^^^^^^^^^This right here. Even if you did NOT degree cam and just lined the dots up, it would NOT be down 100lbs. If you missed it a tooth it would NOT be down 100lbs. So the cam is either WAY off, or it has bent valves. If it had this much blowby, it would smoke.

If you look back on the first page, he says a couple things of merit. Says he has a gear drive and that he did degree it in on 106. Now some gear drives can be a little tricky if you are not positive of what all the numbers mean, but he says he DID degree it and it was right, so it seems he knows how to read a degree wheel. Second thing he says is that it is hard to start when hot. Has to wind a lot. Low pumping pounds would definitely do this. He has stated valve lash, so it would not seem valve lash is tight, plus he says it starts better cold. Tight lash would be opposite..............

so the magic number is 122 and 1/2. So now I got to figure how to get it back in. Guess I am taking the rocker arms off and the access cover on the gear drive.Rocker arms are piece of cake but to get to the gear drive the motor plates and water pump have to come off. Should the cam need rotated clockwise or counterclockwise? Like I said thanks for the direction. Birdtracker

I am thinking one tooth and turn it clockwise.What a pain. Birdtracker

2nd lobe back is intake.

I degree'd in the exhaust once lol.

I'm not sure what the tooth count is on a gear drive, but on a normal double roller set up 1 tooth is 14deg.
Going from 122 to 106 isn't going to pick up 100psi cranking pressure.

Of the timing sets I've come across in the last 30 years, I have encountered 3 where the dot on the upper gear was on the wrong tooth.
These were all found on customers motors that were already running, that the owners had installed cams in, lined up the dots, and the motors seemed to be down on power.
All 3 had the cam retarded a tooth because of the mis-stamped upper gear.
All of these motors ran well, but had cranking pressures lower than expected.
They were all like 10:1 street/strip deals and instead of having the expected 150-160psi on the gauge they were more like 120.

I don't feel a 14.6:1 motor is going to lose 100psi on a compression test by advancing the cam 16deg...... But I guess we'll see.

How did the cam to from being degreed in at 106 to now being in at 122?

I think when I stuck the cover on the intermediate gear, it spun the cam. Thats the only thing that makes since. So I got all the front torn down. If I take the intake off and pull the valley tray, I can check all my lifters, plus pull the cam straight out and turn and go back in. My cam gear has 52 teeth. Got to be an equasion to figure out if its one or two teeth.All the valves open and close as they should. I also thought if a valve was bent I think there would be 0 compression on that cylinder. But I have had bad experiences when I think! Birdtracker

I dynoed a SBC dirt modified motor for a customer a few years ago.
They had been running the car for several events but it just wasnt competitive, so they brought it in to have it tested to see how it stacked up.
It ran beautifully, sounded real good, and had pretty good throttle response...... But it was way way down on power...... Like 100hp or so.
These are pretty bread and butter combinations. If you use A,B,C, and put it together right they all make about the same power. Something has to be pretty screwed up to be off 100hp.
I suspected the cam was in wrong, but the builder(whom I'd worked with quite a bit over the years) assured it was degreed in properly.
"Normal" cranking pressure for these is over 200psi.
I tested one cylinder quick and it was only like 150-160.
After some discussion and exchange of ideas, I tested a few more cyls.
The pressures were all over the place. A couple close to 200, a few down near 100.
I leaked it down........ It had a bunch of bent valves.

Took the motor off the dyno and they took it home. They pulled it apart, and after disassembling the heads found almost all the valves were bent. Some a little, some a bit more.

They can run just fine with bent valves....... But they won't make any power with bent valves.

I will say this, If I hadn't tested that motor myself and saw how good it ran, I never would have believed it could have run so good with the valves so screwed up.

Depending on how tight the piston to valve is on this motor, the cam being off 14* could cause it to kiss some valves.

We broke a pushrod on the 738 once in the burnout and it killed the motor. Went back to pits, fixed the pushrod, fired the motor, it ran like ass and couldn't figure out why. As Fast described, we did a compression check and they were everywhere. Pulled the heads and all the valves were bent slightly......but why? When it broke the pushrod, it caught under a rocker, stopped the cam and jumped the belt drive a tooth. Took the gear off, lined cam back up, touched up the valves and were racing in a few hours. Did all this at the track

On all my gear drives and even chain stuff I set the
TDC first and put on the pointer and wheel... then set
the crank at 106(where it says intake C/L) then roll the
#1 INTAKE lifter at peak lift.. then see if the gear will
slide on EASY... then do the .050 before and after to check...
I havent looked at dots in years after I had a MP one 23* off

360 degrees divided by 52 is 6.923. So each tooth is almost 7 degrees. Advancing it 2 teeth should put it at 108.5. Then leak it.
Doug

Thanks Doug. I need to take the intake off tonight. Birdtracker

That would be 6.9 at the cam right? The crank spins twice as fast so it would be 13.8 at the crank per tooth on the cam gear would it not?

Yep

I was thinking the same thing.
I wouldn't think it's all that easy to get 14:1+ compression out of a 470 without some head milling, and with that Comp .690 cam I can't imagine there was a big surplus of piston to valve clearance on the exhaust side, even with the cam installed at the correct c/l.
With it in at 122, i would think some contact could easily happen.

so I pulled my intake, valley cover, rockers, push rods, and all the roller lifters. The good news all the pushrods are straight and all the lifters are as should be. I paint marked the cam gear and pulled the cam completely out of the engine. All the lobes look good so I reinstalled it one tooth. Will recheck cam centerline tomorrow. So I looked at all the valves and springs. They are all the same height. After degreeing its getting a leakdown this weekend. I am down to the heads any ways so if I gotta take them off now is the time. Birdtracker

Don't need a cam in it to leak it down.

For what you're looking to determine....if the valves are tweaked or not......it doesn't even need to be at tdc. Just hook up the tester and pump some air in and see what the leak % is. If it's pretty high, see of it's blowing by the valves.
The air will push the pistons down if you're not at tdc, but it won't really matter for this test(with the valvetrain not functioning).

I looked up the specs for the .690 cam lobes.
Looks like they move the lifters about .004"/degree at around the tdc mark.
I would have installed that cam at 104 and checked my p/v clearance there, and possibly made a slight adjustment to the installed position if it would have solved a p/v clearance issue.

The cam was supposedly in at 122 now, which is 18deg retarded from where I would consider the "normal" installed position. .004 x 18 = .072, x 1.5 rockers = .108.
So, you lost roughly .100" p/v clearance on the exhaust by having the cam in at 122.
I hope you had a lot to spare.

Fast 68: we are going to find out. The car is pretty light so 106 0r 108 would make me happy. Birdtracker

I guess my point was, I would have figured in a fairly normal build, that cam installed at a pretty normal installed c/l would have only had about .150" or so exhaust p/v clearance.
If you back the cam up 14-18 deg from there you lose .80-.100" of that clearance..... And that's when valves start tagging pistons.
Everyone has their own process of working things out, but IMO, a leak down test should be close to the top of the list of the next steps taken.

I would at least put compressed air in each cylinder and listen/look for leaks at the header. If it bent any of the valves (which I have a hard time thinking 18 degrees retarded couldn't, and which brings up other thoughts if it didn't) it would be the exhaust.