The V8 Owners Forum -

Ian Anderson wrote:How can 1 "woodruff" key slot equate to 2 degrees?
To my eye each "slot" would be approximately 25 degrees apart.

At 2 to 1 ratio to the cam that would equate to 12.5 degrees out

I'm probably missing something but from the picture I cannot see anything like a 2 degree adjustment

Ian

If you take off the crank pulley (e.g. at 0degrees) and slide it back on at at 2 degrees, the crank woodruff key will go into a different slot. So you're not turning the crankshaft by much at all (2 degrees in fact) to get the chain teeth to line up.

What you are NOT doing is rotating the crankshaft by 20degrees to get the 2 degree reading to line up.

Hard to explain!

Chris.

Looking at your photo the crank is 2degs retarded which is actually 1deg cam retard which would give slightly more top end hp.

If you lined up the key way at -2 and the outer row to 0 then that would give you massive changes in timing (2 teeth!) as your sugesting but the outer row is also lined up at -2 so its only the relationship difference between the keyway and the coresponding tooth that changes by 2 degs at a time, which again is only 1deg of cam change.

http://www.cloyes.com/LinkClick.aspx?fi ... uage=en-US

Tom.

Thanks guys I think that makes sense.

But at first sight I thought it was the 20 degree touch

Ian

SuperV8 wrote:Looking at your photo the crank is 2degs retarded which is actually 1deg cam retard which would give slightly more top end hp.

If you lined up the key way at -2 and the outer row to 0 then that would give you massive changes in timing (2 teeth!) as your sugesting but the outer row is also lined up at -2 so its only the relationship difference between the keyway and the coresponding tooth that changes by 2 degs at a time, which again is only 1deg of cam change.

http://www.cloyes.com/LinkClick.aspx?fi ... uage=en-US

Tom.

Tom,
Is it possible that when it's set up using the 2 degree mark, the cam get 2 degrees of advance. ie, the crank sprocket keyway offset is actually set at 4 degrees during manufacture.



Denis

Is it possible that when it's set up using the 2 degree mark, the cam get 2 degrees of advance. ie, the crank sprocket keyway offset is actually set at 4 degrees during manufacture.

Dennis,
not sure I understand your question? Are you saying if you set the cam timing to 2degs advanced then the crank timing should be at 4degs?

The info I had was from Cloyes own website and they stated in bold:

"Remember: 2° crank advance is 1° cam advance"

Tom.

The above may be true. But we dont measure cam angle, we measure everything in relation to crank angle.

Tom.
What I mean is that the marks and numbers on the crank sprocket may be set by the manufacturers so that if you use a particular mark, this gives that amount of cam advance or retard.
So if you use the 2 degree advance mark on the sprocket, the manufacturers have set it so that you actually get 2 degrees cam advance.
My Edelbrock chain set is marked so that which ever mark you use, that automatically gives that amount of cam advance/retard.

Cloyes may have a different approach.

Denis

Aha ok I understand.

And don't know,

The only way will be to check with the manufacturer of the timing chain set.

Tom.

DEVONMAN wrote:Tom.
What I mean is that the marks and numbers on the crank sprocket may be set by the manufacturers so that if you use a particular mark, this gives that amount of cam advance or retard.
So if you use the 2 degree advance mark on the sprocket, the manufacturers have set it so that you actually get 2 degrees cam advance.
My Edelbrock chain set is marked so that which ever mark you use, that automatically gives that amount of cam advance/retard.

Cloyes may have a different approach.

Denis

Doesnt matter what way it's marked. It's always degrees of crankshaft rotation no matter what you call it.

You dont degree or time a cam in with a 360 wheel fitted to the camshaft.

stevieturbo wrote:

DEVONMAN wrote:Tom.
What I mean is that the marks and numbers on the crank sprocket may be set by the manufacturers so that if you use a particular mark, this gives that amount of cam advance or retard.
So if you use the 2 degree advance mark on the sprocket, the manufacturers have set it so that you actually get 2 degrees cam advance.
My Edelbrock chain set is marked so that which ever mark you use, that automatically gives that amount of cam advance/retard.

Cloyes may have a different approach.

Denis

Doesnt matter what way it's marked. It's always degrees of crankshaft rotation no matter what you call it.

You dont degree or time a cam in with a 360 wheel fitted to the camshaft.

Understood, but the point under discussion here is what do the marks on the sprocket really mean.
For instance, if you use the -2 marks, does if give 2 degrees cam retard, or does it give 1 degree cam retard?

Most guys haven't got an adjustable cam sprocket and will be guided only by the manufacturers marks on the chain set.

Denis

DEVONMAN wrote:

stevieturbo wrote:

DEVONMAN wrote:Tom.
What I mean is that the marks and numbers on the crank sprocket may be set by the manufacturers so that if you use a particular mark, this gives that amount of cam advance or retard.
So if you use the 2 degree advance mark on the sprocket, the manufacturers have set it so that you actually get 2 degrees cam advance.
My Edelbrock chain set is marked so that which ever mark you use, that automatically gives that amount of cam advance/retard.

Cloyes may have a different approach.

Denis

Doesnt matter what way it's marked. It's always degrees of crankshaft rotation no matter what you call it.

You dont degree or time a cam in with a 360 wheel fitted to the camshaft.

Understood, but the point under discussion here is what do the marks on the sprocket really mean.
For instance, if you use the -2 marks, does if give 2 degrees cam retard, or does it give 1 degree cam retard?

Most guys haven't got an adjustable cam sprocket and will be guided only by the manufacturers marks on the chain set.

Denis

And again, the answer is there is no such thing as cam advance or retard. You may swing the cam either way and yes that is how it is termed, but it is always actual crank degrees it refers to.

It's no different from setting ignition timing with a timing light. You may swing the dizzy, which runs at camshaft speed. But any changes are always in crank degrees and measured at the crank.

Trying to imply you are changing camshaft degrees would only confuse things no end

Time for an update as we finally got some garage time last night.
Max lift was seen at about 107' ATDC - the card states 104' for this cam. I assume thats an acceptable reading?

Compression measured as follows:
1 200, 2 200, 3 190, 4 190, 5 180, 6 175, 7 170, 8 180

So then started taking some more logs in and out of the problem area, this time running back on the dizzy. It quickly became apparent i have a trigger problem: (yellow trace is the RPM value)


Keeping the revs below the problem area it looks like this: (i.e. its smooth and good)



Here's the toothlog when its running ok:



And the tooth log in the problem area:

What i see, is the graph goes down and the spikes become higher and eratic.
The question is what problem is this?
I tried turning R56 3 turns clockwise, with no difference. I stopped at that point as it was getting late.

I dont understand how people use that log viewer. There is no information on the screen other than coloured lines ?

And those bright blue ones hurt my eyes !!

I cannot read black/light screens at all

stevieturbo wrote:I dont understand how people use that log viewer. There is no information on the screen other than coloured lines ?

And those bright blue ones hurt my eyes !!

I cannot read black/light screens at all

When you save a screen shot, it doesn't show the outer parts that shows what you are looking at. Yellow line is the RPM signal - which you can see is all over the place when its not happy.

The tooth logger - well who knows, thats why i'm posting over at the MS forums, as the old boys will know what it all means.

Are you getting sync errors?
In megalog viewer in the list of options to display (like rpm/map/tps etc) there are a couple of options to display sync errors count and sync error reason code.
What do these display?

Tom.