web cam valve clearance ?????'s

[gpd005]

I have a web cam in my 2000 Honda 416ex and i need to adjust the valves on it. Does anyone know what this should be? I do not have any of the paper work from the cam as it had been installed when i purchsed the quad. Any help would be great! Thanks!

[ohsobad_chevy]

I would check online for some retailers of the cam that you have and then give em a call. Go to google and type in "web cam atv" or something like that, find a retailer, give em a call.

[gpd005]

that's exactly what i did after i posted this actually. They said it should be set at the same as stock.

[ohsobad_chevy]

LOL, ok

Intake: .004
Exhaust: .005

[wilkin250r]

Ideally, you wouldn't want any dead airspace between your camshaft, rockers, and valves. Zero valve lash.

The problem is heat. Things expand as they heat up, which means the valves actually get longer. If you set zero valve clearance when they're cold, they'll get longer as they heat up, and they wouldn't close all the way. That would obviously be bad.

This is why you set that clearance. The intake valves will get dang-near 0.004 inches longer at operating tempurature, and close that gap. The exhaust is exposed to more heat, so they need a little extra clearance, which is why they're set a 0.005". This is why you ALWAYS check the valve clearance when the engine is cold. If you do it while it's hot, then that clearance will be too big, because it will get even larger when the valves cool and shrink.

Now, as far as the web cam goes, you're still using the stock valves, so they'll expand about the same. This is why the valve clearance is the same as stock. It's dependent upon the valves and they're thermal expansion rate, not the camshaft.

[ohsobad_chevy]

Originally posted by wilkin250r
Ideally, you wouldn't want any dead airspace between your camshaft, rockers, and valves. Zero valve lash.

The problem is heat. Things expand as they heat up, which means the valves actually get longer. If you set zero valve clearance when they're cold, they'll get longer as they heat up, and they wouldn't close all the way. That would obviously be bad.

This is why you set that clearance. The intake valves will get dang-near 0.004 inches longer at operating tempurature, and close that gap. The exhaust is exposed to more heat, so they need a little extra clearance, which is why they're set a 0.005". This is why you ALWAYS check the valve clearance when the engine is cold. If you do it while it's hot, then that clearance will be too big, because it will get even larger when the valves cool and shrink.

Now, as far as the web cam goes, you're still using the stock valves, so they'll expand about the same. This is why the valve clearance is the same as stock. It's dependent upon the valves and they're thermal expansion rate, not the camshaft.

Well said bro... :cool: :cool:

[peecout]

it is right here

[sixer3]

Originally posted by wilkin250r
Ideally, you wouldn't want any dead airspace between your camshaft, rockers, and valves. Zero valve lash.

The problem is heat. Things expand as they heat up, which means the valves actually get longer. If you set zero valve clearance when they're cold, they'll get longer as they heat up, and they wouldn't close all the way. That would obviously be bad.

This is why you set that clearance. The intake valves will get dang-near 0.004 inches longer at operating tempurature, and close that gap. The exhaust is exposed to more heat, so they need a little extra clearance, which is why they're set a 0.005". This is why you ALWAYS check the valve clearance when the engine is cold. If you do it while it's hot, then that clearance will be too big, because it will get even larger when the valves cool and shrink.

Now, as far as the web cam goes, you're still using the stock valves, so they'll expand about the same. This is why the valve clearance is the same as stock. It's dependent upon the valves and they're thermal expansion rate, not the camshaft.

would this give a possible explanation as to why the hotcams have the ticking?....since hotcams specs are to set the intake lash @ .005 and the exhaust @ .006,....that there is still space between the rockers and valves when fully heated?

[GPracer2500]

I once asked Hotcams why they chose the valve clearence they specify. I got this exceptionally generic answer:

...Generally most of our cams have a slightly looser valve lash then stock. They are a more aggressive profile then stock, and the engineers decide what the lash should be...
Duh.:ermm:

Somewhere on the Internet (proceed with caution) I read that too tight valve clearence can wipe away the oil film on the cam lobes leading to premature valvetrain failure. I've never been able to find any info that suggests that so I dunno--maybe that was just some guy's baseless speculation. But if there's anything too that, maybe Hotcams figures that an EX engine running their cam is being asked to work awefully hard and needs a little help in the cam lubrication department. Don't take that for anything more than what it's worth though--a speculative $0.02 that could be way off.

[peecout]

so why is it that webcam recommends hardend rockers and hot cams does not?

[GPracer2500]

Originally posted by peecout
so why is it that webcam recommends hardend rockers and hot cams does not?

It just depends on the hardness of the material used to make the cam. The cam and the rockers need to be of equal hardness. If one is harder than the other will prematurely wear.

[peecout]

Originally posted by GPracer2500
It just depends on the hardness of the material used to make the cam. The cam and the rockers need to be of equal hardness. If one is harder than the other will prematurely wear.

So if that is the case, does that mean Webcam is the way to go? I was just wondering because it seems like more people are going with Hot Cam.

[GPracer2500]

I suppose a hardwelded cam (like all of Webcam's 400EX cams) would offer increased durability when mated to hardened rockers. But it's not like Hotcam cams are have a reputation for premature failure.

I believe Hotcams are so popluar because there is no core required. All 400EX Webcam cams are hardwelded re-grinds. They take a stock cam, weld new material onto the lobes, and then re-grind the cam to their specs. Webcams requires you pay a core charge. You get that charge credited back when they recieve your stock cam. Pretty sure Webcam does offer newly built 450r cams (and other's I'd imagine) that are not re-grinds and don't require a core charge.

Some re-grinds are not hardwelded and can therefore use non-hardened rockers.

[peecout]

Thanks a lot for the info. I am going to be putting some $$ into my motor and want to make sure all the parts are going to be a good match up. I had a 416 with a Webcam that I bought built. The guy I got it from said he spent a lot of time researching everything he put into it. I must say, it did run like a champ! It was stolen so I am thinking about going with the same setup on my replacement 400ex.