Hi everyone: I just pulled my 461 apart to upgrade to Eddy heads and an Air-Gap intake, and lo and behold, my professionally built engine had a shattered tip on one pushrod? Upon closer inspection the pushrods were different colors and lengths. I think the builder tried to achieve proper rocker geometry by changing pushrod lengths?? My bad, I used the Pro Comp small block Ford rockers. I have new longer pushrods as required for the new taller aluminum heads and I have upgraded to Harland Sharp OLDS roller rockers. The cam looks fine (luckily, it is a nice Lunati roller piece), but now I know where my tick at idle came from. I did have a couple of the Pro Comp poly-locks come loose in the past, redid them all and thought my problems were gone?? I think the improper sbf geometry put some strain on the pushrods and after 21 dyno pulls at 6000 rpm they are just starting to fail now??? Won't be an issue with all the new parts in there !!! I just thought it was odd to shatter the end of a pushrod like that ???
Thoughts on this subject??? Thanks, Wayne

 

Out of curiosity, were the pushrods comp cam?

 

Who was your builder? How did they dyno sessions go?

 

sounds like someone screwed up, you mentioned Poly-locks so you are saying your valvetrain is adjustable right? then why would anyone put different length pushrods in it? there should be enough adjustment to take care of any issues without doing that. if the geometry is off a lot then the pushrods may be rubbing on the head guide holes and that could cause the damage you have there. could have happened when an adjuster came loose too. or could just be crap parts too..

 

Like I said 21 pulls up to 6000 everytime, she was steady as a rock. Made 496 H.P. and 573 lbs/ft torque. The polylocks must have been OK then, after driving the car for about 3 days a couple of the locks backed off. When this happened I took it back to the builder and he changed the entire set. I thought the problem was solved until I took it apart last weekend. The one tip looks shattered? I didn't realize they were all different lengths until I pulled them out and sat them in a bundle on my work-bench. They are all over the place ??? I will be talking to the builder and voicing my displeasure. He usually builds some pretty stout engines??? May have been the hired help? I don't want to smear his name, he's always been 100% in the past.
Wayne

 

I can't even imagine how this would happen with poly locks unless someone forgot to properly tighten the set screws.

 

Any chance the pushrods are worn to different lengths? I know this is unlikely but if the locks came lose...?

Just because they're good at building engines doesn't mean they didn't screw up. Happens to the most seasoned veterans and it seems like you had a custom setup they may not have had experience with.

Just my $.02

 

Thanks for your input, everything is new and same length now, so shouldn't be an issue. I can't see any name on the pushrods, so I doubt that they're Comp, and the difference is lengths were significant(3/8") so not a wear issue. Just a screw up I think,
Thanks, Wayne

 

Thanks for all your input, should have her rolling this coming weekend !!! Looking forward to lighting up the M & H Racemasters !!!

Wayne

 

One way poly locks fail is by using cheap rocker arm studs. Many of the studs just aren't square across the top and the set screw on the poly lock eventually backs off because it's not engaging all the way around.
Use a good rocker arm stud like ARP. They even emboss their name on the tip which helps the set screw to bite even more.

 

My new Edelbrock heads have rocker studs on them, I will check them for flat. My old studs came with the Pro Comp roller rockers, so were probably crap, that may explain their coming loose intermittently??? I have new Harland Sharp OLDS rockers, ARP stud kit, Comp 9.800" pushrods (edelbrock specifies these),so hopefully my problems will disappear???
Thanks, Wayne

 

Check the ring left by the poly lock set screw. If it's not a complete circle on the head of the rocker stud you have your answer.

 

I like your thinking , thanks for the help !!!!

Wayne

 

I would also recommend using pushrods that do not have pressed in *****. I had a set like that I got from Mondello's long time ago and they worked fine but when I tore it back down the ball tips were dropping out all over .. not good. since then I order one piece chrome moly units, you can get them any length you want if you need shorter or longer ones.

 

Hi: Good call the pushrods with shattered tips were the welded on ball ones, the tapered pushrods seemed fine. I put all my new parts in on Saturday, and the rocker geometry and pushrod clearance look great. I think my problems are now behind me, but thanks for all the great feedback. You guys rock !!!!

Thanks, Wayne