Wrong, the early timing sets (pre-72) had the cam a 0° also known as straight up. The 72 and later timings sets retarded the cam timing 4°. I don't think the factory ever advanced cam timing, they just made the cam the way the wanted it and installed it straight up.

 

You are contradicting yourself a bit so which is it?

When you said one TOOTH in all the previous posts, did you actually mean KEYWAY? On many aftermarket gears the cam timing is adjusted by moving the crank gear to the apropriate KEYWAY for the desired cam timing and then put together with the correct marks on the gear for the chain just like stock or "strait up". It seams to me that either your terminology is off your you don't understand how these gears work. Even then the most advance these gears allow is 8 degrees.

Or are you talking about some strange combination of stock parts? If so then well I gotta go with Bear. I have never heard any stock gears in any other configuration then strait up or 4 degree retard. And for you to suggest any way that it can be done with stock parts, or should be done, or would ever work, is beyond ridiculous and not at all reasonable or advised

BTW, Your Welcome.

 

Just to clarify, as benshere said, it is a '77 460 that I assume has the 4 deg retarded factory timing set. I wanted to replace it with the Cloyes set that is adjustable, and set it straight up. That should essentially be "free horsepower" as I'm going to replace the timing set anyway. I have no intention of jumping teeth on the gears, there really is no need to with the adjustable crank sprocket. Some sets have as many as 6 - 8 keyways in them. I do appreciate the info and just wondered if anyone has done this without any problems.

 

In a side to side comparison the OEM crank gears (early and late) have 1 keyway, no adjustment. The keyway was clearly offset so that it was positioned differently under a tooth. All the material I read on them, said (and I think it still does) that the cam gained back 8 deg that the smog years lost. It has been a very long time (a 76 van was the one I did this gear swap on) ago. I have done the gears you are talking about with 3 keyways, so I know about that.

Nope, not contradicting myself at all. Maybe I have been unable to make it clear, but understand I have personally done the comparisons, run the numbers (calculating just how many degrees each gear, cam and crank will change, per tooth). Maybe I should have made it clearer. My brother did our 460's at the same time, and ran the numbers. For some reason, I bought the ford early gear but maybe they only had one in stock at the time, so my brother told me he advanced the chain 1 tooth on either the crank or cam gear. That I cannot verify or did not witness. I can verify that if you can do the average math, you can arrive at a figure that using the OEM gears you can arrive at a cam advance figure. That is all that a adjustable gear does, advance or retard the cam events as a whole. You do not change overlap, lift at .050 or max lift. It will make my head hurt, but I can do the math if you cannot. I understand how the gears work, and I did mean tooth and not keyway.

If an OEM gear is either 0 (straight up) or -4 (retard) then it follows that for an OEM gear to advance 8 degrees, from a 4 deg retard then the net figure must be +4 degrees. I am thinking you have fallen into the trap of thinking you are the only ones who can analyze.

Its only rediculous to someone who cant comprehend the process. News flash! OEM parts are often "strange combinations" thats what drives the aftermarket. An adjustable gear in only a "degree modifier", and if you can acomplish it without a specific gear, it is the same thing. Truth is, if you cannot understand the processes, you shouldnt even adjust idle screws. Let me be very plain about this, yes it can frequently be done with stock parts, yes, it should be done only if you know what you are doing, yes, it will work, and reasonable or advised is a competence issue. I clearly stated that not all cases could be done the same, it totally depends on the cam figures and the gear.

Now I have a question for you---. If two 460's , 1 a late model truck and 1 an early performance model (aka, CJ with more compression) have gears that are straight up, are you saying that the intake event starts at 0? Do the engines, with considerably different cam events, overlap, lift, duration etc both start the sequence of cam events at the same 0 degrees? Better think about that one! I am also thinking we are getting deep into symantics and you are spending a lot of time thinking I am the dumb one simply because you have never heard of it before. Be careful guys, one of us may indeed be dumb.

Merry Christmas to you both

 

Sorry for the double, but since my last post, I decided to quickly run some numbers, the same ones my brother and I ran way back for the gear teeth. I am not trying to flame you, but it is obvious that you are not clear on what I am talking about by moving the timing chain one tooth forward, or back for that matter. You are welcome to run the numbers, as I have, and tell me what is wrong with this picture-----other than you have never heard of it before

I just went to my garage where I retrieved an old edelbrock timing chain and gears set "True Roller", that I never installed on anything. So, we are not talking "hypothetical" or 'First thing next Monday" here. Its catalog #7830 for a 429-460 cid ford. It has 44 teeth on the cam gear and 22 teeth on the crank gear and also has 3 keyways, I think we all understand what the 3 are for. -4 deg, 0 deg, +4 deg. So, lets do some of the math--. There are 360 degrees in a circle (just so you know that I understand) divide 360 by 44 and get 8.181818, that means each tooth of the cam gear is ~8.18 degrees. The cam gear teeth reflect actual degrees of cam movement. The crank gear is only 22 teeth because the crank makes 2 full revolutions (intake, compression/power,exaust) for 1 rev of the cam.

Irrespective of whatever setting is on the crank gear for cam timing, 1 tooth change on the cam gear will net 8 degrees, plus or minus. The way I see it (I'm sure you will tell me if I am wrong--thats O.K.) If you want to obtain the 8 degrees of advance that an early gear gives you, but dont have the correct crank gear, then advance the cam gear 1 tooth on the chain. That will net you the +4 degrees you talk about with the 3 way key. Now, there is no doubt that the dots will not line up, so dont let anyone else work on your timing set if they cant understand what you did. Hotrodders have done "out of the box" thinking from the start. How is it that when I do it you think its rediculous and unreasonable.

Please show me where my figures are wrong---

 

No, the engine is timed off of 360° base and if you look at cam specs, everything is in degrees, except lift. Zero is TDC, if you retard the cam 4 degrees you subtract 4 degrees from each of the spec number. In the engine proper, that means the valves open and close 4° later in regards to to the position of the piston than when the cam is timed to 0°. You really need to do some research into engine fundamentals. This is stuff I learned in high school.

 

Once again this is basics and you obviosly do not understand engine basics. First off a 4 stroke engine from 0° at TDC to 0° TDC again must go thru 720 for one full cycle of the cam. So double your numbers.

 

What are you talking about? I just said all that, read my post. I just finished saying that all the events of the cam were changed, not the individual events by themselves. I just finished saying that the crank turned 2 times for each rev of the cam. 1 cam rev gets from TDC at the start of the power stroke to TDC of the next. Its good you learned some things in High school. You should have worked harder on your reading skills. I said all that you refer to, but you didnt pick up on it.

You are so busy trying to sound like an expert that you cannot understand what people say, not just me, but others as well. No doubt in my mind I have a better understanding of engine basics than you do. Like I said, 1 tooth of the cam gear nets you 8 degrees of change of every lump and event on the camshaft. It does not change the relationship of each individual event to another. Yep, does not change lift-----said that. FYI, because of the 720 degrees of rotation of the crankshaft for each cycle, it only requires a 4 degree change of the placement of the keyway to affect the cam 8 degrees.

You could be a pretty nice person, but I dont have time for your schooling.

I asked (nicely) for someone to show me where my figures were wrong-----you could not.

 

Benshere I think I gave you to much credit before.

OK I'll prove you wrong, all I need is one sentence but I think you will need more to understand. Because I think I know where your confusion is coming from and why your numbers are so high.

I put my comments in blue in an attempt to make you understand but I fear it is hopeless.

"One" of us may indeed.

How was that do you understand now?

I will admit I was wrong when I wrote this, will you admit you were wrong when you wrote the rest?

Have I (nicely) shown you where your figures are wrong?

BTW, you shouldn't be complaining about nasty tones, your just as bad if not worse. In this thread anyway, Bear and I have gone at each other before in other threads, he got pretty nasty when he was wrong also.

 

You are not listening or comprehending that the 4° is at the cam, not the crank. Like I said, your engine basics are non-existence to poor at best.

 

I think we need to apologize for the highjack.

You will have no problem at all with the Cloyes set at strait up. Many, many people have done it, and I will be, as soon as I have the time to get into the motor of the truck I just bought.

 

I feel I should add some final thoughts. If indeed your brother just advanced the cam gear 1 tooth, and still had the factory timing set with the 4 degree retard. He would have ended up with 12 degrees of advance, 16 from the tooth jump minus the 4 in the stock gear. I could emagine that a 460 with 12 degrees advance on the stock cam might run vary strong at vary low RPMs from idle up to maybe 2500 RPM but would soon run out of breath.

 

More to follow, I will reply after Xmas.

billg302--- I never intended to suggest that anyone should jump a tooth on any gear. I was simply relating an example that worked in lieu of an available pre-smog gear.
I have done exactly what you are inquiring about. I went with a pre-smog gear on a 76 460. I also put on an edelbrock intake, except I used a 750 (really too big for the purpose) holly (sq bore 7010/11 forget which). Later, (125K) I replace the cam with a crane 260 RV cam, probably 260 deg advertised. Because of the cam extra lift and wear on the "sled" type rockers I had to change to the crane adjustable kit and some comp cams roller tip rockers (actually for a bb chebby). In the present group of contributors on your thread, I apparently am the only one who has "done it" and successfull at that. The pre-smog gear does adv the cam events by 8 deg. I will provide a source for that info--later. All this stuff was done by me back in 78/79 and the cam swap in early 80's. I sold my van ~93 after getting a 93 bronco, so I have had to try to recall all the cam figures from way back. I am gradually finding the specs I relied on back then and they are still good. Because of the contentious direction your thread has gone, I would suggest that you not believe any of us, but find some other sources. What you are attempting is a well known by anyone who has experience with early/later 460's. LOL

 

billg302- sorry for the double, hit the submit key by accident

With a pre-smog gear or a multiple keyway new set, installing at 0 (straight up) will put the cam events at the advertised spec for a stock 460 which is for the intake opening at 16 deg BTC. Yes, it is well known that a +4 degree install will give better low end power. My contention throughout this whole "ordeal" is that you will have no problems with valve to piston clearance at this setting. While you may have problems with performance cams, I think they would have to be very radical. At some point you might want to check clearance, but not at this level. The design of the 460 dished piston and the later higher deck (10.322) coupled with the smaller intake valve size of the pass head, 2.075-2.090 means the piston does not get very close at hardly and valve timing
again--LOL & merry christmas

 

As a newbe reading this, ya'll jaw beating each other back & forth, first I was thinking it was good, because all of you are explaining it clearly the events that are happening with the crank & cam rather than beat around the bush with a small tib bit of information like you normally do because your afraid you'll give some big high performance tip away to another builder.

Thats what I'm reading & seeing, reminds me of a bunch of go kart racers in the tech room during a tear down bickering back & forth.

If your hands have touched it, that should mean you ought to know about it from that point on & you either can help somebody on here with their question what is right or wrong or you dont want to help.

Get to the point when helping sombody, more than likely why people come here in the first place.
Neil