[BradKPed]

Looking to buy a set of cams for my Zetec soon, and trying to figure out if I need adjustable cam gears to go with them. Are they just recommended, are they absolutely necessary, or are they not needed? Am I just going to put them on, and then not change the degree at all?



For those who have adjustable cam gears, what are yours set to?

 

[iminhell]

If you can degree a cam, they aren't needed. ... actually they aren't needed for anyone, it's just a convenience for fine adjustment after installation.
You can loosen a stock gear and adjust that way, you just need a way to know how much you're moving the cam.


If people would actually look and know how to read their cam card, adj gears wouldn't be so popular ... maybe.

 

[BradKPed]

So in essence, they're really just for show.

 

[1turbofocus]

I feel there 100% needed and a must if your going to install cams you will need to spend a little time on a dyno to properly adjust them

If your not willing to do adjustable cam gears and dyno it I wouldnt recommend doing cams , what other mods do you have ?

Tom

 

[amc49]

The problem becomes one of figuring out how to measure the tappet lift properly to get lobe center without specialty tooling. As well, the stock sprocket is not easy to mark where it can be referred to easy. Need index marks on both cam and gear, they would be way down around the cam seal and back of sprocket to get that, hard to see there.

If you use a partial thickness rear cam tool like I do (Home Depot .187" keyway stock) instead of the full .200 of the dealer tool you can fit feelers of various thickness to take up slack, tilt cam in the extra looseness, and you would have easily repeatable known points of reference there. Someone would have to take an initial read of degree in different spots there to know where at but after that as repeatable as loosening adjustable sprocket and moving it.

 

[sleepyboy]

If you can degree a cam, they aren't needed. ... actually they aren't needed for anyone, it's just a convenience for fine adjustment after installation.
You can loosen a stock gear and adjust that way, you just need a way to know how much you're moving the cam.


If people would actually look and know how to read their cam card, adj gears wouldn't be so popular ... maybe.

You need to be more clear with this. I understand what you are saying but there are benefits to having them adjusted. Doesn't matter if you have it degreed and installed perfectly to what the cam manufacturer says there is sometimes more power to be gained with adjustment. Specifically on our motors where the cam timing isn't as precise as other motors.

Also who has a degree wheel and other timing tools and actually uses it on our motors besides you? No one is going to take the time to do that, or at least majority of our members wouldn't. Nor would they spend the money on those tools unless they already have them.

I'm a huge supporter of adj. cam gears, but only if they are going to be dyno tuned. It's utterly hopeless to tune them using the butt dyno, I know from personal experience. I was so far off from what I felt was better power and that was with stock cams.

 

[freemind]

Adjustable cam gears DO make a difference

 

[amc49]

I've often wondered just how much those stock rear cam grooves can vary from the stated factory number..................

 

[amc49]

If anyone ever had the 'wherewithal' lets say, to spit out the numbers most likely to produce the usual hp. increase then there would be really no need for dyno at all since it would then only result in a measly couple of hp for all that work. Of course I understand why they don't. And the numbers can easily be buried by simply saying that all engines are different, which I pretty much don't buy for five seconds. The basic engines will all respond pretty close to the same until the engine parts really start getting different from each other or something is wrong with one. Most of that searching time is wasted once the combo is known, it can be plugged in to get almost every bit of it every time. The extra work will result in more power but not big amounts, it may even result in slightly less.

 

[iminhell]

^Correct.
An engine with the same header/intake manifold and cam combo will dyno virtually identical to all others.
All adjusting the cam timing will do is move where the TQ peak is. And the limitation is the duration and ports.
Modify the head, moving the cam can make a difference / may be needed.

Also (as I've said in the past), the lash can either add or subtract from the actual duration.
The ONLY way someone's stated advance/retard numbers would transfer to someone else's car are if the exact same combo were used. That is same exhaust, intake manifold (anything before the manifold is moot), cams, headwork and lash settings.
That +3, -2 is simply making up for lash being off from what the head wants. I'd bet if people would post their #'s and their lash that this would become apparent and that an optimal lash could be found negating any need for adj. gears.


And degree wheel,
I made one. Printed a CD with an image of a degree wheel and bolted it to the cam. Easily something anyone here could do. From there it's just a matter of understanding the numbers.



Also, if anyone could benefit from adj. gears it'd be me. When you delete the VCT from the SVT head you can't use the cam bar to line the cams up; the intake has to be retarded and I've found that doing so with adjusting the cam gear just doesn't move it enough. You can search on that if it's unclear.
Simply put, my intake cam is ~25* away from where the bar would fit in. I haven't moved either cam since I put it together/dyno'd. Could there be more power, maybe. Am I going to move them and find out, no. A couple here or there isn't going to make a bit of difference in how my car runs. It's not like I'd find +20HP by moving them.

But in a car where they are off from the get-go, you will find power.

I mean look at it this way, $300 for gears and $400 for a tune. Which is going to make more power?


And another thing, for all the cheapskates on here, I really doubt they are going to add $80/hr for dyno tuning time to find a couple HP. IMO that's just a waste.
I can think of others things to blow $500 on.

 

[sleepyboy]

I've often wondered just how much those stock rear cam grooves can vary from the stated factory number..................

A lot actually, this is why some Zetec's were "factory freaks" per say and others were just ok.

 

[amc49]

Dunno about a 'lot' but even a small amount can be felt when you're not making much to begin with. The little motor. I remember them chasing a middleweight Kaw GPZ550 all over the place once trying to find out why one tested was a dog as compared to the 'hot' ones. After measuring compression, cam timing, and pulling engine partly down to look to see if Kawasaki USA slipped some add-on HP in the form of slight head porting (they were known to do it if they were banking on a hotrod test showing their bike as the fastest), they chalked it up to slightly mistimed cams and setting them back right picked up like 4 HP on a bike that supposedly made 55. The previously dog of a bike immediately woke up and joined the rest of the 550 pack. Not a lot of power but them little motors are peaky suckers.................

On the early Honda DOHC bikes the number was known for cam timing, the so-called 100I-105E rule. Timed to that virtually all of them run at max output, dynoing really doesn't improve things much at all. Anybody flouting that cam timing pretty much runs slower not faster. There are mechanical reasons for it I won't go into here though. And in that case same basic result in 750, 900, 1000, and 1100 engines.

 

[freemind]

I put down 116whp and 109tq stock before any mods.

 

[sleepyboy]

Dunno about a 'lot' but even a small amount can be felt when you're not making much to begin with. The little motor. I remember them chasing a middleweight Kaw GPZ550 all over the place once trying to find out why one tested was a dog as compared to the 'hot' ones. After measuring compression, cam timing, and pulling engine partly down to look to see if Kawasaki USA slipped some add-on HP in the form of slight head porting (they were known to do it if they were banking on a hotrod test showing their bike as the fastest), they chalked it up to slightly mistimed cams and setting them back right picked up like 4 HP on a bike that supposedly made 55. The previously dog of a bike immediately woke up and joined the rest of the 550 pack. Not a lot of power but them little motors are peaky suckers.................

On the early Honda DOHC bikes the number was known for cam timing, the so-called 100I-105E rule. Timed to that virtually all of them run at max output, dynoing really doesn't improve things much at all. Anybody flouting that cam timing pretty much runs slower not faster. There are mechanical reasons for it I won't go into here though. And in that case same basic result in 750, 900, 1000, and 1100 engines.

That's pretty much how these are IMO. Like you said it doesn't take much on a already weak motor. When tuning the cam gears hp stayed within a 10hp range but when your barely putting out a little over 100 at the wheels 10hp can be a big difference. The tq curve is what really picked up, I gain power everywhere and we tuned it for a broad power band where as I could have gotten more hp but it would loose the broadness of the tq curve. But of course that's all that is happening is the power is being shifted around but it's always been there.

 

[amc49]

I could care less about dyno numbers, I watched someone pull 1000 hp. out of a BBC, make a small dyno change and then get 1200 with same exact motor and nothing changed on it. The numbers are real world unrelatable and I could care less what anyone else thinks about that. Dynos are able to be tweaked to mess with people's heads. Ask the old IROC series guys about why all engines had to certify on exact same dyno to prevent any driver getting the leg up on others with supposedly 'exact' same power readings.

 

[elsolo]

Unless you have free dyno time, or know more than the cam grinder, how much adjusting do you plan on doing?

During install, are you gonna put a dial indicator to measure valve lift, use a degree wheel to know where it's at? Then later on you can use the easy adjust sprockets to make minor can timing changes to tune for track conditions and such? Didn't think so.

 

[1turbofocus]

Unless you have free dyno time, or know more than the cam grinder, how much adjusting do you plan on doing?

During install, are you gonna put a dial indicator to measure valve lift, use a degree wheel to know where it's at? Then later on you can use the easy adjust sprockets to make minor can timing changes to tune for track conditions and such? Didn't think so.

A degree wheel will set the cams to what the manufacture suggest they be set to this does not mean that's where they make the best performance and TQ

Regardless of the silly comments about using dynos , a dyno is the only way to set a set of Adj. cam gears on an engine

The engine knows more then the cam grinder does when it comes to where the cams make the best HP and TQ , only the engine can tell you this and to listen to what its saying you have to be on a dyno , If this could be done any other way I wouldnt of spent 30,000.00 back in 1996 and another 15,000.00 in 2002 to update to install a dynojet dyno

Tom

 

[amc49]

I note as usual the tendency to ridicule rather than PROVE otherwise, which you never seem to have time (or ability) to do. Says volumes to me.......................

 

[1turbofocus]

You meaning me ? please explain ?

Tom

 

[amc49]

Shouldn't have to, you can read.......................and you already know things you've said in the past. Not going to lead you around by the hand like a child.

You have a lot of experience and it shows, unfortunately so does the ultra fat head that often feels no need to justify things said even when insulting people. Then you act like you don't know what people are talking about like here, the playing stupid act.

Dyno output can be messed with 6 ways from sundown and acting like it can't is just.......that word 'silly' keeps popping up and seems to fit well here.