is it ok to get stage 2 cams with stock 400ex?

[DaMeech89]

i was thinking about getting a camshaft, but i didn't know i could get a stage 2 because i thought they for big bore engines.
help plz

[zrpilot]

Do a search, this has many threads.

The stage II really needs a higher compression piston (bore not as important) that helps offset lower dynamic compression ratio that it produces, remember compression is one of the key components for producing low end torque. At stock 9.1:1 compression ratio:

Stock cam dynamic compression equals approximately 8.2:1
HC stage 1 dynamic compression equals approximately 7.8:1
HC stage 2 dynamic compression equals approximately 7.6:1

In other words, the net result is a large loss of low end torque with a stock compression and a stage II cam

A stage I cam would be a better choice on a stock compression ratio.

[sc400ex_rider]

i ask this before, there is a guy on here that has stk comp and stg 2 and he loves it. you will lose some torque but the 400ex has a torque cam and is a torque monster. the same thing happened with my 5.0 mustang that was a stk torque engine 300 ft lbs. i put the middle level SVO cam in it and it was awsome!! it would rev out freely. yes i lost a bit of torque but the increased power and revs was greater for racin. the hi comp does make more power but breaks more parts. that is why they lowered it in nascar from like 15 to 1. there are issues with hi comp and the 400ex. i want to be ridin not fixin my qaud. the 400 is decamed from the factory the xr400 cam has more lift and duration and is like a stg 1. if i buy a cam i want a racin cam!!! im gettin the stg 2 ,fcr carb and an ignition advancer. that is enough

[Nates400ex]

I recently place a Stage 2 on with my LRD pro4 system, Modquad intake and DynaFlow Jet system. The bottom end suffered a small loss.....BUT damn this thing screams. Once I get my 426 kit installed I will be golden!

[sc400ex_rider]

400EX CAMS
BRAND & MODEL IN.LIFT EX.LIFT IN@.050” EX@.050” NOTES
STOCK 400EX .316 .302 234 238 OEM
XR400 .326 .321 240 244 BIKE SR
WB ALL AROUND .345 .335 240 248 SR
HOT CAMS STAGE 1 .354 .354 244 244 SR
WEB CAMS 479 .378 .378 250 250 HR,VS,VG
HOT CAMS STAGE 2 .346 .346 254 254 SR
HRC .350 .339 254 256 HOP-UP
GT THUNDER* .350 .345 256 256 SR
WB TRACK* .350 .345 256 256 SR
WEB 450/451* .350 .345 256 256 HR
WEB CAMS463/9i .385 .370 272 270 HR,VS,VG
(In order from shortest duration to longest)
SR=Stock Rockers, Valve Springs & Guides OK
HR=Hard Faced Rockers Recommended
VS=Stiffer Valve Springs Required
VG=Shortened Valve Guides Required
* indicates same grind
As far a i know the WB track cam DOES require hardened rockers, i got this info from the FAQ portion of the site.

TC cams specs can be found on their website www.legacyatv.com and the HRC copy cam can be found at www.XRsonly.com



i think this is the old stg 2 specs the new stg 2 is very close to the honda hrc cam that is the best 400ex cam ever made

[Kaleigh]

Originally posted by DaMeech89
i was thinking about getting a camshaft, but i didn't know i could get a stage 2 because i thought they for big bore engines.
help plz

I think the stage 2 is meant for bores up to 426.. so its fine for stock..

Colby and Hotcams both told me Stage 1 is intended for stock displacement.

Being as Hotcam makes the cam, I'd think they'd know something about it.

Being as Colby nailed my jetting, cam and piston recommendations, I kinda think he knows what he's talking about.

YMMV. But then, your odometer may be broken.

:devil:

[zrpilot]

Originally posted by sc400ex_rider
you will lose some torque

I agree.


Originally posted by sc400ex_rider
the same thing happened with my 5.0 mustang that was a stk torque engine 300 ft lbs. i put the middle level SVO cam in it and it was awsome!! it would rev out freely. yes i lost a bit of torque but the increased power and revs was greater for racin.

An automobile motor and a thumper motor are two completely different engines with different characteristics. What works on one may not work on the other.


Originally posted by sc400ex_rider
the hi comp does make more power but breaks more parts. that is why they lowered it in nascar from like 15 to 1. there are issues with hi comp and the 400ex.

There is no direct correlation to higher compression breaking more parts if the motor is built, operated (correct fuel), and maintained correctly.

[DaMeech89]

I'm not going to rae, any time soon. I'll take it to the track \and stuff but just for fun. I'm looking for acceleration more htan top speed. Would Stage 1 or Stage 2 give me more accleration?

[zrpilot]

To accelerate you need torque.... therefore a stage 1 cam with the stock compression is the way to go!

[scruff_mcruff]

Originally posted by zrpilot
Do a search, this has many threads.

The stage II really needs a higher compression piston (bore not as important) that helps offset lower dynamic compression ratio that it produces, remember compression is one of the key components for producing low end torque. At stock 9.1:1 compression ratio:

Stock cam dynamic compression equals approximately 8.2:1
HC stage 1 dynamic compression equals approximately 7.8:1
HC stage 2 dynamic compression equals approximately 7.6:1

In other words, the net result is a large loss of low end torque with a stock compression and a stage II cam

A stage I cam would be a better choice on a stock compression ratio.

the loss of tq is due to the cam not the compression loss. the best cam designers in the world can get a 5k rpm window of a cam lobe to work its best. so when you have a 9k rpm engine your going to have to have some weak spots in about half of the rpm range. the stage one consintrates on the mid range with alittle flowing into the top end, where as the stage 2 is the top end so it gives up some bottom.

to the og poster it dosnt matter if you have a stock motor more how you ride, if you are doing alot of off idle pulling or lugging the motor stage 1 would be you choice. if you do alot of mx where your always "on the pipe" a stage 2 would be better.

[scruff_mcruff]

Originally posted by zrpilot


An automobile motor and a thumper motor are two completely different engines with different characteristics. What works on one may not work on the other.

. as long as you have 1 cam lobe operating a valve every motor out there will react the same. obviously all would require different lift and duration combinations but no 1 cam lobe in this world will give the maximum performance through out the entire rev range.

a very wise man once told me that building a race engine is a series of comprimises, you will never get every thing you want. "which dosnt include F1 and nuematic valves"

[400eXr1d3rZ]

Originally posted by DaMeech89
I'm not going to rae, any time soon. I'll take it to the track \and stuff but just for fun. I'm looking for acceleration more htan top speed. Would Stage 1 or Stage 2 give me more accleration?

Drop a tooth on the front sprocket.

[zrpilot]

Originally posted by scruff_mcruff
the loss of tq is due to the cam not the compression loss. the best cam designers in the world can get a 5k rpm window of a cam lobe to work its best. so when you have a 9k rpm engine your going to have to have some weak spots in about half of the rpm range. the stage one consintrates on the mid range with alittle flowing into the top end, where as the stage 2 is the top end so it gives up some bottom.

to the og poster it dosnt matter if you have a stock motor more how you ride, if you are doing alot of off idle pulling or lugging the motor stage 1 would be you choice. if you do alot of mx where your always "on the pipe" a stage 2 would be better. just to clarify: a loss of compression due to the cam profile.

[zrpilot]

Originally posted by scruff_mcruff
as long as you have 1 cam lobe operating a valve every motor out there will react the same. obviously all would require different lift and duration combinations but no 1 cam lobe in this world will give the maximum performance through out the entire rev range.

a very wise man once told me that building a race engine is a series of comprimises, you will never get every thing you want. "which dosnt include F1 and nuematic valves"
I believe your statement to be true in theory, but the modern automobile engine will repond to modifications WAY different then the 400EX quad motor in the real world. A couple of reasons: more sophisticated engine management systems (closed loop fuel injection, atomshephric pressure sensor, coolant temperature sensor, throttle position sensor, variable ignition timing based on many more inputs, for example), multiple cylinders, possible variable valve timing, ETC... So for a poster to say "I put XYZ brand cam in my otherwise stock 5.0L Mustang and everything worked great, therefore put a stage2 cam into your otherwise stock 400EX and you will see the same results on the 400EX is simply not true"

I agree 100% with engine building being a series on compromises. I have said many times here that building an engine is like following an recipe in the kitchen, all the ingredents must come together to make the food taste good.

[sc400ex_rider]

the new stg 2 is very close to a hrc. almost a copy cam. the hrc is the best 400ex cam ever made. all the tq of stg 1 all the mid as stg 2 and more over rev. than stg 2. stg 2 has better rush

[scruff_mcruff]

Originally posted by zrpilot
I believe your statement to be true in theory, but the modern automobile engine will repond to modifications WAY different then the 400EX quad motor in the real world. A couple of reasons: more sophisticated engine management systems (closed loop fuel injection, atomshephric pressure sensor, coolant temperature sensor, throttle position sensor, variable ignition timing based on many more inputs, for example), multiple cylinders, possible variable valve timing, ETC... So for a poster to say "I put XYZ brand cam in my otherwise stock 5.0L Mustang and everything worked great, therefore put a stage2 cam into your otherwise stock 400EX and you will see the same results on the 400EX is simply not true"

I agree 100% with engine building being a series on compromises. I have said many times here that building an engine is like following an recipe in the kitchen, all the ingredents must come together to make the food taste good.

im not talking about management and fuel injection differences. im talking about port sizes and runner angles being almost identical to honda car motors. cause lets face it, these motors are simply one cylinder chopped off the end of their 4 cyls. yes the 400's dual exhaust port is different from the cars but the runner angles and port cc's are so close its basically the same. so the motors will act a whole lot like the street motors will with different cam profiles.

[zrpilot]

Originally posted by scruff_mcruff
im not talking about management and fuel injection differences. im talking about port sizes and runner angles being almost identical to honda car motors. cause lets face it, these motors are simply one cylinder chopped off the end of their 4 cyls. yes the 400's dual exhaust port is different from the cars but the runner angles and port cc's are so close its basically the same. so the motors will act a whole lot like the street motors will with different cam profiles.

Ok... :confused:

[DaMeech89]

thanx guys i think im gonna go with the stage 1