Big Bore Setups - what are you running?

[a250rlover]

Ok guys, looking to see what your setup is on your big bore.

What is your electrical setup?

What do you have for intake and exhaust setup and where is the majority of your powerband (is it a low, mid or top end setup)?

My setup: I'm running ESR stroked 350, RS high output stator, RS flywheel, Dynatek CDI, Nology coil/plug cap/wire. I have a stock air box (lid off), K&N, PWK38AS, Vforce3 with a ESR TRX5 pipe.

[custom R]

Im still waiting to get my parts but im going to be running a 310 sphinx top end by cpi with a 4 mill stroker crank I have a 38 a/s carb rad valve with reed spacer uni filter, no lid on air box, paul turner eliminator pipe,Rpm adjustable timing plate,janson super coil,stock cdi and stator & fly wheel.

I cant wait to see the new shpinx top end and see what its got it's supposed to be alot better than the pro x cyl so well see I;ll give an update on how it runs when I get it all together.

[Qracer]

I was running a 79mm ProX ported by Dave Moore Racing. I was using a 41mm pwk, Trx11 centermount, V-force 2's with a CR intake. The bike was silly fast. I sold the motor & am looking at building a CP Ind. Puma.

[ZSNOW]

if a 265 counts im running a paul turner with a YZ250 piston.

[CorvetteZ06]

i have a pro-x 310 jug with CT midrange porting, v-force 3 reed valve, 38 air stryker, k@n filter, open air box, FMF fatty.

my newest setup is Duncan PC2000 jug w midrange porting, 87-89 crank, duncan spacer plate, 86 piston, pyramid reed valve, k@n filter with open box, 38 air stryker, and CT National midrange pipe.

[havinnoj]

My motor is a 76mm pro-x with a 4mm crank. Race gas, porting for dunes, VF2, open air filter, 39pwk, trx-5, and cr ignition. Numbers were at low 70's - but more importantly the curve was awesome. Started making good power around 5.5k-top.

[QuadRacer18]

im running dunkelbergers old 265. Its a CT 265 kit, high comp. piston, cool head, CT MX porting requiring C12. LRD adjustable full exhaust, lost creek cycles wiring harness.

[ZSNOW]

Originally posted by ZSNOW
if a 265 counts im running a paul turner with a YZ250 piston.

sorry forgot to add. its got a air stryker carb stock rod and v force reeds. its got a procuircut cool head too.

[redrooster310r]

yo.

[a250rlover]

havinnoj - that's some impressive HP numbers... and you're getting that with the TRX5 pipe?

What is your static compression?

[havinnoj]

The hp figure is nice, but it doesn't really say it all. It's the delivery that I am after. I am going to do some fine tuning on it this weekend so I can keep you posted and will try and put up some dyno charts. It was with the trx-5 pipe. Compression is 240.

[a250rlover]

Is the HP measured at rear wheel?

Not familiar with a 76mm... what's your displacement?

I'm running a stock open lid airbox. Did you notice much performance gain with your intake?

[havinnoj]

HP is at the wheels.

76mm piston is a 330 with a stock stroke. With a 76mm crank (+4) displacement is 343cc's. I wanted something that made good power and delivered it really quickly. The rpm acceleration is phenomenal.

I've never ran an airbox so I can't compare it. I believe it makes a difference enough to rejet. VF2's worked the best so far.

[C-LEIGH RACING]

My daughters 250R is a 89 model with a 330 Pro-x jug & stock stroke crank.
Was ported by me for bottom end midrange output.
Dont know a HP number & never been mounted on a dyno other the back side of her racing pants & then her telling me what it was doing.

Engine was built in 04 as a practice & back up engine on another R frame, then mounted on her frame in 05.
Engine was raced at all local & national events in 05, 06 & 07. Only thing touched on the engine since built in 04 was a head dome replaced around mid 05 because I cross threaded the spark plug.
At that time, I lowered the compression from 235 down to 200 so she could crank it, realy though, I was tried of it hurting my old foot trying to start it for her.

Shes sitting in the shop right now, not been touched & we just cranked it up the other day, ran just as good as it did last race.
This engine finished 9th in the national open class 06 then 8th in 07.

I guess that kinda blows the rumor out of the water that a big bore wont last long.
Thats one reason I ran it so long to prove that wrong.
Neil

[mineralgrey01gt]

thats impressive Neil! I plan on sending you my stock jug (or an ESR 310 top end) to have a little "port" work done :)

Everyone else, thats some nice set-up's you all have.

[Hoppedrap]

Mine: 76.5mm x 75mm ESR PV, ESR reeds, 39PWK, RS 200W Stator and lightened flywheel, Stock intake tube no box, CPI big bore.