so...after all the rocker posts, my heads are off for fresh/up. stage VI max/wedge, comp .663lift/312dur. cam, springs 220@1.90 580@1.25 640@1.20, valve clearance .137, 1.5 ratio. shift 6800/7000 rpm, never backed off for winter.

what do i look for other then coil bind,pushrod lenght etc, would like rockers to last more then 75/100 runs
gary

I'm a little confused about your post but let me begin by saying a set of T&D rockers will defiantly last more than 100 runs. The paired shaft (5/8”) are by far the best and cost a couple hundred more but you can take them off one cylinder at a time instead of the whole set of rockers. I say it all the time on here, once you buy a set of T&D’s you will never look back.

single shaft system, i'ved had to "look back" six or seven times in the last five years

if you're tearing up rockers with that cam and amount of runs something is flat out wrong.

3/8 .120 pushrod, real spring pressure, comp springs #943 per cam list at 240@1.90 598@1.25 "new"
rocker breaks horozontal bottom side facing spring, spring dia. 1.55 plenty of clearance. plenty of oil. adjusters are out 1 turn per T&D.
scrub pattern?

Any pictures of the broken parts? I agree that something has to be seriously wrong with that set up. I have run a ton more spring pressure than that on the common shafts with no issues many times in the past. I have never broken one of thier rockers. I bought a set of heads from someone(whole other story)that had T&D common shaft rockers that obviouosly were never cared for and chucked some pushrods and they still were not broken. A number of them had bad bearings afterward and were very beat up but they were still in one piece.

photos tonight

i've never been a big fan of high spring pressures but one things for sure you run too little with a roller and yes you will break parts

i think something is of aswell,you shouldnt kill rockers especialy not good rockers like T&D i would look first at retainer to guide/seal clearance,valve/guide clearance and valve to piston clearance, are the valves perfectly straight?
im not an expert or profesional enginebuilder its just the first things i would have a look at

he has a ? mark about scrub pattern. maybe roller is catching edge of valve. seeya.

What rickraw said I had that problem with the Crane Gold rockers on stock heads,put a set of lash caps on and solved the problem. I just hope your problem is as simple as that.

A friend of mine had a lot of problems with that set up on stage 6 heads. I had the same problems on a set of B1's with the single shaft system. The problem was really spring size. The T&D with the common shaft deal, needs to have perfect geometry, perfect pushrod length, and can only be adjusted down 1-1 3/4 turns, with adjuster backed all the way to the top of the rocker. Also, the rockers are only suited to use a 1.55 valve spring. They relieve the rocker at the fulcrum to fit a 1.60, but it can weaken the rocker. That's why those of us with the bigger springs, with higher pressres buy the paired rockers. Call T&D and they'll tell you all about it.

I run the T&D single shaft with 1.640 dia springs no problem with them hitting my springs but they are 2 years old maybe they changed there specs It's a B1 head

The newer T&D rockers do not have any clearance issues. The older(blue)ones did. They have solved that issue. Just FYI..

how many runs on the springs to get them to lose 20lbs seat pressure?

new, those springs are closer to 250-260lbs @ 1.900.

for now i'll only add that sometimes certain spring and cam profiles just arent happy with each other. my guess is, your valvetrain is going into spring surge and thats whats causing the breakage.

i would up the pressures, and switch to a different spring.....maybe something with a damper.

do you have the cam lobe numbers??

he was suppose to post pics of his broken rockers. guess that isn't going to happen. i bet the retainer is hitting the rocker. when i rebuilt my engine 2yrs ago, previous builder didn't have the stand shimmed properly & the retainer was just scrape the blue off the rocker. these are the blue t&d's, 1.65- 1.60, sb, w9's. i have a perfect scrub pattern, no problems. seeya.

I was beaking 1.5 INDY rockers on my 440-1 heads on a 446 and i built a 572 with same heads but got a set of T&D 1.6 and i had to put lash caps on and i have a bigger cam and i run it all last season and had ( NO TROUBLE )

ahha, some installed hights are off. some as high as 1.977. that puts springs at 180lbs closed. way to low seat pressure. now i feel better somewhat.
2.037 without spring locator. 2" spring with .030 shim should be just right
gary
seeya