727 Bored vs 727 Stroked..?

[Colorado700R]

I got a bone stock motor sitting here

Want to sell it cheap 

Well, if Troy wants it, he's got first dibs since he's helping me pull it and put my stroker together, but I'll let you know Randy

[RaptorRandy]

I got a bone stock motor sitting here

Want to sell it cheap 

Well, if Troy wants it, he's got first dibs since he's helping me pull it and put my stroker together, but I'll let you know Randy

Cool, keep me posted Bro 

[Jay@RacersEdge]

When fuel numbers increase with no increase in power its a waste.

If fuel numbers increase with no increase in power then IMHO something is amiss. When one thing is changed, it changes the parameters of the whole of the combination......... I have seen first hand where after changes that made for more power and a better curve, that fuel had to be removed and the combination became more efficient as well as making more HP & TQ.

One thing I see being overlooked in this whole debate is TQ.........I'll take TQ over a feel good peak HP number any day. The stock bore and stoke engines lack the TQ of the good stroker combos. You put a 77 HP 50-55 ft lb of tq stock bore & stroke combo up against a 77 HP 62 ft lb of torque 105mm +6mm or +8mm stroke combo and see which is the most fun to ride and which performs better in tight trails, up steep hills and is the best overall performing machine if it's set up well.  The TQ monster will outshine the SB/SS nine times out of ten in my experience. There are always exceptions to the rules and I think the RE stock bore is the biggest exception. For the Joe average duner like myself who likes to tree shoot, ride tight trails and dune hard.....then go to the hill and be competitive, a  bored and stroked bike fits the bill perfectly, and with the right cam profile, degreed in properly you can make those HP & TQ numbers with a pump gas friendly final compression ratio IMHO .

Well put

[tonto13]

Randy, I would really like to know what you mean by properly set-up motor. Mine is a +5 stroke/stock bore, web4, p/p stock valve. Have stopped modding for a bit, been looking  and reading trying to find a good combo. I know the combo's are quite a few. I also run nitrous, as I have started doing 300ft drags. Just mainly wondered what are some of the things(tricks) I might be missing. I still trail ride. From what I have heard your 780 was a very strong runner, even against some of the bigger builds.

[DL700]

matching components is very important to make a combo efficent, as with what Randy said, a good combination will use less fuel and make the same or more power.... where torque is made is also important.

recently I heard of a guy throwing one of the biggest cams on the market at a bike with a small hand ported head, bored stock throttle body, and a small single exhaust  in this case going from his megacycle most likely  fuel usage will go up with no additional power


When running the hill a bike  making more torque/power @ 6-7 k will pull a lot harder thru the 2-3 shift and be ultimately faster then a motor making a bit more peaak torque.... having the power over a broader range IS a lot more important then peak power...

my personal bike picked up huge in the 6-7k range going to the larger bore.... making it a lot faster out of the hole and thru the mid range, making a strong smooth pull all the way to the top

[RaptorRandy]

When fuel numbers increase with no increase in power its a waste.

If fuel numbers increase with no increase in power then IMHO something is amiss. When one thing is changed, it changes the parameters of the whole of the combination......... I have seen first hand where after changes that made for more power and a better curve, that fuel had to be removed and the combination became more efficient as well as making more HP & TQ.

One thing I see being overlooked in this whole debate is TQ.........I'll take TQ over a feel good peak HP number any day. The stock bore and stoke engines lack the TQ of the good stroker combos. You put a 77 HP 50-55 ft lb of tq stock bore & stroke combo up against a 77 HP 62 ft lb of torque 105mm +6mm or +8mm stroke combo and see which is the most fun to ride and which performs better in tight trails, up steep hills and is the best overall performing machine if it's set up well.  The TQ monster will outshine the SB/SS nine times out of ten in my experience. There are always exceptions to the rules and I think the RE stock bore is the biggest exception. For the Joe average duner like myself who likes to tree shoot, ride tight trails and dune hard.....then go to the hill and be competitive, a  bored and stroked bike fits the bill perfectly, and with the right cam profile, degreed in properly you can make those HP & TQ numbers with a pump gas friendly final compression ratio IMHO .

Well put

Thank you sir 

[RaptorRandy]

Randy, I would really like to know what you mean by properly set-up motor. Mine is a +5 stroke/stock bore, web4, p/p stock valve. Have stopped modding for a bit, been looking  and reading trying to find a good combo. I know the combo's are quite a few. I also run nitrous, as I have started doing 300ft drags. Just mainly wondered what are some of the things(tricks) I might be missing. I still trail ride. From what I have heard your 780 was a very strong runner, even against some of the bigger builds.

Thanks, I was very happy with the performance of my old 780. As far as my comment

You put a 77 HP 50-55 ft lb of tq stock bore & stroke combo up against a 77 HP 62 ft lb of torque 105mm +6mm or +8mm stroke combo and see which is the most fun to ride and which performs better in tight trails, up steep hills and is the best overall performing machine if it's set up well.

When I said if it's set up well, I  was refering to the whole package IE: engine, gearing, optimum tire size & paddle count, suspension,  swingarm length etc. You can build a bike that makes 92 HP, but if you don't have the rest of the ingredients right on the money....well, someone with a 77 HP bike that has the whole package is gonna get to the finish line first. Sorry if I didn't explain it well in my other post. Engine set up is a very improtant ingredient to the complete package and that comes from experience through trial and error. I learn new things all the time when I'm playing with combinations and sometimes I just get lucky, but attention to detail is key and all the little things add up. I am by no means an expert, I just apply all the same things I have learned over the years from racing Drag cars and Winged Sprint cars. Folks like Dave @ Roosterbuilt, Kenz Cycle tech, Racers Edge, Kenny at KDS, Gerry at Holeshot etc are all much more qualified than I to give you advice on the best combination of light weight high quality parts,clearances, deck height,installed centerline of the cam, ETC. They have a wealth of knowledge, so my advice would be to  talk to all of them and pick the one you are most comfortable with, and go with one of them for either the entire build or the combo of parts you need to  get you to where you want to be.










Randy

[Kamakazi]

dont forget tim barker    nice list though 

[RaptorRandy]

dont forget tim barker    nice list though 

Man.....I did forget Tim    He's great as well.....sorry about that......another sign of old age setting in 

[tonto13]

Yes I know it does take a complete package. I am not an expert either, just a guy who knows enough to get himself in trouble. I like to do my own work so that I know what is in there and how it works. Like you I learn more everyday, and want to learn more. Was just looking for some info or tips that you have learned over time. Or any sources for info to learn, books and such. Just want to optimize mine to the best  my ability. Also when something goes wrong I know how to fix it and who to be mad at, MYSELF!!

[preddy08]

Yes I know it does take a complete package. I am not an expert either, just a guy who knows enough to get himself in trouble. I like to do my own work so that I know what is in there and how it works. Like you I learn more everyday, and want to learn more. Was just looking for some info or tips that you have learned over time. Or any sources for info to learn, books and such. Just want to optimize mine to the best  my ability. Also when something goes wrong I know how to fix it and who to be mad at, MYSELF!!

X1 I know, I'm the same way!

[fireman5166]

so with my mods that I have now I should get a c&c head and boarded tb. my question is on the head is +1 or +2 and tb +2 or +3? I still trail ride but I would like to be able to kill people in the sand. Im at 62 hp now. with the head and tb would I be close to 67hp? I guess what im saying is im so lost. lol. I have 1,500 bucks and want to hit 70 to 75 hp. what should I do?

[DL700]

Just upgrading the head is only going to get u another 2-3 hp, the throttle body is a mandatory upgrade at your point and should be the next thing taken care of, +3 is the way to go.

if you upgrade the cam as well as the head u can be looking @ 8 hp or so between the 2....\\\
The hc3 is going to limit the potential of every head except stock

[Troy]

I upgraded a bike yesterday that started out at 48 horsepower baseline.  It is a Trinity 734 with 11:1 compression, stock head with hotcam stage2, stock throttle body, Trinity fuel controller, Barker duals.  I pulled off my +1 RE cnc head with Web4 cam and put my +2 KDS throttle body on, put a 12:1 piston in and installed a pc3.  The second dyno pull we gained 15 horsepower and there is alot more in the tune.  Tomorrow we are going to try the Dynatek off of my bike to see if we can get even more while we tune it in.  I think 20 horsepower is possible.  That to me is an amazing gain for what we put on the bike.  By the way the bike also had an fci intake the whole time.

[DL700]

thats a funny story...... them damn peeps with their 734's lol

Today I had a bike come in  2006 700R, Nmotion full exhaust, dobeck, home made intake, Dynatek programmable, Hotcams stage 2...... and a TRINITY 108MM BIG BORE KIT...THAT WAS IT!!!  way overkill on the bore without any decent supporting mods!

it made a whole 54 hp and 47 tq  ..... this build had cost him 2k at a well know shop here in Ca.
His bike will be on its way to some true HP shortly!!!