Indy rockers

I am getting ready to put a set of -1's on my dragster and the rockers are the 1.6 Indys. I have heard these are prone to break. The cam will be .728 lift with the 1.6's and the springs are PSI DR1224's @ 1.975 #275 on the seat and a little over #700 open. The rockers are about a year old with about 25 passes. What is the limit for these rockers?

i think you're there already. with less spring press i've had the adjuster push thru the arm. start looking for something decent now. it's only a matter of time.

Yes, I agree. My opinion, you're already there.

I had that kind of spring pressure with the
blue 1.6 Indy rockers, The ball end of the
pushrods turned blue Very bad oiling!! I had
to grind slots from the shaft oil hole to
the pushrods in the rockers. Bought a little
time. But with that much spring pressure they
are Junk. But Indy won't tell you that.
I switched to T&D and never looked back.I
love them..

Just picked up a set of -1's for my car. A good friend has several hundred passes on his Indy rockers (-1 heads) and has not had one break yet. He runs agressive roller cams and shifts in the 7k range. Never broke one yet.

My engine build is very close to his, with slightly different exhaust timing on the cam. With my luck, I didn't want to chance it. I saved up for a little while and bought Harland Sharps from Dram.

I learned my lesson back when I was running small block Fords. I destroyed 3 engines because of valve train failure.

-Dave

In my experience they're good for about 5 years of racing with those numbers, your spring pressure and lift is VERY close to mine, and i run the 1.6 indy's. I think you'll be fine for a while. I bought 1.6 indys again for ease of install when i broke one on a pass last year, but next time around i'm going to go for t&ds or harland sharps. I'm currently doing some metallography on em to see, but they all break due to fatigue (if you ask around, once one goes, they start to all break successively, and the fracture surface is a typical fatigue fracture), every one i've seen it initiates on the adjuster threads. I could be wrong, but i'm willing to bet they cut tap the threads in instead of roll them, giving a stress concentration and point of failure initiation. If i were you i'd run em for another 150 passes or so then switch to the next level up.

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What is the limit for these rockers?

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do you really want to find out? what else will happen when one fails? lose a money round, lose the engine? imho it's just not worth the agg. been there done that with b1 heads and the "as shipped" rockers. not saying that other rockers don't break or that people haven't used the "as shipped" rockers with some success but normally in the long run the vast majority end up getting a quality set of rockers such a harland sharp, t&d or jesel.