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Discussion Starter · #1 ·
how much cc would an 88mm stroke crank with a 105mm piston make? what hp with my setup below? thanks
 

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CoalShedRacing said:
760cc, that single edelbrock carb you have will not properly feed a built 760.
That's what Duncan uses for their big bores... :lol:

CSR is right, even bored out like Duncan's you won't have the flow you need for an engine that large with a good port job.

That's not to say you couldn't build it, you just wouldn't have much in the way of top end power.
 

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allistairc123 said:
cool, thanks, what sorta power would it make?
Assuming your porting isn't all that aggressive you'll probably have some good power down low and good midrange...right up until the bike starts to spit and sputter. Could make it up to 6k rpm or so, but I think with any worthwhile porting it'll hit the wall there. I couldn't give you peak hp numbers because I don't know how well (actually how bad) it'll run up top.

If you're adament about keeping the edelbrock I'd suggest contacting Duncan Racing, since they're the only builder I know of that uses that carb on any build.
 

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just to let ya know..if you want a good worth while build of a 760, plan on dumping over 4k...easy..I'm up over 3 right now and half way done.. I'm sure you can get it done less, but as someone else said in the forum-- The speed/hp of your bike is proportionate to the size of your wallet! I saved since I got the bike in 03 to do something like this! Still had to sell stuff like my laptop and ps2 (which I don't use anymore anyway) to finish it up! :thumbsup: Just giving you a heads up!
 

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rt said:
just to let ya know..if you want a good worth while build of a 760, plan on dumping over 4k...easy..I'm up over 3 right now and half way done.. I'm sure you can get it done less, but as someone else said in the forum-- The speed/hp of your bike is proportionate to the size of your wallet! I saved since I got the bike in 03 to do something like this! Still had to sell stuff like my laptop and ps2 (which I don't use anymore anyway) to finish it up! :thumbsup: Just giving you a heads up!

I like your style. Thats what I did to get my lightning where it is today, I bought it when I was 16 two years ago with(3k miles on it and worked 3 jobs during highschool to pay the note/insurance and all other expenses. Now with college and engineering internship its easier to fund it that toy but its done until whipple decides to bring out the bigger blower. Dumped over 20k easy into her in 2 years, WELL worth it. Now its the rappy's turn just didnt know how quick money can dissapear on these things, back when I use to race I didnt pay the tab......thank god!
 

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I had a lancer evo that was close to that fast in the 1/4 as your lightening, low 11's without juice, my wife made me choose between the car and the quad.... :mad:
What engineering program you into?
 

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03Rappy660 said:
Thats what I did to get my lightning where it is today, I bought it when I was 16 two years ago with(3k miles on it and worked 3 jobs during highschool to pay the note/insurance and all other expenses. Now with college and engineering internship its easier to fund it that toy but its done until whipple decides to bring out the bigger blower. Dumped over 20k easy into her in 2 years, WELL worth it.

Post pics of said Hot Rod. :thumbsup:
 

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It was a sad day... the day I had to sell my 02 Dodge Ram 2500... cummins... 6 speed... 509hp/1016tq... :'(

I had lost my job and it had to go...
 

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pewterpecker said:
It was a sad day... the day I had to sell my 02 Dodge Ram 2500... cummins... 6 speed... 509hp/1016tq... :'(

I had lost my job and it had to go...
Dude,...I woulda worked three overtime jobs at mcdonalds-burger king and wendy's to keep that bitch!
especially a built up cummins diesel. those F#*king motors are awesome! Let me see..you could pull a trailer of like 50 quads with that thing...sorry for your loss bro :(
 

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But back on track, this thread leads me to a question of my own: how many cc's is too much for a good broad power band? It sounds like the 760 is going to be all bottom end. Is the 720 like that?
 

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that 760 I'm building (coalshedracing) will make power across the entire band. believe it or not, most of it will be at 6000- to 9000 rpm range and the curve won't drop until the rev limiter.
 

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Discussion Starter · #16 ·
coalshed, would you share the exact setup u will use for the 760? id love to know!!, id love to build mine with broad power like you are aiming for.
 

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pewterpecker said:
So are you basically offsetting the low end tendancies of the high mass long stroke rotating assembly with a radical valvetrain setup?
I would love to answer your questions, but rather than contradict anything he's doing by mistake, I'll let him answer...It does have a very radical port job though.
 

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allistairc123 said:
coalshed, would you share the exact setup u will use for the 760? id love to know!!, id love to build mine with broad power like you are aiming for.
The parts used can be bought by anyone, its the parts combo that is key. The cam/valves/valve job/porting/intake must all work well together, I've spent a ton of money in R&D, flowbench and dyno time to find the combinations that work well together.

Here is the parts list
4mil stroker crank with chrome-moly rod
CP 12:1 105 piston
LA sleeve 105 sleeve
Ferrea stock size stainless valves
megacycle x4 cam
39mm FCRs set up to work with stock thumb throttle
Custom intake manifold
High Velocity porting

You just have to think of any engine as an air pump, volumetric effiency(sp) is what you are after, with HV porting, its possible to achieve mid RPM VE of over 100%, intake pressure waves are key to this.

There are other builders out there who are making good numbers from a Raptor motor, but they sell peak HP numbers, if you look at their dyno curves(if you can get them to post one) you'll see that they make very peaky HP and a 73HP motor might only make 48Lbft of torque. If you can get to the point of 70+HP AND 50+TQ, you'll have something that gets people's attention. TQ moves a bike.
 

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CoalShedRacing said:
allistairc123 said:
coalshed, would you share the exact setup u will use for the 760? id love to know!!, id love to build mine with broad power like you are aiming for.
The parts used can be bought by anyone, its the parts combo that is key. The cam/valves/valve job/porting/intake must all work well together, I've spent a ton of money in R&D, flowbench and dyno time to find the combinations that work well together.

Here is the parts list
4mil stroker crank with chrome-moly rod
CP 12:1 105 piston
LA sleeve 105 sleeve
Ferrea stock size stainless valves
megacycle x4 cam
39mm FCRs set up to work with stock thumb throttle
Custom intake manifold
High Velocity porting

You just have to think of any engine as an air pump, volumetric effiency(sp) is what you are after, with HV porting, its possible to achieve mid RPM VE of over 100%, intake pressure waves are key to this.

There are other builders out there who are making good numbers from a Raptor motor, but they sell peak HP numbers, if you look at their dyno curves(if you can get them to post one) you'll see that they make very peaky HP and a 73HP motor might only make 48Lbft of torque. If you can get to the point of 70+HP AND 50+TQ, you'll have something that gets people's attention. TQ moves a bike.
I wouldn't speak too soon about other builders not making torque. Here's my 2 year old stock carbed Kenz built little 727 making 50 foot pounds at the rear tires. Notice the run was also on the lower SAE setting.
 

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Make that, here:

 
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