That is fine but it doesn't really help you too much unless you know exactly where the cam was when you recorded the 0.119 number. The only practical solution is to use published numbers which is lift at TDC for the lobe. The cam catalogs usually publish lift at TDC and then you have to do a valve drop test to see how much room you have at TDC. Once you know those numbers then you can figure out which lobes will fit and which won't.

I rolled the engine with clay on top of the piston. I thought the best way was by measuring 10* ATDC?

Anyone know what the limited is on piston to valve clearance?

Piston is chasing the exhaust valve as it closes, and the smallest clearance is something like 5-10 deg BTDC.
The intake is opening before the piston starts down, so its clearance is the tightest at 5-10 ATDC.
Unless I got those backwards

Anyhow, the rule of thumb I usually see is around .080-.100 intake, .120-.140 exhaust - but if you're brave, you can run it closer until you start seeing witness marks on the piston top!

You determine how much P to V clearances you like
I've ran as little as .030 on the intakes and .060 on the exhaust accidently on my old NHRA M.W. Stocker after having the heads milled to NHRA blue print specs without thinking about rechecking the P to V clearances. That motor had its tongue out around 6400 RPM I'm thinking back then NHRA only allow stock Mopar valve springs specs. which were 110 Lbs. on the seats and and right at 300 Lbs. at .509 lift on both valves. I never had a bent valve or any evidence of valve hitting the pistons, I did see a lack of carbon build up on some of the pistons on the exhaust valve sides of those pistons with stock rods which had some of the pistons closer to the heads than others
I know many good SO CA Mopar engine builders that recommended .060 P. to V. clearances on the intakes and .080 on the exhaust on automatic tranny cars, .080 on the intakes and .100 on the exhaust side with stick shift cars back then with stock valve spring pressures
I'm good with .060+ on both valves with todays roller cams and valve springs
Let me throw another rock into the pond on this discussion on P to V clearances with a solid lifter cam compared to a solid roller cam with the same specs and same LSA, I've seen a lot more P to V clearances on solid roller cams than with the same size solid lifter cams
My message is to make sure you check every motor for P to V clearnces on both sides of the motor and make sure and verify TDC on your balancer and degree wheel when setting the cam intake lobe center or verifying the LSA on your cam, check both the intake and exhaust lobes
I've had more than one cam not be ground on the LSA that was stamped on the cam and cam card

My specs are for a 15/1 compression 550 cube motor, so the specs won't compare. 285/296/114 with .867 int and .800ex lift.
On my 499 low deck motor with 13/1 compression and bowl ported 440-1 heads i ran a Ultradyne 283/290/108 with .740? And .680? Two things come to mind to help. That cam needed SPRING! I picked up a bunch by putting a 300+ seat pressure spring in it, and looking back there was more power available if i would have gone to a better pushrod. So if you have good enough valvetrain parts you can run a more agressive cam. That is why i mentioned Jones. You need a plan= lifters,pushrods,rockers, springs, all spec'd to fit the cam design or vise versa.

While that may not be the best way to tell it does tell you how tight it is at the tightest point. But since you don't know exactly where that point is it makes it hard to use that data to compare to another camshaft.

I didn't think where the tightest point was most important, just how tight it is? People have been using the clay method for decades. I know that is not the most accurate, but close enough i figured. My book says to check at 10* ATDC. I will have to get those measures before i buy, but was just fishing for opinions for now. Thanks

Some interesting info here cab. At .060 i may be able to squeeze .060" lift in there. Will have to measure again and see. Thanks

Good springs are on my list for sure.

I called comp and asked for the lift spec at TDC and they did not have that. They tell me the valve should be closed at TDC. I did find some of my notes and did find a valve drop spec at TDC , 368 on intake.

Sounds like you talked to some idiot who didn't even understand the difference between TDC compression stroke and TDC overlap!

WOW......

Comp has a lobe catalog on their website that shows tappet lift at TDC for each lobe. An aggressive roller might have 0.150 tappet lift at TDC. Multiply that by your rocker arm ratio and that tells you the valve lift at TDC. If you have 1.70 rockers then the valve lift at TDC will be 0.255. Subtract that from your valve drop and you'll know what your valve to piston clearance will be with the new cam.

Ok, I’ll see if I can find that.

Lift is .141@106 and .124@110*. So .368-.141=.227?

Never, NEVER ASSUME any math done on the theory of lift is accurate with your parts, NEVER
To many ways for it to be wrong
If you don't have a set of decent checking springs get them now before checking any thing related to valve to piston clearances, use a good dial indicator on the retainers align exactly like the valve stem is and push it down to the piston starting around .030 BTDC every 5 degrees until around .050 ATDC on both valves.
I learned a lot on actual P to V clearances and rocker arm ratio theory checking them this way AKA this way is well worth doing
Make sure and check the max valve lift at the retainers with the lash set also so you can figure out EXACTLY what ratio your rocker arms are

Don't you have rocker arms?

this is what i do when having any doubt

Tex

HS 1.6 and 1.5 on exhaust.