olds 307 and 403

OK, so this is my first time degreeing a cam. I need the easiest method with the heads off. I have the dots lined up on the sprockets perfectly with tdc. I have the cam card that Erson sent with the custom I got from Mark. I just want to make sure the cam is where it needs to be with this Cloyes Street roller timing set. Thanks in advance.

Fun71

You said degree the cam but you made no mention of having a degree wheel or a dial indicator/piston stop to determine true TDC.

don71

If you have a degree wheel and dial gauge with a magnetic base, its pretty much is the same for any. You didn't mention if you have these things, but the bigger the wheel the better for accuracy. Its been a while since I"ve done one, but youtube is a good source to see what others are doing and remind one self of the math involved..easy.

olds 307 and 403

Sorry, I have a degree wheel, magnetic base and a dial indicator of sorts, doesn't have spring return.

coppercutlass

Do your self a favor. draw a cam lobe and write where the sequence of events take place so you can have a visual aid .

don71

Aint nothing wrong with that. If youre really feeling it, when you're done with number one, (cylinder) do number eight...just to make sure.

olds 307 and 403

So I set my degree wheel off TDC on the timing marker, that being 0 correct? My cam card says my intake opens at 29 degrees, so 29 on the wheel correct? So should I check intake and exhaust valve opening and closing?

don71

You really need a piston stop and find true TDC before you go any further.

cutlassefi

x2.

olds 307 and 403

OK, I will make one up, I have seen them online, looks simple enough.

olds 307 and 403

Piston stop made and finding TDC, next step?

ELY442

Install the degree wheel and pointer, crank the motor until piston hits the stop, mark the degree wheel, crank the motor again until piston hits the stop, mark the wheel again, the 2 marks that you made, divide it by 2, the total is your true TDC. Zero your degree at the pointer.

midrange

I'm not 100% sure, but I think this is what needs to be done.
It's been a long time since I saw someone degree a cam, so if I am wrong here, please let me know so I'm not spreading bad info.

edited to add:
I'm sure ELY442 meant this, but I thought I'd better try to clarify in case someone who has never degree'd a cam before, gets confused.

Fun71

You are correct, the engine needs to be turned the opposite direction for the second piston stop contact.

olds 307 and 403

0k I did the forward and reverse method a few times and got +2 and -2, so does that equal the factory 0 mark?

don71

Basically yes, the middle will be zero. That is where you configure your pointer at zero on the wheel. Try not to disturb the pointer and the wheel is tight at zero.

If you do disturb the setting, reset it or it will effect the numbers and your math at the end.

Firewalker

olds 307 and 403

Thanks, I think this timing set looks pretty close, which is a good start. Yeah, getting the wheel set right is a pain but should do this as right as I can. So now am I basically checking the camshaft itself now using the cam card as my timing chain is accurate according to my measurements, correct?

cutlassefi

How do you know your timing set is correct? You haven't checked anything yet.
It's done as an assembly so to speak. The timing set, cam, and crank will all determine where the cam timing is.

olds 307 and 403

I assumed if TDC is right, which it is with the piston stop and CCW and CW rotation coming up with #2 and -2, therefore equaling 0, the 0 on my factory timing marker, set the degree wheel the same, then the rest would be right if the cam is ground correctly. I will see what I get while measuring cam movements. I may get myself a better dial indicator as well.

ELY442

WHOOPS, sorry my bad. You are correct.

Fun71

What you did was verify the sprocket is correct, which is just the beginning of the degreeing / verification process.

There are a a number of manufacturing operations, all with some tolerances, that can all add up to a big difference from spec:

There is a dowel hole drilled in the sprocket.
There is a dowel hole drilled in the camshaft and a dowel inserted into the hole.
The teeth are machined on the cam gear.
The teeth are machined on the crank gear.
The chain is manufactured from a bunch 'o separate links.
The camshaft lobes are ground on the camshaft blank.


What you are doing is checking to see how much slop there is in the entire assembly due to all of the manufacturing tolerances adding up.

olds 307 and 403

Thanks makes sense. This is a used chain, so the stretching is already done.

Fun71

I forgot to say that years ago I installed a cam with the gears dot-to-dot and the engine had no low RPM power. I later bought a degree wheel and checked the cam and it was 8º retarded. I have no idea if the sprocket hole was drilled incorrectly, the cam dowel was in the wrong place, or the cam was ground incorrectly. Anyway, that's my reason for advocating that EVERY cam install gets degreed.

olds 307 and 403

True enough, my timing set could be right on, it may be junk. This timing set could be why 88 never ran what it should. I will spend a bit more time on it. Dale Robinson on ROP said to make sure piston stop is making enough contact and my 0 is actually my 0.

olds 307 and 403

I ordered the Proform checker lifter with the dial indicator attached, once it arrives and will check all the movements. No way it would check accurate enough as is.

olds 307 and 403

Ok, I get the same results on the tdc mark. So do I follow the .050" numbers on the card? So is my 0 at the dial indicator at TDC?

olds 307 and 403

By the way, the Proform checker lifter had a stupid dowel pin sticking out on the GM side, the Ford side was drove nicely in. So I pounded it in and had to file it to fit all the way down in the lifter bore. I have worked two weeks straight, so any help with the next step and what I should be reading on the dial indicator will help.

cutlassefi

If you've verified tdc then your next step is to check events. The cam card will reflect the correct timing based on what I told them, which I believe was a 110+4. Which means an LSA of 110, to be installed on a 106icl. Check it and see what you have.

olds 307 and 403

I saw that on the one video, I will try to copy.

ROCKETMAN269V

What we have used for years is a stock Chevy SOLID lifter. It is the exact same dia. as Olds, and the same height; only the oil hole is in the wrong location. You can't run it in an Olds engine, but it's great for degreeing the cam.

olds 307 and 403

OK, so I went to the top of the intake lobe where it dwells, tried picking the middle. I got 149 going to .050" lift one way and 64 the other way. So divide by 2 equals 106.5, my ICL according to the cam card is 106, close enough for me.

Firewalker

Never had a doubt in my mind you could do it, but a lot of us like to go step by step and get butterflies.

olds 307 and 403

OK, so what other important events do I need to measure? What about the number one exhaust lobe? I would like to get this 350 back together.

olds 307 and 403

I measured intake opening at 2 degrees and closing at 34. I got the exhaust closing at -8 and opening at 40. Specs are 214/214 .472/.472 110+4 LSA 106 ICL. The .050" figures are -6 overlap, intake opens 1, closes at 33. Exhaust opens at 41, closes at -7.

olds 307 and 403

Am I right in thinking this is close enough? It shows everything is one degree advanced correct? The ICL is .5 retarded but I should be able to put it back together, correct?

cutlassefi

You're good, button it up.

olds 307 and 403

Awesome