Any chance it's a wrist pin or a scuffed piston?

It sounded more pronounced to me in the 3rd video on decel like the knock doubled up.

Kevin

I cant see anything abnormal with the fuel pump. I worked the fuel pump arm against a piece of wood and I didnt hear anything abnormal. The fuel pump is a CV products billet Alum pump. The arm extends about 1.50 inches from the mounting flange of the pump. I dont have a stock pump to compare to.

Fuel pump pushrod measured 3.205 inches in length. The condition looks good. Both ends of the pushrod still show chromoly hardened finishes. OD is 0.435.

It was a little tight pulling it out of the bore, but it seemed to move freely when I moved it through its normal range of motion. This was once the engine cooled down enough to work on it.

Cam lobe is in good condition.

However, is the pushrod supposed to ride on the camshaft at all times like a camshaft lifter?

Is the correct pushrod length 3.220 or 3.250?

Does anyone have a stock mechanical fuel pump to measure the extension of the arm from the fuel pump mounting flange?

Note the attached picture, there is a gap between the pushrod and camshaft lobe. Not sure if this is normal or not. Either way I would think this would cause a noise at all times not just on a hot engine....

On both the OE pump from our RT and the new one just out to check the rod,
1-5/8" from flange face to tip and 1-1/2" to wear witness mark.

Hope this helps, Joe

PS measurements on Comp Cams pump rods:
Comp's #4646, with tip for roller cam, 3.211" (new in package)
Comp's #4626, out of Engine w/knock, showing acceptable tip wear, 3.222"

I have never had a stock OEM pump or a Holley or after market Hi Po Carter pump have any clearances between the pump arm and the pushrod, NEVER. They where all preloaded some
I make it SOP to rotate the motor over on the starter with the pump out and the plug out and use a small thin screw driver to push on the pump rod while bumping the starter over to find the closed position on the cam fuel pump lobe and then finish the pump install by putting grease on the pushrod to hold it in place and put the plug back in before installing the pump IHTHs
I do have several stock OEM pushrods as well as some new D.C. Mopar Hi Po pushrods, the new ones aren't worth using The ends are real course finish, not like the stock ones at all

jlatessa, Perfect! Thank you for the measurements. Exactly what I needed. I appreciate the support!

Cab Burge,

Thank you also. I'm using a CV products fuel pump and I'm comparing the arm length/extension etc.


I may have a lead on a stock pump that I will borrow just to see if the pump arm is higher up or applying more preload to the fuel pump pushrod.

I will report back...

Please do I'm wondering what's up on your deal now

Start the engine with the fuel pump off the engine.

I didnt listen to the vids but another thing to possibly consider is a cracked piston skirt.

I had a BB mopar I did when very young that I got pretty aggressive on putting in the pistons and from day one it had a knock like described.

I would run it very very hard and it never broke till a drunkin (I was really young) night of running through town in low gear at 5700 for a long period when the skirt let go and I had a smoker that was an easy fix.

Is that a cam bearing that also feeds the mains? If so what if you have been running bearing material through things or partially blocking things?

It sounds like you have a nice setup going and although im overly anal at times id be pulling it and inspecting things very intensely to the fix.

One would think it would be semi easy to find all the issues on tear down.

But whatever the case I hope you resolve it without further damage.

Thanks to everyone for your help and support on this concern.

The excessive fuel pump pushrod clearance issue was resolved with NO change to the noise. No worries, this needed to be corrected anyways.

I decided to remove the engine and inspect. #2 rod bearing was the cause of the noise. Hard to believe there was no change disabling spark for that cylinder. All of the other bearings look to have normal wear.

Hopefully, the crankshaft can be polished. Enjoy the pics!

Nice catch. Could have been a lot more $$$

I think I would pull that rod and piston out and check the big end for roundness instead of wondering why that bearing failed
Was it checked before assembling the motor? If so what was the bearing to crank clearances?
Any chance of debris in the oil passage to that rod bearing being stuck up in the oil passage in the crankshaft I'm sure the crank journal should polish up well enough to be usable
When I was a lot younger, and a lot less knowledgeable than now, I would have tried to polish that journal in the motor in the car
Now I would remove the crank and take it to a good crankshaft grinding company and have them look at it to see if it would polish and still be useable

Another update...

Took my parts to another machine shop and unfortunately they sat there for 3 weeks with no work done so I picked them up.

Here are the pictures of the cam bearings. Wasted! Looks like the machine shop never clearanced the bearings correctly like they said they did.

In addition here is a picture of the rod with the failed bearing. Note that the rod cap does not have this heat discoloration like the rod itself does. I plan to measure the big end of the rod myself or possibly take the rod to another machine shop for their inspection and measurement.

However, my question is the following.

Just because there is discoloration does that mean that the rod must be reconditioned???

If the big end of the rod measures to spec, no out of round, taper etc. Can it be reused without reconditioning?


I also found that every rod bearing had a piece of the bearing itself broken off. I assume this is due to improper assembly...???

WOW...... You did the right thing for sure.

A well needed freshen up vs alot of new parts in this case and you have the winter to do it. Good Luck.

Metal from one could have caused the failure on the other. I would say the cam bearing were way to tight and that rod bearing failed do to poor assembly.

I would recheck everything and make sure it is on the loose side not the tight side of clearances.

Good Luck!

Wow that was a tight cam fit.

Do you have a radiused crank(fillets).. if so
those bearings could have pushed things tight
(side clearance)

When you see cam bearings getting smashed down, there is an OILING issue. Don't know if your restricting oil or something, but there is no way those spring pressures would drive the cam into the bearings like that if they had oil.



I used to run 360 pounds on the seat with new springs. I also grooved the number 2 & 4 cam bearing journals to get oil upstairs all the time. The cam bearing a always showed witness marks from the groove in the cam on the bottom of the bearing.


The next upgrade was going to be roller bearings on number 1 and 5 cam bearings. I sold it all instead.


Anyway, you have an oil issue.

Wow just wow.

I have seen rod bearings that looked like that from the rod being jammed into the cylinder crooked and the assembler beat the piston/rod down the hole until it rotated enough to saddle the rod journal on the crank. Classic smashed corner of the rod bearing syndrome. I'd look those journals over very carefully for gouges from the corner of the rod itself.

Mr. P Body,

The crank is a Eagle 4.15 Stroker 6-bolt crank. Not sure if that is a radisued crank or not but I believe it is not...

Does the previous picture I posted of the crankshaft journal help to answer that question?

I checked the rod side to side clearance before disassembly and it was not too tight if that makes a difference