cam degree feedback, please.

[falcon fanatic]

Having installed a 264/274-12 cam and using the centerline method to degree it, I find a centerline of 103* with the timing gear installed on the +4 sprocket. It happens that I also get highest lift at 103*, so this must be accurate. If I am not mistaken, the recommended installation for this cam (at 4* advance) would be with the centerline at 108*. IS THIS CORRECT?

If so, I'm thinking I should reinstall the timing gear at +6 or +8, no?

Thanks for any and all feedback.

 

[AzCoupe]

Correct, you want a 108 centerline. So if you set it on the +8, it should come in pretty close.

That just proves the point, that you should always degree the cam, and never rely on the dots. I've heard of cams being as much as 11 degrees retarded, and if installed dot to dot, it would actually be -15 degrees. That would completely kill the bottom end power. Imagin the fun of having the motor installed and broke in, then trying to figure out why it won't run......

 

[wsa111]

108 would be 4 degrees advanced from the 112 L/C.
You want to put the gear on -2. 6 degrees will bring the L/C from 103-6=109 & you will be 3 degrees advanced then. Bill

 

[falcon fanatic]

Thanks Mike, I'll reset and remeasure, just to be sure. No wonder my stock cam pulled all the way to 4700!

Bill, If I get 103* when I'm set at +4. Setting it at -2 would give me 097*, way off the mark unless I'm totally confused.

 

[Gene Fiore]

Correct, you want a 108 centerline. So if you set it on the +8, it should come in pretty close.

That just proves the point, that you should always degree the cam, and never rely on the dots. I've heard of cams being as much as 11 degrees retarded, and if installed dot to dot, it would actually be -15 degrees. That would completely kill the bottom end power. Imagin the fun of having the motor installed and broke in, then trying to figure out why it won't run......

Been there...done that...sad to say.

 

[WerbyFord]

I *think* Bill has it right, though it is always vague to set up a cam because:
a] they are not always ground "straight up" - That is, if the cam is a 112 LSA (Lobe Separation Angle), "Straight Up" would be LCA (Lobe Center Angle) of 112i (Intake) and 112e (Exhaust).
b] The chain/gear sprocket is sometimes marked in CRANK degrees, but sometimes marked in CAM degrees. Best way to find out is to check with a degree wheel.

In your case, my *guess* is that:
a] Your cam is a 112 LSA, but it is ground with about 5 degrees advance ground in. So dot-to-dot, you'd have 107i LCA and 117e LCA.
b] You used the +4 setting on the gear which is probably crank degrees, so now you have 103i LCA and 121e LCA.

But it is also possible that:
a] Your cam is a 112 LSA, but ground straight up, with 0 degrees advance built in. So dot-to-dot you'd have 112i LCA and 112e LCA.
b] Your gear is marked in CAM degrees. So at +4, you will advance it 4 CAM degrees which is 8 CRANK degrees, giving 104i LCA and 120e LCA, close to what you measured.

I would use the "0" setting on the gear, and check the Intake LCA and the Exhaust LCA to see where you are.
The best way to get the LCA's is *not* to use the point of max lift, since that is very insensitive so you can be off by several degrees easily. :nono:
So the best way is to look at the .050 opening and .050 closing on the wheel, and go halfway in between.
Then post back and see what's what before you button things up.

While you have the degree wheel and dial indicator on there, I always measure at least one intake and one exhaust lobe even on a new cam and degree it to get the degrees at :

Intake:
.006 lobe open
.020 open
.050 open
.100 open
max open (which you said was 103 ATC right now)
.100 closing
.050 closing
.020 closign
.006 closing



Exhaust:
.006 lobe open
.020 open
.050 open
.100 open
max open
.100 closing
.050 closing
.020 closign
.006 closing

One reason is that "Back in the day", Neither Ford nor anybody else reported the standard ".050 lobe lift duration". But, Ford did list .100 lobe lift duration, so this is handy for comparison. It will also give you the "ramp rate", which is handy for assessing valve spring needs.

Good luck, it is a lot of measuring. But I have never regretted degreeing a cam.

 

[falcon fanatic]

First, allow me to eat crow: Bill was right. After setting cam at +8 and ending up with 96* centerline I've set it at -2 and gotten 109. That seems good given the advertised rpm range for this cam (1400 - 5200) and the extensive mods I have in this head. I'm not sure Im comfortable revving much past 5k, but I guess it's up to the c-4 to decide that.

Werby, thanks for the good information.

 

[wsa111]

Werby, glad to help. Three degrees advance will be fine.
If you have ARP rod bolts i would rev it to 5500 as long as you have the proper valve springs.
Since this cam is mainly a street cam you need at least 80# valve spring seat pressure.
For street use it will be fine since Joe Sherman classifies hydraulic cams as a girls cam.
If you have a stout bottom end & plan to race it i would go to a solid lifter camshaft which will require closer to 135# valve spring seat pressure for a camshaft with a quick rate of lift & higher lift. Bill

 

[AzCoupe]

I did it backwards too.

 

[falcon fanatic]

302 valve springs, which I believe will be fine for this setup. Full roller rockers (1.65:1) The bottom end is a mystery as was rebuilt by previous owner. I do have ARP head bolts, but I don't suppose that makes much of a difference in how high I can rev.

I guess joe sherman (whoever he is) likes adjusting his valves every 3k miles. hydraulic cams rock. I got over that after owning an MGB for a few years, and that was only four cylinders thankfully.

 

[wsa111]

Werby, 302 valve springs are not the best choice. you need more spring tension for that camshaft.
302 valve springs first have no damper to prevent high rpm harmonics.
Second you need at least 80-90# seat pressure for your valve springs, unless you want to invite valve float over 4500 rpms.
On my previous engine with the 274 camshaft i ran 110# on the seat & my shift point was 6200 rpm's.
Purchase a decent set of valve springs for your application unless your grandma is the only driver.
Your choice,but i highly recommend stouter valve springs.
Mike, sells the proper spring for your camshaft as well as other vendors.

Since you are running the full roller yella 1.65 rockers don't forget to tap the oil supply at the left rear of the block with a 5/16" tap & install a plug, otherwise you might develop an oil leak at the left rear of the engine, cause the head gasket was never designed to hold full line oil pressure at that point. Bill

 

[falcon fanatic]

Actually, Werby is the other guy's handle (Werbyford). I'm James.

Hmmm, I installed these springs on the recommendation that they would be adequate for this setup. I guess we'll have to see Truth is, since I don't trust my bottom end much I will be having a self-imposed 5000 rpm redline. Since my stock springs where hanging fine to 4500 rpm (albeit with a stock cam), hopefully these will eke out another 500.

Good tip on the oil galley. I noticed that the holes in the gasket where much smaller than the galleys themselves. However, why would this setup produce more pressure? I know this arrangement blocks off the original passage that fed the stock valvetrain, but then you've got 12 oil-through lifters and pushrods to divert that volume of oil. And let me tell you, when you run this sucker with the valve cover off, theres a lot of oil spraying around

 

[wsa111]

James, make sure you plug the oil galley in the block by tapping the orifice with a 5/16" tap, make sure you put some sort of material in the galley while you are tapping it & also remove all chips with a magnet.
Then put some sealer on a 5/16" set screw as a plug.
The yella -terra blocks off the oil supply at the rear rocker stand boss. If you don't block off the oil supply below the head gasket you will eventually develop an oil leak at the left rear of the block cause the headgasket cannot seal full line oil pressure.
Yes the pushrod oiling system does shoot oil out of the rocker arms at the adjuster, but that is normal.
Chevrolet valve covers have even used a baffle right over the rocker arm stud to deflect oil to the rocker arm rather than spray it all over.
A large majority of valve covers do not have this baffle & that includes the ford valve covers, cause the regular rocker shaft oiling does not need that baffle. However.
James on the valve springs you better use the springs for the cam you have. Ford small block valve springs are an aniquated spring.
Do it right the first time & get a spring that has at least 80-90# seat pressure & comes with a damper in the spring to prevent valve spring harmonics at higher rpm's.
You spend all the money on high doller rockers but are willing to put junk valve springs in.Bill

 

[falcon fanatic]

I purchased this cam based on the following description "It has great low and mid range power with a smooth idle and works well with automatics with stock converters and manual transmissions." It is also described as having a good idle, good vacuum and OK to use with stock compression. Seeing as it is only a half-step up from the mildest cam that CI sells, the 264/264, and the fact that I have slightly higher than stock compression (calculated 8.9:1 with 52cc chambers) on a head with mild porting, mod log, big valves, header, etc, it seemed like a slightly aggressive but otherwise safe choice. But I just can't get this thing to idle worth a darn.

I'm pretty sure that it's not the cam that's the problem, but I've gone through the basic tuning procedures, adjusted the valves on the loose side (1/4 turn past contact) and I just can't get it to idle without turning the idle speed screw way in past the transition holes. Even then it shakes and lumps around quite uncomfortably, even at 900 rpm. Vacuum I've not measured, but it is noticeably low using the brake pedal pressure method .

I haven't driven it except around the block becasue I have fenders and bumper removed at the moment. I may discover that after all I degreed it wrong. I imagine that being too retarded would have an effect on idle, wouldn't it? I guess I'll put my car together and do some driving.