In the three years that I have had my 347 together it has wiped a lobe on three different flat tappet cams. All have been from Comp, the first was a hydraulic the other two were solids. It has been a different lobe each time, I used new lifters with each one and followed the break in instructions each time. It always has good oil pressure. Details on the motor: Ford block, AFR heads, roller rockers First Cam was .544 lift 246 duration @ .050 Other two were .528 lift 236 duration @ .050 I am looking for ideas on what could be causing this to happen. I not really looking to put a roller cam in because i am not looking to spend that money at this time. Thanks in advance, Stephen
sure will. also when breaking motor in are you useing an oil with zinc or an additive? without it the cam can and usualy does go flat very soon. back on spring thing, if your useing high pressure springs on break in that could be it also. use stock type springs to break a motor in , its more work to change back to the cams springs but it can save ya a cam.and motor. my 2 cents anyways.
the valve springs may be too much. also what type of oil are you using. you need to put a zinc additive in for flat tappet cams now.
Forget about it. Go roller. No break in, and no stress, and only one more cam swap! Wrong springs ate mine. I used hi zinc oil, and an additive. Still ate a couple lobes.
I am using the springs that cam with the AFR heads, they were suppose to be good for the lift I wanted to run in the motor. But with the other issues I have had with company I bought the heads from I wouldn't be surprised if just told me what I wanted to here so I would buy them. I use rotella diesel oil during the break in and after the first oil change, when I got back from other there in October I changed the oil and put Castrol in it then. That is also the time I started hearing the popping on hard acceleration. I guess I will get the springs for the next cam I buy and run diesel oil in it all the time from now on. Thanks for all the quick replies!
That rotella is what I used, and is supposed to be "diesel oil" and high in zinc. I also ran a bit of the comp cams additive, and still ate the lobe. But mine were GT40 heads with roller springs good to .460 or so, and I had a flat tappet cam in right at .460. So I was pushing it, and pushing it hard. I got a few oil changes in and about 3 or 4 years before my cam ate the lobes. So I know I was well into "broken in" before it cratered. Ask the cam provider about what springs you need, not the head manufacturer. And if at all possible, just go roller. A lot less stress, and pretty much no risk.
the zinc has been removed from rotella now and delo. valvaline vr 1 has it but i still use an additive with it too.always use a lighter spring on break in . the springs in the afrs are most likely way to stiff for break in. the zinc has been gone quite awhile now so may be why urs wiped after a few years . i add the zinc with every oil change. a roller is way to go if ya can afford it . its cheaper than haveing to replace the bearings and possible crank after the cam wipes for sure. but ive been lucky only lost one cam and that was in a clevealnd rite when they did away with zinc and it wasnt known. since no probs but you must do the zinc and low pressure springs to break in.
. one last thing... if useing a flat tappet cam always be sure the lifters are rotateing in bores when you spin motor over . if they arent good by cam lobes too.
Yeah... Too much spring, too much lift (spring bind), or improper break in. They say when you break in a cam, you should use weak springs, then swap in your 'good' springs when it's broke. Or, if you have dual springs, take out the inners. I have never done this, but I may just have been lucky. ??? On a 'solid' cam, you must keep your lash set within tolerance. Improper lash can wipe one. The metals get hot, expand, and if your lash is too tight... bind/wipe. Too much lash can wipe one too. If the lifter comes up on the ramp before it takes up the lash, the sudden pressure applied to the side of the ramp can dig in once the rocker slams into the valve. I don't know about this, but I have heard that valves can hit the pistons, not enough to destroy the engine, but enough to bind against the cam. ??? Are all 3 lobes on the exhaust? That might be an indication. ??? I hope you have better luck with number 4.
When I bought the Rotella, in order to break in the cam, I made sure it had zinc in it. it had a label on it that said something along the lines of "High in zinc and etc." Remember, this was April of 2005...
I don't want to get into a huge discussion to hi-jack the thread, but... Does anyone know if zinc dissolved directly into the oil takes the place of zinc as an additive? My thought is that pennies are zinc (after 1982), and zinc dissolves relatively easily. Could one not remove the copper from a penny or two, then braze/solder them in the engine as sacrificial elements? This is done for corrosion protection in many applications using solid zinc bars. Edit: I wouldn't even be opposed to putting a zinc slug (deplated cent) into the oil filter each oil change if it would work. The fast moving and pressurized oil would errode the zinc off the slug, and the filter element would keep the slug from roaming around in the engine.
