[atleastitsnotaford]

Can't wait to see numbers. I would love mine to put down 65-70 hp. I believe 800cc with the right cam, and piston can do it on pump gas..........?

 

[atleastitsnotaford]

We should be able to see 65HP or close to it without more CC

\What combination do I need to get 65+ hp to the tires, on pump gas, without nitrous (cause I want the power all the time, not just when I push a button), and without making it a pain to start and ride, like those guys that have the heavily modded 450's?


Not saying 65 can't be done with stock displacement, just saying more displacement might be a better way to do it.

 

[atleastitsnotaford]

If you got the 727 kit with 13:5:1 CP piston or 12:1 for pump gas (you may need to run 50/50) head P&P, +3 throttle body, Web cam, a good exhaust (Sparks or Barkers), and a power commander you would have 65+ HP.

P.S my nitrous isn’t to make 65HP it’s to make 85 :rock:

Even Alba's stage 3 "aggressive" kit only claims 61 hp, and that's on race gas, with a more aggressive cam than I want. Engines seem to get temperamental when the cam is that aggressive. So assuming I went with that setup, and the 727 kit (6%increase in displacement, 0 increase in stroke) that would, in theory, put me at 64 hp peak. So with the +3 tb, it may put me there, but again, on race gas, at a loss of low rpm smoothness.

I believe Eric's 824 kit with an 11:1 and stage 2 cam (stock springs/rockers) some mild porting, stock valves, and the basic big 3 (any brand) will net 65-70 hp at the tires all day long on pump gas. I may be wrong about that, but I think for the long term, the 824 will be the better way to reliably make big power.


85hp? hmm, I thought you photoshopped the nos bottle on there.

 

[atleastitsnotaford]

I barely know how to type so there is defiantly no photo shop going on with me :lmao: Can you do me a favor and take my quote out of your post :thanks: Again sorry for making this a who’s a better build in Eric’s thread. You seem to know a lot about the 824 kit that I didn’t think was even going to be around for months. Can you tell us more about it?

How's that? (If I took it all out, my post wouldn't make much sense.)

That is a nifty nos bottle mount then.

Hmm, more about it, ok:
stock 102mm x 84mm.........(5.1cm x 5.1cm x 3.14159 x 8.4cm = 686.387cc
824 kit 108mm x 90mm.......(5.4cm x 5.4cm x 3.14159 x 9.0cm = 824.479cc
(824.479cc - 686.387cc)/686.387cc = 20.119% increase in displacement
(90mm - 84mm)/84mm = 7.14% increase in stroke

Using as an example, Alba stage 2 kit (11:1 piston, mild cam, mild port)nets 54.75 hp. As a general rule a % increase in displacement will result in an equal % increase in hp so 54.75hp + (54.75hp x 0.20119) = 65.765 hp

The 7.14% increase in stroke is important to note because it will result in more low end torque (around 55ft-lbs) wich means a broader, smoother power curve.

That's all I really got, anything more will be finalized by Eric over the next few months until the kit actually becomes available to the rest of us.

 

[atleastitsnotaford]

your general RULE is wrong.... if the VE stays the same the hp will increase on a percentage with the cc size....


basically if the head only flows xx amount, and is pushed to its potential with the current cc size(more then likely) then the increase in cc size will have greatly reduced Hp returns... i seen it all the time with other bikes....yes, you will see a faster ramp on the hp/torque curve but its highly likely a very small hp increase..

id be willing to wager on the 100+ cc increase only making an additional 5 hp over the 686 if that, same head and all......

Yes the VE must stay the same for the hp increase to match the cc increase. All the engines I've messed with in this manner have flowed well enough that the ve did not significantly change. Are we really that close to the max flow of the xx head? If so, maybe all the r&d would be better spent on a new head.............