Pushrod problem

[Captainfab]

OK, so a L31 Vortec 350 originally came with a roller cam. Is the cam you installed a factory style roller cam? Did you purchase and install new pushrods at the same time? If so and someone gave you pushrods for a flat tappet cam, that is likely the issue. But as already has been said, the pushrods bent because there was an interference issue somewhere. Either the valves contacted the pistons, the spring retainers bottomed out on the top of the valve guides, or both. I agree with TechNova. Your engine needs to come apart and be inspected for the total extent of the damage. I would be very surprised if bent pushrods is the only damage.

 

[Alexisobs95]

Could be, along with improper valve lash adjustment. What kind of shop would sell you the wrong push rods (if that's truly the issue)?

Another reason I like to use a length
checker.

Well when I contacted them about what cam would be best for this he only told me spring were gonna be changed then I told him about this problem and he said yeah sorry o forgot to sell you hardened pushrods

 

[Alexisobs95]

OK, so a L31 Vortec 350 originally came with a roller cam. Is the cam you installed a factory style roller cam? Did you purchase and install new pushrods at the same time? If so and someone gave you pushrods for a flat tappet cam, that is likely the issue. But as already has been said, the pushrods bent because there was an interference issue somewhere. Either the valves contacted the pistons, the spring retainers bottomed out on the top of the valve guides, or both. I agree with TechNova. Your engine needs to come apart and be inspected for the total extent of the damage. I would be very surprised if bent pushrods is the only damage.

I didn’t purchase new pushrods I used the original ones I checked everything nothing was bent he’s gonna sell me hardened pushrods and he said that will fix the problem

 

[Supercharged111]

If you have your stock rockers, you don't need hardened pushrods. Hardened pushrods are only if you went to threaded rocker studs and guide plates.

 

[Alexisobs95]

If you have your stock rockers, you don't need hardened pushrods. Hardened pushrods are only if you went to threaded rocker studs and guide plates.

So what would I need ?

 

[Supercharged111]

So what would I need ?

You would simply need to measure for the correct length pushrod and get those as previously stated. Then correctly set lifter preload. My guess is you messed something up, or the valve retainers crashed into the seals as clearance wasn't checked there either. I cheated on both of my trucks and just slapped the stock pushrods in and set lifter preload where the truck was happy. Haven't had any issues, but I really should check my pattern. I suspect it's not pretty on the dually, but I did verify that my retainers had enough clearance to the seals before buttoning it all down.

 

[Captainfab]

No, hardened pushrods will not fix your issue, just make your wallet a little lighter. The person that told you that is apparently just a parts sales person, not an engine builder.

 

[Erik the Awful]

Given that my pushrods are easily turned, how soon do I have to adjust them - what are the consequences of running with them as they are?

I dislike spinning the pushrods. I've been able to spin a pushrod with a valve slightly open. I prefer to wiggle them up and down. If I can wiggle them at all, it's not tight enough. Once I can't wiggle them up and down at all, they get another half turn.

 

[PlayingWithTBI]

There are lots of different techniques. If you tighten down the rocker arms until you feel no up/down slop, then you can rock the rockers back and forth to feel the internal spring inside the lifter. It will collapse around 0.030". Keep playing back and forth until you feel it start to collapse, then crank it a half turn more. The best way is old school - start the engine, let the lifters pump up until they're spraying oil all over the place (you could buy clips that would help reduce splatter), then crank them down until they stop tapping, and go another 1/4 turn.

That's the way we used to do it in the 70's

 

[badco]

Ptv on most stock engines with small cams are usually. .250 or even more. Lift doesn't have as much effect on ptv as duration @.050 lift and since there isnt many computer controled cams over .220ish @.050 id look elsewhere. Stock heads hit seals around .480 and guides around .520 stock springs will bind usually before .480
I would double check timing marks