Degreeing a Cam, or not.....

Would you run it or take it apart and correct it?


  • Total voters
    34
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Kent, let me address the question no one has. You mention the cam is on a 110 LAS. That cannot be changed without either regrinding the camshaft or replacing it with another one with a wider LSA. The LSA is ground into the camshaft. And you're correct on more than one count. Larger cubic engines sometimes respond better to wider LSAs and especially with power adders like nitrous. It's not an end all be all though. What I would do is do a search for @crackedback 's "Hillbilly timing tape" and do that to your balancer......unless it's already marked and it should be a good one on a 512, so you may not need that. Find TDC with a piston stop and verify the marks are correct. Then you can actually check the camshaft numbers without pulling much more than the radiator and pulleys.
 
That EFI is choking your the flow capabilities of of your ported heads.
I ran a Holley 950 cfm carb on my 512 and I believe it would have taken more and that was with a set of old school ported iron heads.
How about your intake was it port matched to your TF heads?
I believe they are machined to match. Flow may be an issue but the Super Sniper is rated to 700 hp aspirated and 1250 hp boosted. So I thought it was enough
 
That’s a tiny cam for a 512 engine. As stated too small of fi system also. Degree the cam at least. I doubt that ur engine even pulls to 5500. It’s a torque monster for sure. A 1000 4150 style carb will pick it up like u won’t believe. My 470 gained 2.5 tenths going from a 750 to a 1000. Kim

I should have said in my first post that the cam specs were recommended by Oregon cams and where I said the specs were copied from what they said not my words. I took it for granted that it would be appropriate. These are his words.

"244/252 @ .050”, 282/290 adv, .516”/.537” lift(1.5:1 rocker), 112 sep, .016”/.018” lash

This is a very good street/strip grind that should make power from 2200/6400 or so. Will need a 3000+ converter and will work well with your compression ratio. Normally I would put this on a 110 lobe separation but with the nitrous and fuel injection I think 112 to 114 would work better."

It went through the trap at 5500 rpms. I will have to get time slips for 60 ft times
 
what was the trap MPH on the 12.3 runs? what about the 60ft times?
is your car setup to be a drag car or is it just a street car?

5500 rpms and best was 1.735 60 ft. 110 mph at the trap
Setup is for street and strip. ss springs and competition engineering shocks. Torsion bars a a bit heavy from PST. MT drag radials, full interior
 
Kent, let me address the question no one has. You mention the cam is on a 110 LAS. That cannot be changed without either regrinding the camshaft or replacing it with another one with a wider LSA. The LSA is ground into the camshaft. And you're correct on more than one count. Larger cubic engines sometimes respond better to wider LSAs and especially with power adders like nitrous. It's not an end all be all though. What I would do is do a search for @crackedback 's "Hillbilly timing tape" and do that to your balancer......unless it's already marked and it should be a good one on a 512, so you may not need that. Find TDC with a piston stop and verify the marks are correct. Then you can actually check the camshaft numbers without pulling much more than the radiator and pulleys.

I have a sfi certified damper with timing marks from 10 to 0 to 50 degrees. I could find TDC with a piston stop. How would I then check the camshaft relative to the crankshaft? Regular degree wheel mounted to the crank? Would I pull the valve covers and check the lift of the valves/rockers and degree off of that. If I am on or off specs, then we have solved at least if the cam is ground correctly according to the cam card. Whether or not it is correct for the car is another whole story. Do I have that correct?
 
I have a sfi certified damper with timing marks from 10 to 0 to 50 degrees. I could find TDC with a piston stop. How would I then check the camshaft relative to the crankshaft? Regular degree wheel mounted to the crank? Would I pull the valve covers and check the lift of the valves/rockers and degree off of that. If I am on or off specs, then we have solved at least if the cam is ground correctly according to the cam card. Whether or not it is correct for the car is another whole story. Do I have that correct?

Yes, that's right. From finding TDC, then I would just go through the motions and check "where" the camshaft is installed. Same process as degreeing. You can find out if it's off without tearing the front off. Of course, you'll need the radiator and pulleys off to access the balancer. You can put the dial indicator directly on the valve spring retainer, but you need to make sure it's dead aligned as perfect with the valve stem as possible.
 
If u had that cam in a 440 or smaller I’d say ok, degree it in and have fun. This cam now in ur 512 is like a magnum cam in a 440. More or less stock lift. If this cam had another .040 -.060 more lift I’d say ur good to go. But as it stands now, no. I will say I’m not an expert so take my words with a grain of salt. Just one mans opinion. Kim
 
One thing cannot be argued with regarding the smallish cam in that 512 and that it that beeotch will peel up the pavement on the bottom end and melt tires when he gets it right. It'll be fun.
 
What would you do ? As asked by the original poster Kent from post #1.

Here is a train of thought, you are working with a reliable cam grinder Oregon Cam. They know you are building your own engine.

So they did not say to go 4° advanced or 4° retarded with a multiple keyway crank timing gear. If this was the case had they recommended to do this then definitely Degree the Cam if you are advancing or retarding the cam.

(Small block pictured here but you get the idea, timing straight up dot to dot.)
20200830_175453.jpg


Pretty much was a straight up dot to dot timing set install with a single keyway crank gear, working with your Oregon Cam guy. Much better chances of it being right with this senario going straight up.

If you want to check it like @RustyRatRod stated using degree tape on the front damper, TDC the piston stop. Then pull the valve cover and see what degrees your intake and exhaust valves are opening. Compare this to the numbers on the cam card. If they match you are good.

Without tearing the front of the engine apart.

If the degree numbers don't come anywhere near what the cam card says then time to pull the timing cover and find out why.

So the OP asked our opinion of the information that we have gathered so far. What would you do ?

Law of averages and knowing how fussy and thorough Kent is I am going to say that the cam timing is correct now as he installed it.

My opinion, others may disagree. Can take it all apart if you so choose.

Resized_20210707_151659.jpeg
 
Before taking stuff apart maybe run a compression test first because it's relatively quick and easy. With your low-10 SCR and that cam I'd call it good if it cranks close to the 170-180ish neighborhood? Now if it cranks140s-150s then yeah maybe it's off and wants to be advanced a bit more. Otherwise...the cam's IC isn't your problem.
It could very well need more detailed tuning, BUT since you're judging it on track E.T. I kinda think it's gonna take some more camshaft to get you where you want to be...good luck!
 
You have a mech lifter cam. You can use that feature to see if the cam might benefit from advancing or retarding it.
Unless the engine build is an EXACT copy of another where all the same parts were used & the engine dynoed with the cam position changed until max hp was obtained, then it is just guess work as to what the correct cam position is.

I would try decreasing the lash by 0.004" & retesting. This closes the int valve later. If the performance improves, you should try retarding the cam. If the performance decreases, try advancing the cam.

Crane cams advises that if changing cam position, less than a 4* change & the butt-meter will not notice it.
 
@Kent mosby here is a degree wheel that you can download (save) to help you understand valve timing events. If you are crafty enough you can print it out to the Diameter size of your damper and tape it on there to do the test @RustyRatRod is talking about.


degree wheel.jpg
 
Before taking stuff apart maybe run a compression test first because it's relatively quick and easy. With your low-10 SCR and that cam I'd call it good if it cranks close to the 170-180ish neighborhood? Now if it cranks140s-150s then yeah maybe it's off and wants to be advanced a bit more. Otherwise...the cam's IC isn't your problem.
It could very well need more detailed tuning, BUT since you're judging it on track E.T. I kinda think it's gonna take some more camshaft to get you where you want to be...good luck!
What is IC? a compression check is easy. I will do that this weekend
 
I will tell you my experience im not a professional engine builder or anything but I degreed mine and luckily I did because I found out the timing gear was cut wrong and the cam was retarded 24 degrees iirc when it was dot to dot. I have some pictures somewhere I will post them later
 
what's dead on.

Well, in my mind the answer to that is obvious.
It’s the C/L where you would have installed the cam if you had your choice.
If you were taking the advice of the cam grinder, and they said “put it in at 108”, and you verified that’s where it was before putting the timing cover on, then this thread wouldn’t even exist.

This thread was started because the OP feels the performance of the car is not up to par, and since he doesn’t know where the cam is installed he’s questioning whether or not that’s where the missing performance lies.
If he knew the cam was installed as per the cam suppliers recommendations, I suspect there would be a different slant to this thread.

I sold the Comp equivalent to that cam to someone with a 512 with TF 240 heads.
He had it dynoed and made very good power.

Could you put a bigger cam in it? Sure.
But the cam isn’t the major fault in the package that’s holding the car in the 12’s.
 
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I ordered a tdc tool and will check it next week when the tool arrives. No local auto parts store had one in stock
 
I ordered a tdc tool and will check it next week when the tool arrives. No local auto parts store had one in stock

IC is the intake center line. That's the "where" reference about where the cam is installed in the engine. When you look at cam specs, you see lift, duration, lobe separation, valve events.....the IC is the amount away from the lobe separation the cam is installed. Say the cam has a 112 LSA or lobe separation angle. A popular "place" is 4 degrees advanced. So that means the cam would go in at 108 IC or 4 degrees advanced from that 112.
 
Printed out a couple of degree wheels from the Stock Photo above.

Printed them to the 7" size instead of the std 8" size so they fit nicely on the mopar dampers.

For checking cam events without opening up the front of the engine.

20210708_104945.jpg


Can cut the center of the degree wheel out and just leave the outter numbers to temporarily paste on to the front damper.

20210708_103758.jpg
 
Printed out a couple of degree wheels from the Stock Photo above.

Printed them to the 7" size instead of the std 8" size so they fit nicely on the mopar dampers.

For checking cam events without opening up the front of the engine.

View attachment 1715762208

Can cut the center of the degree wheel out and just leave the outter numbers to temporarily paste on to the front damper.

View attachment 1715762210

Thanks for this. I will do this next weekend (10 days) and post results.
 
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