alky compression?

[J-Madd]

If you could enlighten me about angle of what, what is my squish band and MSV, I would really appreciate it. I'm trying to get all the info i can.

 

 

I won't pretend to know much about how to set up a dome. I am just regurgitating what I have read over the years. MSV is mean squish velocity and there is a certain speed your looking for (I don't recall what it is), measured usually in fps (feet per second). When you change the squish band width or clearance it changes the velocity. YOu get too much velocity and you can get deto (or maybe preignition), too little and you don't maximize the power output of the motor. The MSV can also dictate how far the motor revs out, or when it starts pulling. This would have to be matched to the rpm range of the pipes I would think, to optimize power out put.

 

The squish band is the part of the dome that is near parallel with the piston crown. Builders tend to run a narrower (or is it wider?) band for for the quarter mile vs 300 ft. The band can also be varied to accommodate for rider weight I believe. Same can be said for the angle, I think . Builders may run a different angle for 1/4 mile vs 300 ft. It would be best to talk to a builder to get the best dome for your motor.

 

If you don't know the deckheight, here's what I do (I find it hard to measure it using feeler gauges, and I don't have a stationary dial indicator). Check the squish with any dome and make a note of it. Measure the step in the dome (the height of the sealing surface that the o-ring goes around, measured on the inside), and subtract the difference. If you have for example a 0.050" squish clearance with a dome with a 0.045" step, your deckheight should be -0.005" ( 0.005" in the hole). You'll need this info when you go to order the dome. Your builder can tell you what angle, width, and clearance to run, but he'll need the deckheight to get the clearance right. If you know what specs you want to run, you can call or email Noss and you'll have your custom domes in a couple of days.

[patsbansh]

Thanks for the info it will definitely be helpful and what do you know, I learned something new yet again.

[mailman]

I won't pretend to know much about how to set up a dome. I am just regurgitating what I have read over the years. MSV is mean squish velocity and there is a certain speed your looking for (I don't recall what it is), measured usually in fps (feet per second). When you change the squish band width or clearance it changes the velocity. YOu get too much velocity and you can get deto (or maybe preignition), too little and you don't maximize the power output of the motor. The MSV can also dictate how far the motor revs out, or when it starts pulling. This would have to be matched to the rpm range of the pipes I would think, to optimize power out put.

 

The squish band is the part of the dome that is near parallel with the piston crown. Builders tend to run a narrower (or is it wider?) band for for the quarter mile vs 300 ft. The band can also be varied to accommodate for rider weight I believe. Same can be said for the angle, I think . Builders may run a different angle for 1/4 mile vs 300 ft. It would be best to talk to a builder to get the best dome for your motor.

 

If you don't know the deckheight, here's what I do (I find it hard to measure it using feeler gauges, and I don't have a stationary dial indicator). Check the squish with any dome and make a note of it. Measure the step in the dome (the height of the sealing surface that the o-ring goes around, measured on the inside), and subtract the difference. If you have for example a 0.050" squish clearance with a dome with a 0.045" step, your deckheight should be -0.005" ( 0.005" in the hole). You'll need this info when you go to order the dome. Your builder can tell you what angle, width, and clearance to run, but he'll need the deckheight to get the clearance right. If you know what specs you want to run, you can call or email Noss and you'll have your custom domes in a couple of days.

 

 

The "m" in msv is for maximum not mean. The msv is measured in mps or "meters per second".

[J-Madd]

Thanks for the correction. Maximum makes more sense. Feet per second/meters per second is probably user preference of standard vs metric. But if meters per second is more commonly used, thanks for that correction as well.