What's my problem??? missing HP + goofy curve
 

Sorry I don't have dyno graphs to post. My set up(ARE 346, TEA 5.3., TR 230) was showing valve float at 6400 with YT rockers and 987 springs. I changed the springs to the new crane duals and my dyno curve got wierd. The peak HP was achieved at 6100(422rwhp), where it dropped to 400 at 6300 and stayed there until rev limiter. What do you guys think? Lifters?

What is your preload? What length PR and how much off the heads? (Milling)

Does the graph look wavy above 6K?

:cheers:

Heads are milled .025, and I have 7.35 pushrods. The curve is basically smooth. The only drop is at 6200/6300 and it remains smooth until 7000.

Any other ideas?

Some folks encounter valve float with YT when springs were on the edge. I think Verbs had a similar experience with his YT's & 987's.

With the heads milled .025 the 7.35 pushrods sound right on the mark.

If the graph is still funky with the new Cranes, I might swap the stock rockers back on and see if that had an effect on the graph.

Tried that as well. The only difference in the curve was it was about 10 hp lower. Same early peak, drop, and flat to redline.

Could the Crane springs, at a wrong install height, overpower the stock lifters?