Okay I know some of you think I'm a loose cannon when it comes to motors (that is why I post so much here) but I have a quick question for anyone willing to take the time out and viewing the next to last image on my gallery page. Shouldn't the piston come up further (the pic is at Top Dead Center) therefore causing more compression. I read someone post that thier TVI 720 kit compression was lower than what it claims to be and wondering if I too am in the same boat.

 

i have the lower compression piston in my 720 not sure what it is really, don't really care now. ran one of the higher compression 720's this weekend. mine won every race. the funny thing is i'm saving a lot of money on race gas[img]i/expressions/face-icon-small-smile.gif[/img]

 

I read it was like 9.5.1 or something ( I don't recall the exact number)... but I would have liked it to be at least 11:1. When I went to a Ron Wood piston I felt a big difference all over the powerband. I just want to ensure for the money I spent I got a fast bike.

 

9.5 isn't that about like stock? well what ever it is it works.

 

Even though the new piston may only come up about the same as the stocker, you gain a lot of compression by the added cc's. Also looks like it's got a decent dome to it.

You are now pushing 720 cc's into the same space that you used to push 653 cc's in to.

When I put my 440 kit in my old EX the new piston was flat, deck heigth was identical, but compression was raised from 9.1:1 to 10.3:1. And thats only with a 40 cc jump!!!!! By adding 70 cc's and a dome you should be well over 11.5:1.

I would love to see a pic of your combustion chamber to see what machining was done to that funky "corner" if you've got one.

 

If that is the case I as a trail-rider can get the 12.5 and run pump. As its not a true 12.5.

 

there is a lot of questioning about the first batch of 720 pistons, and there compression, to some it seems very important that they have numbers that sound right. that being said what ever that piston is it runs good it hangs right with a 760 pami, gas for gas. after running the higher compression version i didn't see a difference, except mine pulled the wins out rider was the difference in those cases, but the difference between the two isn't worth the discussion. for the nitrous i'll stay with the lower one but there is to much, debate by people that haven't even run the lower compression piston, probably haven't even seen one of the engines run.

 

Geez, does it ever end??????[img]i/expressions/face-icon-small-disgusted.gif[/img]

 

Sandman your right... let me ride the damn thing and see how it fares. I was just comparing that flat piston to what my Ron Wood Piston was. I would like more compression, I felt it all over the powerband with the previous piston. If there is a way to measure it down the road I may just get one. Hopefully this weekend I finally get to break in the motor and I will give a full report on the ride. Weekend after I know my Stage III buddy is going to flag me down hard and if he wins I'm never going to hear the end of it. He will say that his Ron Wood is the best, reliable, yadda, yadda, yadda.

 

my kids race pretty good and i told them someone has to say go so they might as well be nice and be the one to say go. so be nice to your stage three friend and be the one to say go.