Its a long post but please help.Ok so heres the deal... My fresh 390 tonite upon first fire bent the #1 pushrod within the first 10 minutes of run time. So what happened is I got the motor to TDC with # 1 plug out and set up distributor to #1. Motor fires up but had a loud exhaust leak I thought. Ran motor for a few minutes to check for leak and realized in my stupidity I still has the # 1 plug out. So I refired the motor again with #1 back in and it made a consistent tick with the revs up and down. I was almost certain it was lifter noise not bottom end and kinda wondered if my .090 restricter plugs in head might now have something to do with it. I have white header wrap that was turning brown in color as the motor got hot. I realized that the #1 exhaust header wasn't changing color though so I felt it while running and it wasn't getting hot. I then knew that cylinder was dead. Removed valve cover and exhaust and intake pushrods on # 1 are totally bent! So now is this some sort of problem deeper inside engine and just a coinsidence or is this just the reason for running the motor with my plug out. The only other thing I noticed is there was some moisture under the valve cover and some whiteish tint(not too bad though) in the oil on the stick. I did forget to cover my engine one nite without my tarp over it and only the lift plate over carb hole and it rained with the lift plate having some open hole to allow in water. The oil level has not risen though as an indication of a water jacket leak in intake or head gasket allowing water in oil and level to rise. How bad is minor water to new motor???

 

O one more thing to add to the weirdness I just noticed that #2,3,4 cylinder pushrods on same same side are all my old pushrods and my #1 pushrods are new ones I purchased. My machine shop checked all my pushrods for straightness when I had all my parts in there when they did a pushrod length check for new cam and told me they were straight except for a couple that for some reason where a tiny bit shorter than the others so I only went out and bought two pushrods cuz they said the others were fine to reuse and then the new ones are the ones that fail. And yes they were the same size as the rest I was very carefull when I matched them up!

 

Check push rod lengths. You may have gotten some long ones. IIRC them make a standard, short and long length.

 

So I've drained the oil and it was grey. I wonder if the assembly lube from the new cam (which was brown) had something to do with color as well. I'm wondering if I should measure the the oil that came out to see if it is more than I put in. I used 6 lts and a bottle of ac delco break in oil supplement. I just really hope it not my intake water jackets leaking I've had that problem before once. I just had .040 machined from the head sides of my edelbrock intake to match up with my machined heads to fit. but I used silicone grey on front and back surfaces and aviation gasket maker around water jackets like my machinist said.

 

I'd take the intake off to see if you also have a bad intake seal water jacket failure. Could possibly be hydrolocked in the bad cylinder due to water from a jacket failure or the moisture from your earlier rain parade. Use all new pushrods from a reputable company and no Chinese immitations. How do you like the header wrap? I was thinking about putting it on my buildup. Good luck.

Chris

 

Hydro lock would have caused a bent connecting rod, not bent push rod.
Usually the oil will have strange tint depending on what additives you used. Water usually makes it greyish white. It could have just had moisture from sitting outside that once you started running it mixed with oil.

I would be checking valve clearance, is it hydraulic or solid lifter? Adjustables or non's?
What cam?

 

Make sure the valves in that cylinder move smoothly - if you got water in it, the valve could have rusted to the valve guide and they stuck - result is a bent pushrod.

Also, when tightening down the rocker shaft, if you don't do it very evenly, you can bend one slightly and never notice it until its run.

After assembly, for each pushrod, rotate the motor until that pushrod/lifter is on the backside of the cam, and spin the pushrod to see if it's bent.

The grey color of the oil is probably cam assembly lube if you used that grey moly stuff.

 

Update: Happy to tell ya that after replacing pushrods and swapping out oil it runs very nice and oil is crystal clean after about 15 minutes of run time. Only issue I have now is it wants to overheat when the temp gets to about 210. I'm running a new camper special 3 core rad (copper) with a flex fan but without a shroud due to the body lift on truck and a stock shroud won't work unless modified. I'm not running any coolant right now due to not wanting to spill on driveway but will coolant make a big difference while running? I think I'm changing over to a electric fan setup tomorow with a temp sensor that will engage at 180 degrees or so. What do you'all think?

 

Don't get excited yet, a brand new engine with no coolant will run hotter. That 3 core will carry your heat just fine.


John

 

Yes, it will tend to run warmer til it gets a few miles on it and loosens up. Depending on where you are, the lack of shroud may cause issues. Changing to electric fan would cure that issue. I did mine and use a 180 deg sender and works great on my hot rod. What I've done so far is it's a dual fan unit, and put one on sender unit and the other on dash switch. For the most part it works great but if I need a second fan I turn it on manually. It also helps with heat soak after I shut it down, as I can turn fan on for a short burst to cool things off.