22r rebuild problem

[soulfire]

Am I about right with the amount of Km's traveled?

Or should I be waiting longer or doing this earlier?

Cheers

[o_man_ra23]

From memory 100kms sticks out.

[neal]

Soulfire: This is how i would do the retorque. first i would remove everything bolted to the head, e.g exaust, inlet manifold, so the head (head gaskit) doesn't move when you loosen the bolts. then i would loosen all the bolts in the right sequence and torque again in the right sequence (hopefully it will be lubed to get the correct reading). At any cost you dont want the head gaskit to move.

O man ra23: Woudn't loosening the bolts one at a time warp the head.

[o_man_ra23]

sorry neal, you fail!!

If you loosen all bolts, then the head will have a chance to move, just the pressure of the torque wrench tightening them back down will make it move. Doing it one at a time while the head is at a stable pressure will prevent movement, and distortion. If you change the heat of the head while you are doing it, you risk damage. But if you do it while at room temperature (ie let the motor cool properly), the head will have no reason to flex/warp. Head deformation happens as a result of heat and pressure, neither is present in great quantities while the engine is stationary at room temperature.

[mudgutts]

found this link to a very simple home-made manometer.

http://www.powerchutes.com/manometer.asp

meter rule, 4mtr clear tube. clear tape and some two stroke oil.

how much difference is your compression per cyl?

if they're all very close, should be very even in intake volume per cyl so that would bring it back to the carbs.


you'll be amazed at the difference balanced carbs can make. my old Kawazaki GPZ600R couldn't rev past 4.5K without shaking the front forks violently. once i had them balanced, it could rev to 11.5K smoothly. i was shock at the difference.

[soulfire]

found this link to a very simple home-made manometer.

http://www.powerchutes.com/manometer.asp

meter rule, 4mtr clear tube. clear tape and some two stroke oil.

how much difference is your compression per cyl?

if they're all very close, should be very even in intake volume per cyl so that would bring it back to the carbs.


you'll be amazed at the difference balanced carbs can make. my old Kawazaki GPZ600R couldn't rev past 4.5K without shaking the front forks violently. once i had them balanced, it could rev to 11.5K smoothly. i was shock at the difference.

cheers mate, i'll give that a go!

[neal]

I should have mentioned just crack the bolts while undoing them (so not to remove tension) in a proper sequence and then re-torquing them in the proper sequence.

O man ra23: you are right i would have failed. but how do you prevent the head from walking if you undo and do one bolt at a time.

[o_man_ra23]

There are 10 bolts. The combined pressure of 9 of them is enough to hold the head down while not running, and the space provided between 2 bolts is not long enough to cause a potential warp while not running. If one bolt is left loose however, then when you run the motor you will have troubles due to the heat cycling.

[neal]

If you loosen one bolt out of 10, would'nt that cause the head to walk by decreasing the tension in that region.

[o_man_ra23]

No, not enough area is loosened and when you re-tighten it, the rest of the head bolts have held it in place, so it won't walk. Not unless the head has changed shape between when you loosen the bolt and when you re-tension it, but that only happens due to a dramatic change in temperature, or if there is a strong pressure pushing on it.

[Steve M]

As owen said, the loosening is only to take off that stiction crack. There is probably less tension difference between the bolt you're working on and the rest of the head in this process than there was in the last stage of torquing down the head initially.