How is measuring the difference in valve lift at the trouble spot between checking springs and real springs not taking into account the play?

The spring force will be loading the entire valvetrain from the roller tip all the way to the camshaft.
All the defelecttions from bending the rockers and shafts, to the compressive loads on the pushrods, lifters, and then back to the bending load on the camshaft, accounted for in the lift measurement.
In Dave’s case, that’s going to be about 400lbs of force on the valve side of the rocker, and 600+ on the pushrod side.
Seems like that should be enough to take up the play.

With his parts the deflection might provide enough added clearance for it to work(he’s looking for another .016).
I’d take the measurement to find out of it were me.

I agree the zero lash thing is a mistake.

No, i had no idea of that spec or what its for. .139" is what i just measured with cam in at 106.75 I'm using the pro gear 9 way timing chain set and its a bit confusing with this cam. I set it to straight up dot to dot and get 106.75 with a 108 lobe sep cam. If ya set it at 2R i get 108.25. I don't get it. I now have the head off ,so i can get more accurate measures using a bridge and a lifter indicator tool that slides into the lifter bore. The cam measures .430 lobe lift dead nuts, so my indicators are accurate.
If ya want to get picky, i get 65.25+148.25=106.75. I checked the opening and closing at .050 numbers and get 25*@.050 lift and 58*@ .050 before close. Cam card says 30.5 open and 58.5 close. I don't get it. I have installed and degree'd a couple dozen cams or so and never had an issue like this cam.

The lobe lift at TDC is shown in Comp Cams lobe master catalogue, is this the kind of number you are talking about Dwayne?

Well, according to the lobe specs in the catalog, your old cam should have had .141” lift at TDC, with the cam installed at 106.

Which means, in theory(assuming your .139 measurement is correct), the new cam would actually have a tiny amount more clearance........at TDC.

Both cams should be moving the lifter about .004/degree at that point in the lift curve.
So, if the closest point for v/p clearance is 10ATDC, you’d have another .040” or so tappet rise at that point.

All that being said, it would have to be a pretty lazy roller lobe to have 269@.050 and only have .139” tappet lift at TDC, installed at 106.
Should be .150” or a bit more.

All of which means the loss of all the clearance between the two cams still makes no sense.

However....... your .050 numbers of 25/58 come out to 263@.050, not 269.
On a very aggressive .430 roller lobe, the difference in lift at TDC, with both cams installed at 106 would be about .010”.

What are you getting for open/close points at .020 lift?

The lifter bore tool you’re using has the radiused end for the roller cam?

What did you use to set/verify the wheel is correct at TDC?

The cam card calls out what the cam “should” be.
You should be able to have the specs coincide within a degree.
If you can’t, either you’re doing it wrong......... or the cam doesn’t match what’s on the card.

You can double check yourself by plotting out the old cam.

I am beginning to think this cam is f'ed up. I have never had so much trouble. I will get the valve replaced and try a clay test. I will give ya a call this week Dwayne, would be nice to start with good parts. Thanks

The cam card is just numbers on a piece of paper.

The cam measures what it measures.

With the tools on hand to degree the cam, you can make up the cam card.

I trust what I measure.

However, nothing you’ve come up with thus far with all the measuring has explained where the clearance went.

I’m not understanding the problem.
You were at 106.75, then you retarded it “2deg”, and it ended up being 1.5deg(108.25) instead.
No biggie.

Your right, there is no problem with the chain gears. I am just a bit frustrated at the moment. I have a ton of hours into this and have gotten nowhere really and a bent exhaust valve. It never takes me this long, should of been back together by now and running. I did remeasure the lobe again at overlap and yes its 139/140. Sounds like a good idea to pull this cam.

Cam is it at 106.75, and the lobe lift at TDC is .139/.140?

Put the old cam back in, do the same test.
It should be within a couple of thou, if you can get it close to being in at 106.

Then check the v/p clearance the same way that you have been with the new cam.

the difference between checkers/indicator vs clay is always between .030-.050 every time I have done it.

The old cam uses intake lobe number 7072, correct?

Here are the specs from the lobe catalog.
You’ll notice the lift at TDC spec is .141, if installed at 106.

The same as what you’re getting with the new cam.

Meaning, the V/P clearance at that point should be the same between the two.

Check the lobe lift between the two at the closest point(10ATDC?), they should still be within a few thou of each other.

As I said earlier....... you have yet to come up with anything that would point to why the new cam has way less clearance.

I have no explanation. First time for me using checking springs to check v/p clearance. So I think it would be best to check with clay once I get a new valve in that head and go from there. As for having the same lift as the flat tappet, I really think its time for a new cam. This cam is in at about 1* more retard, not sure how much that changes things. Thanks for that info Dwayne.

This is as good as it gets. These are the numbers i got with clay when i built the motor using the flat tappet installed at 105.5, .160 intake, .230 exhaust. Now cut head .045 and a .010 smaller head gasket = .055 less clearance. I also noticed once i got the head off, the intake valve is not centered in the valve notch and was touching on the right edge of the brow. I think alot of my numbers were skewed because i was not getting the degree wheel zeroed. I bent two piston stops just trying to find top dead center. I will never attempt a cam change in an engine with the heads on. Its just too hard to get accurate numbers. With head off i use a bridge with a dial indicator and a lifter tool that inserts into the lifter bore with another dial indicator. I will have to measure the exhaust valve and get one ordered. Does brand matter, because i have no idea what brand valves are in these heads?

Dave, Sorry for your troubles. What is the cam grind, profile and manufacturer? Who did you get the cam from and why aren't they helping you with these troubles?

The cam is a Bullet solid roller. 269/275@50 on a 108 with .430 lobe lift. I called Bullet last week to speak with Greg about it, but he was out sick and the guy I spoke with could not answer all my questions. Greg is very hard to get ahold of when he’s there. Too busy.

Tim Goolsby is another knowledgeable guy to speak with over there too.

If I have time today, I might be able to determine which lobes fit these specs. Assuming there is only one profile peculiar to 269/430 and again one to 275/430. These issues are more an engine builder issue than they are cam manufacturer. So you are the builder and bought the cam directly from them?

You might be on to something with that.

Thanks for offering and I apologize to everyone for all the bad info. I will have to get all new data from the pass side since it still has a head on it. I know how to fix this, brand new heads.

A new set of pistons from Diamond with correctly placed and sized valve notches for your cam and valve gear that you have is a lot cheaper and more effective way to fix your ride. You may not have enough meat in your current pistons to safely cut deeper valve notches. Diamond warned me about the chambers in the Victor heads and spec'd my piston domes/valve reliefs accordingly. No problem whatsoever with 280*/283*, .690" solid roller cam. Call them and plan ahead for future valvetrain changes. Won't cost anywhere near that $4000-6000 price tag you spoke of earlier. The clay don't lie if it's done right,as you found out. Add a good top ring and a little extra gap and you could also spray some safely and make alot more power than a new set of heads- for less money. You got a great project. Good luck. Jeremiah has made some great power with those Victor heads. Send him a PM. I'm sure he would share his experience. He's a real nice guy. Bill