Is there any reason why they don't make a .100 and .120 over piston for the 400L?

 

I think that bubba had a .120 piston on his big bore bike.

 

Hmmm, the hpd catalog shows the next size after .080 over to be .140?

 

I thought Bubba had .140,well i guess Bubba or Dana will have to answer this one.

 

Honestly why would you want to go that big?? I know I have seen Bubba say that if he had it to do over again, he wouldn't go with an overbore, in my opinion, going with an overbore is going overboard!! [img]i/expressions/face-icon-small-smile.gif[/img]

 

Well when you are .080 over you don't have much choice. It's a whole lot cheaper to go big bore than to resleeve and have to have it reported. Also in the sand which is what I ride in most of the time, a big bore will outrun a stock bore due to the amount of torque a big bore has.

 

The AZ Bad Boyz are doing some motor stroking, that might be an option.

 

Guess you have a point if you are already at .80 over. You may gain torque, but dang you lose so much on top end power... And, like Modquad said, you could always go with AZ Bad Boyz.

 

I'm sticking with polaris, no yamaha parts in my engine. Plus that stroker isn't proven and can it run with the with hpd power valve. Also with the stroker you have to get a new cylinder so it isn't a whole lot cheaper than the power valve system. I'll be suprised if I loose any top end and I'll sure beat the standard bore to the top of the dune. Like I said I ride in the sand most of the time, I'll have to find a stock bore race mod to race in the sand and see what happens. Plus how much top end do you need in a 300ft drag race. The best time I've ran so far is a 5.55 at 54mph with the worn out .080 engine, we'll see what the big bore does. I have no doubt I would lose to a stock bore on hard packed ground though.

 

Well, if you are going to be running 300 ft. then, I wouldn't worry about it either, I can't say how much you would lose with an overbore compared to a stock or slightly overbore. I have read that the overbore has some compromises and the power between the 2 if you look at Aaen's big bore vs. HPD's Race mod you will see there is at least a 10 hp difference. I can't really say though, I have never ridden a big bore.