JtadaK

So I have a new bottom end 406, and went to readjust my valve lash today just to find one pushrod completely bent up and outside of the lifter. In the process it snapped the very top of the lifter where the spring seats. Then looked over the rods and another (on the same side of the block) was bowed but nothing like the one that was bent. Went to the perfomance shop and it's going to run me about $100 for the two rods and the lifter. He told me by running these solid lifters/cam I only will have about 2,000 miles before I have to get a new set. I've heard they're not as long lifed as hydraulic but dang! I am hoping he is wrong, because I will drive this car every day. I don't go very far but I do drive every day. I was just hoping he was wrong to some extent.

And if anybody wants to "share" a pair of 7.8" rods and a solid popup lifter pm me (:

Anyway you guys have any idea why the rods would be bending like that? The twisted rod could have not been seated in the lifter when I adjusted them the 1st time, but the second rod was still seated. Any help will be greatly appreciated, especially because I've been working on this thing for a month and a half now, finally got it running and now this!

t-top havoc

iTrader: (3)

What kind of rockers are you using?
Did you adjust the clearance cold as per directions?
What cam are you using?

A feeler gauge is needed to set clearances.
The ppl I know use roller rockers on thier solid cams.

How many miles did you get to drive when you found the bends?

Couple things come to mind--
Push rods are too long
Or
Over tight adjustment.

sofakingdom

iTrader: (1)

What cam? (part # only; not "mild", "Stage 2", etc.)

What lifters? (part # only)

What push rods? (part #)

What valve springs? How are they set up? (part #s, not "stock", VascoJet", etc.; measurements made with spring mic, not "my machinist said", "the heads came with", etc.)

JtadaK

I'm limited in what info I can give right now, I appologize. They are roller rockers with solid roller lifters (popup). I did use a feeler gaude and adjusted them to .025 like Crowler said. The only problem is I found out now the motor need to be warm while doing this.

sofakingdom

iTrader: (1)

Then unfortunately the quantity and quality of the advice that any of us can give will be similarly limited.

Who is "Crowler"? Does he know what cam and that other stuff you have? Maybe you can ask him.

JtadaK

Haha, Crowler cam. I think the lash may have been too tight since I didn't adjust them while the motor was warm.

sofakingdom

iTrader: (1)

That's a mfr I've never heard of...

Any chance it could be Crower? Them, I know.

Since you don't even say what the heads are made out of, I'll mention that if they're iron, you'll LOSE about .002" of lash from cold to hot, and if aluminum, you'll GAIN about .005" going from cold to hot. So it you set em to .025" cold, no way it would have changed enough, to damage parts.

JtadaK

Yes Crower. GM cast heads. Sorry this is my first rodeo and I'm learning as I go... That makes sense but when I checked the lash when I went to readjust the valves some were tight maybe the valves weren't completely at "full lift" when I adjusted them in the first place. Nonetheless I'm probably going to check them periodically after I get them set gain when I get the replacements.

sofakingdom

iTrader: (1)

All heads are cast... usually either cast aluminum or cast iron... GM uses both... what material are they cast out of?

Always a good idea to regularly check the lash for changes, until it's been running and stable long enough to get a feel for how quickly it changes normally, so you can recognize sudden abnormal changes and maybe catch a failure before it happens.

JtadaK

Haha! Sorry, cast iron. That's exactly what I plan on doing. I've heard solid rollers need a lot more maintence then hydraulic too.

ASE doc

Generally, the only thing that will bend a push rod, unless you're running cheap pushrods(you need chrome moly), is running into a hard bind. Like the valve against the piston top. Solid cams are really the territory of expert engine builders, generally only run by racers. They are not the way to go for anyone who is new to engine building. You don't know what springs or even for sure what cam you have. You don't really know the details of your valve train or if you may have interferrence between the pistons and valves at overlap.

I hate to play devil's advocate but I'd rather risk hurting your feelings than see you destroy this engine. You don't need to be running a solid cam if you don't know how to set up a valve train. Tear down the motor and switch to a hydraulic roller. Measure valve clearance at overlap(10 degrees BTDC on the exhaust stroke to 10 degrees ATDC on the intake stroke) measure clearance on both intake and exhaust valve throughout this area to verify atleast .100 clearance.

The hydraulic roller will relieve you of the concern over valve train maintenance. As far as performance goes, hydraulic rollers are available in grinds that will push the limits of any streetable combo.

ASE doc

I wish to appologise for being a jerk in my last post. I don't mean to tell you what to do. If you want to continue running a solid cam, just take some time and educate yourself on the fine points of valve train setup. One point I didn't even mention in my post was valve spring coil bind and matching springs to the cam.

There are several great books out that will give you at least a functional understanding of what you need to do in order to protect against this type of failure. Look at HP Books for their many publications on building the small block chevy.

Good luck Bro. I hope to see you at Woodburn this year.