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Hey Kyle, should be the same as the stocker. I would think the only way it would be different is if you changed valve composition such as titanium or stainless. The expansion rates of those metals would be a little bit different. I don't think it will be different for just a cam change.
 

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protraxrptr17 said:
Hey Kyle, should be the same as the stocker. I would think the only way it would be different is if you changed valve composition such as titanium or stainless. The expansion rates of those metals would be a little bit different. I don't think it will be different for just a cam change.
the above post is totally wrong .. sorry to say.

here is the specs ..

intake : lash = .20 mm
exhaust : lash = .25 mm

set the lash with a cold motor. recheck after motor is warmed them cooled.

hope that helps bro. need anymore questions?
go here ..
http://www.hotcamsinc.com/speccards/YFM660S1-A Cam Card.htm
 

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Well, learn something new everyday. Sucks to be to be TOTALLY wrong. Wonder why it's .05mm more? Maybe because the valve stays open longer, so it doesn't transfer as much heat back into the head, causing the valve to expand more than with the stock cam.

Heard from your buddy from Texas today, I have already sold all my a-arms though. Seemed like a real cool guy.
 

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protraxrptr17 said:
Well, learn something new everyday. Sucks to be to be TOTALLY wrong. Wonder why it's .05mm more? Maybe because the valve stays open longer, so it doesn't transfer as much heat back into the head, causing the valve to expand more than with the stock cam.

Heard from your buddy from Texas today, I have already sold all my a-arms though. Seemed like a real cool guy.
Nah it dont suk you were just trying to help, but thats what makes forums fun :))

Hot cams recomends this extra clearence on most all of their cams, and its for a couple reasons.

By adding .05 or any extra amount of valve lash will cause the valves to open and close slightly different than with the smaller amount used on the stock cam(s).

It also sort of effects how and what amount of force is transfered from the cam thru the rockers (if any) to the valves (or vice versa), so a little extra clearence will allow the cam to have moved ever so slightly more forward thru its cycle before it has to resist and push the force supplied by the valve spring.

There is a lot more to it from actual timing of the valve opening and closing, to the amount and placement of wear on the cam lobes. I just think that may be better left for someone with more cam experience etc.

One thing I do know is that if your really in tune with how your engine runs you can notice slight differences from different lash settings (if there is a large enough differnce) and I have been happy with mine set slightly less on the intake and right on HC's specs on the exh. it just seems to work with my set up thats all, and could be different for every engine.

Hope that helps.
 

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440ex4me said:
protraxrptr17 said:
Well, learn something new everyday. Sucks to be to be TOTALLY wrong. Wonder why it's .05mm more? Maybe because the valve stays open longer, so it doesn't transfer as much heat back into the head, causing the valve to expand more than with the stock cam.

Heard from your buddy from Texas today, I have already sold all my a-arms though. Seemed like a real cool guy.
Nah it dont suk you were just trying to help, but thats what makes forums fun :))

Hot cams recomends this extra clearence on most all of their cams, and its for a couple reasons.

By adding .05 or any extra amount of valve lash will cause the valves to open and close slightly different than with the smaller amount used on the stock cam(s).

It also sort of effects how and what amount of force is transfered from the cam thru the rockers (if any) to the valves (or vice versa), so a little extra clearence will allow the cam to have moved ever so slightly more forward thru its cycle before it has to resist and push the force supplied by the valve spring.

There is a lot more to it from actual timing of the valve opening and closing, to the amount and placement of wear on the cam lobes. I just think that may be better left for someone with more cam experience etc.

One thing I do know is that if your really in tune with how your engine runs you can notice slight differences from different lash settings (if there is a large enough differnce) and I have been happy with mine set slightly less on the intake and right on HC's specs on the exh. it just seems to work with my set up thats all, and could be different for every engine.

Hope that helps.
AKA Jerk Rates :tup:

yes you hornballs, that is really a technical term.
 

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.006" intake and .008" exhaust. Don't let the intakes go below .004" and you'll never have a problem.

Experience always trumps theory :lol:
 

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UBETRUN said:
.006" intake and .008" exhaust. Don't let the intakes go below .004" and you'll never have a problem.

Experience always trumps theory :lol:
...and this lash works better than the recommended specs from hotcams? hmm .. well next time i need to adjust my valves, ill have to try it .. see how it runs.


and for the guy that was wrong about the specs .. its all good man :tup:
its just one of those things lol.
 

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The metal is a different material with the Hotcams than hard welded(web or megacycle) or stock cams.The expansion rate is different.I did try slightly tighter settings but just barely. I cant really hear anything over the drag pipe anywayLOL
 

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SCHOLLE said:
The metal is a different material with the Hotcams than hard welded(web or megacycle) or stock cams.The expansion rate is different.I did try slightly tighter settings but just barely. I cant really hear anything over the drag pipe anywayLOL
yea my buddy has the same setup as you ( drag pipe and hotcam) .. it runs great. we have the same setup except for the pipe. i cant even race him unless im on the left side because its soo damn loud.
 

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SCHOLLE said:
The metal is a different material with the Hotcams than hard welded(web or megacycle) or stock cams.The expansion rate is different.I did try slightly tighter settings but just barely. I cant really hear anything over the drag pipe anywayLOL
I thought the Hot Cams and the stock cam were the same, and the other (Mega Cycle and Web) were different. :wtf: ???
 

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440ex4me,
Man, that was some real good info. Never thought about some of those things you said. Have we ever done business or anything? Your name sounds familiar. Please post in this forum all the time. We need good stuff like that.


NitrousGuy,
Jerk rates. Not a new term to me, just a different meaning. I always thought jerk rate was figured by stroke/second x friction :smooch:




UBETRUN,
That is tight!! I'll have to try that. I never thought about valve clearance being a variable adjustment such as jets, gear ratios, and tire pressures.
 

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When you add slop, you give up lift. I ran .006" and .008" on a Hotcams Stage 2 and never had a problem. I tried a tight .004" on the intake once and it wouldn't run right after mid throttle.

On my Craycraft cam, there is even less lash... :hey:
 

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Hey guys thanks for the kind words etc

Although I learned the basics years ago on v/8 chevy stuff (actualy the guy I learned from just went and died this year, sad cause he didnt even make 50) much of it is still from trial and error.

It is helpfull to have some experience or knowledge cause it saves you the bigger oops that cost more $$$ to fix but messing around with valve lash can pay you back some in performance.

I had even found the point on this engine that the lash was too tight and then knew where to be above for the utmost lift etc, but with the tight piston to valve clearences I need on this one to make good power its a gamble and these parts aint cheap so be carefull if you mess around with high comp and hi lift cams on a 4 stroke.

Now when I would set the lash on the ole warrior it almost didnt matter much cause it was mostly stock and all the concern was based on wear not marginal gains or changes in power.

Point is that this is an area to find extra or make your engine perform better to your needs (low end torque or top end hp etc) but there are other areas that will give more bang for the buch and need to be done before being that worried about messing with different valve lash settings.

And the deal about different materials being used is interesting, and one that some will debate a whole lot due to some info being generic. An example is how some believe that since the HC steel is not of an exact hardness of the stock cam (cant verify this myself so take it as opinion of others etc) it can still wear or be worn by the stock rockers. From my experience there isnt any wear on the cam itself (for the EX anyhow) as I had run a stage1 for most of a season and there wasnt any measureable wear, but others claim to have seen different results and I didnt bother with the rocker pads cause I was intending on changing over to a web cam shortly after (been over a year and still have it sitting in my too box lol) I actually had both the hotcam stage2 and WB track cam at the same time and those are really close except that Web advises using hard rockers on that cam (wb doesnt ? and there the same exact thing) and HC doesnt.

Its really all about set up, and I will set the lash differently when I swap over to the new web with a whole lot more lift and less duration (should provide much better torque and a smoother pull from a broader power curve) than what its set at now with the stage2 HC. It can be a little anal to be botherd with these small adjustments etc but there isnt much more to do for finding extra power from the enginge outside a stroker crank.
 

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Discussion Starter #15
hey guys i talked to hot cams and they said 8thousandths and ten thousandsths o nthe stage one does that sound right
 

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That should be fine, just a little less lift and a little more noise than my recommendation of 6 thousandths and 8 thousandths (.006" and .008").
 

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Discussion Starter #17
sorry to bring this back up but im still confused on clearences the clymer book says on factory intake 04-06
and exhaust was close to the same i dont wanna mess this bike up when adjust these and i want to get it to be exact and i got 3 differnt answers and hot cams has gave me two diffrent anwsers im so confused :wtf:
 

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tat900 said:
sorry to bring this back up but im still confused on clearences the clymer book says on factory intake 04-06
and exhaust was close to the same i dont wanna mess this bike up when adjust these and i want to get it to be exact and i got 3 differnt answers and hot cams has gave me two diffrent anwsers im so confused :wtf:
Dont let all the different setting recomendations get you crazy or confused, and just take a deep breath and look at what it all means. Also remember some of the numbers are in inch, and others in mm.

When you set the valve lash on this type of cam set up etc you are changing the amount of space between the moving parts (rocker and valve stem etc) and also the timing that the valve first begins to open, and also the actual amount of movement of the valve.

So basically when you increase the amount of space between the parts (more clearance/larger number) you cause the valve to open slightly later, and not as much if less clearance was used. Unless excessive this should do little more than cause some valve train noise (clicking).

The reason some may suggest larger clearence is to reduce any potential added friction on the cam and rockers (especially when hp springs are used), reduced chances of problems from user error (setting it wrong etc) and also to reduce the chance of mechanical damage that can occur if too much lift and too little piston to valve clearence cause the two to meet etc.

Only thing that I question is why hotcam recomended two different settings.

If your settings are anyware between the oem and cam mfg's etc I wouldnt give it any worry, and though you can make ever so slight changes to performance by messing with slightly less or more clearance its just not worth the effort most times, and you shouldnt even bother etc.

hope that helps explain it a little better
 

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Only thing that I question is why hotcam recomended two different settings.
Simple Answer, The exhaust valves get hotter than the intake Valves and will expand more...

The intake valves are cooled by incomming air.
The exhaust Valves are always heated by exiting air.
 

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RidingBlind said:
Only thing that I question is why hotcam recomended two different settings.
Simple Answer, The exhaust valves get hotter than the intake Valves and will expand more...

The intake valves are cooled by incomming air.
The exhaust Valves are always heated by exiting air.
Ok then the difference was between the intatke and exhaust, and they didnt offer two different settings for both.

Sorry if I mis read that, but it sounded like he meant they changed their minds :)
 
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