porting?

[woodsracer144]

ok so i have yet once again a question on porting... i found a 250cc cyl thats a true 250CC, im gonna be running a tt track this year and its open but its a port jobe by FTZ, it was on a cart and the guy is getting out of it, the dude has a cr125 done by them too.. any ways, its a top end port job, so when im looking for a more mid range is there something i could do as far as the exhaust, carb, intake that could change the hit? also what about running the CR ingition over the TRX? first race is may 15th so i need to get moving if i wanna make it there...

[Honda 250r 001]

nope man, if its top end porting, your never gonna be able to make that work well on a mx track. if you mix and match it will jus run bad. Just get your cylinder professionally ported for your selected pipe, carb, reeds, compression, fuel, timing etc etc.

[TORNADO]

I agree with Honda 250r 001. Its been setup for topend, so I can bet the exhaust port has been widened and raised at least 1-2 mm's. Not much you can do besides resleving and back filling the ports and runners with epoxy. If you have a topend pipe and big carb, go with that setup for tt. I would rather use a screamer for tt racing anyway. More pull down the straights.

[woodsracer144]

Originally posted by TORNADO
I agree with Honda 250r 001. Its been setup for topend, so I can bet the exhaust port has been widened and raised at least 1-2 mm's. Not much you can do besides resleving and back filling the ports and runners with epoxy. If you have a topend pipe and big carb, go with that setup for tt. I would rather use a screamer for tt racing anyway. More pull down the straights.

the track im going to be racing the most is only a 1/8th mile... i didnt know if my carb choice, and pipe could tame it down to a more of a mid hit...

[rsss396]

if you have the long rod motor and 86 style piston that requires you to run the 5mm spacer plate than the spacer plate can be milled down thus lowering all the port timing.
The cylinder head squish then needs to be cut to open it because the piston will be hitting it or very close.
send it off to a professional and it can be fixed.

[Honda 250r 001]

Originally posted by rsss396
if you have the long rod motor and 86 style piston that requires you to run the 5mm spacer plate than the spacer plate can be milled down thus lowering all the port timing.
The cylinder head squish then needs to be cut to open it because the piston will be hitting it or very close.
send it off to a professional and it can be fixed.

just seems like too much work. I would rather just sell it to someone who wants a top end cylinder, and get an existing cylinder ported. Might be cheaper too?

[250rPRIDE]

for tt it sounds like you got a great cylinder, but anyways you CAN tame it down a lot on top and make it hit way harder in mid, i have a top-end port because i do drag a little and i am pretty light and ride fast open areas, anyways when i know i am going to be just hitting the trails for while i change from a hi-rev pt pipe to a type 6, carb from a pwk 40.5 to a 38mm as, air filter from k&n to uni, put in a cr250 reed cage intake set up, bump compression with a thinner head gasket, and mabe a little gearing.. after all this WOW you wouldnt believe the bottom to mid gains. yes i know about port timing and some say its not the best way etc.... but let me tell you i do it and it works great, put it on and give it a shot.. goodluck and let us know how you make out

[woodsracer144]

well the cyl im going to be running is a 90's cr cylinder, its done by FTZ

http://www.ftzracing.com/images/AtvPorting.pdf

theres the link,

i need to pick up a piston for it so once i get that done i'll be smokn, as far as carb and pipe, i have a lectron 40mm jetless carb that im buying as soon as i get on a different computer(school has access to all my stuff on this one, have to do it on my folks computer) then i have a LRD BB adjustable pipe and a PC 304 scilencer for it. i have the LRD one as well but i need the center core and repacking... im not sure if i will run my cool dome or FTZ's CR dome, the CR dome is a race dome, the one i have for my Cool dome is a 20CC

[LONG-ROD]

ya for TT, hell ya run it. your wide open most the time. what pipe will you run ? sparks TT pipe is great for flat track, TT. get your compression up in the 230's, 38 air striker, 21 cc dome and squish .020, 86 piston w. spacer plate milled. with a nice top end port and a 13/38 gearing it will ripp. now I get to hear it about the .020 squish, lol

[woodsracer144]

long-rod read the post above yours it tells you all the pipes and carbs i'll be running...

[LONG-ROD]

lol, not sure how I missed that. so it will be on alky ?

[woodsracer144]

Originally posted by LONG-ROD
lol, not sure how I missed that. so it will be on alky ?

nope. gonna try E85, just wanna run the lectron cause its jet less and its a 40mm.. if i run flat track i'll do ice as well...

[LONG-ROD]

humm, let us know how it runs on E85. have only seen it on a turbo ktm 525 and ktm 450. never did run right. maybe the electron is the way to go with E85. I have no idea on that fuel. I know you can make tuner cars ripp on it.

[woodsracer144]

Originally posted by LONG-ROD
humm, let us know how it runs on E85. have only seen it on a turbo ktm 525 and ktm 450. never did run right. maybe the electron is the way to go with E85. I have no idea on that fuel. I know you can make tuner cars ripp on it.

E85 makes it run REALLY lean, there were guys running it in their 400ex's and seeing HP gains, im not sure how much more you have to richen it but i think it was about 25%, Colby at C&D was using it in a drag bashee...

my Girl Friends gramp works at an atv shop and he pulls atvs and build motors for the ice, he works as a flag guy at the CWIRA races. the shop he works at has a dyno so im gonna take it there and see what kind of HP i'll get out of it and see what i should run for best power (carb settings pipe settings, and fuel) its gonna be afew weeks befor i can do that, i gotta see what he will charge me to test it, first race for me is may 15th, i still have to get tires adjust my susp. and get some seat time, shes gonna start comming up fast! they tracks a 1/8th mile so im hoping that this cyl would be able to handle all those BB 450's and a strocker Shee thats racing out there... because its so short i think i want more of a low end and get the gearing down correctly cause its not a top end track, i dont think i'll get out of 4th...

[86 Quad R]

250rPRIDE<----- what he said. :)

i've seen 'em FTZ's first hand and you cant go wrong with them woods... with what ur wanting to do and with the paa power delivery they have and "they are high strung" can be tamed a bit. there is tail of a local engine getting in the 50's in OK.

ADDED: if memory serves me right, the ftz may be flat top and with the 20cc. may put you in the e85 range.... regardless, gives you plenty areas to play with compression. ;)

[woodsracer144]

i had a pro x cyl done by them a while back but i didnt have that quad long... that quad was a TT quad and i was looking for more of a woods set up and i didnt want to piss with changin shocks and all that so i sold it but when i had it it was a fast motor! i had twisty part then you would go down a little hill in a gravity cavity and back up this steep hill and comming up to the G out the power would just kick in and i would wheelie down the hill in to the g out and rocket up the hill... it was wicked. that was a FTZ P&P on a pro x cyl and then i ran a sparks TT pipe. i really miss that quad now... oh well just get to build another one...

[woodsracer144]

whats this thing on the left side of the reed cage? im going to be running a boyseen rad valve, B 02? i think it is... something like that...

[woodsracer144]

pic

[86 Quad R]

more than likely its for a pulse signal for fuel pump. :cool:

[woodsracer144]

Originally posted by 86 Quad R
more than likely its for a pulse signal for fuel pump. :cool:

so just pull it and then put a plug in it?

what kind of power should i get out of this engine? a

[86 Quad R]

i done told ya......... afew posts back.:ermm:

as for the nipple. yea you can juss plug it off but since ur TT or ice racing. you may need a fuel pump. you wont know for sure till ya start tweekin on it. :cool:

[woodsracer144]

so about 50's? how would i run a fuel pump with a OE style tank? could you bore the OE pet cock out and make it run more fuel through it like they do with the LT when they do the Zilla hybreds?

i hope i dont need a Fuel pump... ihope to have it running with in the next 2 weeks... i gotta press a new bearing on my counter blancer and get some other small suff done too...

[woodsracer144]

ok so what piston do you think i should run? a CR or one of the TRX pistons? its a 66.40 mm bore? thats got a nikasil

[86 Quad R]

whelp the best thing to do is to either contact ftz and see which they use in their builds or look at the dome of the old piston and head and go from there. if they use the CR, then go with that, ect.

[woodsracer144]

Originally posted by 86 Quad R
whelp the best thing to do is to either contact ftz and see which they use in their builds or look at the dome of the old piston and head and go from there. if they use the CR, then go with that, ect.

the guy im getting the cyl from doesnt have the old piston for it, FTZ said they ran many different set ups depending on if you would run a base plate motor or stroker ect... so im not really sure what i should run, some pistons say for a nik cyl so would it matter if i would run a piston thats ment to be bored over and stuff?