For those that have followed my dilemma, I am in the process of installing cam #3. To refresh, first cam was flat tappet, wiped out half the lobes in less than a couple of hours running. Conclusion was way too much spring pressure. Found out heads I bought was set up for roller cam. I ask & they said it was fine for flat tappet. They lied. Cam #2, another flat tappet, went in along with a new set of valve springs. (took a friends word). Cam #2 wiped 2 lobes within about 50 miles. I got it tore down again. I borrowed a friends Moroso hook and pull valve spring tester. Springs just break seat around 120lbs and go to about 280lbs at full compression (not binding). I called Comp Cams and he said this is the exact specs they should be. So why another 2 wiped out, I'm not sure. Anyway cam #3 is a retrofit roller. Comp Cams says valve spring specks are the same for this one as the flat tappet. I'm confused because I thought it should be more. I'm not planning on spinning this motor much more than 6000 but I don't want to encounter valve float either. Any comments or suggestions? Thanks.
cam for you First to cams, spring pressure killed your breakin period. Once a lobe starts to go there's no stopping it. Just a matter of how long before it goes flat. Now the question is, did you completely clean out your oil system? Wipe the pan out, flush the system. Roller cams do need a breakin period, just not like a flat tappet cam does. Valve float is a matter of the right cam profile/springs for the rpms you want to run. Valve float will happen if you go past the cams/springs rated rpms. Only way I know to increase your rpms is to use light way parts, rockers, pushrods and most important, titanium retainers. They're good for about another 400 rpms before float. Speed costs money, how fast do you want to go?????
mavaholic what is your break-in procedure? Stock 5.0 rollers have a rev limit of 5800 rpm built into the computer. In your post you indicated you wanted to go to 6000rpm. I don't know what size cam you are using but how close are the spring pressures to a stock 5.0? Also, if 120 and 280 are OK according to comp cams application maybe the problem is elsewhere. As RR said, did you get it cleaned out good, also when you prime the pump by hand (with a drill) do you get good oiling up to the lifters? Is your oil pressure OK? Is it an adjustable valve train or a positive stop valve train? What heads are you running? If it is adjustable then about 1/2 to 3/4 turn past zero lash is correct. Mavaholic, I've seen you post on here many times so I know you probably know all of this, just trying to come up with ideas. Good luck, EFIMAV
Thanks for the replys. I am running AFR 185 heads with adjustable valve train. I also do the break in procedure as outlined in Comp Cams literature. I have done all that you guys suggested. I have talked to alot of knowledgeable guys about this and the thing that keeps comming up that I didnt do was remove the inner spring for break in. Its not written in CC's procedures but I've been hearing it alot. I think if I had done that, the second cam would have worked out OK. Oh well, this is my first high performance build up and it has been one hell of learning experience. Thanks again.
Dont get discouraged. Just stick with it and look at the positive (as hard as it is to do). I had the same problem with an old 460, but instead of taking a chance, I left the inner spring off for break in. Works great. Once you get her lined out, I bet it will fly...those AFR heads are really nice pieces, and from what I've seen/heard, they work even better. Also, while breaking in a cam, dont let it just sit at one given speed, vary the rpm, say, between 1200-2200. That makes the oil splash around more, lubricating the cam/lifters better. Remember, the only oil it gets is from the reciprocating assembly and the "leaks" from the cam bearings. Another consideration, dont break in a cam with synthetic oil, use a good petroleum based oil (non-synthetic). I bet you'll really like that roller
ok...so the break in for a double spring is take out the inner spring....i will remember that...as to not duplicate the same problems....
Another thing to consider is don't use the cam lube supplied with the cam, but rather the cheap molybdenum assembly lube you get at the parts house. General consensus around here is that the stuff they supply isn't always up to the task. I've always used the black stuff (moly) and have yet to flatten a camshaft.
FYI cam lube I have always used STP as a cam and bearing lube in all my engines and have never had a problem, It also doesn't make your oil black after run in.
I only use roller cams. Seen to many problems. Performance valve springs being the biggest problem with cam failure. There is a guy with a camshaft break in tool. He breaks it in and numbers the lifters for you. Scott was his name runs an all ford custom grind camshaft. I can't think of the business name at the moment. I am considering swapping in a custom grind roller from them late this year(winter project)
cam break in Cam research is the name of the company that has the break in service, I just had a solid flat custom ground from there including the break in service. Hopefully I will hear it run within a couple of weeks.
