Camshaft degree reasons
 

I know everyone recommends degreeing in your camshaft and I’m sure it’s good advice but most of the time it’s a check to verify and you move on. My question is how often is it off or not right? Then if it is, there doesn’t seem a lot of ways that you can correct the issue especially a Pontiac that doesn’t have that fancy aftermarket adjustable cam timing gear like the ones available for SBC.

So my point being that from what I can tell the majority of cams installed don’t require any corrective measure so are we blowing this operation out of proportion to actual issues? Please educate me because I’m having trouble understanding why a guy in their garage doing one cam install on his muscle car needs to go out and spend the time and money on degreeing a new cam vs just lining up dot to dot. Obviously if they choose to advance or retard cam timing using the typical aftermarket timing gear set with multiple key ways that’s something different.

I was under the impression that every cam shaft isn't ground correctly so when I built my engine and my cam degreed in perfectly I thought I made a mistake. Still, I consider it basic part of a proper engine rebuild. Just like all parts these days, it pays to verify.

My current Bullet was supposed to have 4 degrees advance ground in it did not exactly 4 degrees off! Same chain, gears that was right in for the previous Comp cam in it!

It’s SOP and not difficult to do. Cams and other parts can definitely be out of tolerance and you wouldn’t otherwise know. Plus the degree kit isn’t that expensive, and you’ll be the cool kid who knows how to do it.

Most cams will come in very close dot to dot. I can't remember if it was the last engine I built, or the one before that, that I had to throw in a couple of degrees more advance to get the recommended timing. It's worthy to check it, just so you are informed if the final build becomes turdish. Reference the recent 350 thread a month or two ago, where an engine build should have been fairly hot, yet fell flat. One of the first questions was "did you degree the cam?" If cam timing is only off by a degree or two, but then gets exacerbated later by chain stretch, it could become disappointing.

A mild driver build with an 066 cam or Summit 2800 could easily be stabbed dot to dot. But if you go through the trouble of carefully planning out performance parts, you might as well do those parts the honor of a degree wheel check. I've used a paper plate and a printable degree wheel from the internet to check cam timing. You'll learn a lot, and be satisfied you confirmed it.

Interesting. I just ordered a custom bullit cam. I currently have a Comp Hi Tec which was supposed to be +4 and when I went to degreed it, it was not +4 so its a good thing I checked instead of assuming. I'll be checking the new Bullit when I get it as well.

its kinda pricey but...if you have the stuff and u buy a random cam its nice being able to measure everything and have an idea what your working with
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also, not everyone runs a cam to the spec on the card. take the 290b i have on the shelf....its recommended to install at 106 icl.....more than one person told me they did better running it at 103 icl. bop belt drives and milodon have adjustable cam gears. some offset cam keys woukd be nice but it seams those dried up.

i put plenty of cams in dot to dot and did fine...i just now start playing with this aspect myself....smh...cost me 400 bucks to learn wth i was doing lol

I totally understand wanting to verify and check but you’d think that a custom cam that you had ground for your application is going to be on the money or running a basic off the shelf cam dot to dot would be good too.

What I’m questioning is that since offset keys and things to dial the cam in aren’t readily available how is it that degreeing a cam has become such an essential check, in other words what do you do when it’s off a few degrees? What’s the remedy? Doesn’t seem like you have a lot of options and I’d imagine if it was such a big the deal the aftermarket who is dying to take your money would offer a solution that to my knowledge doesn’t really exist on a Pontiac, so again my question remains, how much of a big deal is it in actual use vs internet stories?

Doesn’t matter, I’ll be doing mine and spending the $150 for a tool I’ll hardly ever use again just to verify but it’s almost pointless without the ability to use offset keys that aren’t readily available if at all. Sometimes I think we just blow these things up in our heads to become bigger issues than they actually are.

Good chains are in 2 deg increments. You can still find cam keys, its not that big a deal.

Do you feel lucky? It's not a matter of "how often", rather "how much is this going to affect me if it is messed-up?"

Not "out of proportion" considering the labor involved in diagnosing and correcting it later.

Consider the number of machining operations that ALL have to be correct to achieve advertised results.

1. Crankshaft keyway properly positioned in relation to #1/#2 crank throw
2. Keyway in crank sprocket properly positioned
3. Keyway or dowel properly positioned in cam gear
4. Keyway or dowel hole properly positioned in camshaft
5. Camshaft properly ground
6. Lifter bores properly located within the lifter bosses

Given the typical quality of aftermarket parts in Today's world, the timing set is questionable, the cam is questionable, and even block or crankshaft cannot be assumed to be correct.

https://www.summitracing.com/parts/mrg-987g

https://www.summitracing.com/parts/mrg-988g

Degree it no matter what. It's easy once you learn. It is a learning curve that we all go through. I have never had a cam come in spot on. It's always better to know for sure ..

Always degree any new cam.
And don’t just check ICL and call it good- like a lot of “experts” recommend is the most accurate.
That’s just BS- and verifies next to nothing.
You need to check & verify all the timing events on the cam card.

Case & point:
Just 2 weeks ago, I degreed a new Comp Cam for a new 469” Pontiac build.
Right off the bat, I found the individual valve timing events were all over the place- each varying from 6-13 degrees retarded.
The ICL when checked- came in 4 degrees retarded (installed dot-to-dot):

-If someone didn’t know any better, and just installed the cam “dot-to-dot”…
-If someone went one step further and thought degreeing the cam meant just verifying/correcting the ICL…

Fortunately, instead- this incorrectly ground cam with the funky lobes- was immediately removed, and sent back to the mfg.
The replacement cam was received & installed- and that grind when degreed came in perfect on the numbers- timing event numbers and ICL verified- installed “dot-to-dot”.

Worthy of note here, as mentioned & related to topic- this is the first Comp Cam of the last 4 engines I have built in the last 2 years- that actually came in on the numbers when installed “dot-to-dot”.
The last 3 required 2-4 degrees advance of the crank sprocket timing gear to come in.
I use Rollmaster Timing Sets.

A lot depends where you purchased the cam from. If it's a custom grind cam manufacturers grind the cam straight up, unless specified at to point of order.

One of the more popular "billet' timing chains is almost always off when installed dot-to-dot.

2 & 4 degree keys are readily available, although they're actually closer to 5 & 8.

Timing chain sets offering three offsets, +4 , straight up, -4 are usually eight degrees each.


Back in the day magazines made a big deal about advancing and retarding camshafts for improved performance. Most of them recommended advancing high performance street camshafts four degrees. They seldom mentioned that almost all aftermarket shelf grinds had four degrees of advance ground into them. They never mentioned the "four degree" slots was actually eight. So the trend was to install the cam that already has four degrees of advance and advance it another eight by using the four degree advance slot and then wonder why the car ran like poop.

The old normal when hardly any custom cams had advance ground into them was to use a 2° offset key to retard the cam and the 4° advance slot on the timing chain, you'd end up with three degrees of advance.

All the above was figured out with a degree wheel.

All the years I been doing it, they are never exactly right out of the box.

It's not just the cam, nevermind the cam specs possibly being off, you also degree for other reasons. All the key ways on the crank, on the cam sprocket, on the crank sprocket, on the cam itself all are built with a tolerance that isn't exact and all those tolerances stack up.

All it takes is a keyway to be off a degree here, a degree there, and next thing you know you think you've lined up your dots not knowing the cam is off 2-3 or 5 degrees in one direction or the other.
Will it run ok? Sure. But not optimum.
I've seen them off as much as 6-7 degrees and I remember an engine builder telling me he's seen even more.

So it's always best to check to make sure the basics are set. Then if you want to get fancy and check intake to exhaust lobe relationship on overlap and move things around to really dial things in.

I look at it as peace of mind. I’ve had a few cams that were way off. Had to actually send one back. It might run ok if it’s a few degrees installed one way or the other but I don’t want to leave any power on the table because I didn’t have it checked to make sure the ICL is at 108 like intended. If you got a cam that degrees into spec and you got to have the timing gears dot to dot then you got a good one. .

In my engine class we degree 12-16 camshafts a year. I have a data pool of about 30 years worth, all kinds of engines. These are approximate results from all those engines. About 1 out of 10 engines are within 1 degree of perfect. +- 1/2 degree. About 6 out of 10 are within 2 degrees. +-1 degree. about 2 out of 10 are within 4 degrees. +- 2 degrees. About 1 out of 10 is off more than that. The worst Pontiac engine I have degreed was out 14 degrees. It was all in the timing set. This was over 20 years ago and it was a cheap "Wolverine" timing set. No idea if they are still around. I tried it several times and after giving up in frustration, I installed a used timing set I had laying around as a test. It came in within a degree or two. So the keyways in the "Wolverine set" were off by a bunch. That was a real outlier.
As far as effects: In a street Pontiac engine 400-500 HP, I doubt most people would notice a 1 or 2 degree variation in cam timing. Engine may be a little soft at lower RPM's if retarded 2 degrees. People with a well calibrated "butt dyno", would probably feel a slight difference at 4 degrees. So is the process absolutely necessary? Not really.

But it is part of doing a really nice engine assembly. Part of "blueprinting" an engine. As part of the process, most engine builders verify the opening and closing points of the intake and exhaust valves and the lobe lift. Along with setting the intake centerline right where the cam grinder expects it to be. More peace of mind for the best finished product.

To accurately determine correct install. When the cam is advanced it pumps up cylinder pressure and moves the power curve down, when the cam is retarded the opposite happens. If a cam is bought to be installed at whatever ever recommened centerline..that is what you want. Its when one installs a cam that for some reason is way advanced or retarded loss of power or engine damage can happen.

That's a great idea, I would have never thought to do that.

I had a Summit 2801 come in right on dot to dot!

That would also say you had a timing set and a crankshaft that had keyways that were on spec.

All it takes is one or more of any one of them to be off a hair and it throws the whole mess out of whack.

Most recent summit cam I did was a 1223 roller. Used a nice cloyes 9 keyway timing set. The rotating assembly was an eagle crank. So everything was aftermarket.
The cam lsa is 110 and cam card wanted to see a 108 icl with the timing set dot to dot. Meaning the cam has 2 degrees advance ground in

I checked it and it was 107.5. I was pretty pleased all that aftermarket stuff was basically spot on. So it's not all bad out there. Ive had factory stuff much worse lol