Well actually the 0° is with the lobe separation divided evenly and the cam is concidered straight up. The smog set up, retarded the cam 4°, there by making the split uneven and opening the valves 4° later in the intake cycle of the engine. At this point I still have no ides of what you are talking about. Because moving the timing chain one tooth pretty much guarantees and engine that runs like crap.

 

Well bear, once again, you, in spite of your wealth of knowledge, have learned something from me however trivial. Where were you when I wanted a 427/454 FE for my old Cyclone.

Neither 16-32 deg of advertised cam advance (irrespective of the cam timing events built into a stock 76 460 van engine) or advancing the crank gear 1 tooth made our vans run like crap. I have no doubt you are correct----except maybe in this one case. I will be holding a class in the near future on vacuum advance, no charge for your attendance!

My old Remington 45/70 405 gr rounds (think I have about 10 left) are not black powder and I suspect they are lightly loaded so anyone shooting a trapdoor Springfield does not wind up wearing the trapdoor in the middle of their forehead. I would love to have a lever action (if the lever action will handle that case length) and be able to load like I wanted. Even if I did, there isnt anything around here to hunt with it.

Merry Christmas all----

 

I never said the exhaust gases got reburned I said that the EGR gases "diluted" the fuel air mixture, and as defined by webster means: : to make thinner or more liquid by admixture, to diminish the strength, flavor, or brilliance of by admixture, in other words there is less fuel and air, and specifically oxygen in the chambers.

The gases have to be displacing something, and the carburetor meters fuel based off a vacuum signal, so now without the egr functioning the volume in the chamber has to be replaced with something, and since the fuel is a relative constant, then what is going to increase is the oxygen in other words usable air.

The fuel curve is going to stay the same and in the end will be lean without the egr functioning, because there will be more oxygen in the chambers than before necessetating the need for more fuel.

I mean after all if the egr is inert then why would you need more fuel before with it functioning than after? Doesn't make sense.

 

You seem to be totally unaware of how a carburetor works. Suck more air thru it and more fuel comes along with that air. If the EGR dumped the exhaust gas into the fuel/air mixture in front of the carb then your theory would work. It doesn't, so it does not work your way.

 

With the cam advanced (or retarded as much as you claim), how you are keeping from pounding valves and pistons into non-function junk is beyond me. Either that or your pistons have a very high pin height, lowering the top of the piston least 3/8" down in the hole for a very low compression. Otherwise you can't run a "normal" engine with these kinds of cam advances without mechanical interference problems.

 

When I took mine out of commission, I was able to fatten the mixture with more fuel, and made more power. So all that exhaust gas was doing something detrimental to the performance otherwise why would guys like you and me want to take it off?

 

On the lo-po/comp engines, you can damn near never hit the piston there is so much clearance at any reasonable cam timing. I qualified my statement by saying that the stock low lift cam was what we were talking about. I built a 460 CJ engine from a 70 429 CJ. The only reasonable pistons were dished for a 460--dont recall the DH or year, but the dish was 20 cc's (measured). The TRW kit which included dished pistons, measured at 22 cc's, but I had already used OEM style pistons. I used a 460 crank and the OEM 429 CJ rods. The cam/timing gear setup was for the 429, so the crank gear was one of the 32 deg (adv) sets. Now relative to what cam events, I cant say, didnt go that far, it was a decent street cam, no need to change (more money). Using clay, I found that I needed to scallop the edge of the dish very slightly to maintain ~.100 for the intake---the big ones. The exaust clayed more that ~ .080 so I didnt measure.

Point of all the above crap, is that on a later pass/truck 460, you will not have to worry about clearance, certainly wont hurt to check, but there is room enough for your tool box (not really) on top of the piston. From the start of this thread, thats what he was talking about, a regular pass/truck engine.

I even put a crane 260 RV cam in my 76 with the non-retarded crank gear (+8 deg) and had no interference.

Stock CH pistons no relocated pins-- BTW what the hell is "non-functional junk"? Stop talking that S##T. I have about decided you are a knowledgable, pretty decent guy--although a bit young. How about stifleing the language, or you are off my Xmas card list

 

The motor I am getting is basically a stock reman mid 70's 460. The only option available through this company is the RV cam (they deal mostly with stock replacement engines). After building Mustang 5.0's for so long, I'm looking for something a little more steetable and not a pain in the a** to drive. This won't be a stock motor when I'm done, but I am looking for streetability. I believe the compression ratio is 8.5:1, which leads me to believe there is a lot of clearance there. Emissions tests are not required where I am, but I was going to install an EGR manifold just in case I do sell to someone who requires emissions, all I have to do is remove the block off plate and install an EGR valve. The truck currently has the stock manifold with the valve removed and the EGR port blocked. There are NO emissions equipment on this truck at all. It runs strong for a tired motor (has blowby- oil out of breather). I can light up the 35" tires with no problems.

 

Non-functional junk = Blown engine...... and doing what you claim you have done will cause that.

 

My $0.02 on the EGR mixture thing.

The carb will always feed fuel in relalation to the amount of air passing thru it. Because all the air passing thru the carb has oxygen and the EGR gasses do not pass thru the carb power and cruise mixtures should not be signifcantly effected by the removal of the EGR. There are 2 exceptions though;

This assumes there is no oxygen or unburnt fuel in the exhaust stream. In the perfect engine there would be almost none, but in a real world carbed engine there may be a good amount, and most likely oxygen. Because of the removal of extra (though minor) oxygen it is possable for an engine to run a little off tune (most likely rich) after the removal of the EGR

Also during cruise/light throttle a good part of the fuel the carb feeds the intake is feeding thru the idle/progression circut. The amount of fuel flowing thru this circut is a function of the amount of manifold vacuum (and of course throttle position), and because vacuum will tend to increase with the removal of the EGR, this will again tend to make the engine rich, but we're retuning our idle/progression circut anyway right.

Both of these exceptions are VARY minor, too minor to be noticed, and way evershadowed by changes in ignition timing, tempurature, and altitude.

PS I can't beleive I am agreeing with Bear.

 

Yeah, when I started reading your post I started laughing about you agreeing with me. Is the world ending tomorrow?

 

It just may

 

When I claim it, you can take it to the bank. I have no need to embellish--. If I dont know, I will say "Dont know!". Now out of all this credit I have been trying to give you lately, I have to back up a little bit. You have make an absolute statement about what I have done ("--will cause that"), You are absolutely, positively wrong. Now, with all the credit for being somewhat knowledgeable I have tried to give you, you disapoint me. Now I am going to have to verify everything you say.

Oh well, thats what happens when a young guy starts talking You may be a good kid, but no Xmas card for you--.

 

Benshere,

This advancing the cam 32 degrees, I don't know what you did and I have no reason to doubt you, but. I have built quit a few engines, and worked shoulder to shoulder with some real old school master machinssts that had forgot more then I could hope to learn about getting HP out of old domestic V8s, and I have never heard of any reason or scenario where 32 degrees of cam advance was used. To my recallection I can think of no reason to go over 12 degrees (4 deg retard to 8 deg advance). I understand the point your trying to get across is that there is lots of room, that advancing the cam will not cause interference problems, I don't doubt that. But lets not plant the idea in the heads of the readers that it's OK to just "go one tooth" and guess it's a 32 degree advance and that it will run well. You said yourself your not sure, and you indicated you did not "degree" the cam.

I can beleive that, if the cam was advaced 32 degrees that it may run without damage. There would be LOTS of room, the valves are closest to the piston during the overlap between the exhaust and intake as the piston reaches TDC of the exhaust stroke, with this overlap period happening so much earlier the piston is still on it's way up the bore and a good distance away from the valves when it happens.

The timing of the overlap period is also the biggest reason why the engine would NOT run well. I cut these from the CompCams website; http://www.compcams.com/Technical/TimingTutorial/

"The exhaust stroke of the piston has pushed out just about all of the spent charge and as the piston approaches the top and the intake valve begins to open slowly, there begins a siphon or "scavenge" effect in the chamber. The rush of the gases out into the exhaust port will draw in the start of the intake charge. This is how the engine flushes out all of the used charge. Even some of the new gases escape into the exhaust. Once the piston passes through Top Dead Center and starts back down, the intake charge is being pulled in quickly so the exhaust valve must close at precisely the right point after the top to keep any burnt gas from reentering. This area around Top Dead Center with both valves open is referred to as "overlap". This is one of the most critical moments in the running cycle, and all points must be positioned correctly with the Top Dead Center of the piston."

Then later in the article;

"This begins the overlap phase, which is very critical to vacuum, throttle response, emissions and especially, gas mileage. The amount of overlap, or the area between the intake opening and the exhaust closing, and where it occurs, is one of the most critical points in the engine cycle. If the intake valve opens too early, it will push the new charge into the intake manifold. If it occurs too late, it will lean out the cylinder and greatly hinder the performance of the engine. If the exhaust valve closes too early it will trap some of the spent gases in the combustion chamber, and if it closes too late it will over-scavenge the chamber; taking out too much of the charge, again creating an artificially lean condition. If the overlap phase occurs too early, it will create an overly rich condition in the exhaust port, severely hurting the gas mileage. So, as you can see, everything about overlap is critical to the performance of the engine."

If the intake valve was opening 32 degrees early the piston would push exhaust gasses into the intake manifold, causing all kinds of problems. The exhaust would close so early that none of the final scavanging could happen and you'd end up with exhaust gasses still in the cylinder, causing all kinds of performance problems. Such an engine would backfire like crazy, and if by some miracle you got it to run well enough to drive it would ping to no end, and have little power.

Can it be done sure, should it be done NOOOOOOOOOOOOOOOOO!

 

Whoa! Someone is not understanding what I was talking about.

The discussion I was in was talking about was a low compression pass/truck 460 mod yr 76-77. The reference to 8,16 or even 32 degrees was relative to the specs for the particular crank gears that were OEM on various 429/460 ford engines. Yes, I made the statement that I did not degree the cams and did not know what the particular events ground on the particular cam were. I referred to the ford specs, SVO I think, for those various cams. For example, a hot tip, for the 460's and 351M/400's and still is to replace the later crank gears with earlier pre-smog gears. I did that on my 460. In a very close comparison of the 2 gears, it was obvious that the keyway was ~ 1/2 a tooth to the advance side.

The early 460 crank gears supposedly added 8 deg of advance to the cam, that the late gears took away. Since there was no change to the cam event specs, the total cam was advanced 8 degrees. Now here is the part that i was trying to say, without going into the bloody detail of the issue. I did not know if the cam opened the intake at -8, 0, or+8 whatever it was, the early gear advanced that event by +8 deg. It depends on where the OEM cam started from. A +4 slot on the gear does mean the cam is advanced only 4 degrees.

In the same listing for cam specs that I saw, way back when, the 429CJ's/police inteceptor models had a cam advance of 32 degrees. As I said, I dont know relative to what. If you have doubts about that spec, start looking up OEM specs I am going to also try to refresh my memory.

I gave the examples of what I did and it worked. My 1976 460 E250 Club wagon got a new timing gear and chain and an early crank gear at ~ 52K before pulling a 31' tvl tlr to grand canyon from Fl. Much later due to my own mistake ( a screw hose clamp--from the gear changes) fell through the open dist hole and eventually got in the chain and broke it. Then I put in a crane 260 RV cam, also had to install their adjustable rocker kit, with comp roller tips (1.72).

Things may have changed a little now, but then, the only piston available for a 460 was a cast dish without going to custom pistons. Couple that to the small intake valve of the pass 460 (2.06?) and there was lots of clearance. Not like even the same engine with flat tops. The intake would nest in the dish part, excluding any change in DH.

The later engine was a 70 429 CJ motor. I made it a 460 by changing the crank and pistons, which went from flatops w/2 notches to a 460 dished piston. Those were the big valves 2.24. It also had this mythical 32 deg crank gear. I said that I did not degree the cam, because the car (69 galaxie 500XL) was heavy and OEM was fine. I did clay the pistons to check clearance on the 460 pistons. Plenty of clearance where the valve went into the dish, but a little close where the dish came back up to the flat top.

The poster was asking about a 77 truck motor (I cant scroll back to the first post) and some minor rebuilding information about clearances. My answer to him is that he is 99% safe going stock replacements.

I am not advocating installing a chain 1 tooth ahead, while it may be possible, depending on the can and gear. You also have to remember that each tooth on a cam gear is different that each tooth on the crank. The crank turns 2 times for each cam turn, so any calculation must take that into account. We can read volumns on cam theory, its there to read and I am not disputing any of it. I did not mean to take any crank gear and advance it 1 tooth. In the case of the 460''s you may be able to get away with advancing a later retarded gear 1 tooth but not an early gear on the same engine. Degreeing a cam and clay is the only way to tell. Too many variables, I certainly wouldnt apply to all. Sorry for long post and appologize for not being clear---no speaka the english very well

BTW--Tx opossum for challenging my statements in a gentlemanly fashion, that can be fun at times Bear take note---