Camshaft Info for 1932 900 Light Eight

[petri]

Does anyone have any camshaft infiormation on this engine? I presume it's not much different than any other year this engine was used. I would like to know max cam lift and a cam lobe profile if one is available. This cam is supposed operate Inlet Open at 20 deg BTDC and Exhaust Closed at 20 deg ATDC. That's 40 deg of overlap. Has anyone measured this and or been able to set up their cam to these specs? Any experts know how wear effects these numbers?

thanks

Howard

[Owen_Dyneto]

Hollander's shows all 319 cubic inch engines 34 thru 39 as interchanging, though that doesn't mean the grind was the same for all years of the 319 engine, and perhaps you should just consult the parts books to see what was identical. For example 33 and 34 Std. 8 cams had different part numbers and different profiles. As to the maximum lift, you could just measure it. As to profile perhaps you could buy a copy of the engineering drawing from the Studebaker Museum if it still exists.

[petri]

Thanks for the response Owen Dyneto.

I just rebuilt my engine and I was interested in these numbers because I tried to check the IO and ExC timing which is marked on the 32 Light Eight Damper. They were quite a bit off, 10 deg or more each. I gave this some thought and even measured and plotted a profile of the cam lift. Then I thought about this for a while and came to the conclusion that very little cam wear goes a long way at the leading and trailing edge of the cam profile. In fact, I measured maybe .004" of wear on the lobe, not very much. But while .004" doesn't make much difference in max cam lift or time of occurence, .004" is at least 8-10 deg of angular rotation at the profile ends. The profile is rising so slowly in this region that it takes a lot of angular rotation to get any lift. And of course the cam is turning at half the crank speed.

I also found out that at least one cam regrinder who will put new lobes on your cam doesn't have the patterns for this cam. They will look at the profile, compare it to others that are similar, maybe a Ford or Chevy or Locomobile, whatever, and just reproduce that for you. I guess that gets a car up and running but it sure wouldn't get it back on the numbers.

In any case I understand my measurements and have concluded that a little wera is all that is necessary to quickly lose the valve overlap but it doesn't seem to effect the engine operation at all. I guess these old low rpm engines are pretty forgiving of these kinds of problems.

Howard

[Rusty_OToole]

Are you allowing for clearance ramps? Solid lifter cams have clearance ramps that take up the valve clearance very slowly before pushing the valve open. This is to control valve noise.

This means accurate valve clearance is critical for checking duration. And the clearance used for checking cam action is not necessarily the same as the recommended running clearance.

[petri]

I set the #1 cyl valves to a tight .004, probably .003 cold. Seems pretty tight to me.

Howard