Head torque specs

Discussion in 'Whizzer Motorized Bicycles' started by JE, May 17, 2008.

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  1. JE

    JE Guest

    I just got done putting the first 50 miles on my Whizzer and noticed the head is leaking a tiny bit.Bill re torqued the head after shaving it and reinstalling it. It's got the copper head gasket and proper washers under the bolts.I just need to find out the proper sequence and inch pounds of torque to use.

  2. MoonKS

    MoonKS Member

    Hi JE,

    I don't have any sequence info - but Quenton said in my Break-In thread for my 2007 NE5:

    "The torque specs for the 8 MM head bolts is 175 to 180 INCH pounds, and the 10 MM bolts should be torqued to 210 INCH pounds"
  3. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Hi JE,

    Start with the large 10 MM bolt near the spark plug, go directly across to the other 10 MM bolt, then across and forward to the 8 MM bolt, then back to the oposite side, next tighten the rear corner 8 MM bolt [behind the spark plug], then straight across to the opposite corner [nearest intake port], then all the way forward to the 8 MM bolt at the front [flywheel side], then across to the 8 MM bolt in the front [sidecover side], then lastly the rear center 8 MM bolt. Start at 140 inch pounds, then 160 inch pounds, then 175 to 180 inch pounds, and finish with the two 10 MM bolts at 210 inch pounds. A few words of caution, many if not most, cylinders don't have the same depth of threads in all holes. If the head was milled, it is possible the bolts are too long and "bottoming out". If the 8 MM head bolts still have the small thin washer attached, you might want to remove them [a simple pair of wire cutters will work]. The large 10 MM bolts don't have any washers under them, I usually make a set when I re-work my motors. Never tighten the head bolts while the motor is hot. If you are using 2 washers on each head bolt, remember, I don't.

    Have fun,
  4. JE

    JE Guest

    Thanks Quenton.
  5. Sean Durham

    Sean Durham New Member

    that figure is wrong. I tried torquing my head bolts to your numbers and stripped the cylinder.
  6. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    The numbers are correct! The NE 8MM bolts 180 to 190 INCH pounds. The 10 MM 210 INCH pounds.

    The WC-1 cylinders use smaller 6 MM bolts and 95 to 100 INCH pounds torque.

    If you stripped the bolts either your torque wrench is broken or the threads were all ready in trouble.

    I have rebuild or upgraded hundreds of these motors and have used the torque numbers mentioned above for over 10 years.

    Be sure to replace thin head bolt washers for THICK washer to stop head bolts from always working loose.

    Have fun,
  7. Sean Durham

    Sean Durham New Member

    I appologize, the mistake was mine. I had the wc1 cylinder, I decided to upgrade to a ceramic cylinder since I'm attempting to modify my pacemaker ii to a decent performance bike.
  8. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Just to let everyone know the latest cylinder isn't ceramic! More trash talk from Taiwan. The latest cylinder is an aluminum NE cylinder with ceramic paint, something I started doing in 2001. I used ceramic cylinder paint made by Dupli-Color and baked it on in an oven at 200 degrees for 2 hours. Black ceramic paint lowers the operating temp by over 50 degrees, of course Joe Lin isn't using black [yet], because he doesn't know black works best [yet].

    Be sure to obtain thick head bolt washers for the 8MM bolts [can use vintage Whizzer 5/16" washers]. The two needed for the 10MM bolts must be made as there is very little room between the head and the bolts.

    Have fun,
  9. mason_man

    mason_man Active Member

    This ceramic coating is sprayed everywhere, exhaust port, intake port, top deck of cylinder.
    Bead blast it all off if possible! the NE cylinders use to be 24mm intake valve, 22mm exhaust.
    This one is 22mm and 22mm why?
    and now there dropping in a 24mm intake valve but leaving a 22mm valve seat, why?
    Not that you can't still upgrade this one. Intake port is just a little bit bigger than the WC-1'S intake port. you can also move the piston all the way to the top.

    Ray 20150808_142656.jpg 20160225_195638.jpg 20160225_195648.jpg 20160225_195656.jpg 20160225_195714.jpg 20160303_182328.jpg 20160303_183044.jpg 20160303_183537.jpg 20160303_183627.jpg 20160417_175330.jpg 20160303_183537.jpg
  10. sbest

    sbest Active Member

    Your pictures get me excited to do a flathead.

    My lawnmowers all got porting, header, valve jobs and wedge planed heads over the years.
    Just cuz I could! No stall in the heavy stuff!


  11. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    The intake valve was reduced to 22 MM and the carburetor reduced to 16 MM and later models use a 20 MM. It is difficult to change the seats as they are installed during the casting process and have a grove cut around the seat where the aluminum fills and holds it in place. In order to increase the seat size you would have to mill block and "press" in the seat. This works with the NE cylinder because of the wider fins and lower operating temperature.

    You ask why Joe Lin would put a 24MM valve in a 22MM seat, for the same reason he does most downgrades, cause he had the parts and needed to get rid of them. If you want another puzzle about Taiwan engineering, ask why some camshafts are advanced three teeth instead of one. Answer.... cause they messed up a bunch of camshafts and the gear was installed wrong. Instead of fixing the gear location, he just advanced the camshaft extra teeth to correct the timing. Sure confuses the correct camshaft timing.

    Have fun,
  12. mason_man

    mason_man Active Member

    The 16mm carb was used with the 24mm intake valve starting in 2008. Here's a NE-R with one, and with the baked on black paint. wasn't a good idea. Let me show the results, even with some mods this baby ran lean and HOT.
    I made the needed corrections and more.

    Ray 20150415_093412.jpg 20150415_093424.jpg 20150415_093449.jpg 20150415_093519.jpg 20150104_135047.jpg
  13. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    I don't suggest painting head. The [block] head normally runs hot because it is a thick block of aluminum with small fins. I have been milling the fins deeper and adding many more. This process lowers the head temp almost 80 degrees. The cylinder in your post is one of the salvaged NE versions. When the seats were not installed correctly, they machined the cylinder for the oval shaped valve seat. Many problems from the salvaged cylinders, including one of the block retainer screws hit the rear of the head and caused sealing problems, the gasket under the block leaks and allows incoming gas to find a direct path to the exhaust port, and block shifts or works loose and causes the valves to loose the seal on the 45 degree angle. I normally remove the block, replace gasket with copper version, coat block with sleeve retainer, re-install block, grind screws flat, and deck cylinder. Only advantage to cylinder with valve block is valve size can be increased with out replacing seats.

    have fun,
  14. mason_man

    mason_man Active Member

    20160421_205324.jpg 20160421_205430.jpg 20150621_130806.jpg 20150621_160433.jpg 20150706_132834.jpg 20141213_110045.jpg I haven't had any problems with the head. I mill them, they heat coat it.
    Cylinder needs more work done to it to use the bigger carbs,a bigger intake port. Help it breathe,exhaust port needs just a little work.
    The 1"intake valve makes a nice differences, bringing the piston up, spot on.

  15. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    Don't you love the way the intake port is located everywhere but center. That is exactly the same way I upgrade the "valve block" cylinder. The combustion chamber on the "Block" head is a great design, too bad they didn't add a little more "meat" between the chamber and the rear center head bolt [where gasket most often fails]. I mill the head down .090" for serious motors, and .065" for normal upgrade.
    I use Toyota valves, what are you using? I also found the head flows much better if you remove the "cup" from the valve head.
    Have fun,
  16. mason_man

    mason_man Active Member

    Ron Houk supplies me with the valves.
    You mentioned earlier that the 10mm head bolts needing the thick head bolt washes, you can use the 5/16 (same as the 8mm head bolts washers )
    You need to use the high speed steel step drills.

    Ray 20160423_103853.jpg 20160423_103905.jpg 20160423_103924.jpg 20160423_104019.jpg 20160423_104036.jpg
  17. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    I just use vintage 5/16" washers and chuck them in my lathe and drill them with a black oxide bit, and "presto" it is perfectly centered and I let the machine do the work.
    Do the valves from Ron have the same stem O.D. as the original stems? The Toyota stems are .002" smaller and I have to change the guides. I think the stock are .217", and the Toyota are .215"

    Have fun,
  18. mason_man

    mason_man Active Member

    Yup, the valve is plug and play.
    Are you looking for a bigger valve? ;)

    Ray 20150114_142906.jpg
  19. Quenton Guenther

    Quenton Guenther Motored Bikes Sponsor

    No, already have several O.S. valves, just trying to find valve with same stem size as original. I know several sell the O.S. valves with the smaller stem and suggest using them in the larger guide, just don't agree with concept.

    Have fun,
  20. mason_man

    mason_man Active Member

    20160515_152049.jpg 20160515_152058.jpg 20160515_152155.jpg 20160515_152120.jpg I have a NE cylinder I'm going to use the 1" intake valve.
    Then use the 24mm intake valve and valve seat in a WC-1 cylinder. ;)

    Ray 20160515_152049.jpg