has anyone done the duncan national kit?

just got off the phone with duncan racing(there only 15 mins. away from me!)and was talking about doing the 440 national kit. he recommended race gas but i want to run 91`octane.has anyone done this kit? how does it perform? it`s gonna run around $1500.00 (including hardened rockers,new valves & seals) plus $250 to install.is that a good price?

The guy i travel to all my races has this kit and loves it. I have riden it several time and am not all that impressed with it. My 426 with out carb out runs it pretty easy. my $0.02

what about the curtis sparks 465 kit? can i still run pump gas? is this the kit to get?

Port and flow head (includes 3-angle valve job) $375
Big bore custom sleeve $100
Install sleeve & precision cylinder boring $175
Piston Kit from JE Pistons $199
Complete engine teardown & assembly
(only required when complete motor is shipped) & Degree cam $500
Sparks Cam w/ exchange $199
Heavy duty valve springs $110
Install rod & true and weld crank $75
Ignition Advance Key $15
Heavy duty connecting rod $239
Heavy duty cam chain $100
8 Plate Heavy duty clutch kit $139
Hard faced rocker arms w/ exchange $200

465cc National Kit Total $2376.00

I spoke to Lorne Duncan, (I live nearby too) and was interested with the national kit until I became a member of this site. Instead I'm going with the 426 with the xr cam and Edelbrock
carb. I'm having a friend at Crower Racing do the headwork and will probablly have Alan Fox do the rest of the motor work to get it ready for the desert. Don't get me wrong though, Duncan makes great stuff, but I think I can do just as well the other way and not pay through the nose for it. With the money I'll save, I'll still have a great motor+new clutch and basket, with Duncan they will try to convince you to do the clutch as well.

[Chef]

you will NOT be able to run pump with a sparks 465...The most popular one is on alcohol at 14:1 compression...that is by far over pump gas recommendations..try to stay under 11:1 for pump gas.

[KingRage12]

Hey Bud,
I am the local building here on all our motocross engines. I have the top 12 bikes on the track with my own little blend, and I have had no luck with the 440s other than torquey woods machines. My best moto engine is a 425 flat top motor that runs on pump gas and does not require hardened rockers. Just lots of work in the cylinder head. I have 1 462 out there and its pretty strong but the power is real narrow and on the bottom, this is due to the dwell time the longer stroke provides. If interested I can build you a strong 416 which is what I like or a 425 for under a 1000 and I guarantee my work. Right now I am on 2 week turnaround on them. Oh and by the way, we have run every carb from stock to eld to lectron, and dollar for dollar a modified stocker will get you around the track just as fast. I have the local championship to prove it. Good luck with your decision. Thanks Dee RAGEATV.com

[ChadEXer]

The Sparks 465 will take about 9 months turnaround time,,thats rediculous!! if he is that backed up then i think he needs to hire some help!

Originally posted by KingRage12
Oh and by the way, we have run every carb from stock to eld to lectron, and dollar for dollar a modified stocker will get you around the track just as fast.

I like the sound of that..:D

[exriderdude]

i would go with sparks before i would go with duncan:cool:

[dhines]

dollar for dollar a modified stocker will get you around the track just as fast.


Can anyone tell me exactly what is done to modify a stock carb?

Thanks,

Dennis

[ChadEXer]

Originally posted by dhines



Can anyone tell me exactly what is done to modify a stock carb?

Thanks,

Dennis They remove the choke and bore the openings!

[Tommy 17]

mine is smooth bored... i think thats what they call it... it looks like a tornado inside of it... its really shiney and its got a swirl effect to it...

who does this smooth boring of the carbs?:D

Originally posted by cameron69
who does this smooth boring of the carbs?:D

Only place I know of off hand is Sparks racing and it cost like $175. It takes it about 2mm bigger than stock I believe..they have a small write up on it on sparks webpage.

How much to modify the carb?