From time to time, over the past couple of years or so, folks have been posting threads on some of the Forums about failed bronze tip fuel pump pushrods. There has of course been some discussion about all that, but no real wind-up as to what is actually going on here.

Since there has not been a solution, some folks have switched to composite fuel pump pushrods in an effort to get out from under this problem. However, that may not be the best choice either, since it is not that uncommon for composite fuel pump pushrods, or for that matter composite distributor gears, to break inside a running engine. And that can leave you with quite a task to clean all the broken pieces out of the engine, not to mention having a running failure when you least expect it. For that reason, I don't believe composite engine internal components are a good idea in our traditional SB and BBC's.

I think it is much better to get to the root cause of what the problem may be with the metallic parts in question. Because bronze fuel pump pushrod tips and bronze distributor gears won't generally ever break on you, in a running engine, even if they may have some wear issues. Bronze parts such as those, are softer material and are expected to wear, thus preventing wear on your steel cam. They are maintenance items, much like solid roller lifters. You can't expect to install them and permanently forget them. At the very least, you should periodically inspect them to see how things are going.

In any case, I think it is about time to do a failure analysis of bronze tip fuel pump pushrods to get to the bottom of the failures some folks are experiencing. To accomplish this, I'm in the process of gathering as much information as I can about this issue.

So, if you'd like to be part of this failure analysis, please share the details about your bronze tip fuel pump pushrod failure, by answering the questions below:

NOTE: Just as important to this overall failure analysis of what did NOT work, is what DID work. So, if you've run a bronze tip fuel pump pushrod, and have had no issue with it, please answer the questions below as well.

1. Did your bronze tip fuel pump pushrod fail on you, or has it been fine?

2. If your bronze tip fuel pump pushrod failed on you, what brand was it?

3. If you experienced a failure, would you consider it excessive wear, or did the bronze tip mushroom to the point that you could not get it out of the block?

4. How many miles did you get out of it, or have gotten out of it so far, if it was primarily a street car?

5.How many passes did you get out of it, or have gotten out of it so far, if it was primarily a drag car?

6. What percentage of the time was this engine operated on the street, and/or what percentage of the time was this engine operated on the track?

7. What rpm did this engine most commonly see?

8. What is the psi rating of the mechanical fuel pump used with this pushrod. The psi is determined by how stiff the diaphragm spring is, which in turn, determines the load applied on the bronze tip.

9. What specific oil or oils, and what viscosity version of that oil or oils, did you use or are using with this pushrod?

10. Did you use any aftermarket oil additives in the oil used with this pushrod?

11. I'd like to get my hands on as many failed pushrods as I can for evaluation. So, would you be willing to send me your failed bronze tip fuel pump pushrod for that purpose? If you really want to keep the pushrod, I'd be happy to return it to you after the evaluation.

After gathering as much information as possible, including physical evaluation of failed parts, I'll post the results of the analysis. And hopefully, we'll have a workable go-forward plan at that time.

Thanks for any information you are willing to share.

540 RAT

Mechanical Engineer

U.S. Patent Holder

Member SAE (Society of Automotive Engineers)

Member ASME (American Society of Mechanical Engineers)

To see my entire 130+ motor oil “Wear Protection Ranking List”, along with additional motor oil tech FACTS (with over 40,000 “views” worldwide), here’s a link:

http://540ratblog.wordpress.com/

 

Interesting post. often wondered about the bronze parts. Running a Lunati billet cam and Crower solid rollers, on the 4th summer with this setup and see 3 to 4 track days [Road America and the Milw Mile with the SCCA] a season, plus some street time, probably 1500 to 2k miles. Shift lite comes on at 7200rpm. I run Brad Penn 20w50 oil, No failures [knock on wood]. Running a Holley fuel pump with std fuel pump pressure 6psi and a MSD dist. T

 

1 yes the bronze tip was almost gone.
2 comp cams
3 it mushroomed and was nearly gone. I had a heck of a time getting it out of the block. It is hard to get to the tip end. I put a flat file to bronze edge and rotated the rod till it ground the mushroom away so it finally came out.
4 I looked through my records and I had @ 8600 miles
5. You don't list it, but I might have had 900 miles of driving around road racing tracks.
6. @ 10% track miles
7. I have a OD 5 speed 4.11 common highway cruise 2500+ rpm max track rpm shifting at 7000 and sometimes into the 7500 rev limiter into the braking zones.
8. I have always used the stock AC-Delco mech fuel pump with return line. When I had a pressure gauge on the fuel log it generally ran at 4 - 4.5 psi always sub 5 psi
9. VR1 racing oil your oil tests showed it to be one of the top oils. This motor is a solid roller. I blend oil weights to achieve my desired oil pressure in a non bypass system with a high volume pump so it is somewhere between 10W-30 and 20W-50.
10. no additives
11. I will look for it in my racing broken parts box and send it to you. I am driving around right now with a composite dizzy gear and fuel pump rod. Only one comp cams dizzy gear has ever failed on me. But it was at the track shifting many times a lap at over 7000 rpm.

I set my dizzy gear engagement depth with a morroso gauge. you shim or un shim the manifold dizzy hole depending on the head and intake combo