ah64pilot

Ok fella's, I've got a convertible that keeps eating pushrods. I think I know what might be causing it but I want to know what you guys think. What should I check first?

cutlassefi

First place I'd look would be coil bind and/or the slot not being long enough in the rocker. Is the rocker sitting on the radius of the stud?

Octania

getting lube to it?

RandyS

Had a 400 that used to eat pushrods, clogged oil passage to lifter.......
Bad lifter would do it too.........

kitfoxdave

Material hardness of the metal

TripDeuces

I see a nice shiny spot on the shoulder of that rocker stud, where it transitions from bolt head to threads. Is the slot hitting it? Also the push rod itself looks like it has a little digger in it. Is it bottoming out on the guide plate at full lift?

I'll give my three cents:

1) Coil bind
2) Rocker slot too short, see 3 below
3) Interference ..........rocker on retainer, guide plate, push rod in push rod hole in head, push rod on top of lifter (outboard edge at full lift, assuming this is a roller with the two lifters tied together)................basically any where things could possibly touch, rocker studs not perpendicular to head pad (tapped crooked)

ah64pilot

Hey guys, sorry...I didn't take my own advice and left out some pertinent information.

The cam is an Engle 20-22 .496/.512 lift 226/230 @ .050". The rockers are the Comp. Magnum - kit. The pushrods are part of the kit. It happened once on the #4 intake pushrod a few weeks ago and Comp. warrantied it out. Now it's happened on the #5 intake. The geometry looks good and as far as I can tell it is all getting oil.

I pulled the rocker and the cup looks fine, it doesn't have any burrs inside that would chew up the pushrod. I will pull all the pushrods and check for oil at the lifter just to make sure it is getting it. If that checks out the only thing I can say is that it's got to be the pushrod material itself.

I have run these same heads, that same cam, and the same valve springs on a couple of combinations and never had this problem. I hate to jump to parts before really isolating a "problem" but the cheap Comp. pushrods are my first suspect.

kitfoxdave

If you still have an old push rod that you won't be using take a file to it. Compare that to one of these pushrods. The hard ones will barely scratch the surface...

507OLDS

If those are the pushrods that come with the comp kit,I would be suspicious of those.

Incorrect pushrod length/incorrect geometry.
Bad material of pushrods.

That cam isn't big,so I wouldn't think coil bind is the problem.I have used that cam with stock springs before,but I would not recommend that.

Eightupman

Just a couple questions because I am unfamilliar with your build. What heads are on there? Early 425 heads? Any extra milling on the heads or block to change the geometry? It reeks of a pushrod that is too long or the wrong rocker ratio... OR a lifter that is locked up and won't pump. If it had stayed in the same spot, I'd say bad lifter. Since its moved, I'd point at the pushrods.

John

ah64pilot

They are exactly that, the ones that came in the kit. I am thinking about seeing if they will warranty the whole kit and then getting the HS pedestal system for it. We'll see, time is limited...the car is supposed to be in a parade on December 1st.

507OLDS

Actually,I was thinking that the pushrods were too short.I know this is not the same engine as the one I had,but the 455 that I did,with C-heads,the same JM-20-22 cam,and the same rocker kit,needed .990" pushrods. I know the pushrods that come with the Comp kit are stock length,which are almost always too short.
What does the wear pattern look like on the tip of the valve?

ah64pilot

So what I can tell so far is that the geometry is not perfect, but it isn't so far off that this should be happening to the pushrod. The roller is hitting the valve stem just to the exhaust side of center.

Would the 9.654" pushrod that comes with the kit cause that much damage if it is too short (as opposed to a 9.900)?

oddball

Just food for thought, might be quicker/cheaper to try quality pushrods than totally change out the kit. The Comp roller tips are decent equipment for what they are.

OLDSMORAT

They might taste better with a little salt and pepper. Just kidding. You want me to come over. And check them out. I have a adjustable pushrod gauge. So we can get an accurute measurement for you and check the ware
pattern on the valve stem. You know I'm right down the road
Your personal Santa Claus
Rich

507OLDS

Check the contact point on the valve stem at seat,mid-lift,and full lift,and see where the pattern is.

Yes,a pushrod that much shorter or longer,can cause problems.Incorrect pushrod length can also cause premature valve guide wear,among other things.

ah64pilot

Will do...I'm about to crank it up for a test to make sure I am getting oil to the rocker via the lifter. I am beginning to worry that the Mondildo lifters I reluctantly put in the engine are not oiling properly.

I don't have any extra 5/16" pushrods so I am temporarily using a set of 3/8" hardened $200 9.800 pushrods in the #3 and #5 cylinders to check the oiling. I cannot use guide plates so there is more movement than there should be but it'll be ok for a 2 min. run, I hope.

I may ruin the 3/8" pushrods by doing this, so as a last check, is there anyone out there that needs them? They are brand new...Bueller?

ah64pilot

I have some Trick-flo length checking pushrods...do you have a caliper to measure them with? my biggest problem is that I hate being in the garage alone when I'm not in the mood to work on the cars. When it's something new, or something I WANT to do, then it's no problem...but right now the last thing I want to do is work on this car. It's Thanksgiving for crying out loud! I could use a buddy to keep me company, it might help motivate me to keep chugging along

Short story, what time do you get off? LMAO!

ah64pilot

Update: the lifters are oiling properly so lubrication is not a factor. My test run last night showed oil from all 8 rockers on the D/S within 45 seconds of running at idle.

As I first suspected, I am gonna default to the pushrod's themselves and order some that are the correct length and material hardness. Maybe I can get Comp Cams to warranty them out and fix their product offering so that they send a length that is a little closer to correct for a stock setup.

cutlassefi

I'm not sure that's your problem. If they're not hard enough why are they not scored around the guide plate area?

Hmmm, let us know what you find out.

ah64pilot

The guide plates were not rubbing on the pushrod and there was no binding at the shaft, only at the tip where it contacts the rocker arm...I'm guessing because the geometry is incorrect.

If you look at the tip it looks like the rocker is peeling back the material when it goes to full lift or closed (I don't know which one). I'm thinking it's a geometry problem but will go to a better pushrod while I'm at it.

cutlassefi

What's the pattern on the valve tip look like?

ah64pilot

Well, after 300 miles with no noise I am gonna go out on a limb and say the problem is licked. The problem was...duh duh duh...the High Energy pushrods themselves. They were my first suspect but I wanted to eliminate other variables first. After a little research we found out that the kit came with the Comp "High Energy" pushrods. They are not hardened and are a stock replacement. They were getting oil and the geometry was correct...they just couldn't handle the 120 lb / 300 lb open spring pressure.

I drove the car 200 miles today to Austin and will participate in the Blue Santa parade in downtown Austin tomorrow morning. The car is running great now. I am so glad there wasn't something more involved causing the problem.

I ended up replacing all 16 pushrods with the Comp "Magnum" pushrods that are chromeoly hardened and made to use with guideplates. So far so good...

Steve

gearheads78

good to hear its fixed

507OLDS

A good 20yrs,and they STILL haven't changed what pushrods they put in the kit.Of all the people that would know what pushrods are needed,Comp is one of them.Don't get me wrong,they make some great parts,and I have some of them in my engines,but they know not to put a pushrod like that in that kit.
SO,what we know is that we need to buy the parts separate,still.

cutlassefi

You mean to tell me that Comp Cams messed up?! OMG!!!

Well said Brian,
Here's the kit.
http://www.compperformancegroupstore...&Category_Code=

They list the High Energy pushrods as being hardened in another part of the website and obviously show them with the guide plates that come in the kit.
Just because a company advertises the most doesn't automatically mean they're the best. They make more mistakes than you know.

ah64pilot

Yep, they suck ***** just like Competition Engineering and their rear shocks for A-body's. Great parts, just a PITA to figure out which ones you need because you can't use their catalog for shee-it.

I'm building a personal list of all of these mismatches, maybe one day I'll post it up.

P.S. Tack on a parade and 200 more miles to my above post and still, not a noise one

TripDeuces

What was that parade for in Texas........................Secession from the Union? Lol, couldn't resist.

Glad to here it's working out btw

ah64pilot

How'd you know? It was right in front of our NATION's capitol lol! Check out the pics I posted in the General section...it is a toy drive for Obama kids, lol now I couldn't resist

442rocketdave

I have four sets of Comp Cam pushrods and they are not too good I keep them for stock engines only and for making things with, I see you also have the comp cam guide plates and I just bought a couple packs of those from summit and when I drilled them out for the 7/16 studs I was amazed at how hard they were! Thats about the only thing I have found they make well, I have 2 of their cams that did not run good compared to Lunati but they all have their short falls. Glad you fixed the problem.

MXman112

I had a set of those pushrods that came with the kit and bent the crap out of them. Did all the checks that have been mentioned here and found no issues, so called Comp Cams to no resolution. Bought a set of TFS-21408450 rods and problem was solved till I broke a rod bolt.

My thought is Comp got a bad batch/bad metal.

442rocketdave

MXman112 They must have been getting bad batches for a long time, I have 4 sets over about ten years and all of them are junk. I am just coming back to this and I dont know who TFS is? Can you give me some input on the company and where to find them. Thanks.

507OLDS

TFS = Trick Flow Specialties A company that makes a variety of Ford & Chevy parts.They were bought-out by Summit Racing a few years back.They are about a mile down the road from the Summit store in Ohio.I have their pushrods in the 507 with solid roller cam.No problems.

442rocketdave

Thanks 507OLDS I am in the middle of building my motor and I have given up on the guys at Mondello, since Joe's gone its not the same. Rocket Racing seems to have the edge lots of new products and it cost alot more nowadays and I don't want to make costly mistakes. I am an old school Olds racer. The new stuff has me excited about racing again.

scumdog

Different motor but same problem.

I fitted the 429 Ford in my F100 with an Isky 272 hydraulic cam, Cane roller rocker and C.C pushrod/guideplates.
Stock and verytired valve-springs.

Various rockers always seemed to come loose, sometimes .040 clearance after 500 miles, this went on for 3-4 years.

Long story short: It wasn't the rockers that were backing off - it was eating pushrods, still have no idea why but they looked a lot like th ones in the O.P s photos.

Sides of the push-rods couldn't be marked with a file btw.

Manley stuff now (from memory) and all good