Went for a cruise yesterday and after getting into it a bit I heard fairly loud knocking which i beleve is coming from the top end but not sure. When i got home the knock eased up a bit and also heard loud rocker noise. i pulled off valve cover and found a .015 rocker gap.
could it be a collapsed lifter, if so how can i determine for sure? should i close the gap and see what happens?
It's a 455 rebuilt 2 years ago with 2k on it. It's been running great and I do have a hard time keeping the pedal off the floor. In 1st the rpms climb to 6k+ very quickly.
Any suggestions appreciated
Thanks Rob

 

Hopefully its just a lifter and not the dreaded cam lobe. With the cover off and engine running should be able to see if you lost lift, add piece of tin in bottom area of head to keep oil off exhaust. The early 400 engine could handle 6000 rpm's burst, not sure 455 can, sure someone with more knowledge will help.

 

6k rpms can be high depending on the build... Stock near stock I would be inclined to keep it under 5500 for sure

 

Not stock, Ebrock alum heads, icon forged piston, eagle rods and mondello cam and lifters.

 

I pulled of a couple rockers and found this wear pattern. i only pulled 2 and both were identical. Wrong pushrod, wrong stud? either way looks like builder error.
Could this be related to the noise im hearing now. Input always appreciated
Thanks

 

The gap you found was probably from the poly lock backing off.

From looking at your location of the roller on the valve tip you definitely have the wrong pushrods in that engine. Most likely need to be longer.

 

Thanks, what problems can arise from short pushrods other than chewing the rockers and putting metal into oil. Could this have something to do with this knocking. I'd like to get as much info as I can before I speak to the builder.
Thanks, Rob

 

Premature valve guide wear for one. The short pushrods alone won't cause a knock unless they are allowing contact between the rocker and something else. That would have been present the moment you fired it the first time.

 

Thank you for help, although I don't fully understand how the poly lock could back out when the nuts are tight. I also found another rocker to have a gap of.050. I had friend crank it over and I could see all of the valves opening.
Another question, after the rockers got chewed, does that metal rich oil lubricate anything else or does it drain directly into pan.
Thanks, rob

 

Let me tell you what your builder did.
The rockers, valvetrain setup is wrong. He ground the bottoms of the rockers so they would clear the shoulder of the rocker stud. Then in addition he used a longer than correct pushrod to further keep the rocker off the stud shoulder. The noise could be coming from anywhere in the valvetrain. I'll bet the pushrod is hitting the inside edge of the pushrod cup as well. In addition if the whole assembly was binding, you may have done some damage to the lifters/cam.
Fix the rocker situation first, then you can see if anything else needs to be addressed.

Smitty, the pushrods look to be too long, not too short.

Beob, you asked my opinion so I'll give it to you, your builder is a hack. Make him fix it, or reimburse you for the repairs.

Hope this helps.

 

Yes that does help. I actually supplied all the parts, but he should've told me if something was wrong. The builder is an older guy who just lost his wife and hasn't returned my call. I have a feeling I'm gonna have to pull the cam
Thanks

 

Another question I have now, how can i determine what the correct length pushrod should be?
Thanks

 

You can't until you make sure you no longer have any interference with the rocker stud.

 

Even if I do contact the builder I don't think I want him to touch it. Would you recommend new cam, lifters, rods and rockers?

 

Be happy to but I need to know the following;
Which Mondello cam is in it
Carb
Exhaust
Rear gear
Tranny
Converter
Majority use
A/C
PB
I'm guessing stock Edelbrocks with flat tappet style springs?
If not have you thought about going with a roller?

Thanks.

 

Actually I meant is your recommendation that those parts need to be replaced. But I'd love to hear what you recommend I use. I would consider a roller cam.
Cam JM-25-28 .523 .544 280°/292° 236° 248° 108° 2000-6500
Carb. Holley 750 DP
Exhaust. Headers, flowmaster H pipe
Tran th400
Converter. 10 inch, not sure of stall speed
Rear gear. Thought to be 3.31 but might be higher, will recheck
Ac. No
PB. Yes
Ebrock. Heads. Stock
Use weekend toy
Comp ratio. 10 to 1

Thank you!!!!

 

Drained oil and cut upen filter today. Found a ball of very fine powdery metal stuck to magnetic drain plug and oil looked ok. In filter I did find some metal grit in between fins. Not sure what to make of this.

 

Got a pic?
What intake are you running?
How high are you going to spin it?

 

Pulled maifold off and found one chewed up lifter and cam lobe looks a littled chewed as well. i also found that the lifters are not directly over the cam, it appears as if the cam is pushed too far back. could that cuase my problem if so what would cuase the cam to be too far back? I am going to swap cam and liftesr and still not sure if pushrods are incorrect. Any inptut appreciated.
Thanks, Rob

 

Ouch! Those lifters look painful.

Your cam is in the right position. The center of the lobe rides on half of the lifter, more or less, which allows the lifter to constantly rotate.

- Eric

 

Ok that makes me feel a little better, I think.
Thanks

 

Pm'd you.

 

Damn Rob...WTF did you do?

 

Yikes..

 

I did everything I was supposed to do, not sure if the builder did. i understand it might be wrong length pushrods. I need to determine that for sure so I can shove the proof in his face! Anybody know how I can do this?
Thanks

 

Did you know he was gonna grind out room on the rockers? Please say no....if not, that's a huge piece of evidence right there. Even if you provided them, his job was to say "no good" if they weren't going to work. I'm guessing he did this to every single one?

 

No I had no idea, and all of the rockers look the same. I went to his shop over a week ago and showed him rockers, he didn't have much of an explanation. I mentioned about wrong size pushrods, his answer was that if they were wrong I would've had problems since day one, it wouldn't have ran well for 3 years. All he told me was to try a few things to determine source of knocking. I called him several days ago and hasn't returned my call. I have a feeling I'm not going to get any satisfaction from him.

 

JMO. It only has 2 K on the motor so years its been running (what seemed like good) are not relevant. What oil were you running?

 

Yes i agree. For the first 1k or so I ran joe Gibbs BR30 with 2 bottles of STP oil treatment. STP was put in under builders direction because of a slight knock during break in. He said 30 weight was to thin, the knock went away. I did not mention this to him but will if I speak to him again.
For the second thousand I've been running 20-50

 

If you have to run 20w50 in a freshly rebuilt engine, there's something wrong.

- Eric

 

Here's a pretty good video on how to do it.

If there are any other tips to doing this, I'd like to know myself as I'm getting new heads and rockers soon.

 

That was very helpful, thanks. Will do that today

 

i did pushrod length test and can confirm they are too long. definitely not centered on valve stem. But can this cause that lifter to be so severely damaged?

 

For Pete's sake man, you have your answer right here. Go bust his *****. 1000:1 he'll deny it but rip him a new one and don't worry about who might be watching. I don't give a rats petunia what oil is in the engine it should not influence a knock in a new engine. And if it knocked when NEW and it was band aided it was just to get you out of his hair long enough to keep him from having to fix something he screwed up and got paid for anyhow.

 

Absolutely. When they're too long they can interfere with the pushrod cup, which yours show signs of. From there you'll get a binding issue at full lift. Will that effect the cam and lifters? You betcha.

 

Confront him and call the local better business bureau if you have to. File a complaint so others can see there is a problem. It may get him to fix it.

 

Personally I think he should tear down your motor and redo everything. He band aided it with STP instead of fixing a knock early on. Now you have metal shavings throughout your motor. What if some got into the bearings. Tell him you know people make mistakes but a good shop does the right thing and fixes mistakes. Its only good business. My builder has a reputation of taking care of anything that might have been their mistake. Never heard and will never hear them say add STP to fix a knock on a rebuilt motor.

 

First I'd like say thanks to all that have responded, you've been a big help. The plan now is to pull motor this weekend and bring it to the local speed shop. They will go through everything and flush it out. If everything looks ok I will reassemble top end with a roller cam from Cutlassefi. I don't want that builder to touch it, and going to wait to see what else is wrong before I show up at his house.
Rob

 

Rob, I would walk in there let him know the gig is up. Show him this thread, and let him know that this is only the beginning. BBB, County Department of Consumer Affairs, as well as outing him publicly. Try to get him to come to some kind of monetary settlement. Even if you can get 50% back, it will help ease the pain!