[BIG E 86]

engine shop completed my 406 engine buildup , two days later i was headed back to machine shop, with the car on a flat bed tow truck,they came to the conclusion , that the cam didnt match up with the heads thus beating up the cam shaft , please help any suggestions would be greatly appreciated ,they
are standing by their work ,so i am glad of that. THANKS
content of engine
406
KB147 PISTONS 030
SCAT 5.7 I-BEAMRODS
DART 200 ALUMINUM HEADS 64CC
COMP CAM XE262H-10
VALVE LIFT 462
ADV DUR 262-270
DUR@050 218-224
LOBE SEP 110.0

[automotive breath]

Originally Posted by BIG E 86

...they came to the conclusion , that the cam didnt match up with the heads
thus beating up the cam shaft...

You think they meant to say the springs on the heads didn't match the cam?

[F-BIRD'88]

That cam does not need killer valve springs.

Replace the killer race valve springs on the Dart heads with a Comp 981-16 or similar stock diameter replacement spring with not more than 110# seat or 290# open pressure. Consider breaking in the next cam with used OEM stock SBC valve springs with reduced pressure, say installed at 1.75" ++ seat height and then swap in the new springs after breakin and a good week of driving.

Make sure to add a good dose of zinc additive (GM EOS or same) to the first and every oil change. Do not let the engine idle during the break in and keep the idle above 1000rpm for the first week of driving.

Consider choosing a similar spec Isky cam + lifters. They seem to be of much better quality.
www.iskycams.com

Try the Isky 270 Mega cam PN 201271 with new Isky hyd lifters and Isky 205D springs installed at 1.70". (install them at 1.75"+ for the breakin then shim them to 1.70" after break in and a week of driving.

If you prefer a dual pattern version 270 Mega cam grind order Isky #201271/281-10

Reduced spring pressure really helps sucessful flat tappet cam run in.

[techinspector1]

Not making any sense. With only 0.462" valve lift, I can't see a problem, even with stock springs....
Of course I guess it would have been pretty easy to over-rev the motor, float the valves and have a crash.