Dyno results for camshaft degrees?

[witech]

I know there are very few that will understand this(maybe just a few guys) but I was just wondering what kind of results the real tuners are getting with going extreme on cam timing. What are the stock cams usually set to on the whatever brands you work with ?
Ive found that running 106intake and 106 exhaust is good for stock sized engines and ones using quiet cores. Then bumping up to 109/107 seems good for larger bores. And of course huge engines you can play around as high as 115 degrees for mega power. These are all for ported motors . I have seen good results retarding the exhaust less than the intake as well. Like 2 or 3 degrees of separation.

[witech]

Hmm I wonder if anybody here even knows how to degree a camshaft?

[cataway]

i have noted that this forum in not high performance oriented
i have the way and means to check and adjust how ever i have had no need to experiment with these new cams simple because
i know many experiments have been done to find the optimum settings, after doing a few dyno runs i believe it

[Buttermilk]

Very interesting thread.

I believe that degreeing in a cam, or altering lobe centers, is perhaps one of the least understood parts of a 4-stroke engine.

This is an area where I've personally been trying to increase my understanding of what the effects of changing the lobe centers does to specific engines.

When I look at cams that are available for various 450's, it really suprises me at the different lobe centers that different cams have.

We are changing cams on my son's 450R, in part due to lobe centers. The cam we were running had 108 lobe centers for both intake and exhaust. The new cam we are going to run is 110 on the intake and 104 on the exhaust. We are expecting at least a 2 horsepower gain. Some due to the lobe centers, some due to the cam profile. I've been told by a reputable source that twisting the 108 LC cam by 5 degrees would result in a ~1.5 hp gain. Never got around to testing that, however. Chose instead to go with a different cam.

While I have yet to do any specific testing with degreeing in cams and altering the lobe center, I do have some understanding of it.

The YFZ450 cams are quite interesting as well, when you consider what different cams have the lobe center set to.

What engines are you testing on? I'm very interested in what you're doing and the results you are getting.

Regards,

Rog

[witech]

Are there any atv web site for tuners? Kind of sad that so many will spend countless amounts of money on engine kits and mods and dont have a clue how to get the parts to work together .
Ive been degreeing cams for quite a while now and just slapping a cam in a motor and setting it to stock timing specs can result in some seriously lost power ,drivability ,and tuning issues. if you ever wonder why 2 identical stock quads can be night and day difference first place to look would be checking degreeing of the cams.
The worst ive seen was an intake at 111 degrees and the exhaust at 97. That quad was a pooch.

[Buttermilk]

I don't know of any specific atv websites that really get into this particular side of the engines. I tried to start a discussion of this topic on www.atvdragracers.com but without much success.

I have a friend who has a 450R built by a well known engine builder that makes nearly 62 HP on a stock bore/stroke '05 model.

We were changing the cam chain out a few days ago and I was suprised to see the cam was installed using the stock cam gear and wasn't degreed in at all. In fact, the head on this quad was decked by ~ 0.065" and the cam was actually retarded by a few degrees due to the head being decked. Quite interesting I thought.

Regards,

Rog

i have a 02 400ex that i have been trying to get someone to do my cams but if some one was to give me a break down no how to do it i ahve all the tools just need a step by step on how to get it done thanks. my mods are stage 3 hot cam 440 kit 12.5:1 shaved head and cyl p&p 450 flat slid carb hmf pipe 450 cam chain

[Buttermilk]

www.webcamshafts.com has a how to article on their site for degreeing in cams. There are several articles on various websites as well.

Regards,

Rog

can any one give a step by step on how to degree a stage3 hot cam i tryed the websites but no help

[witech]

.065" decking ? Ya that would definatly retard the timing. Must have modded the piston quite a bit for valve clearance. I pretty much deal with Cannondale systems . They came from the factory with ability to change cam timing independantly without buying special cam gears.
Cam timing is how I was able to get 56.5 horse out of a stock part engine. With a large diameter dual exhaust tube retarding the exhaust cam beyond 110 and intake to 113 jacked the high rpm flow way up there. Low and mid power and torque were near normal but it allowed the engine to pump air way up to the rev limiter.
Taking the same engine and setting the timing to 108 intake and 107 exhaust brought the low and mid power up around 5 horsepower but dropped peak power down to around 51. You had your chioce of a top speed screamer motor or a mx motor by just a few adjustments.
One thing i have noticed is the more restrictive the exhaust you have the less you can retard the exhast cam. That comes in handy for those who race with a legal exhaust.

Those running a single exahust cam are limited for playing with advancing and overlapping the lobes due to having to use aftemarket cams.
Anyone ever notice spitting fuel back up the intake of a engine ? Thats pulse waves coming back up the intake .The exhaust pressure not getting scavanged out completly and going back up the intake . That where messing around with overlap can eliminate the issue.

witech can you tell me step by step how to degree my cam or do a right up on it . hell if you live close to me ill let you do it.

[witech]

I dont have a 400ex degreeing procedure but all engines are the same. Its not very hard to understand and do once you mount up a degree wheel and dial indicator.
http://www.thedirtforum.com/degree.htm

[witech]

The web also has plenty of videos on how to do basic cam degreeing . For the most part cams are degreed to 106 degrees from the factory . On a single cam engine advancing(lowering the number ) giver more low end torque . Retarding raising the number (higher) gives more top end power. Some engine love 106. For most everybody except extremist you should not advance much more than 3 or 4 degrees and retard more than 5 degrees from 106. My personal preferance for all around engines that need to do it all is 108 +- 1 degree.
I wouldnt advance a 400ex cam due to them being a restrictive flow engine and they already have plenty of low end. It would just fall on its face at high rpm advanced.

[honda400ex2003]

sorry a month old now but how does the ignition timing come into play or does it all? Does it help or hurt it depending on how much the cam is degreed? I am interested to find out a bit more about this topic, i plan to do a bit of reading from the links above also to try to help out a bit. steve

[Thumpin440ex]

I know this is old, but the only big thing that deg a cam will do is move the power band up or down the rpm range. Now if you have a cam that has diff intake, exhaust durations, along with lift on either side, that is where the diff will be had greatly.. Also center line angle, lsa of it.. I honestly would not waste time deg a cam in a quad.. Take time to get flow numbers on the head, what kind of riding you mostly do( low rpms-mid or high, racing tight woods, with short sperts, or long stretches where you can really wind it out) have one ground based on that.. :)


John