After installing cam, car idles OK put no power after run found all 16 pushrods bent. rods on cyl 3,4,5,6 are bent the worse.

It sounds like cam timming is out, I am going to tear it down and check timming, but I am pretty sure it is set right(this would be my first in many not, but could happen)

If it is not cam timming what could it be. Over tighten rockers? Spring height? Combination of them both.

LT1 with cc306 cam

springs:
LS1 VALVE SPRINGS 918's

Part number 26918 Comp beehive springs

Part number 26918

1.055/1.290 single beehive ovate

I.D. .660/.885

seat load 130@1800

Open load 318@1.200

Coil bind 1.085

rate (lbs./in)313

Excellent Springs for most applications up to .600 lift

Utilizes stock spring pocket and retainers.

 

Other than the springs was the rest of the valve train stock? FWIW I bent a pushrod right off the bat when I did my heads/cam with the same springs and a cc503. Go get yourself a set of hardened pushrods and some guideplates, put in 7/16 ARP studs, good set of NSA rockers. Problem will not repeat.

 

gmpp 1.6 roller rockers, other then that stock.

one push rod ok, but 16, there is a problem here.

 

If I read your thread correctly, you used stock retainers , If so did you check retainer to guide clearance for you max lift (1.6 on a cc306= .544/.576)? LF

 

sorry, no the retainers are crane that match springs.

 

I assume you checked for proper push rod length?

 

No. I just ran with the assumstion that 100's others are running the same combination with no problems.

 

There is a mechanical bind somewhere, I also recommend a good set of push rods(check rocker geometry for proper length). Mock up one cylinder with the intake off and rotate by hand and check for bind(retainer to guide,coil bind, valve to piston, ect). Hydraulic lifters make this check a pain in the butt. A dial indicator set up on the retainer should show if you are reaching max lift. LF

 

Every motor will have slight differences regardless if they are identically built. You still need to check for correct geomitry and push rod length.

 

Alright to get this straight

If the cam timing is right then I need to check pushrod length.

I do know that the springs are not bottoming out, the valves can travel more with the cam lob at top. so I don't think there is any bindding with the valve train. But I will check if not cam timing.

 

I just noticed your location is South Carolina, so is mine . What part of SC are you located. LF

 

Fort Mill, just south of charlotte

 

Cam timing isn't the problem. If you set the preload correctly, you're on the base circle of the lobe...it doesn't matter what the cam timing is when you do that.

I don't think it's a problem with clearance between the rocker and the spring as the beehive springs are narrower at the top and shouldn't be within .060" of the rocker at any point.

I suspect that the preload was set incorrectly as in too loose. Incorrect pushrod length can cause a catashrophic failure when the roiller tip comes off the valve and hits the retainer. This can pop the retainer loose, leading to dropped valves and general carnage. Since this didn't happen, I suspect the pushrods just came out of 'battery' due to too little preload and bent. Since you have to replace them anyway, measure for the correct length pushrod and install them using the guide found on Shoebox's page. You'll be fine...

 

I'm in Graniteville, just outside of Aiken. Good Luck with the hot rod. LF

 

I wondered if it was from loose rockers. Unfortunetly I had to do the cam change outside and it got dark and rained, so I could have easily messed it up.

Since then I put another set of stock push rods in that I had laying around. Reset valves and has not bent yet, but have not really run it very long.

With this cam and no tune would it cause no power, This is a dog now, I mean barely move down road, thats why I thought cam was out of time.