At The End Of My Rope

Jeff,

There are two versions of that cam.. 114 and 116 LC..

288-94 H and 288-96H..

I don't think the cam is the issue.


Borrow one?

Go to Harbor freight or a similar store.. they have lots of them cheap..

Here's an example..

http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=66541

Now, your not going to build the space shuttle with that tool, but it will get you a good idea..

I have two of these in the shop, a very expensive one, and a very cheap one.. and they read within a thousanth of each other. The inexpensive one is less accurate when measuring real large things, but at around 2", it's just fine.

JW

 

Thanks Jim. I borrowed one and should have the measurements tomorrow.

If they are within 2.060 - 2.090, then I assume I'm swapping cams?

 

DAYUM, Jim. I never noticed that before.

My cam is listed on the card as a 288-94H, but the specs are spot on 288-96H. I never took note of that before.

 

Jim is the 288-96H a FAST RAMP grind?

 

Jim,

With an adjustable valvetrain, why would the valve stem height not be corrected for by adjusting the valves?

 

PM me your address again and I will mail you a pair.

 

Thank you, Michael. My brother has a pair and I'll be getting them in the AM. I should have the tip heights measured by the afternoon.

 

Good question.

 

If the tips were high the valve train geometry would be off. possibly binding up briefly, very briefly, possibly causing the lifter to bottom out, therefore losing a **** ton of lift. the thicker oil would make it harded to bottom out the lifter, sorta proving the theory.

 

Would this result in a bent pushrod. In theory wouldn't something have to give?o No:

 

Nope, it would result in a valve not seating, in that context.

Still tying to get my head around this, and my brain is small and getting old.

Devon

 

Would the .030" deeper cup in the Chevy lifter affect valve train geometry?

 

Yup. Likely by requiring about .030" in additional push rod length, assuming that everything else was correct.

 

No, not on a fixed shaft design like ours. The only variable we have regarding valvetrain geometry is on the valve side, unless shimming the rocker shaft on the pedestal is a consideration. The pushrod side, long, short, what have you does not affect the rocker tip/valve tip interface.

Devon

 

I think the valve would still seat. the problem lies within the way the rocker seats against the valve tip, or the pushrod. picture in your mind the way the pushrod lifts the rocker. in a perfect scenario the push rod would push squarly against the rocker, but the rocker moves in an arc. if that valve stem height was too high, the start of the push would be too early in the arc; forcing the load on the pushrod from the inside of the tip to the outside of the tip. when it should be from the center to the outside only. hard to explain, but I have a visual in my mind.

 

Is it normal for my head to be hurtiing?? ou:

 

Yes, as does mine!

In the end, Yards gets help with a solution, we all learn from it it we're lucky!

Devon

 

Yards,are you sure on that .030",I checked some Crane and Comps stock spec'ed sbc lifters and they all came .050" deeper than my sbb lifters provided by TA.I believe the 350 and 455 Buick lifter specs are the same.

 

My problem is that I cannot remember a lot of stuff anymore. Mechanically, you're way ahead of the game as far a I'm concerned. I await news of your progress!!1:TU:

 

I smell a new set of Aluminum heads! :Brow: :TU:

And if your brother didn't have a set of calipers, I'd overnight you a pair as I have three sets.