Bent Pushrods!?

[ullose2]

I have a 350. It has almost 2000 miles on it. I just got the bottom end rebuilt because the cam bearings went to crap and the metal shards from them were going all through the bottom end. I only caught this because i decided to change cams and get some head work done after getting back from PF. Thats another story in and of itself though. Anyways, got that taken care of, got a 5 angle valve job, and everything in the heads checked, shop says everything is fine. here are the cam specs of the old and new cams.

Old- .490 lift int./exh. 292/297 adv. duration int/exh LSA 112
New -.525/.546 lift int./exh. 284/292 duration int/exh LSA 110

Otherwise nothing else has changed however, when I went to fire the motor to break in the cam nothing happened. I checked timing and all that. I made sure to adjust the valves before putting the motor in the car. Anyways, to make this short I have bent pushrods. I thought maybe I had adjusted the valves too tight, so i got a new set adjusted them again. I turned the motor over maybe twice witht he starter and they were bent again. I have no clue why this is happening. I asked the machine shop if this cam would be compatible with my current combo as far as clearances and they said it would be fine. They also degreed the cam. If you need any other info to maybe diagnose this please let me know. Im taking the motor in early tommorow and I really dont feel like giving these guys anymore money. Thanks alot.

heath

[ProBell]

Look to see if you have long slot rockers. I had a problem with bending push rods because the rocker arms were binding at full open.
Randy

[kamaroman68]

I had this same exact problem. Turned out that i tightened the rocker adjustment to far. I had to replace the lifters too because the clips that hold the plunger in came out on all of the lifters. I used the standard procedure of zero lash and then a quarter turn but they still got screwed up. The other problem you may have is piston to valve clearance which according to your machine shop should not be. I would double check. I finally got my engine right by setting the rockers loose and tightening them with the engine running until the clacking went away. Good luck Chris

[ullose2]

Thanks for the reply. the rockers are harlan sharp 1.5 roller rockers, and they are the long slot, but I hadnt thought of that before.

I just got back from the machine shop and they said that the timing chain may have been installed wrong. Im glad they said it because they installed it and degreed the cam. I looked at all the valve springs and I didnt see any marks from them binding. I double checked to make sure i got the correct length pushrods, and I made sure the lifters were ok. I will post as soon as i know something.


Heath

[ullose2]

I thought that i had adjusted the valves too tight also, but we tried that. the rockers werent loose, but you could still spin the pushrod. They dont bend when i turn the motor over by hand, but when i use the starter they do. I geuss i will see. Thanks alot.

heath

[kamaroman68]

i find it interesting that they degreed the cam and are now telling you that maybe the timing chain was installed wrong?????? Chris

[ullose2]

Well I just went to the machine shop and the timing chain was installed wrong! Holy crap. Im pretty angry. I have bought 2 sets of pushrods over this and Im kind of thinkin they should buy the next set since it was their error. Do you think its right to do this. I think it is completely justified. Im sure im not the only whos been in this situation and i wanted to see if you thought this was too much to ask. Thanks alot.

Heath

[6'9"Witha69]

The last 2 sets of pushrods s/b on them at this point. One set is obviously yours to keep so that is fair.

[Madspeed]

You might hve bent valves as well.
If it was me I would want full compensation for all the parts I paid for.
I doubt you will get it though
Ill cross my fingers for ya

hope all turns out well

[David Pozzi]

Yes, you the shop should do a leakdown test of the engine to determine if a valve has been bent. Force enough to bend pushrods could bend a valve.

[ullose2]

I think the shop is checking the valves, and they did admit to their mistake. I just hope they will at least get this next set of pushrods. I think i would be happy with that. They said come back in the morning, to check out the progress so I will post what they say when i get back. i really appreciate all of your advice since I havent dealt with anything like this before.


heath

[David Pozzi]

I've seen a couple of mistakes concerning the Cloyes three keyway crank gear. The have three keyways, maked with a triangle, square and O. Then there are three teeth on the sprocket that are similarly marked. It's very easy to mistake the square with the O.

[ullose2]

It ended up having all 8 valves bent, and one roller tip messed up on one of the rockers. The shop is replacing everything as far as i know. They ordered all the new parts including new head gaskets without asking so I think they are doing it free of charge. I geuss I will see tommorow.


heath

[ullose2]

The shop replaced everything for free. They even got more anti-freeze, oil, filter, new gaskets and even found a broken rocker arm and replaced it. I wouldnt have thought a shop would go out of there way for a young guy like me. I was surprised and very pleased. Now all i have to do is get the motor back in and get in runnin and i will be set. I would definately recomend these guys.


Heath

[6'9"Witha69]

Sounds like you are dealing with a shop bent on keeping a good reputation (sorry for the pun).