Aftermarket High-Performance camshaft problems/questions?

[rg97]

Hi. i just ripped apart my cdi on my 83 200x because my ebay high-performance cam came in! i have the service manual (and my dad!) and i took out all of the necessary parts to get to the cam. once i got the old one out tho, i thought i would measure and compare the new cam to the old one to see what kind of performance i would be getting and wouldn't you know it when i measured the intake with some calipers, the lobe is SMALLER than the oem. the measurements are: (intake-oem) 32.49mm o.d. (intake-'hi-performance') 32.34mm o.d.:wondering i dont care about the exhaust. Is something wrong or maybe it already had a hi-performance cam when i bought it? plz help!!!! :wondering

:TrikesOwn

[Blown 331]

What about the duration? Maybe your new cam holds the valves open longer. A lot of times a bolt in performance cam won't have much more lift because the stock valve springs won't handle it.

[shortline10]

Their is nothing high performance about the cam that bikerchicks sells on ebay . Its a POS in my opinion and also the pin for the advancer is a few degrees off .

[rg97]

i'll have my dad check out the duration on his lathe. he said the same thing you did ;)

[rg97]

Their is nothing high performance about the cam that bikerchicks sells on ebay . Its a POS in my opinion and also the pin for the advancer is a few degrees off .
I agree shortline... that is the one that i bought and i do think they are either lying or they dont know what they have. but... when i e-mailed them about the cam, i got this in reply: It is definitely different than the OEM 200X cam. The specs are different
and it does give a little better performance than the original 200X
cam.
If you do not want it and want to return it before you use or install
it you may do so. If this is what you want please let us know and we will
issue a return authorization number for it.
Mike

I agree that their cams are crap

[shortline10]

I've already gone threw this with them ( bikerchicks) but we tried the cam and it was a POS . I couldnt get the motor to idle for nothing with that cam and the bike ran hot . send it back !!!!!
Save your money and get a web or a powroll cam .



I agree big al... that is the one that i bought and i do think they are either lying or they dont know what they have. but... when i e-mailed them about the cam, i got this in reply: It is definitely different than the OEM 200X cam. The specs are different
and it does give a little better performance than the original 200X
cam.
If you do not want it and want to return it before you use or install
it you may do so. If this is what you want please let us know and we will
issue a return authorization number for it.
Mike

I agree that their cams are crap

[christph]

Since we are talking cams and I will soon be in the market for one for my 200x, does anyone have any general comments about Powroll vs. Webcam. It looks like Webcam has a few more options but I'm wondering about quality.

[rg97]

Since we are talking cams and I will soon be in the market for one for my 200x, does anyone have any general comments about Powroll vs. Webcam. It looks like Webcam has a few more options but I'm wondering about quality.

ive never had any personal experience with a powroll, but the web that i have is a very nice in my 90 (now 160cc) racing engine. web is a little bit less expensive too and they have a mild cam while powroll only has torque, mid, and top end

[H2Sbass]

Overall O.D. is not the amount of lift on a cam. The difference between major O.D and minor O.D is what determines lift. As well, duration plays just as big of a role. Also, a different cam grind works more by changing the shape of the powerband as opposed to just "more power". A cam with very high lift and long duration (which is most performance grinds) usually won't run very smooth at idle, that is part of the trade off for more top end hp. Many of the E-bay high performance cams are actually just cams from a different model of bike, for example, an atc 110 high performance cam is usually just an sl 90 stock cam (still a different grind). I suspect many of the atc 200/ 200x performance cams are actually stock xr 200 parts.

[WIkid500]

I run a full roller mega cycle in my 200x love it. Not a cheap solution but defiantly a good one. Makes great power through the woods along with the Powroll stroked crank.

[Dirtcrasher]

I agree with many but it will really perform when you remove/mod the airbox lid and jet it correctly.....

[2222tecate]

I have a white brothers full race cam it is amazing, i did have 12,1 . I decided to step down to 10.25 for different reasons, i like 10.25 for fast woods/ , 12, 1 if you were in a mud moto race, and were just holding it wide everywhere, if you ever get off the rrrrrrss with 12,1 and this white brother cam, your done,. I run 28 flat-slide , h/d spring , titanium kibblie white valves, lightened flywheel, a very rare unique carb manifold, js performance porting/head work/ vesrah rod, ect..

[barnett468]

i'll have my dad check out the duration on his lathe. he said the same thing you did ;)



Hello


You can’t determine the lift by measuring it that way because your new cam may have a slightly smaller base circle. To measure the base circle you need to measure the distance from the center of the cam to the point 180 degrees opposite of the peak of the lobe. Your dad will not need to do that however his dial indicator will tell him what the actual lift is on both cams but that’s not the problem it will tell you very little the following explains why.

He can also buy a cheap degree wheel from a high performance auto supply store for a few dollars and tell you most everything you need to know.

Here’s the primary aspects of a cam.

1. Duration as Blown 331 mentioned but there are two types of measurement for this.

a. Advertised duration - This is how long the valves are actually open in degrees typically measured at .006” valve lift and affects the rpm range at which the motor will operate ie 1000-4000 vs 2000-5000.

b. Partially affects engine vacuum

2. Duration measured at .050 – This determines the following.

a. The angle of the lobe face.

b. The amount of area under the curve the valve is open.

c. Partially effects the amount of vacuum an engine has.

3. Lift obviously

4. Valve timing ie the amount in degrees each valve opens and closes from either 0 or 4 degrees ground in cam advance.

a. Intake Valve closing time determines dynamic and cranking compression [not static compression].

5. Cam advance- determines intake valve time therefore compression as mentioned and also determines the rpm range at which an engine operates same as advertised duration but adjust ment is minimal.

6. LSA/OVERLAP – Partially determines how wide the rpm range is ie 1000-3000 vs 1000-5000 and the amount of “lope” an engine has at idle.

7. Intake centerline


Powroll has been at this a long time, other cam mfg’s may also be good as mentioned, I suggest not buying cams of unknown specs from “chick’s” or anyone else.


Hope this info helps.

[barnett468]

Hello rg97


CORRECTION FOR MY ORIGINAL POST

3. Duration measured at .050 – This determines the following.

a. This will partially determine the angle of the lobe ramp [face], when calculated in a formula along with the duration measured at .006.


ADDITION TO MY ORIGINAL POST

8. Cam durations, lift, and cam timing all contribute to determine the amount of air volume a particular engine can flow and the speed at which that air travels through the ports at varying valve lifts.

The amount of air an engine flows is also partially affected by the swept volume ie bore/stroke, intake and exhaust port flow, carburetor flow and exhaust pipe flow and engine scavenging capabilities.


Sorry I don't have an edit button on the site.

[Scootertrash]

Sorry I don't have an edit button on the site.

The edit button is at the bottom of your post window to the left of the "reply" and "reply with quote" buttons:

167220

[barnett468]

Hello Scootertrash

Thanks for the info however I've been over this with several other people. It does not exist. I cut and pasted that line below for you. I know it is out of order but that is what it does when I post it dorectly into the window try it you will see but yours will say edit.


Reply Reply With Quote Reply With Quote Blog this Post


Thanks again for the attempt.