Install straight up or advanced/retarded?

[turbov6joe]

What is the consensus when installing the Comp 212-212 112º LS cam, straight up or advanced/retarded?

 

[Russ Merritt]

Are you degreeing the cam, or just lining up the dots? If your lining up the dots, put it in straight up and forget about it.

 

[Chris McDade]

Hey Guys....What's up?

Don't the comp cams have 4 degrees built into them? I would do what Russ says....Maybe

 

[Russ Merritt]

Yea they do......If it's going to be a "big shot" motor he should degree it to know for sure where it is. If not, lining up the dots straight up will be fine.

The engine you sold me Chris couple years back is in my race car now. It has the 218/212 roller and I degreed it and had to retard it 2* to get it perfect.

 

[Chris McDade]

Im glad the block is working good for ya. Any times in the race car yet?

Maybe we will get to meet one of these days.

Later

 

[Blown&Injected]

Thought that 1* = about a 50 rpm movement in the power band. Hardly seems worth worrying about

 

[turbov6joe]

In motors past I made sure #1 was on it's compression stroke at TDC and lined up the dots....just testing the waters this go around to make sure some kind of new info has not surfaced in reference to advancing/retarding the 212-212 in the last year or so. I'm not sure what constitutes a "big shot" motor, but I'm hoping this combo will be worth 124-127 mph trap speeds. A few weeks ago I trapped 122 mph with the stock cam and heads on a pump/methanol state of tune. This go around I have fully ported heads and the 212 to add to the mess.....and to think I swore to myself I wouldn't mod this car past bolt ons! I'll tell ya one thing, knowing that I ran 122 mph with the flow numbers the stock TTA heads gave me leaves me with mucho confidence that this combo should really fly...we'll see, y'all know how that goes??? Later! BTW, Chris are you going to BG this year? Isn't it hard to believe that BG is less than 5 months away!

 

[getchasum]

Originally posted by Chris McDade
Hey Guys....What's up?

Don't the comp cams have 4 degrees built into them? I would do what Russ says....Maybe

I found 4* in my Crane also. I didn't feel good about retarding it 4*, but I did to get the center line correct. What I don't understand is why they come w/ 4* advance in them? WHY?

 

[wbrophy]

It's called chain stretch

 

[Russ Merritt]

"Big shot" meaning someone who's tryin to get every last bit of power available from the engine. Sounds to me that's exactly what your tryin to do. DEGREE IT! Lining up the dots really doesn't mean squat. You should be checking it. Not very hard to do and there won't be any what if's........ You'll be happy you did.

 

[chevyII]

I know some cricle track guys that used to assemble there engines then check cranking compression. They would change the timing to maximize the numbers,its alot easier with a dry timing belt though.

 

[MAX PSI]

I aways degree a new cam install. I use the intake centerline method. Just get the motor at TDC on #1 and set the cam at what ever the the cam card says that the centerline should be for #1 intake + or - .5 degrees. That way it takes into account if there are any mistakes in the timing chain and gears, cam or crank. Most of the time it will line up the factory dots. If you want to get fancy you can check the centerline on all the lobes to make sure the cam is ground correct. I usally don't.
When you advance or retard a cam you need almost to do back to back pulls/runs to compare the differances. Just because someone's setup preformed better 4 degrees advanced doesn't meen your combo will.
Most cam manufactures do add some advance in there cams. But if you installed per their cam card you wouldn't know the differance, unless you are comparing it to a stock cam. If you installed it with the dots lined up and found 4 degrees advanced and had to "retard" it to get the centerline right, you installed it straight up but had to correct for some differances in the timing chain/gears.
I hope this helps.

 

[Blown&Injected]

There is only one engine that I have had where I did three cams with no other changes and it seems hard to even tell the difference between the different performance cams let alone a degree here or there.

It seems a few degrees one way or the other is moving the power band - it does not appear to have an effect on max power, just moves it a small amount one way or the other.

The cam manufacturers say it is not necessary to degree the camshaft. The tool makers that pay the guys on Hot Rod TV say it is important, and subsequently the guys on TV say it must be done but you never hear for what reason, why, and what happens if it is off + or - X degrees - Oh yeah, it sure looks cool on the engine stand.

How does Advancing or Retarding the camshaft's position in the engine affect performance?

Advancing the cam will shift the basic RPM range downward. Four degrees of advance (from the original position) will cause the power range to start approximately 200 RPM sooner. Retarding it this same amount will move the power upward approximately 200 RPM. This can be helpful for tuning the power range to match your situation. If the correct cam has been selected for a particular application, installing it in the normal "straight up" position (per the opening and closing events at .050" lifter rise on the spec card) is the best starting point.
http://www.cranecams.com/?show=camQuestions



AN EXAMPLE USING AN RPM 300 CAM
Advanced Cam Position: If your intake happens to come out with .100 gap, and the exhaust with say .080 gap, your cam is in an advanced position. In this position, the came will produce more low-speed power or torque. However, there might be a slight loss of power at high RPM.
Retarded Cam Position: If, on the other hand, the intake came out with .080 gap, and the exhaust at .100, your cam is in a retarded position. In this position, there will be some loss in low-speed torque and power, and probably some subsequent gain in high-speed power.
Split Overlap: If the intake and exhaust gap read out exactly even, or within .005 of each other, you have a split overlap. Generally speaking, all racing cams run best in the split overlap position. While there are exceptions to this rule, it is usually best for overall performance.
http://www.iskycams.com/techinfo_index.html

 

[Chris McDade]

Hey Joe,
I know I can't believe it's only five months away. Yes, I will be going. You know I don't miss that trip. Im getting ready to pull the motor and go through it. So I will have a fresh rebuild for BG.
Im going to put a new 218/218 flat tappet in and refresh the heads. I might put new bearings in depending how they look.

Good luck on your new mods.

Later

 

[wakebdr2]

advancing the cam

hey guys, i was jsut wondering if advancing the cam did any good for these little engines. any feedback would be cool. thanks, -caleb

 

[Cheeseburger]

Degree your cam in..........i have had some perfect and some off.
Then test your car at the track and determine if you are happy with your power band.
After doing so, you can then make changes by advancing or retarding the cam if needed........at least thats the way i do it!