder sleeve/piston skirt to plunge into the cases (with the stock stroke). Increasing the stroke in combination with short rod and spigotless cylinder is the issue. The stock engine case opening is 60mm (case boring to 62mm might possible) never-the-less the stock cylinder hight is 69mm. 56.5 mm stroke -69mm cylinder hight is 12.5 -now we have to factor in the piston pin to deck hight- which is about 12.8mm at this point allmost half the piston wrist pin will be out of the SCUT cylinder at BDC.

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I reinstalled my 132 kit but I think that slow600 switched to a bbr kit, so I would check with him to see if he still has the 132 kit laying around.

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Welp, it doesn't seem the TT will bring back all the lost threads and posts. Since this thread was also lost with the format change. I figger it needs to be updated. There also was further posts and discussions that were lost

The Kitaco crank has a 11.5mm stroke over stock= 56.5mm. However, the fact that It does use a shorter connecting rod- this crank/rod does not share the stock pistons compression height. Most all of the XR pistons are around 12.8mm (give or take .2/3mm) compression height (top of wrist pin to piston deck). With that said- the Kitaco 145SE piston must have about a 11.5mm compression height. We have some opitons- so here it goes agian...

Daytona HD timing chain supplied by TK Racing, and custom .050 and .063" cylinder spacers to make up the difference in compression height

2009_0818100XR0027.jpg

TB 132 kit supplied by slow600

2009_0818100XR0030.jpg

Engine Case boring to the max 62.5mm service provided by FirePowerMinis, just started to break out a the cylinder dowl need for the 61mm SCUT piston to fit in the cases

2009_0818100XR0033.jpg

Kitaco 145SE stroker crank

2009_0818100XR0035.jpg

61mm TB SCUT Piston

2009_0818100XR0038.jpg

2009_0818100XR0043.jpg

At BDC with the stroker crank

2009_0818100XR0042.jpg

At BDC with the stock stroke crank- for a comparison

2009_0818100XR0052.jpg

With the .062" cylinder spacer

2009_0818100XR0044.jpg

Assembly at TDC with the .063" spacer

2009_0818100XR0046.jpg

I was unable to install the timing chain because of the add spacer .063". The .050" (piston was at .010" below deck) spacer helped- but I was only able to force a old timing chain on. Its supper tight! To be honest- I wouldn't run it, its that tight.

2009_0818100XR0053.jpg

We have a few options:

-A custom 92 #25 link timing chain.

-Deck the head .030"-ish to lossen up the timing chain- with the cylinder spacer

-Spin down the outer ring of the piston (half the spacer.030" and half the piston.030"). However the TB 132 pistons doesn't have enough material above the top ring to take all .063" off and be safe.

From the pics I'v seen- it looks like the Takegawa SCUT piston have more material above the top ring....?

However, I don't believe there is enough piston left in the cylinder at BDC. I would recommend assembling a inexpensive runner with a Powroll 9mm stroker crank (Powroll crank uses the stock compression hieght- no need for a cylinder spacer) and a TB 132 kit for around $500 R&D =165cc. Lots of remove TB 132 kits out there...

Edited by gman255

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Are you sure about running a Powroll 9mm stroker? I have one, it might give me new hope on my conversion. At least until the kick starter gear takes a dive.

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Yup the Powroll 9mm storker. With one of your TB 132 kits?! It should be less than 13:1. CR I'll crunch some numbers.

I got to ask- how many times have you broken those gears?? And when was the last time?? What was the engine combo??

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I never had (I broke everything else multiple times), but Spike had a long rod stroker a long time ago that would break a kick start gear about every couple weeks (at least). In fact, that's pretty much how I learned how to work on these motors, because I would watch him all the time. He ran a Powroll 9mm long rod, longer cam chain, spacer plate, web cam, GPZ 58mm piston, 200x carb with HRC needle. Back then, everyone was hush hush about what they had, but that's basically what he had. I sure there was some more top secret stuff.

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What!! lol^^

I've spoken with a few other XR100 engine guru's with hot kits. The have stated the kick starts primary gear is constantly engaged with the main shaft (always spinning under load). Their breaks have been at the kick starts primary gears- not at the ratchet gear or the kick start shaft.

Assembling my Kitaco stroker short block- Took a few minutes to understand kick start gears orientation...

I'm running about 15.1 compression in the Retro- We shall see how long the KS gears last- and if it is in fact relative to High Compression (retro, or Big HP and Torque #'s Kitaco 145SE kit- my 145 with also have Big CR)

BTW- Theorized some compression numbers for a 165cc combo (TB132 and 9mm stroker- with the stock head) It was about 13.3:1 for a guess. Could kill about a 1/2 of a point off the CR with a .032" copper head gasket

FYI I'm not recommending this engine kit/build- Or responsible for your engines life span or failure. Installer be ware- You will be your own Research and development- My documentation was for a "What if" and "is it possable".... We- Leave the rest up to the Gods Of Speed

Edited by gman255
Added Disclaimer

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