Trouble degreeing my car

[Technology]

Sorry, in the title, I mean cam, not car. And the "Use full editor" feature doesn't work.

 

Alright, I got the measurement stuff all set up and when I had the dial indicator on the cam directly, I couldn't match any of the readings up to what the cam card was saying. Then I asked a guy I know who has done a few and he said measure at the valve. So I tried that, and am actually able to make numbers line up. Specifically the intake opening and closing degree measurements at .050" lift.

 

On the cam card, it says check clearance at .050" (at tappet). What does that mean?

 

Why would I get the correct numbers at the valve, and no where near correct at the cam, when every article on degreeing a cam says to measure from the lobe (using a solid tappet).

Edited September 10, 2010 by Technology

[StarquestRescue]

I used Indiana's lobe center line method. http://www.b2600turbo.com/degree_your_cam.htm

[hschwartz3]

i'll be watching this thread with some interest. like you, I couldn't get all get all my cam card numbers to work out either. No matter what valve lash setting. .001, .003, .006. I just gave up and used the centerline method john mentioned above. Works fine, just didn't have that warm and fuzzy feeling like i was expecting.

[Technology]

I tried calling schneider today, but it must have been too late on a friday (4:30 their time). I got my intake lobe centerline already, but what can I do with that? is that what you "degree the intake lobe" to? On my cam card it says degree intake lobe to 112. Do they mean the centerline? If so, then It's pretty dang close right now, .5 degrees off, but I need to be sure.

 

btw, there seems to be a comfortable clearance between the retainer and the valve stem seal. That's at .0000 clearance. So with .008 intake and .010 exhaust, it shouldn't be a problem at all.

[Richie_Rich]

When degreeing a OHC you need to go off the valve.

I use a magnet shaped like a half donut.

http://img149.imageshack.us/img149/4529/dscf0053pd9.th.jpg

I also use an indicator with a roller wheel to find TDC.

http://img150.imageshack.us/img150/9462/dscf0049tq0.th.jpghttp://img150.imageshack.us/img150/8196/dscf0047vz5.th.jpg

You can see the magnet in the pictures.

 

I adjust the rocker to zero lash.

With hydraulic rockers I took a lifter apart and put shims in it I made.

[Indiana]

Its because of the ratio of the rocker arm. If that isn't making any sense just ask. Set your lash to zero and see what duration you get and that's also on the card right? That should be the "advertised" duration. They have two sets of numbers right? Once you get the duration you can watch when the valve begins to open and when its closed and then you can just take the middle of those two degrees and its the same as the .050" lift numbers. They give you the .050" numbers because that's much easier to read your dial indicator at .050" and the degree at that point then when the valve appears to move by watching your needle on the indicator. Either way the result is the same. One is a double check for the other. Its not .050" from the highest lift its .050" lift meaning it only moved that much so at valve close your indicator can be set to zero after you find duration/lash for your particular head. This adjustment only works on your motor for that cam and that head etc you can't take that and use it on another motor later everyone is a little different. If the lash is not set to get the duration first that can change the degrees since the ramps might not be the same on either side. The valve might open quickly but close slowly so you need to get the duration first so you know that the open and close degrees you write down at .050" lift are correct. Divide the duration between the .050" degrees and that's the centerline you are at now. You adv. or retard to the number on the card for the centerline as the cam was made to have. If you have an adjustable cam gear now all you have to do is leave the cam at the centerline that's in between the .050" numbers you just found and just move using the cam gear bolt to what the centerline spec is on your card. Done. You can set your lash now where ever it is you want it but your duration will now actually decrease over what the advertised spec is since that's what a zero lash but that's not a point they always tell you about. This is another reason that OS valves are such a big improvement since they are thinner and even though they might open a few degrees later and close sooner there is more flow while they are open. If you don't get true TDC the very first thing then all these numbers are off. Remember turning always clockwise or the slack in the oil pump plunger will screw you up. You can take something and force that plunger out and hold it there it does help a bit since you don't have to back up so much before you reverse and go clockwise again.

[mtaylor530]

Where do I find the thread on the guy who re spec'd/blueprinted? his Shnieder cam and got 100 more hp?

[Technology]

Where do I go to stay on topic. Use the search mang.

[Indiana]

Putting in a reground cam and not doing it is making it worse than using an old stock cam. -and there's where you "gained power" but you really just did what you were supposed to and why would anyone know what the power was before and after? Someone just wasted dyno time.

 

So how's that coming along? One trick is that the longer the bar or handle you use to turn the crank the more fluid your movement is on the dial indicator when looking for that one degree or one more thousandth on the dial indicator. Its harder on a new tight motor that's not been ran too. I make sure the mount for the dial indicator is secure and if you roll the motor over several times make sure the indicator comes back to rest at the same reading every time. Don't let someone come by and bend your pointer wire, you get to start all over lol.

[Shelby]

in some cases degreeing a biger cam will get you more power thru part of your rpm range,, idealy you don't want a steep up ramp with hp at a narrow point in that peak,, you want a power band to jump up to say 3300 rpms and keep climbing to 7k rpms ,,now if you not going to high rev the engine you may want to shift that power band to t he left and down lower into the rpms range you will be runing at ,, to do that you'd advance the cam slightly to have it come on quicker , and retarding or makeing it later shifts the power band up higher into the rpms range

 

the amount of total power make in any of these positions may be the same but where it comes on will change how the car performs in a qt mile track

[Technology]

Yeah, I thank you guys for responding with positive input and suggestion, rather than speculation or guessing. I put the intake centerline at 112.5 degrees, and the cam card asks for 112 degrees, so I think that's close enough. It is slightly retarded from what would be a "straight up" installation (that's by just looking at the adjustable cam gear) and that makes sense because the head and block deck were cut down slightly. I am pretty confident that this is correct, because the cam card lists what degree the cam opens and closes at with a .050" reading on the dial indicator, and those readings were pretty much exactly where they were supposed to be on the degree wheel.

 

I didn't bother checking the exhaust because it's all on one cam and whatever it may be, there's no way to change it. So if the powerband is really crappy, I might try adjusting it slightly, but methinks it will be ok. I know a couple guys that have added tubular headers on their evo's and both gained 40whp. So at my power level, and with this new cam, I would bet good money I'd see close to the same gain.

 

Also, chiplee said he saw nearly 30 additional HP with the 292, so I expect somewhere near that, which would put me in the 420whp range. Add a header, and I'm at 460. Theoretically, of course.

[Komeuppance]

Did Chip ever degree his cam though...

 

Good jerb on the degreeing BTW.

 

-Robert

[Technology]

I thought he did after a while. I guess I'm not totally sure.

 

As far as difficulty, it's a 5-6 out of 10 for a decent garage mechanic. Someone who's built a motor shouldn't have any trouble putting it in with the engine in the car. And as long as the dial indicator is reading from the valve, it's pretty easy to make sense of it all. I will be posting up dyno charts as soon as I get it on there. I hope to fix up the exhaust first and route the wastegate into the downpipe before the dyno.

[Technology]

Well I started it up today. I need to reset the timing, but it runs fine. It cams now. That's well worth it.