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Degree wheel?


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You can print them and tape to cardboard. Just curious why you need that to cut the domes though. That would be a linear measurement.

I need new domes cut for my motor cause those ones that came with it weren't right. I was just told that I need to degree the motor to have them cut..... What am I supposed to do to have them done?

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Is it just the squish? Check it with wrong domes then make adjustments from there. You can also get an idea by measuring the step in the dome, then the deck height (how far the piston is in or out of the hole.) For example if the piston is 0.020" out of the hole and you want a squish of 0.040", just order new domes with a 0.020" step.

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I honestly don't know if its just squish or not. Believe the guy said that they were the wrong profile and wrong squish. I don't have a base gasket yet cause I was just going to get one when I got the domes not thinking that I'm going to have to measure with a gasket I place. What gasket would be ideal and what is the ideal squish?

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What motor? The base gasket is gonna affect port timing as well as squish. As far as the dome being the wrong profile, a degree wheel won't help you at all there either. There are too many variables to suggest an optimum squish. The combustion chamber volume, piston angle, dome angle, squish band length and angle, bore, all play a role in the MSV. For example, off the shelf Cub 421 domes usually do good with about 0.045". You can run them in the high 0.03x" though.

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It's a 485 cheetah. I'll be using it for strictly 300' sand drags. As far as the degee wheel I was just told that that was what I had to do. So could I put it together without a base gasket and take what ever measurement are needed and just tell whoever I have cut them that there was no base?

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You could, but then the problem is that they would still only be estimating the step in the dome. Many different base gaskets are made of similar yet different materials that tend to squish down a little bit. So say a .020 base gasket might actually be .015/.016 after torquing it all down.

 

I would bet that whoever told you to get a degree wheel is doing that so that you know when you are exactley at Top dead center.... Just my guess and I know it is definitely the most accurate way to do things.

 

So, if it were me, I would buy 2 base gaskets. Torque the cylinder down to spec with a gasket in place and use your degree wheel to find TDC. Then use a dial indicator to find what your deck height is. Use the other base gasket when you do your final assembly.

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For example if the piston is 0.020" out of the hole and you want a squish of 0.040", just order new domes with a 0.020" step.

I think you miscalculated. That would be .000 squish. If the piston is .020 out the hole, you would need a .060 step to yield a .040 squish. Am I thinking right?
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