Here's goes nothing..., Rick & I have readied our steeds and are on our way! Options

[byndbad914]

Don't assume TFS heads are "slam dunks". When I worked for Ford Performance Solutions in the 90s they had a few sets of their (then new) twisted wedge heads wipe the guides out in under 3K miles.

We weren't having any issues on our engines. Turns out they sold a set of "recommended" pushrods with their heads - I never pay any attention to that crap and only put pushrods in that I have personally measured based on getting perfect geometry. Turns out we ran pushrods 1/4" longer (on good blocks with non-decked new heads) than they recommended.

They had a HUGE recall and replaced the guides (we said unnecessary but we believe that was their "excuse" v. saying they were stupid) but also included the longer prods we spec'd out. No issues after that.

I would say you need to really look at the geometry and make sure the prod length makes sense. Also, take a pair of calipers and measure from one of outer bolt pads to the deck at each end and make sure they are similar. Then check that dim against the other head - that will quickly tell you if they were decked or there is an inconsistency in machining. They are symmetric heads so they all roll off the exact same assy line but hell, you may have an early casting on one side and some sort of improved later casting on the right (wouldn't be the first time I have seen that).

Scorpions aren't that great and Yella Terra ain't much better. You should be OK with a hyd roller but you couldn't give me either brand for my race engines (and FPS sold 'em both all the time but not something I would run).

Too hard to type, PM your # again and I will call you (IMG:style_emoticons/default/laugh.gif)

[messix]

i'd run a dial off of base the cam for the push rod to the rocker pad measurement on both banks to tell whats up.

[rick 918-S]

Were home, Looks like your getting some good info here. (IMG:style_emoticons/default/bye1.gif)

[Brett W]

The TFS heads have had there quality problems solved. I remember that issue that Tim mentioned as well. Supposedly they fixed that issue with the Ford heads. It won't be an issue with the LS series heads.

Bill and I measured the spring coil clearance and I measure a little more than .060 between all the coils at full lift. Like others mentioned a rocker arm geometry check is definitely in order.

I realize solid lifters can be a pain in the ass, but at least there is no confusion in the lifter preload. Either they are right or they make a lot of noise. May look at that as an option.

[wbergtho]

Yeah Brett,

I'm starting to consider a solid cam and solid lifters. I'm going to pull the heads and have them looked at closely to see if there are any machining differences. Before I pull them, I'm going to get a second opinion on my preload. If the preload seems excessively high, I'll try shorter pushrods. we'll get to the bottom of it. Hey Brett, I think I set a new WR getting home in 13 hours! The car seems to like the higher RPMs.

[byndbad914]

I agree TFS fixed a lot of issues, but I wouldn't put it passed them to mess up something new. Most likely the heads are good but not guaranteed.

don't arbitrarily try short pushrods. I missed the pic of the broken rocker (you posted it while I was typing my previous post). I bet they press the cup in, have too little meat there and the hoop stress combined with some issue you have is causing the rockers to fail. To do that damage and not damage a Prod means the rocker is weak.

As for Prod length, with bolt down rockers, you need to watch how much compression you get in the lifter to determine pushrod length. Geometry is unadjustable other than shimming, but that should be kept to a minimum.

Sometimes lifters don't want to bleed down while you adjust and they want to lift the valve - that is okay. The old-skool rule of thumb still applies in that you should finger tighten to zero slack, then have only an additional 1/2 to 3/4 of a turn to seat the rocker on the stand, then you final torque. If you get more than a full turn you should consider shorter pushrods and that is the only reason to do that.

After it is fully seated and torqued, then you roll the engine over by hand and verify geometry. I wrote a magazine article on how to correctly read rocker geom about 10yrs ago now for one of the Ford magazines now that I think about it hahaha - forgot about that 'til now. Anyway...

It is completely possible that the geom is F'd up from the factory - a set of aftermarket Chevy heads came out about 2yrs ago cast in China, machined in Australia and hit the states (this is pretty much standard procedure for all the alum heads and many are being machined in China now as well). The geometry was complete crap, so the owner of the biz having the heads done came by Troy's shop (I was correcting this stuff while I was visiting him hahahaha) and we showed him that he had to relocate the stud 1/8" to fix it. Little crap like that will make a huge difference in geometry. I really shoulda charged that guy for that (IMG:style_emoticons/default/idea.gif) he has made a FORTUNE on those heads now.

[wbergtho]

i'd run a dial off of base the cam for the push rod to the rocker pad measurement on both banks to tell whats up.

Great idea. It will tell me if there are any machining differences.

[messix]

i'd run a dial off of base the cam for the push rod to the rocker pad measurement on both banks to tell whats up.

Great idea. It will tell me if there are any machining differences.

you could also check it against the spring seat also.

the geometry being off is the most likely culprit, but you'd think it would be glaringly apparent to cause this kind of and frequent failure.

is it only breaking intakes or exhuast? or both?

[messix]

i just can't help but think after looking at the photo of the broken rocker that there is very little "meat" around and above the push rod cup.. me thinks very bad design.

[wbergtho]

is it only breaking intakes or exhuast? or both?

Both. And only pass side.