Advancing Cam question

I've read a lot on this and am still a little confused.

I have a 509 purple shaft 108 LSA

I've read to advance the cam 4 degrees to help the bottom end. But I'm confused if that is 4 degrees at the crank or at the cam. I have a summit timing chain with several keyways to advance or retard timing. Do I want to advance 8 degrees at the crankshaft or 4 degrees?

Thanks!

With a degree wheel mounted on the crankshaft you should advance the cam in crankshaft degrees, don't try using camshaft degrees I would degree the cam off of the intake lifters at first and then check the intake lobe timing at the retainers to make sure the intake valves are timed off of the intake lobes correctly, IE if you use the 4 degree advance keyway on the timing set check the intake lobe timing to make sure the cam is installed so intake lobes are at max lift at 104 degrees after top dead center, not at 101 or 111 ATDC

OK. Just to be 100% sure - When people say advance the 509 cam 4 degrees, that is 4 degrees advance at the crank? I read several posts by someone to advance the cam 8 degrees at the crank to get 4 degrees at the cam. And I have no idea if he knew what he was talking about. He was saying he was using a Mr. Gasket 985G offset key on the crank. I look up the 985G and it says it is a 2 degree offset. And I look at my timing chain set and now I am thoroughly confused.

Edit:

So I believe the markings on the crank gear are crank degrees. So if I want to advance cam 2 degrees, then I use the A4 marking on the timing gear.

BUT

Does the 509 like 4 or 8 degrees advance at the crank? (stock 1970 440, TM7 (for now) and Demon 750 carb, 4 spd, 4.10 gears Challenger)

The cam straight up is at 108 Intake centerline. 4 advanced would be 104.

I've installed that cam in lower compression 340/360 and 440s at 100 ICL, so it can be cranked more advanced than 4 degrees.

Stop confusing yourself, EVERYTHING is in crank degrees!

Dang it. I get confused bc this one guy kept spurting 4 degrees, 8 degrees, calling a 2 degree offset key a 8 degree offset key, etc.



OK. DEGREES IN CRANK DEGREES. Got it.

Now the question is what would one suggest for my setup?

stock 1970 440, TM7 intake (for now, could go with a Performer RPM later - though I had clearance issues with that intake on my other Challenger.) and Demon 750 carb, 4 spd, 4.10 gears Challenger


Thanks for bearing with me.

He is right as when talking cam advancing and retarding in degrees its usually always in crank degrees since the degree wheel is set up on the crank. Ron

Does that include offset cam bushings? The Comp 4760 set has 0, 2, 4, 6, and 8 degrees but doesn't say whether crank or cam degrees. I assume it's at the crank since 8 cam would be a whopping 16 crank.

With the stock engines comp, id advance it to 100 ICL if you could. Not sure you will have the intake to piston valve clearance though. At least try to get it to a 104 ICL though, if clearance allows. That cam doesn't have a lot of low end, so the advance will help.

Your smart in choosing the RPM for later vs the TM7. It will make your 4 speed more driver friendly.

Agreed, the closer to 100 the better.

Is this stock 1970 440 a magnum 375 HP or a non magnum 1970 350 HP 440 motor?
Either way shoot for between 105 to 102 degrees on the intake lobe center in relation to top dead center using the 4 degree keyway on the crankshaft gear
Make sure and check the cam timing, DO NOT ASSUME that when you align the dots the cam timing is correct
I've had several different sets of Cloyes True Roller 440 three bolt timing sets that had the cam dot position between two teeth on the cam gear, if I aligned the cam dot to the driver side of the motor it made the cam timing 12 degrees retarded in the 4 degree advance position if I aligned it so the cam dot was to the passenger side of the crank dot it was almost no advance or retard on the cam timing
Trust and then always verify

Thanks for all the responses.

I can advance it up to 8 degrees with this timing chain set. I'll see where the cam is really at when I degree it. I will go to 100 if it is safe to do so. But I don't want to pull heads to check valve clearance. Should I just go to 104 or 102?

It's a magnum 440 from an RT Challenger.

Remember the scene in the old Dirty Harry movies with Clint Eastwood asking the guy on the ground" Are you feeling lucky" Are you feeling lucky? You don't have to remove the heads to check the piston to valve clearances as long as you have adjustable rocker arms, use a pair of solid lifter to do the cam timing check and piston to valve clearance check by using the adjusters on the rocker arms from around 15 degrees before top dead center to around 20 degrees after top dead center, slowly tighten the adjusters up with a dial indicator on the valve retainer to measure how much you are opening the valves before touching the pistons at 15,then10, then 5 BTDC and then at TDC and do the same checking on the other side at5,10,15 and finally at 20 degrees ATDC. Make sure and count the numbers of turns you tighten the adjusters up at each checking point and then back them off the exact same amount before moving the crankshaft to the next checking point I quit checking once I have at least .100 P to V clearances
I use a set of soft, light pressure, checking springs on the intake and exhaust valves to check V to P clearances and then reinstall the proper valve springs when I'm done doing all the checking Maybe you can find some small diameter springs in a hardware store over there to use on your motor also

Thanks! I never heard about that method before. I do have a set of adjustable rockers so I will try it. Thanks again for the learnin'!

confirm the dampener slit is at true TDC (piston stop) degree it as said & if the guys say 100 is the goal then achieve that or as close as your timing gearset adjustments will let you. As said check PV clearance. check wipe pattern/rocker to retainer/retainer to seal/coil bind/pushrod to rocker, those clearances & adequate lifter rotation. remove inner springs/adequate ZDDP/breakin oil/gun the eng to seat the rings. alot of prep but when done you will have a spot on long block & you have ONE shot to get a very good ring and cam breakin as opposed to an average breakin or even a poor one

Thanks RR

https://youtu.be/1LcYEZwOIQQ.

Spend a few bucks get the tools ...there are some great how to video..on youtube..

I forgot to mention that you should use a set of solid lifters and pushrods to check the valve to piston clearances with light weight checking springs when checking the lobe timing, sorry The hydraulic lifters can and usually will collapse without oil pressure giving you a false reading
Another check you can, and should do, is to check the exhaust lobe timing after you get the intake lobe where you want it, the exhaust lobe should have the exact same amount of advance that the intake has, IE cam is ground on 108 lobe separation angle and you install the intake lobe at 104 ATDC, the exhaust lobe should be in at 112 BTDC I have had several cams over the years that where not ground on LSA that the cam card called for
Good luck on yours

That cam is going to be tight, it may tell you just how far you can advance it. If you cant get it to at least 104, get a different cam.

Cab, good info (going in my notes). Also if running juice lifters I would mockup with a pair of junk hyd lifters and your intended pushrods and with the top cup JB welded securely in place the same distance below the snap ring as the preload you intend to run (or washers below the cup to do the same thing, cup height). this duplicates operating conditions exactly.