OK here's one for you guys to consider...

If I were to run my cam timing 4 degrees advanced with a stock cam, and retarded the ignition timing to say...8 degrees btdc, would I have a pulling SOB, an engine slowly being destroyed or would it not make a difference?...would I still be too far advanced in my cam timing?

Between TorqueKing, you guys and my local speed shop I can not get a concensus as to where to run my cam gears...Straight up or Advanced?

 

Dan,

Maybe it would be a good idea if you took a look at how to degree a cam (maybe 20 minutes on CompCam, Crane or several other sites) and get your own perspective on what happens when you change cam timing from the original grind using just the cam timing gear. All those sites cover their products in a very thorough manner. I know I'd do just that if I couldn't get a consensus from the sources I was using.

George

 

I have the question in to Edelbrock, so I will upfdate y'all soon.

Thansk for your help.

 

Look at it this way, if you install the new chain and advance it 4 degrees, you are actually advancing it 8 degrees because you started at 4 degrees of retard. That sounds like trouble to me. I put my Edelbrock chain at 0 and have no detonation problems and have more power. I did this before I changed the cam, And with the CompCams 268h, I still run it @ 0. No problems!!!!!!!!!

 

I've answeres this once. Don't worry about a consensus. If you do this you WILL have trouble.

 

[updated:LAST EDITED ON 31-Aug-02 AT 12:35 PM (EST)]Here's where I am frustrated...If yu run straight up gears and had good results, then changed to a performance cam that I believe has 3 or 4 degrees advance built into it and still have no trouble, why would I have trouble running the 4 degree advance on my stock cam? Is it the timing or the stock cam that will give the problems. From a methematical standpoint it just doesn't add up.
qtrmiler says I will have trouble, Torqueking says he runs 4 degrees advanced with no problems.
Qtrmiler, have you run a stock cam 4 degrees advanced?

 

Quotes from this thread:

"Look at it this way, if you install the new chain and advance it 4 degrees, you are actually advancing it 8 degrees because you started at 4 degrees of retard. That sounds like trouble to me. I put my Edelbrock chain at 0 and have no detonation problems and have more power. I did this before I changed the cam, And with the CompCams 268h, I still run it @ 0. No problems!!!!!!!!!"

"I advanced my 460 3 degrees using a eldebrock timing set, a mild speed pro cam, but I did not take the time to degree the cam. about six months later I started to develop a miss, I yanked the heads and I had sunk two exhaust valves. I took the heads to my head guy and the first thing he said was to much cam advance. So you see straight up is the better way to go Eric"

"I've been building, racing, & towing with 385 series engines since the mid seventies. If you want to bring it home on a hook, go ahead & advance it. Those good old cast pistons just adore detonation. I've had them detonate after just going in straight up. If there's any doubt of my credibility I can show you my 8(close to 7) second Mustang with a .030 over 460, maybe my stock 13.00 Cyclone Spoiler? My best advice is if you aren't going to degree the cam, straight up is as much as you want. You'll be better off going to a better head."

"Without going into a lot of detail, when when degreeing a cam it allows you to change the centerline of the lobe separation. This moves your torque rpm range up or down. If your cam is ground on a 110 degree centerline and you use the timing gear to change the lobe separation to 112 degrees centerline, you've actually retarded the cam timing two degrees. Sounds crazy, but if you change the centerline to 106 degrees, you've advanced lobe separation four degrees."

 

In 20+ years I have run every concievable combination including custom making an intake or two. The theoretical mathmatics of cam design & their degreeing is not as simple as 1+1=2, stock cams are made to work for emissions & have a very narrow range of area to gain & lose performance in the way they are degreed. An aftermarket cam is more forgiving & usually is already ground to a point that it's almost fool proof. There's always a chance that this'll work, it all depends on the engine, I have done a few & it has worked once, the rest with the obvious end result. If more power & economy is your bag you should cosider other options such as a different cam, intake, & exhaust. Case in point... my E-350 20' motorhome has a stock 460. I freshened it up, installed headers & a free flow exhaust, & tweeked the carb & timing (also a straight-up lower gear), It will out-pull a lot of things it shouldn't & get a good 14 MPG... without an overdrive & injection. I built one some time ago with the same combo, Holley injection & an E4OD & it gets 18/20 MPG. This is the type of results years of trial & error & experience gets ya.

 

OK I hear you...Now a question...If I go ahead and try it, will I know it is not going to work before it is too late, or will it perform great and then die a slow (or quick) death? If I try it and it is too much advance, I am just out some gaskets and some time to change it back. That is if I can tell I am in trouble.

I agree experience is king, but I need more than guys just saying "I don't think it will work". Don't mean no disrespect.

Thanks

 

No disrespect at all, just questions . You might be able to hear the detonation. Best way is to keep an eye on the plugs to see if they are getting speckled for aluminum, but it's usually too late. Might be able to feel the power loss too. You'll know whe you do break a piston too, she'll sound like someone want's out but you still have oil pressure. Might give it a try if you feel lucky, I'm usually not

 

Ok, I finally found this thread. I was mentioning that I have a Comp Xtreme energy cam, and a timing set with multiple keyways. The cam is ground 4 degrees advanced, I installed it strait up on the timing set. It runs very well, and even with 9.7 compression, and 36 degrees total timing, it still doens't ping on 87 octane fuel. This is a 302 though, these guys have far more experience than I do, so It would be wise to listen to them and go strait up, unless you plan on degreeing the cam. I think most of these blunders from overadvanced cam timing have sprouted from the fact that cam was not degreed, and more advance was placed into the motor than was intended. 4 degrees in theory would get the torque available sooner, but I'm learning from the 20+ years of experience from some of these guys, and all of a sudden that 4 degrees doesn't sound too appealing. Like I said, my advance was already in the cam, so what I did and what you're doing are two different animals. I can talk theory all day, but experience will get you running better.

'77 F100, 302 (the aftermarket Prodigy), C4
Cadet Second Lieutenant John F. Daly III
South Carolina Corps of Cadets, The Citadel
The TorqueKing

 

You said it Torqueking. Sometimes too much of a good thing can kill ya!!!!!!!!!

 

Well, I went ahead and tried it at 4 degrees advanced, took it on the freeway, and i noticed right away that the vacuum guage reading was quite a bit lower than it used to be, and I didn't have the power I was expecting. Then...
It hiccupped...Just lost power momentarily. Off the freeway and back in the garage. I must bow my head to the advices I was given and didn't listen to. I'll be tearing it down and bringing the cam timing back to straight up.

I only drove it five munites, and I can't see any damage, but it's just not right.

Now another question...
If you can't run the timing gears advanced with a performance cam, and you can't run it advanced with a stock cam, when CAN you run advanced timing gears? Why do they offer it if you can't use it? Someone must be able to run it advanced, but who?

Thanks for all the help.

 

You can run it advanced or retarded, depending on the cam centerline grind. That's part of degreeing a cam, determining the actual centerline. Most catalog performance cams are produced with 4 degrees of advance in them, as installation is generally performed by people seeking 'bolt-on' hp. Virtually all custom grinds are finished at zero advance, the reason mid-performance gears have the four degrees advanced/retarded or straight up.

A truck cam centerline is normally 110-112 degrees. Put four more degrees on there and you'll have a problem. Winston Cup grinds have centerlines as low as 96 degrees, so you can see the multitude of combinations possible in degreeing a cam.

With all the possible variations of cam centerline grinds, racing timing gears normally have a minimum of nine keyways to adjust timing to track/conditions and the cam grind being used.

There's no secret to degreeing a cam and the process, even if you just read it, will tell you a lot about the performance of your valve train. Advance doesn't always mean advance.

 

Edelbrock say to NOT run it advanced.