Originally Posted by F100cleveland
My valve train started makin some really loud clicking noises. It started about a week ago, but very very soft. Just figured that I had a rocker that was getting a tad loose, so I didn't worry about. Well, it got REALLY bad. So yesterday I pulled the valve covers off and found that 3 of the guide plates on each side broke. What could cause this? The only thing I can think of is that the pushrod was too tight up against guideplate and made it rock real slightly and it broke. So I had 6 pieces total break off, they all look the same.
You don't mention whether the 6 pieces that broke off were all intakes or not. The photo shows an intake guideplate that is broken. 8.050" sounds waaaaaaay too short, are you using standard length rocker studs? I generally use +.100" longer studs to gain more clearance and better rockerarm geometry at the valve tip. My "Cleveland & BBF" pushrod length checker has a minimum length of 8.350".
The photo clearly shows the impression made by the meeting of the pushrod and the guideplate. This undoubtedly occured during the opening of the valves. If they are all on the intake side, then I'd start by looking at the one that isn't broken. Take a look and see if it is fracturing.
I'd check to ensure that your pushrods are not contacting any material in the cylinder head, too. Checking to ensure that they are straight, is a good idea, too.
You may want to consider posting a bit more information about your valvetrain. EG: camshaft lift, lifter type.
I can't imagine using a set of 3/8ths inch pushrods with a modest camshaft and hydraulic flat tappet lifters, so something tells me that you've gone to the upper limits in off-the-shelf cams or possibly even a high lift custom grind. If that is the case, then you probably should be using taller rocker arm studs. Your installed spring height could also be a factor with a standard length stud. Do you know your installed spring height? Did you assemble your cylinder heads yourself?
There is very clearly a clearance problem. It should have been resolved during assembly, and if it was, then as previously mentioned, you may have bent pushrods. A bent pushrod could take up any otherwise available clearance. It is very easy to check for bent pushrods. If they are straight, you could buy new (I'd replace all of 8 them!) guideplates, notch them and try again. Going to longer rocker arm studs will mean new pushrods, probably not a bad idea if they are worn.
It is fairly tough to make any real recommendation without the details of your valvetrain. Even your deck height plays a role in it...but 8.050" sounds completely wrong. 8.408" is a stocking length for a 351C by Comp, 8.500" is a stocking length by Crane. You're nearly a half inch short, if your measurement is accurate. It sounds like you used a pushrod length checker for a 351W/BBC. You need to use one for a BBF/351C or tall deck BBC.