50 hp club

[TucsonCannibal]

Ok, can you get to 50hp with a Timbo 450 piston, stock crank, ported head and an open airbox?

[wistech]

QUOTE (TucsonCannibal @ May 14 2006, 07:05 AM) <{POST_SNAPBACK}>

Ok, can you get to 50hp with a Timbo 450 piston, stock crank, ported head and an open airbox?

Well I got Kara's engine to do it using zero aftermarket internal parts. It was even using the lower compression stock ASSO piston and stock cam timing . Her engine doesnt have the low end grunt of the strokers but when it gets spooled up above 5,000rpm it just keeps climbing.

Most all power is in the cyllinder head just waiting to be extracted. The bigger pistons and stroker cranks add mostly torque. You will get about 1 horse per jump in piston size and 1 for the stroker crank . The stroker adds around 5 ft lbs of torque or more.

My point is the best bang for the buck will always be porting and for those that need more then go with the more expensive items. The head is what unlocks the power to all the other parts. You can big bore and stroke all you want but if you dont do the porting first you will never see 50hp. Ever wonder why you see so many of these expensive engines do so poorly? Because the headporting was little more than a light cleanup job.

[azcannon]

I do a light clean up job and mild porting and like it a lot. I don't need a drag motor I need a fun dune / trail bike that may see 1 or 3 races a year. Don't discourage light porting too much it still makes power and stays wery fun to ride. Funny thing is they really should just be like that and not so constrictive - its a shame they didn't get cast better and machined some because at the manufacturing level it would have been easy.

[wistech]

QUOTE (azcannon @ May 14 2006, 01:59 PM) <{POST_SNAPBACK}>

I do a light clean up job and mild porting and like it a lot. I don't need a drag motor I need a fun dune / trail bike that may see 1 or 3 races a year. Don't discourage light porting too much it still makes power and stays wery fun to ride. Funny thing is they really should just be like that and not so constrictive - its a shame they didn't get cast better and machined some because at the manufacturing level it would have been easy.

Well back when these engines were designed all they had to beat was a 400ex. But today if you want to compete and beat everybody else mid 40's is not going to cut it. Your right some of the stock castings are awful but can be repaired. i think thats why some of the stockers are just plain dogs no matter what you do to them.

[cannondale27]

Its true that light clean up works fine but right now I have to say that there is absolutely no downfall to all out porting.They run great no burbbles or hiccups.Just as good as stock except alot more power!About only reason I could see not doing it is they do suck alot more gas.

[yamadjs08]

One day Ill join this club...


...Hopefully LOL.

[theJeStEr1340]

QUOTE

About only reason I could see not doing it is they do suck alot more gas.

I can vouch for that, I have run out of gas 3x, once in a race, doh! and a few time I have went out to practice and came right back off to fill it up.

[wistech]

Even at the ice races we had to fill up between heats running the walsh fuel tank.

[wistech]

Steve your journey to the elusive 50 has inspired me . How about a badge of acomplishment. I had my sister map these out for us today. She will have a sheet of black and red done tommorrow.

[timbomoose]

Looks nice John! Your sister does very good work!Nice right up Steve and charts!
Will have to agree with the gas guzzling especially with the harley injectors.On my 5th tank of gas and haven't even left the yard!