Why Degree A Cam Shaft?

[Immortality]

Recently in a thread there was a lot of debate about the need to degree a cam shaft when doing a simple cam swap. Our esteemed LS expert said there was no need.

Yea but if you're an engine shop these things don't take very long as they have guys that do different things.
It all depends on how much work is going to be done. For a street car with a cam a lot of the things you mentioned aren't worth dooing. Like degreeing a cam like who does that on a cam swap and tune for a street car?

Well here is great proof that you should always degree your cam shaft. In this case we have a VCM cam, a reputable supplier of many a cam found in Commodores these days. When the cam was installed straight up it was found to be off. They ended up going +4° to get the intake valve lift at TDC correct as per the cam card provided (video time indexed at the start of the cam timing segment).

Degree your cam shafts people, and if it's been done at a shop ask if they will degree the cam!

edit: I'm not saying the problem with this cam install lies with the cam, as the engine builder explains in the video, there are many area's where the error could have occurred. The point is to check/verify and remedy.

 

[shane_3800]

You miss represent my point.
My point was it's pointless if you can't adjust the cam and if you can you should be adjusting the cam on the dyno to tune the power curve in.

 

[Immortality]

Buy a adjustable timing set

Degree the cam when you install it, the manufacturers know something about cam timing....

If you have to do it with the car on the dyno it costs a lot more time/money and then you still need an adjustable timing set.

 

[shane_3800]

Buy a adjustable timing set

Degree the cam when you install it, the manufacturers know something about cam timing....

If you have to do it with the car on the dyno it costs a lot more time/money and then you still need an adjustable timing set.

Yes but the whole point behind adjustable timing sets is to tailor the power curve.
Back in the 70's NASCAR teams used off set bushes to change cam timing (now the cam gears are adjustable). NASCAR teams retard the cams for top end power on tracks with longer straights and broader corners then on smaller tracks they will advance the cam timing for low end torque.

There's no set point a cam has to be this is why you have the adjuster there on aftermarket gears. If you are only ever going to rev your car past 5000rpm once a year there's no point having your cam at zero you may aswell advance it a degree or two.

And with dyno costs if you're building a performance engine you should be, well you will be on the dyno any way.

 

[Immortality]

LOL.

Your quote was about street car cam swaps. Not race car builds that are tuned on engine dyno's.

The cam in the video above was retarded 4° when installed straight up which for a street car would have made it lazy and exactly the reason you check your cam timing when installing a new cam shaft!

 

[shane_3800]

So now I'm at home and I watched the video.
I have several thoughts about this subject.

Firstly is a cam is 4 deg out off centreline I would be hesitant to call that cam company reputable at the least because if they get the centreline so far off on the cam grinder how can you be sure all the lobes are even on the correct centerlines. The degree process showen only checks one cylinder, the guy that started SAM (School of Automotive Machinists) states that you should degree all four corner cylinders this way you can check cam specs are good but at the same time check uf the block is straight.
But if a cam is 4 deg out off zero how much confidence can you have in that cam being correct on every lobe, so do you degree every lobe? Of course not.
I'll show you a video of the correct tool for the job of cam checking.

In that video he uses a cam checker but you don't even need one of those fancy machines as you can do it on V-blocks with a dial gague.

I've been able to degree a cam for about 15 years it's not rocket science but I find too many people seem to act like it's the be all and end all and if you don't do it you don't know what you're doing. But yet these same people don't understand why you do it, they just play monkey see monkey do and pretend they're a good engine builder.
Like I said in the other thread I have a deep understanding on why and how cams should be degreed but that knowledge also gives me the ability to understand how to do it the other way.
Too many times people fall into the old dog no new trick phase and totally dismiss another way of doing things, but I'm happy if people do because that only leaves me with more room to move ahead.

I'll leave this video here that shows how to actually use a deck bridge.

Oh and BTW that is Keith Dorton who is one of the top 10 engine builders in the US. Tony Bischoff and Darin Morgan make the top two and both work at BES.

Oh and if you don't know BES.

That engine makes 1.63ftlb per cube the maximum is 1.67ftlb per cube it's volumetrically impossible to surpass that which is the max of 124% VE. Go find an engine that does more than that and get back to me.

 

[Immortality]

You can obfuscate all you like but you are wrong. As stated earlier, it is impossible to know where the error was, maybe it was the key way in the crank, maybe the pin location on the cam.

He used nothing fancy to degree the cam and he does it as every good engine builder would.

The fact you think you are an expert is the joke, the only deep understanding you have is posting youtube videos from your hero Richard Holdner. You made a comment about not bothering to degree in a cam for a simple street car cam and tune job, now you start posting **** about high spec race engines with external belt drive timing system with vernier adjustments that have exactly nothing in common with your average street car.

So you are such an expert that you can degree a cam by simply putting the cam in the car with a standard non adjustable timing chain and knowing it's spot on..... The joke is on you!

BTW, what shop do you work at? Just so I know where to not send people when they ask!

 

[shane_3800]

You can obfuscate all you like but you are wrong. As stated earlier, it is impossible to know where the error was, maybe it was the key way in the crank, maybe the pin location on the cam.

He used nothing fancy to degree the cam and he does it as every good engine builder would.

The fact you think you are an expert is the joke, the only deep understanding you have is posting youtube videos from your hero Richard Holdner. You made a comment about not bothering to degree in a cam for a simple street car cam and tune job, now you start posting **** about high spec race engines with external belt drive timing system with vernier adjustments that have exactly nothing in common with your average street car.

So you are such an expert that you can degree a cam by simply putting the cam in the car with a standard non adjustable timing chain and knowing it's spot on..... The joke is on you!

BTW, what shop do you work at? Just so I know where to not send people when they ask!

Again you fail to comprehend what I'm trying to say.
For a street car you don't really need to degree a cam because you can adjust it on the dyno to suit your desire.
In a race shop you degree the cam purely for records and reference so when you start adjusting you can record what works on the day at the track.

You have a shot at me about posting videos yet you started this thread with a video.
And on that note here's some more you wont watch yet project you know what you're talking about.

 

[shane_3800]

Also every Comp Cam I've seen degreed is spot on. VCM obviously have either poor machinery or poor qualitt control to let a cam out the door 4 deg out. And like I said does that inspire confidence that every lobe will be aligned?

Do you recomended every engine built to have every lobe degreed?

 

[vc commodore]

Also every Comp Cam I've seen degreed is spot on. VCM obviously have either poor machinery or poor qualitt control to let a cam out the door 4 deg out. And like I said does that inspire confidence that every lobe will be aligned?

Do you recomended every engine built to have every lobe degreed?

So how would you pick a cam being 4 degrees out, if you didn't degree it? Very few street car engines hit a dyno


Oh and stop comparing race car engines with street car engines...You don't have an engine screaming at 7,000+RPM driving down to the local shops everyday...