Cam, TC question (s)

[Mark Barnes]

Now that I'm getting my motor assembled, I have to ask this question (or two).
When installing the cam, what influences the decision to install it with "X" advance? I read that guys install them with 2 or 4 degrees advance and wondered how they come up with a specific number. In my case, my cam is claimed to have 4 deg. advance "ground in". Might it still be necessary to add advance at install?
Question 2- the torque convertor I have on hand is rated at 2400 stall, flashing to 2800. Cam power band is 3000- 6000, with 6500 redline. A couple TC manufacturers have called for a 3000 stall convertor, so at the end of the day, can I still use my existing convertor without losing any benefit on the low end? Will adding advance at cam install help the power band and TC kind of "meet in the middle"?
Been 40 years since I've put a motor together, much has changed. Thanks.
** Just intended to be a decent street car. **

 

[PurpleBeeper]

I'm not an expert, but this is my understanding:
1. I've always installed cams "straight up" (zero advance/retard). In general, advanced makes the car quicker off the line drag racing and retarded gives it more top end power. If you go too far one way or the other, pistons start hitting valves...no bueno.
2. TC - I'm not sure. What is your goal for this car? From what I've read, what's really important is the "K-factor" of the torque converter. The "rpms" listed for most converters are just arbitrary and used for comparison. My "gut instinct" is your converter is about right for a quick street car.

 

[IQ52]

I'm not an expert, but this is my understanding:
1. I've always installed cams "straight up" (zero advance/retard). In general, advanced makes the car quicker off the line drag racing and retarded gives it more top end power. If you go too far one way or the other, pistons start hitting valves...no bueno.

So that we're all clear on what you mean by 'straight up'....If a cam has a 110 LSA and is ground with 4 degrees advance do you time the cam dot-to-dot........or rather, where would you set the intake centerline (ICL), at 106 or 110?

 

[67belvedere/225]

I would defiantly check the cam once installed , there are many videos on how to check cam timing
and it s nice to know where your cams is , because if you don't like where you power is you can know what to do , advance or retard or torque converter . I juts installed my cam and used a the of set bushing to do it. its got 3 degrease advance . the easiest way is to do camshaft centre line . But defiantly do it

 

[67belvedere/225]

I bought a spare engine and came with a new cam, I called up the cam grinder and recommended 2200
stall. I had the tc set @ 2400 , April first she coming out . c ant wait to see how she performs

 

[Mark Barnes]

So that we're all clear on what you mean by 'straight up'....If a cam has a 110 LSA and is ground with 4 degrees advance do you time the cam dot-to-dot........or rather, where would you set the intake centerline (ICL), at 106 or 110?

I sure would like to know the answer to that one...

 

[beanhead]

I sure would like to know the answer to that one...

'Straight up' means the Lobe Separation Angle(built into the cam and unchangeable) and Installed Centerline(you can change this one) are the same number, regardless of where the dots are on the timing set. Degreeing the cam makes sure the installed position matches the timing events on the card, which is the recommended timing. The card would say something like "These specs are for cam installed @ 106 intake centerline". So get that cam's IC to 106, and wherever the timing set dots may fall to get there, so be it.
In other words the dots on the sprockets don't mean jacksquat, even though many refer to dot-to-dot as 'straight up', they're just a starting point. 'Straight up' is LSA = IC, and if a 110 LSA cam is installed at an IC of 106, it's installed 4 degrees advanced regardless of where the dots are or if advance was "ground-in".

To get the torque converter matched well, figure in the cam duration, weight, rear gearing, and rear tire size. I don't know what cam you have but if the power band is rated at 3000-6000 (those ratings don't mean much) I'd think your converter isn't the best match but if you're just cruising with some occasional street-stomping it will probably be fine. It really is amazing what the 'right' converter will do though...it's probably one of the best bang-for-the-buck upgrades you can do. If you really want to get it 'right' call some of the converter shops with all your specs and see what they suggest.