I just bought one of your 401A3 cams for my 355 and was wondering how to degree it in. SHould i do it straight up or advanced or how do you suggest? ITs just a mild street car.

thanks,

Lucky3,

That cam is ground with 4° advance in it, so you can put it in 'dot-to-dot'. However, at that point, before you re-install your manifold, turn the crank until #1 cylinder is in split-overlap position. Your #6 cylinder will have both valve closed. Of course this is at TDC, for both cylinders.
I just use a 6" Machinist's steel rule, and check the relative lifter heights out of the lifter bores on #1. The intake lifter should be about .030" higher than the exhaust, with an OK range being .025" to .040". If the intake is anywhere in this range, your engine will run good. If the exhaust valve is the same height or higher than the intake, the cam needs to be advanced, either by a bushing, or even by advancing a whole tooth. It just depends how far off it is. And this does not mean the cam was ground wrong, but that all the clearances involved have stacked up the wrong way. As long as you get the intake lobe in the 'sweet zone', the engine will work as promised......

UDHarold

I just use a 6" Machinist's steel rule, and check the relative lifter heights out of the lifter bores on #1. The intake lifter should be about .030" higher than the exhaust, with an OK range being .025" to .040". If the intake is anywhere in this range, your engine will run good.Harold... does this rule of thumb hold true for other cams, or is this unique to the grind being discussed?

Originally posted by novadude:
</font><blockquote>quote:</font><hr />I just use a 6" Machinist's steel rule, and check the relative lifter heights out of the lifter bores on #1. The intake lifter should be about .030" higher than the exhaust, with an OK range being .025" to .040". If the intake is anywhere in this range, your engine will run good.Harold... does this rule of thumb hold true for other cams, or is this unique to the grind being discussed? </font>[/QUOTE]=
It works with any cam that is designed to be run advanced which covers about 99% of the cams you will be involved with. ;)
It is not what I would do with a race engine where I want to know exactly where the ICL is (at least where it is when the engine is not running :D ) but when all you need to know is that the cam is advanced about 4 to 6 degrees this works very well.
It is also a very good "double check" to be sure you didn't screw up when degreeing the cam ;)

Mike... when you say ANY cam that is designed to be ~4 deg advanced, are you talking single pattern only, or does this trick work with dual pattern cams too? It would seem that asymmetrical cams, or cams with more exhaust duration would throw off this relationship, no?

:confused: Maybe my thinking is wrong.

Originally posted by novadude:
Mike... when you say ANY cam that is designed to be ~4 deg advanced, are you talking single pattern only, or does this trick work with dual pattern cams too? It would seem that asymmetrical cams, or cams with more exhaust duration would throw off this relationship, no?

:confused: Maybe my thinking is wrong. =

Any cam.
Doesn't make any difference if it's got big words behind the lobes :D
The basic opening & closing relationships are the same regarding advanced or retarded cam position when checking this way.
If the cam is advanced the intake will be further open & the exhaust further closed.
If you move one lobe you are effecting the whole cam in regards to "cam advance"
If you take a 110 separation cam that is advanced 4 degrees the intake lobe is at 106. If you now retard the exhaust lobe 4 degrees so the lobes have a separation of 106, the cam is no longer advanced, it is straight up. To get back to 4 degrees advance you would need to move the intake lobe to 102 degrees,, again advanced.
There can be a slight difference in height because of lobe design but it will not be .030", more like a few thou.

Confused yet :D