Hey all,

The other thread about cam gears slipping and the fact that the Skunk Cam gears are not really at 0 made me think. I also confused myself about cam gear degrees and crank degrees. Is it 1 degree on gear = 1 degree on crank?

Here is a link demonstrating how Skunk cam gears are off a little at 0: http://ferrari.colowatch.com/php/sho...=&view=&sb=&o=

Does this mean they are advanced by 1/2 degree when they read 0?

Also, is each mark 1 degree?

I have mine set to +3 marks intake and +1 marks exhaust. Is this really +3.5 intake/ + 1.5 exhaust?

Thanks,

FB

 

That may have been true only for his pair of cam gears.
The best way is to line your stock gears up with the aftermarket ones and compare. I had some cam gears once - and when I lined them up with the stock greas...the aftermarket ones were off by 3-4 degrees!

Also, 1 degree at the cam = 2 degrees at the crank.

 

Hey HX,

That's what I thought/had heard: 1 cam gear degree = 2 degrees at crank.

Now when people say they have cam gears at +2/-2 or whatever, do they mean cam gear degrees or crank degrees?

Per a few other threads, the Skunks are all that amt off compared to stock. As TOO says in the article, it's not necessarily that bad, you adjust them for most power. Prob just something to keep in mind.

If that pic of the Skunk gears is accurate, was I correct in stating that my gears at +3/+1 are really +3.5/+1.5?

Thanks

FB

 

Yea when people quote their setting, they refer to the cam gear setting not the crank.
The reason you want to know the crank degrees is for when you set your ignition timing. If you advance you intake cam 2 degrees...you have to retard your ignition timing (through distributor) 4 degrees to get it back to 16 degrees.

It is true that if the gears are .5 or 1 off it doesnt matter performance wise since you are going to tune them anyway...but its then harder to do the ignition timing.

 

HX,

You the man! Thanks for clarifying for me.

~lates,

FB

 

and each mark isTwo degrees! becareful. Also, my skunk2 cam gears were dead on. I think that they fixed that problem on the first ones. Make sure you tighten them before the first use, because mine came with handtight bolts!

 

That depends on the company correct? Like I believe AEM cam gears each mark = 1 degree while others (Skunk2?) each mark = 2 degrees?

 

Yep, each mark is 2 degrees.

Dustin

 

What brands have 1 mark = 1 degree?

I would much rather have that instead of 1 mark = 2 degrees

 

It really does depend on the brand, I know Skunk2 is 2 degrees per mark.

Dustin

 

Holy crap,

That means I'm really at +6/+2?

Maybe that's why my idle is so hurting, heh.

In general, would this give me lots of low end/mid range and cost a little uptop? My low end/midrange feel very strong. Would retarding the intake help top-end?

I thought that retarding exhaust helped top-end.

Can anyone comment on the general effects of adjusting cam gears?

Thanks,

FB

 

Try this out Berkel
http://www.theoldone.com/archive/cam-gear-tuning.htm

 

Damn dude,

You rock! I had read stuff like this a long time ago, but I think any knowledge leaked out, heh.

Good stuff.

This makes sense as to why I have so much low end and mid range right now, since both cams are advanced quite a bit. I should probably back off the intake a little bit, and I'll probably get more top-end... IT's nice to have low end though...

Take care,

FB

 

to further confuse things: don't forget about the adjustment for the milled head.
in my case 0 is +2 and -4 is -2. ign. timing chicken scratches on the dist. are then off also - use a timing gun. if i remember right, you are milled 20 thousandths (vs. my 30 thousandths) - not sure what the correction is for that.

 

i can also tell you that advancing both gears as far as they go will give you more bottom end.
(I DON'T RECOMMEND THIS UNLESS YOU WANT ALL NEW VALVES, THOUGH )

 

HX_Guy: My STR gears are 1 mark/degree

 

Hey Go,

Wait a minute...

Now I'm lost again

You are correct that I am milled 20 thousandths. If you are milled 30 thousandths, and 0 = +2 for you, what does that mean for me? Anyone please comment on this.

I thought that milling the head retards everything, right?

Wouldn't that mean that I need to advance more than on an unmilled head?

Thanks,

FB

 

i know, it makes my brain hurt. i've drawn circles and arrows on paper trying to follow this ("which way is advance?!?! "). we need help, i don't understand it enuf to explain it.

-AEM

 

or is that for clockwise rotating engines????

 

well i am confused as hell...most people seem a +2 on the intake and a -1 on the exhaust is a good all around combo...is this correct??? and if so what should i do to the timing??? what about when i install my hondata unit at the end of the month???

 

ok, i totally screwed up i had it reversed...

the settings i got after among the 30 dyno pulls at the time were +2/-2 which is int/exh.

looking at my aem cam gears again they say:

intake advanced 2 notches (out of 10)
each mark = 2° crank so that's +2 plus advancing 2 to make up for the retarding caused by the milled head.

exhaust is at Ø
so that's -2 plus advancing 2 to make up for the retarding caused by the milled head.

ignition timing
now i'm not exactly sure what's going on here, but i'm beginning to think i'm set at 17 by gun which is 16 because of the milled head. i think i remember that if you advance your gears, you retard your ign tim and viceversa but don't quote me...(so i'm thinking you're advancing ign tim to make up for the ret. caused by the milled head...nothing is making sense...better stop)

moral of the story
don't mill your head

and yes, in general +2 int give or take 1 and -2 exh give or take 1 is a good place to start, from what many people say...

 

F***!!!! that doesn't even make sense. +2 does not = +2 (for me)
i think he set my gears wrong! damn, no wonder i was so confused
i think he should have done +4/0 which would be +2/-2

...

 

Well I'm at +3 MARKS and +1 MARK on Skunk gears. If the marks are each 2 degrees on the cam gear (4 at the crank??), then I'm at +6/+2. Since I'm milled, this should mean that I'm not that advanced, more like +4/0, which isn't as bad, right?

My ign timing on a gun was about 16 BTDC. Not sure if this is really 16 more or less.

I checked my plugs yesterday after a drive, and they look ok, except one may be showing signs of detonation (crack on electrode). I wonder if I'm too far advanced?

I think I will try to retard my intake to +3 degreees (+1.5 marks) and set exhaust to +1 (+.5 marks)...

If anyone has some definitive info that would be cool...

Thanks for raising the issues Go

Specifically, I'm still wondering how much milling the head increases compression, also compensations for milling the head with cam gears and ignition timing. Someone IM'd me about this so it would be helpful for others...

FB

 

Well, you can offset the milling of the head by setting the cams back to (0,0). Just put a 50mm punch through the alignment hole in the cam cap, into the hole in the cam. Then you'll have (0,0). From then on, you can adjust accordingly. I'd be worried about advancing too much, especially with Spec B's and a milled had. HTH, -C