Generation IV Internal Engine - PTV - Need some help




View Full Version : PTV - Need some help


mowpow
05-11-2012, 10:17 PM
I'm building a TSP LS 402.
Pistons are +5cc
Cam is 242/248 112, gross valve lift .610/.615
Heads are TFS 235's CNC 70cc
Yella Terra 1.7 rockers
Lunati Hydraulic lifters 72332

I measured and purchased the pushrods, no clicking at zero lash.

I set up clay on #1, torqued down the head and turned the engine over a couple times. To my surprise, there are no noticable impressions in the clay.

I repeated the test with solid lifters and longer pushrods which yielded the same result.

Given that there are valve reliefs I would still think there would be some impression made.

Does this sound like a springs issue?

Update - I read the technical specs on the heads and the springs are good for 650 max lift so I don't think it's springs. This could also be timing right? If my timing is off wouldn't this be a symptom?

Thanks,
Mowpow


427 zeo6
05-11-2012, 11:53 PM
Where is the intake lobe centerline of the cam set? Sounds like the cam is massivley retarded if there is a bunch of valve to piston clearance. Are you sure timing chain marks are dead on?

CAMSTER
05-12-2012, 12:27 AM
I see this all the time....


mowpow
05-12-2012, 09:34 AM
I have it currently -2 due to my first degreeing but I bet my measurement was off. I'll recheck timing at 12 and 6 and go from there. Thanks for the help!