[P@blo]

https://www.summitracing.com/parts/cca-31-1000

Click the "instructions" link. Not sure what to say as I was just relaying manufacturer's installation instructions. To me this did not make sense from what I read other guys posting.

Dog bones do not move if they do comp says wrong cam base circle is all I know thus far but could be on the wrong track.

[shermanator2]

Originally Posted by P@blo

https://www.summitracing.com/parts/cca-31-1000

Click the "instructions" link. Not sure what to say as I was just relaying manufacturer's installation instructions. To me this did not make sense from what I read other guys posting.

Dog bones do not move if they do comp says wrong cam base circle is all I know thus far but could be on the wrong track.

OK, I guess Comp Cams really means Compromised Cams then. Maybe they do this to lock people into buying a cam that only they make. Maybe they can pull this off with Ford people, but I hope that Pontiac people are smarter.

With a properly designed dog bone or a properly designed lifter, they could use a properly designed cam with faster ramps and/or less lifter side loading.

It is also interesting that the dog bones that 69HotBird posted pictures of are not the same as what is shown in these instructions. I thought those were from this kit, but maybe I misunderstood.

[P@blo]

It could be that the instructions are for a different engine and that the lifter would drop too low in the lifter bore on certain smaller base circle cams?

Here's the confusing part for me. The other member removed material (0.035") from the beveled edge (top portion of dog bone) to create the added clearance to allow the lifter not to move the dog bone during operation. But the lifter will travel up the lifter-bore the same even on low lift cams so why is added clearance needed?

We have a lot of wiggle room for the bottoms of the lifters on a small base circle cam so it might be a non-issue but if the highest point of a lifter only travels so high in the lifter bore despite cam lift choices, why is clearance being added so the dog bones do not move on certain cams? Would this not support comp cams instructions?

Again I apologize if I am coming across stupid but unless I can make sense of something I am unable to process information.

[shermanator2]

Originally Posted by P@blo

It could be that the instructions are for a different engine and that the lifter would drop too low in the lifter bore on certain smaller base circle cams?

Here's the confusing part for me. The other member removed material (0.035") from the beveled edge (top portion of dog bone) to create the added clearance to allow the lifter not to move the dog bone during operation. But the lifter will travel up the lifter-bore the same even on low lift cams so why is added clearance needed?

We have a lot of wiggle room for the bottoms of the lifters on a small base circle cam so it might be a non-issue but if the highest point of a lifter only travels so high in the lifter bore despite cam lift choices, why is clearance being added so the dog bones do not move on certain cams? Would this not support comp cams instructions?

Again I apologize if I am coming across stupid but unless I can make sense of something I am unable to process information.

The way I read the instructions is that Comp Cams makes a special series of compromised cams for small block Fords just to go with that kit.

What 69HotBird did was cut a relief in the bottom, not the top, of the dog bone so that the fully round portion of the lifter could protrude into the dog bone. This would be required for any properly designed cam using the HT2184 lifter in a Pontiac. High or low lift will not effect this. It is not for certain cams. It is for any cam.

As you point out, based on JC455's measurements we have plenty of room at the bottom, so high lift cams should not be an issue.

[242177P]

If the 2184 is THE lifter to use, would it make sense to source round .875 ID shims?
Like the dogbones, they'd still need to be fitted to the block, but that's a lot easier
than milling a step into the bottom of a dogbone.

[shermanator2]

Originally Posted by 242177P

If the 2184 is THE lifter to use, would it make sense to source round .875 ID shims?
Like the dogbones, they'd still need to be fitted to the block, but that's a lot easier
than milling a step into the bottom of a dogbone.

Unless these were epoxied to the block I don't think this works. If they are floating, the "corners" of the lifters will catch these and lift the shim washer and the dog bone up.