Horse power ???

[LONG-ROD]

I would like thank everyone for all the help I have received sofar. I have an 87' trx 250r I have been restoring I and I would like to know about how many ponys I am going to have, for I do not have near by acces to a dyno. This is what I have a Ct pro-x 310 cylinder not sure of the port job, as in mild or aggresive, 73.45 mm L.A. sleeve piston and a billet head, " the one CT Raceing sells. The head has a 30cc dome for 50/50 blend of race fuel and pump. I have Works platinum pipe & silencer, boyseen rad valve with carbon fiber pro reeds. I grinded out the rad valve so it is the same as the 39.65 Kiehen carb wich has a air filter pod in the stock box with no top. I am not sure what jets are in right now, but I will get it tuned in right. Any pointers on what jets to start with would be great, Kansas City, summers 85-100 degree high humity most of the time. As far as egnition ect. stock. Not 100% sure what is in the cases, as far as clutch, I know it is very difficult to pull, since the hydraulic lever failed, but I am also use to dirt bike clutches which are pretty easy on the pull. Any ways if anyone could give me so heads up what to exspect would be cool or if anything I have said raises a RED FLAG let me no. My info came directly from the owner of CT Raceing, They have been great in the participation of my build, Note: I am a very exsperianced rider "20 years this fall" and ride mostly fast trails, and dunes twice a year. Thanks

[bluetrx]

a dyno operator told me my bike should make right around 48hp its an 86 with stock cylinder bored over to 69mm, hot rods 5mil long rod 4mil stroke making displacement 284, pro design cool head with cr head gasket and machined combustion chamber to make 230psi cranking pressure race gas only, v-force reeds, 38mm pj, k&n filter with no air box, fmf fatty pipe, power core 2 silencer. he has seen alot of bikes on his dyno and i trust his estimate. if this is correct i would guess youre in the neighborhood of 60hp

[LONG-ROD]

That would be nice, could you explain the diffrence between a long rod and a stroked mill.

[8686]

If the porting is good and the bike is tuned properly I'd say he's around 50-55 at the rear tires.

[cobradaler]

what is the hp on a stock 250r motor? anybody know?

[havinnoj]

Mid 40's with a CT portjob and half race half pump gas.

[LONG-ROD]

So you are saying that the 310 kit with all my mods on 50/50 is only going to get me 5-10 horse over stock.:(

[havinnoj]

Show me the source that says a stock motor with no portwork puts out 35-40 rwhp.

The 38 hp they refer to here is at the crank.
http://www.atv.info/page.cfm?name=ATV%20Facts

A pipe test from ATV Source years ago. Very slight mods but very close to stock is roughly 30hp at the wheels.
http://www.atvsource.com/articles/product_reviews/2001/102901_250r_dyno_charts.htm


A superb 310 on full race gas will put out roughly low-mid 50's. A CT ported 50/50 mix of gas will be close to 10 less - if you compare apples to apples.

Comparing dyno numbers is like fighting on the internet. Use 1 dyno only and use it to help your curve improve.

These are my educated opinions.

[bluetrx]

Originally posted by LONG-ROD
That would be nice, could you explain the diffrence between a long rod and a stroked mill.


the diffrence between a long rod and a stroked crank is exactly what it sounds like. the rod end on a 4mil stroke crank is offset 2mm further from centerline than the stock crank so the piston travels 2mm lower in the cylinder and 2mm higher in the cylinder this requires a 2mm baseplate spacer to keep combustion chamber quench correct, it also affects port timing. a long rod is beneficial because it increases dwell at tdc and bdc (longer dwell makes more torque), and reduces rod angle (less stress on crank and rod). a 5mil long rod just raises the piston 5mm in the cylinder this requires a 5mm baseplate spacer the effect on port timing is very minute (is that how you spell my-noot because it looks like mi-nit). becaus i run a 5mil long rod and 4mil stroke i use a 7mm baseplate spacer.

also the same guy (amir at crazy deals) who told me my bike should make 48hp on his dyno told me that a stock 250r makes 30-32hp on his dyno

[trailwart]

ive seen stock cylinder dyno runs that have been at 48hp up to 55hp. ive seen the 310 and 330 prox jugs dynoed at 45 up to 63hp. depending on porting and pipe/carb combination it will vary widely. dont get cougtt up in the #'s game on hp. because im sure what you would want is usable power. most of those stock cylinder dyno runs were drag porting and the curves were a joke. my 330 probly dont have only 50-60hp but i really dont care about the exact # because its all about the tourque for me, and a wide power curve. i do alot of trail riding and the "light switch" powerband is not what i want. if you want hp do a DS busa conversion

[kiesta00]

if you're looking for a big upgrade in horsepower, go to a Puma cylinder. They're just starting to release the cylinders and have high hopes for them. The cylinder fits on the oem studs and all you have to do is bore your cases for the bigger piston....85mm I believe :)

[havinnoj]

Originally posted by kiesta00
if you're looking for a big upgrade in horsepower, go to a Puma cylinder. They're just starting to release the cylinders and have high hopes for them. The cylinder fits on the oem studs and all you have to do is bore your cases for the bigger piston....85mm I believe :)

If you make this comment, you need to give the disclaimer as well - nobody has them running yet, nor have any R&D in how the portwork or setup for the cylinder.

Just let him know his cylinder will be a guinea pig if he buys one now. Wait a year or two until builders know how to make them sing. :blah:

[C-LEIGH RACING]

A dyno is a test bed to see if the mods you have done to the engine was of any good & along with that, see what fine tuning changes are needed to produce the most power output.

You want to know a horsepower amount, use the seat of your pants, what it will do in the real world, that will tell you the most about your engine.

A well known 2 stroke porter, named Eric Gore, said on the front page of his web site, Speed is 95% rider 5% horsepower, remember that.
Neil

[LONG-ROD]

Well it looks as if I need to be more clear in my questions. I do not want another motor, I like CT would not haveanything else, and I do know that high horsepower will not get the average rider around any fast, I simply want to have knowledge of not just my machine but the motor thats in it. I do not want more power or need more power, just simply wanted to know if anyone super smart trx people new ABOUT how much these motors put out with the mods I have. Thank you. C-Leigh I wish my buddys could understand why I can smoke them on the trails when there on there hopped up R's and I am on my wifes blaster or crf 150r, CORNER SPEED EVERYONE.

[C-LEIGH RACING]

Originally posted by LONG-ROD
Well it looks as if I need to be more clear in my questions. I do not want another motor, I like CT would not haveanything else, and I do know that high horsepower will not get the average rider around any fast, I simply want to have knowledge of not just my machine but the motor thats in it. I do not want more power or need more power, just simply wanted to know if anyone super smart trx people new ABOUT how much these motors put out with the mods I have. Thank you. C-Leigh I wish my buddys could understand why I can smoke them on the trails when there on there hopped up R's and I am on my wifes blaster or crf 150r, CORNER SPEED EVERYONE.

There you go, I see you already understand that a dyno numbers nothing but something to brag about.
Those arms & that butt can tell if its got what you need to win.

You'll do well dealing with CT.
Probably been more R engines ran through that shop than any other out there & Allens the R king.
Next time you call, talk to miss Roxann, she knows much as Allen does.
Neil