I have some comp cams roller tip rockers, that do not look exactly like factory rockers at all. my friend says that I can not use them because I am going to rev past 5800 rpm. Is this true? They are 1.6 they are not full roller rockers so can I use them on a 302 that may see 6500 rpm. Thanks Steve
theres not a thing wrong with roller tip rockers. I had a set on my 355 chevy race motor and they seen 7200 rpms every pass. Now i wouldn't trust them much past that but they are a good upgrade from stock and are well worth the cost.
They will work.... ...you just need to make sure that the geometry works. Pushrod length and camshaft lift affects where the roller tip sits on the valve stem. Get yourself some tech info or advice into checking this information. Seth
Also...... Keep the valve lash set on them. I have seen them back away and I have seen them get tighter. I used to run roller tip rockers(proform's). About 3 years ago at the bracket nationals I lost 3rd gear (drive) during the 2nd time run on Friday. I raced the car Friday and Saturday, made a total of about 20 passes with 1st and 2nd gear, I was shifting at 8,000 rpm and going through the traps at about 8100 rpm. I broke a rocker both days (luckily I had a complete extra set, so I kept racing), but considering all the above I do not think that was to bad. I guess what I am saying is they WILL hold-up. Always my .02 cents.
I ran those exact rockers on my 302 for a lot of years, no problems. Your lifters, if hydraulic, may not like going past 5800 rpm, but those rocker arms won't care. Just be sure you don't try to run the rail-type rockers with pushrod guide plates or close tolerance pushrod holes in the heads, they'll interfere.
cityboy, all you have to do is read and follow what everyone as posted. Seth has once again hit the nail with the hammer, you must check to make sure you have the right push rod length for the cam you are using. Now double check and use the 800 number that Comp cams gives and talk to the experts and I'm sure you will hear the same story. You can get the number from Comps web site. Take care and keep us up to date on how the motors coming along. Terry Gates AKA Bossmav
Thanks Gentleman, The camshaft that I plan on using is a Herbert solid lift cam, it is pretty small compared to some. I am not sure what the rail type rockers are, but these heads do have guideplates. Also how do I know what length of pushrod I will need? Can I get custom length pushrods? I have never had to use anything out of the ordinary when it came to pushrods. Thanks Steve
Rail-type rocker arms have an extended side skirt that rides on either side of the valve tip. Keeps the rocker arm centered on the valve if you aren't running guide plates or close tolerance pushrod holes in the heads. Requires valves with extended tips, otherwise the rail can hit the spring retainer, were very common on early 302's and 351's. My '70 351W heads were like this. If you look at the Comp Cams rocker arm listing in a catalog for small block Ford you'll see they list rail and non-rail rocker arms.
Get this book... .., it is without a doubt the most informative book on Ford engines and components that I have ever seen. It is modern (1999) and covers camshaft selection, valve adjustment techniques, stroker and non-stroker engines, induction, factory and aftermarket cylinder head reviews, wiring harnesses for EFI, ignition systems etc. as well as your pushrod selection. The best book I have ever purchased. It is available through Amazon.com used and new starting at $12.25-I just checked they have 10 of them. I bought 2 of them at Barnes & Noble for about $20. Absolutely a must have for anyone building a small block ford. Ford Windsor Small-Block Performance by Isaac Martin HP Books Seth
I agree, that is one of the most informative books for a ford enthusiast!! It is well worth the money, mine is almost worn out!!
I feel DUMB, I have to ask some questions for what seems to be darn near everything. My heads are 69 351 castings that have been ported, they have 7/16 studs and guideplates on them. How do I know if I have to use rail type or not? Thanks Steve
If you have guide plates you CANNOT run rail rockers and you don't need to. The guide plates will keep everything centered and provide extra support for the pushrods. What you do have to look at is if the valves your using have extended stems that were intended for rail rockers. Longer valve stems mean you should run longer pushrods to keep the geometry correct. Ford made slightly longer pushrods to use with these valves. Sorry I don't remember exact lenths anymore, it's been a long time since I dealt with this. And definitely don't feel dumb. Everyone else who "knows" about this either found out from someone else or read about it in a book. That's why we're all here on this forum.
Assemble one rocker arm to the motor. Cover the valve stem tip with black marker, adjust to zero lash (not the way it will be run), turn engine over several revolutions. Check to see where the roller runs on the tip. It should run on or near the center third of the valve tip. If not and it comes close to rolling off the stem, the push rod length needs to be changed.
