Your confusing me, so my new piston with a 50cc gain and 12:1 compression did nothing for me and all my power gain came from the porting I had done to the head. Whats the differance between your 02 and the 05 (which you dont)? How many pistons will Kenz 67hp stock bore chew through in 5 years of hard duning and draging? I will let you know how mine is doing in a couple years. You should just find another stock cylinder and stay with the stock bore so that you can keep handing it out to all those big bores lol

I gotta go now, i'm goint to go pull the head off my raptor, box it up and send it to kenz.....thanks

 

A cam will more or less put the power where you want it(low-mid range-top end), more then it actually add's hp to the motor or rear wheels....smart guy.

 

it wouldn't be the first time kenz has fixed trinity's work..... damn did i just say that...[img]i/expressions/face-icon-small-blush.gif[/img]



i guess then im a lone ranger on this one, where is maddog he might back me up.

so not one person is going to agree with me that boring the motor doesnt do much for hp???
it may help torque.

and understand this kenz is local to me, which is why i chose him for my builder, if i lived in texas, i guarntee you i would have went with craycraft. if i was in so cal i would have went with CT, i dont feel the need spend the extra $400 for shipping when i can drive down the street for much less.
my 02 needs a overhaul, sure i can re-sleeve to go back to the stock cylinder, im reading for a teardown with new bearings, seals, shiftforks. cases are split why not but in a new rod and crank.

oh and a 12:1 helped out, just not the 50cc.

 

I think it's the combination of the bore job higher compression ratio, the Port work and multi angle valve job.
I think the stroke to bore ratio is more favorable on the 734 than on the 686.
I know Trinity's Dyno reads high as it was publicly admitted to by one of their employee's on another forum but that should not discount how hard Raptor 734R's bike runs. I am sure he is in the 60 plus HP area I don't care what the all knowing say. If he had the same thing done on an old 660R engine would it not be in the same HP area?
I feel because the 700R is so new and there's not much out for it that people don't want to believe that it has some serious potential. I do wish Trinity would either upgrade to a Dyno Jet or get their Dyno recalibrated. Then they would have more credibility and would get their due respect for beating everyone else to the punch on the 700R and tapping into it's HP potential. I think they have hit a home run with their 734 Kit. I do think that with everything the same except for the bore job on a stock bore 700R one could expect to make about 58 RWHP[img]i/expressions/face-icon-small-cool.gif[/img]

 

i dont get how you can make 40hp gain without touching the cam.
its not the point about trinity's dyno. im trying to get the point across he didnt have to go with such a huge bore
686's make in the 60-65hp range we all know this
and 727, 730's make 65+ but thats stroking
the 700r have termendous potential, and you have a damn fine looking one. where is your 734kit?

 

Thanks for the complement, myself I'm sticking with the stock bore for right now. I'm waiting for web to come out with their cam for the 700R and then I'll do the piston, port work and multi angle valve job and see what results I get[img]i/expressions/face-icon-small-wink.gif[/img]
I'm going to lay back and see what the builders come up with before I consider changing bore/stroke combos [img]i/expressions/face-icon-small-cool.gif[/img]

I must be missing something here, where you getting a 40 horse gain? stock bore with no headwork, just the bolt ons you can get 50 to 51.5 HP and a buttload of torque to go with it. With the big bore kit and headwork you get 60 plus, now I'm no mathimatician[img]i/expressions/face-icon-small-wink.gif[/img] but where I went to school that sure as hell aint 40 horse[img]i/expressions/face-icon-small-confused.gif[/img]

 

I like what RaptorRandy27 mentions about the potential of the 700, it is what I have felt for quite awhile and think alot of people are having a hard time buying into it, while dealing with Trinity they sure seemed pretty excited about the power they squeezed from my raptor, and more so the torque, from talking with them it sounded like the 734 was making almost the power of their 780 stroker? and this was only the first kit available that I know of. I look foreward to see what other shops come up with and how extreme one can get with the mighty fuel injected raptor [img]i/expressions/face-icon-small-smile.gif[/img] Who knows?

 

I recently added a 105.5mm piston and jug to my DS650. I already had the race head, exhaust, carb, cams and 13.5:1 compression. When I added the extra bore (726cc total now) I stayed with the same compression and saw a 6 hp gain at peak. The cool thing was how much quicker my motor revved below 5000 rpm and I showed a whopping 12 hp gain at 4500 rpm. The bore kit really added average hp gains from bottom to top. The torque is the reason. Any time you increase displacement, as long as your other componentry is still in balance, you will increase torque. A stroked motor will increase torque more than a bored motor will but it costs twice as much to stroke and it is very invasive. Rev speed above 5000 rpm didn't really improve much. Any time you change the bore to stroke ratio you will change your revving and power characteristics. Not as much as you would by changing cams but it is still a factor. I believe part of the reason I increased rev speed is due to the increased torque. It allows you to get to higher rpms quicker which subsequently, each rpm tier makes more power than the previous tier until you reach peak hp. I think the quicker revving was diminished at the top end by the additional piston weight that is unavoidable whenever you increase bore (if you were already running a featherlite before you bored it). Obviously the higher the rpm the more of a factor piston weight becomes when it comes to how quickly an engine revs.

Adding displacement, be it bore or stroke will increase average torque. If no other variables change and the power curve remains basically the same and your componentry is still in balance, you will have more horsepower at every rpm than you did before.

Ron

 

727(aka 730) is just a 105mm bore...no stroke.

720(102mm bore w/ +4mm stroke)

760(105mm bore w/ +4mm stroke)

770(105mm bore 2/ +5mm stroke)

And there is other strokers with the TB +4mm.....using 101mm pistons and so on.

 

Speaking of +4mm stroke with 686cc piston. Anybody try the Hotrod crank/rod setup along with the Hotrod 10.5:1 686cc piston?
Sounds like a reliable setup, only thing is you have no choice but to use the Hotrod piston with a relocated wristpin to accomodate the longer rod. Also, not sure if they they will ever offer other comp/bore pistons for that same kit.

I guess if it runs good you would just resleeve it for the 686cc piston every couple of years.
The only other concern I had was the piston/valve clearance with larger valves since the valve relief doesn't appear to be that great from the pics on their website but then again it may be a generic pic.