texasthrottle

iTrader: (1)

stumbled across this on Flowtech inductions site. such a simple thing that can have an effect on so much performance.....

“I installed it dot to dot.”

This is one of the most popular comments I hear after less than ideal results are seen when a camshaft installation is completed. Just the mentioning of this sends chills down my spine.

The proper installation of a camshaft and its peripheral valvetrain is one of the most important jobs an installer must do when maximizing the performance of any engine combination. Any short cuts or miscues in this regard, and the overall success of the project, and its ultimate performance, will definitely suffer.

How can something so simple be so problematic?

Let’s start with the basic premise that everyone can have a bad day at work. Who’s to say the crankshaft keyway was machined absolutely “dead on” when the machinist set it up? I mean, even a slight error of a degree or two is no big deal considering the thousands and thousands of engines out in the world. They run, don't they? Maybe it wasn’t even a bad day but something that is machined off the mean number but still within manufacturing tolerances. What's a degree or two among friends?

Now we have the next piece of the tolerance puzzle, the timing set. There are a series of variables that can occur with this component. The relationship of the keyway to the crankshaft sprocket teeth, the location of the cam dowel hole to the cam sprocket teeth and then there’s always the possibility of “both” items being off. Why worry? Well, if each facet is off in the same direction, it is a cumulative error that will change the engine's dynamics. That's why verifying the intake centerline as it relates to top dead center is very important.

When you're installing these two pieces to the engine, who’s to say they are so perfect, there’s no reason to check them?

topher455

iTrader: (6)

I cannot find any flaw in that logic. Paying attention to details is, as always, CRITICAL.

The Alchemist

iTrader: (19)

The only caviat to that is you need an adjustable timing gear because if it's off by say 2 degrees, one tooth on the timing gear isn't going to give you that difference. What the difference is with one tooth difference, I don't know, but unless you have adjsutable timing gears, which I thought I saw a vendor selling recently, dot-to-dot is as best as you're going to get.

topher455

iTrader: (6)

Or an adjustable set with multiple keyways like the rollmaster. At least if you degreed it you would know it is right. If it is out then you would have to get a different gear or timing set. Im all for the peace of mind.

The Alchemist

iTrader: (19)

I totally agree with you, but I just don't want people to think that they can degree their cam with stock timing gears/chain.

PREDATOR-Z

Sure they can but they would have a hard time to adjust
(they can verify dot to dot readings on degree wheel Vs cam card)

topher455

iTrader: (6)

Sure you can... Just not to the degree you want. LOL

Damian

iTrader: (89)

You can degree cams on a stock timing set, it's just not 100% accurate. I've done it before and gotten it pretty damn close.

topher455

iTrader: (6)

Thats what I was saying. It never winds up being dead nuts on.

sandking

iTrader: (7)

Would'nt this apply more to custom grind cams? Are the "Off the shelf" cams off to the point where they need to be checked? I know for piece of mind, but has anybody seen a shelf cam wrong? I am not sure, thats why I am asking, dont flame me

slow trap

iTrader: (22)

the CUSTOM grind cams are the same as the shelf grinds,i mean as in ground on the same machines.just slightly different in most cases by maybe on a tighter lsa,mixed lobes or other minor things but they are ground by the same people,which is probably a majority by comp cams in memphis.

topher455

iTrader: (6)

There was a thread a few days ago where a bunch of guys said their cams were off. Some were off the shelf some were custom. It shouldnt really matter whether they are off the shelf or custom since most cams aren't ground in house anyway.

allbaugh_04

iTrader: (6)

What about "doctoring" a cam, doesn't that somewhat eliminate the chance of the grind being off?

PREDATOR-Z

No, that just tells you how it is cut.

The Alchemist

iTrader: (19)

Okay, so lets say the cam is off by 1-2 degrees, with the stock timing gears how would you correct that? From what I understood, if you go one tooth in either direction, it would be quite a bit more than the 1-2 degrees that the cam was out.

I'm asking because I'd like to know the answer myself. My tr224 is installed dot-to-dot just like everyone else does. Certainly the next cam that gets installed will go in with an adjustable set of timing gears so that everything is 100% spot on.

topher455

iTrader: (6)

Since the cam moves at 1/2 the speed of the crank you can index (the stock set) fairly easily. It just takes more time and wont give exact results. Look at the crank sprocket of a crank keyway adjustable set and you'll see what I mean. Its just hard to wrap your head around.

http://store.summitracing.com/largei...le-55000_w.jpg

texasthrottle

iTrader: (1)

the cam isn't the only thing were looking at....we're looking at the cam in relation to everything else that's spinning with it.