Honda 400ex Cam ?????

[blue_ex_rider]

Ok here is the deal I have a honda 400ex with a 440 kit and 8mm stroker crank that makes it a 490ex . And I was wondering what cam would be best for me to put back in it all I do with the bike is run drag races with it 200ft and 300ft . I have a lectron 41 mm carband sparks x6 exhaust and oversized valves and ported and polished head. I was wonderin what everyone thought would be the best cam for my set up. I was leaning toward the sparks x4 cam but havent heard alot about them. So if anyone could give me there input onthe best low end cam for drag racing there help would be greta.



Also I was looking at pistions for it as well and was wondering abiut which would be the best way to go I ahve heard that cp makes the best piston but also spakrs has one that is about 50 dollars cheaper . I am looking at like a 12.5 to 1 or 13 to 1 because I run nitrous and cant go much over that. Any help on this would be greta as well and thanks in advance.

[Big - D Racing]

the same cam I run, which is the most aggressive cam you can buy, it is the web cam 463/9i. Your quad has to be crazy as fast with the stroker on nitrous. You have similiar mods besides the stroker. I run oversized valves and all that too. Compression with nitrous I would stick to 12:1. In terms of a stroker piston Sparks is the way to go, I believe they were one of the first engine builder to build a 400 stroker.

Here is info on 400ex cams:

I see a lot of questions about 400EX cams. I thought this might be helpful. I picked up this info from various places...if anyone sees errors point them out. The Hotcams specs are straight off their website and I called them to get the specs for the old version of the stg 2.

The lift is how far the cam opens the valve. The duration is how long it leaves it open. The more lift and duration the more aggressive the cam. Big lift and duration numbers work best at high RPM while more mild numbers are best for lower RPM.

Also, the more lift and duration of the valves the more important it is to have a high(er) compression piston. This is because with high lift/duration there is more opportunity for air to escape through the valves as the piston begins its compression stroke. With an aggressive cam some dynamic compression (i.e. the actual measured psi of compression while the engine is cycling) can be lost. This must be made up for with a higher compression piston. An aggressive cam with a stock compression piston may actually perform worse than the stock cam because too much compression is being lost through the valves being opened so much.


cam: Intake lift; Exhaust lift; Intake duration; Exhaust duration

stock............... .316, .302, 234, 238

XR400.............. .326, .321, 240, 244
HRC................. .350, .339, 254, 256
GT Thunder....... .350, .345, 256, 256
WB Track.......... .350, .345, 256, 256
WB All Around.... .345, .335, 240, 248
WEB 450/451..... .350, .345, 256, 256
WEB 479........... .378, .378, 250, 250
WEB 463/9i....... .385, .370, 272, 270
Hotcams stg 1... .354, .354, 246, 246
Hotcams stg 2... .354, .350, 254, 248
HC stg 2 (old).... .348, .349, 254, 254
Hotcams stroker. .358, .354, 262, 257

Notes:

--Numbers are listed in inches and degrees of crank rotation (lift duration at approximately .050" lift).
--The Hotcams stg 2 old version is identified by "HCDG NO. 08" etched onto the cam--not sure what the current version says.
--White Brothers All Around is etched with "WB1870".
--White Brothers Track is etched with "WB1498".
--Notice that the WEB 450/451, GT Thunder, and WB Track are all the same grind.
--Honda part number for the HRC cam (it's actually an XR400 HRC cam) is 14000-NKK-000. I don't think they are still available from Honda.

[blue_ex_rider]

Do you have any numbers on the sparks x4. Also how much did the web cam you have run you as far as price goes and are you sayin that you would go with the web cam over the soarks x4. Also I moticed you have a duncan motor I was looking at a duncan head 3 angle vlave job port and polish and hd springs and everyhting like that and some one was going to sell it to me for 700 and it has never been ran. But someone told me that duncan isnt known for fast mottors they said go sparks or lrd but sparks wanted 1700 and lrd wanted like 1600. Would you go with the ducan for under half the price or go with lrd or sparks. Thanks for the help.
And yes the stroker mottor runs pretty good with the nitrous low 3.6's in 200ft . I am hopimg after the rebuild and I put the cut trany in it tha maybe I can get into the upper 3.4's and maybe set the national 400cc modified record. We will just have to see how it turns out.

[Big - D Racing]

Duncan's porting and polish work are is better than most. And is my top pick, when you get into the actual motor parts such as piston, crank, etc. they build them to be as strong as possible whie still being reliable. So in that sense they don't make the fastest, but I would call them the strongest. My 440 puts out hp in the mid 40's not too many 440s that can claim that and I have the most reliable aftermarket cylider on the market, the PC 4000 which is not a stock cylinder with a sleeve. It has bigger cooler fins, a cleaner finish, a stronger cylinder wall, hd studs built as part of it from scratch. I would run my duncan against any 440 on the market. Now make sure you are actually buying a duncan, ask for receipts, etc. Duncan did my hole head from the oversized vavles to port & polish, the hardend rockers, the shortened guides, and titanium valve springs. Everything is done on a flow bench to get the optimal and max hp. No name is as big in atv racing as Duncan they are known throughout the world for building the best. And they have a proven history of championships more than any other builder. So I would trust their work over anyone elses. However with the 400ex they do not offer a stroker kit.

I got my cam for $180 I believe. I don't know the details on the sparks x4 ask for the specs on it and compare it to the web 463/9i. I doubt it is more aggressive than it as I have never heard of a cam being more than it.

[blue_ex_rider]

Thanks for the info big d

[blue_ex_rider]

Anybody else

[blue_ex_rider]

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