Mrs. PG has been reading over my shoulder, She votes for a long AND a short stroke at varying RPM's..................[img]i/expressions/devil.gif[/img]

 

Yes, before I say anything else.... Welcome HACKMUNCH! Please stick around for a while... You seem to have a pretty good understanding of engines and I look forward to lots of valuable discussions.

 

sure will as it seems like you guys can help my quest. are you guys getting 25hp out of a full built lt230 engine?

 

<div class="FTQUOTE"><begin quote>Originally posted by: HACKMUNCH

Ok well i am running the megacycle 330x2 cam for the klx125 (same as lt230 cams) and it seems to be a good all around cam but i am more than likely going to go with the high lift 393-00 lt230 megacycle cam. the reason why the larger lift cams might not be making more hp is because of low compression and low velocity in the intake track. your only gonna get so much cfms through the 28mm intake track of the lt230 head. i would think with the higher lift cams, porting must be done and larger carb would have to be used to get the larger lift cams to work. the place i got the needle from is carbparts.com and yes they are in cleveland ohio. anyone have any hp #s out of the 230 engine stock and then a fully modded one?</end quote></div>


The valve in the 230 is 32mm and the 250 has a 33 that will transplant over. How do you know the intake track is 28mm?

I'm going to have to look at the megacycle cam to know which cam is what....

I have some dyno charts from my sim program....

I'm thinking 25HP would be tops, with the best parts and best work, but let me go look.

 

ok, the 393-00 is what we've been calling the stage 1 megacycle. The 393-20 is too much for any practical use on the trail,,, and my sim shows a HP loss for that one (whatever that means).

Not sure what the "330x2" cam is. I looked all over the catalog.

Porting is the only way to take advantage of a high lift cam. I was told after .280 lift, flow seems to stop going up. It didn't matter what you do to the ports, it didn't hurt the flow, but didn't help the flow either. (This is telling me a bigger valve is necessary).

 

<div class="FTQUOTE"><begin quote>Originally posted by: JustRandy

Yes, before I say anything else.... Welcome HACKMUNCH! Please stick around for a while... You seem to have a pretty good understanding of engines and I look forward to lots of valuable discussions.</end quote></div>


Me too! Don't let me scare you off, I'm the comic relief....

 

<div class="FTQUOTE"><begin quote>Originally posted by: PoolGod230

Mrs. PG has been reading over my shoulder, She votes for a long AND a short stroke at varying RPM's..................[img][/img]</end quote></div>

LOL

A couple of references to rod and bore size come to mind, but.... no comment. [img]i/expressions/devil.gif[/img]

 

<div class="FTQUOTE"><begin quote>Originally posted by: HACKMUNCH

the reason why the larger lift cams might not be making more hp is because of low compression and low velocity in the intake track. </end quote></div>


Is a compression of 10.25:a low? If the intake track is only 28mm, and the valve is 32mm, how is there low velocity in the intake track?
Maybe the best thing is filling the port up some???

 

A couple good Bore vs stroke pages to read:

http://en.wikipedia.org/wiki/Stroke_ratio

http://g-speed.com/pbh/bore-vs-stroke.html

 

if you goto the megacycle site and your looking at lt230 cams look up to the next engine listed, it says drz-125 thats the same thing and you will find the 330x2 cam. now i am not 100% sure on the lt230 head but on mine the intake track is 28mm. where can you get a 33mm intake valve for lt230? anyway if more lift is not helping us we need more duration for sure then. 235 degree of duration is good to about 95oo rpms, if we want a real spinner we need to get into the 250 duration stuff. yes 10.25:1 is low in my mind. i would think to take advantage of the additional lift 12:1 would be a minimium. now the engine i am using is 190cc, it's 70mm bore by 49mm stroke. i have seen dynos as high as 22hp out of the engine i have.