So I'm wanting to retard my cam by 1 tooth. The amazing John Erb said it would liven up my flathead. i have never messed with the cam or the valves on a flathead. Can i just take off the timing cover , then chain and then turn it while still inside motor or do i have to actually have to take it out.
Better off buying an adjustable timing gear, actually in my opinion better off not messing with it at all. Remember, like most tuning decisions, the lord giveth and the lord taketh away. Whatever you gain on the low end you're going to lose on the high end and vice-versa.
One tooth would be over 16°!!....Way too much, around 4° would be more normal...Have to look into what locates the cam gear on the cam [I forget!] and moding it to get the degrees..
Just four bolts locate it. Flathead Jack sells gears with multiple hole sets, or you could drill your own. Again, I don't think playing with cam voodoo is for the uninitiated and I (respectfully) think the OP may not be ready for this kind of thing, especially if he didn't yet know that flatties don't have chains.
well, i'm glad i gave humor to some of yall. Yes I screwed up and said chain. my error for hurrying and typing. i realize its gears and just wondered if i could re-tard it by not removing the cam. First this idea comes from John Erb, If you don't know him , look him up. extremely intelligent man that has build about everything including Mccoulloch blowers. His thought is change a tooth and get more out of it. Now Seb is saying that is 16 degrees, i have no idea. did i build the motor and put a mccoulloch blower on it and it runs great. YES. but we are just looking for a little more. i have a isky 3/4 cam in it but if you can get valves open and closed better, it will / should run better with the blower.
A very bad idea. Any "3/4" cam is already sacrificing some low end. Retarding it that much will really kill your bottom end. Will drive like **** if it will even run.
The cam gear has 44 teeth and the cam turns at half the crankshaft speed. If you move the cam by one tooth, then 360 degrees divided by 44 teeth equals 8.18 degrees per tooth, but that equals 16.36 crankshaft degrees. I never heard of John Erb, but flatheads have been around since 1932 and if moving one cam tooth was a "thing" then there would be hundreds of threads here devoted to it, after all, this is the place where guys gather to learn improvised horsepower. I don't know what you want "more" of, but as I said before there's no such thing as a free lunch and no such thing as free horsepower. Even with a "normal" cam advance/retard of 4 degrees, there are sacrifices to be made in driveability. What good will it do if you can't get the engine to idle less than 2500 rpm, or , on the other hand, get it to rev more than 2500 rpm? Oh, and by the way, you don't have to remove the camshaft to move a tooth. It doesn't work that way and John Erb should know that.
I am not sure that laughing best describes it more like better covers it. Almost sounds like some of the stuff you would hear in the barn drinking whiskey out of a mason jar, "yep we turnt them head around backward so it would breath mo better, then when we put that positracks in the transmission the thang would really run" I have played with cam timing using stock and performance cams a bunch over the years just to see what would really happen. I have come to the conclusion that just a little bit makes a world of difference in most cases, and the motor doesn't seem to care of it has valves in the head, or in the block or the came shaft is located above or below the vales. For best results in most cases if you want to change the cam timing change it very little for best results overall.
Before attempting this, learn more about cam timing and yes for street driving advancing usually works to enhance low end where the engine spends its life, And for racing even a high rpm engine has to pull through the lower rpm to get screamimg. So I think advancing is the solution. But how Much? first you need to degree what you got to see where the events are starting, than you need to determine when you think you want to change them too. You can't make a blanket statement to cover everything, you cant say retard or advance til you know where you are and where you want to be. I run A couple of GMC inlines and we found stock timing marks are not consistent. each engine needs different keys made for offsetting to correct what we think are manufacturing tolerance stack ups. And I did do one stockish engine that need a full tooth to get the cam straight up!!! That was 13 degrees, and right now I don't remember if it was advanced or retarded but it was to get it to a 108* intake lobe center. And as all you Flat Ford guys know, don't mess with the GMC Boys!!! LOL Frank
Many years ago I cobbled up an adjustable cam timing gizmo for Chevy V8s that adjusted very simply via an access hole in the timing cover, and put it on my Corvette (I have an old photo of it somewhere). This was in the days before easy access ch***is dynos so all testing was seat of the pants and 1/4 mile. Don't remember the adjustment range but the same as you got with those offset bushings. In the 1/4 mile (high 12s) it did not make enough difference to overcome other factors (track conditions, driver error) and on the street it felt best at full advance, which is where I ultimately left it.
I once had an Isky Flat head Ford cam that was ground so far off spec moving it a full tooth might have worked.
LMFAO must have been a Monday cam. Timing sets and cam shafts often miss the mark, which is why any engine builder worth his salt will tell you to degree the cam. I have had some real cam shaft nightmares in the past that probably would not have been if I didn't know any better. Some I have just sent back, others I have made adjustments to. I actually have a crane cam and a cloys timing set in a Chevy engine that I screwed together back in the '90s that degreed right on the ****on, could be the I got lucky and the timing set was off enough in one direction to compensate for the cam being off in the other direction or that they were both correct but it is rare that you don't have to jiggle something a little bit or live with it being a little off. M*** produced stuff makes for m*** produced complications.
Yep you get the crank key off a tick then the timing set then the cam index and the next thing you know all those little variables stacked up and it's off a few degrees or more. Makes you wonder how many people just drop them in and go. Never realizing they could be leaving a significant power gain on the table. Or trying to tune on a lazy motor that's just the cam timing off.
More common than you can imagine. Pull the radiator the grill and the timing cover @ 5 and be cruising by 9. "yep I still gots grease under my nails but I am stylin babe."
Crank it again, backfire thru the carb. Won't start. Check everything..."Hell, it's a TOOTH OFF!" Durned apprentice and his wacky tabacky... Do it myself next time! 911 Porsches have DOHC, 2 cams each bank. Timing sprockets are drilled in multiples, and a pin locks each one in place, covered by a LARGE washer and nut. These are 'degreed' every time a hydraulic set of tensioners are replaced, or stretched chains. One tooth off? Possible interference of piston to valve. And a strong wager it wouldn't start. Advancing/retarding timing is limited to 4 degrees, after nailing true top dead center. Period!
Never a problem in a flatty, if a valve smacks a piston you got some serious problems right there. In a perfect world the intake valve chases the piston down the hole and the piston chases the exhaust valve up the hole. Sometimes our world is less than perfect. Some of the older twin cam Maserati had valve timing that you could adjust with a screw on the timing chain. One Saturday morning when I was living on the peninsula my old man calls me @ 5 and says meet me at the shop, and pick up my car. You are going to Oakland to x machine shop and picking up some valves @ 6. The shop is not open but the fella that owns the shop is going to let you in, he won't open the door if he doesn't recognize you and he will recognize my car. So I am off and running. I get the valves and back to his shop and he says, "These damned old Maserati! I did a valve job on this one and when I fired it off it sounded like it was timed a little fast so I was going to slow it down. You know I have always turned that damned screw the wrong direction so when I went to turn it I said nope that's wrong and guess what I turned it the wrong way. damn it!!!" it had to go out on Monday so I pulled the head and started getting the new valves fit while the old man worked on something else before we could go to breakfast which turned out to be a late lunch. But it was running perfect when we drove it to the burger stand. There are no short cuts in this game.
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