GT350 Engine Refresh - Part 2

[honeybadger]

Nice videos man. I just watched them in the other thread.

Those MMR tensioners are concerning too. Glad you are ditching them.

Do you think there is a way to bush the pick up tube support bolt with a grommet to aid in vibration? Or is it pointless?

For sure. I'm switching back to OEM plastic and will just change them out once a year.

And Ford seems to be thinking vibration as well. The challenge is that the tube connects to the oil pumping - which is bolted to the block. So giving some flex to the pickup would lead to some stress on the oil pump I believe. I've FP a ton of pictures and video for them look through. Curious to see what they say back.

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[Droopy1592]

What’s an alternative to the MMRs?

 

[JAJ]

For sure. I'm switching back to OEM plastic and will just change them out once a year.

And Ford seems to be thinking vibration as well. The challenge is that the tube connects to the oil pumping - which is bolted to the block. So giving some flex to the pickup would lead to some stress on the oil pump I believe. I've FP a ton of pictures and video for them look through. Curious to see what they say back.

Once the bracket broke, the oil pickup tube became a teeter-totter pivoting on the second bracket by the oil pump. With the far end loose from its bracket, the only constraint to it wobbling around was the oil pump seal. The seal absorbed all of the vibration, which explains why it was damaged. It would have failed eventually - it was actually a race between the seal failing and the second bracket letting go from fatigue.

In terms of "fixing" it, you have a choice between allowing it to move a little bit with bushings, or stopping all motion by putting in a third bracket that picks up one of the head studs between the two existing brackets. Since the pump seal is damaged by motion, I'd go for an extra bracket. Just sayin'...

 

[usaf_branham]

Are you going to put a set of those L&M GT350 cams in during rebuild?

 

[shogun32]

In terms of "fixing" it, you have a choice between allowing it to move a little bit with bushings, or stopping all motion by putting in a third bracket

or maybe shorten the bracket dramatically and go horizontal with it instead of flat (at bolt face), 45deg, then 90deg. FPC (without requisite balance shafts) are lousy with harmonics which could explain why Ford went with a molded-in plastic setup. A new pump and matching pan is shy of $600. Would seem to be a good idea.

If you move the bracket mount way down to the straight/horizontal section and optionally use a shore-30 rubber liner on the clamp, that would probably work better.

 

[honeybadger]

What’s an alternative to the MMRs?

OEM for me. Would rather change them out annually and run the OEM onces vs go for a really beefy setup. On a big HP build I can see the benefit of billet, for this use I think OEM is better.

Once the bracket broke, the oil pickup tube became a teeter-totter pivoting on the second bracket by the oil pump. With the far end loose from its bracket, the only constraint to it wobbling around was the oil pump seal. The seal absorbed all of the vibration, which explains why it was damaged. It would have failed eventually - it was actually a race between the seal failing and the second bracket letting go from fatigue.

In terms of "fixing" it, you have a choice between allowing it to move a little bit with bushings, or stopping all motion by putting in a third bracket that picks up one of the head studs between the two existing brackets. Since the pump seal is damaged by motion, I'd go for an extra bracket. Just sayin'...

This is actually a great idea. I'll explore spacing in the pan to see if this will work.

Are you going to put a set of those L&M GT350 cams in during rebuild?

I don't plan to. The cost is fairly high and I am not convinced they're worth the $$$ yet. I might when I do a full refresh of the engine and I'm already spending thousands.

or maybe shorten the bracket dramatically and go horizontal with it instead of flat (at bolt face), 45deg, then 90deg. FPC (without requisite balance shafts) are lousy with harmonics which could explain why Ford went with a molded-in plastic setup. A new pump and matching pan is shy of $600. Would seem to be a good idea.

If you move the bracket mount way down to the straight/horizontal section and optionally use a shore-30 rubber liner on the clamp, that would probably work better.

Interesting idea. I'll be curious to hear what Ford says as they analyze it.

 

[BlackandBlue]

The pickup bracket was destroyed by a resonate frequency on the pickup tube. The seal may have been torn up more when the bracket was attached than after it broke. The energy has to go somewhere and both ends are going to absorb the energy. As soon as the bracket broke the harmonics of the tube changed and couldn’t store energy.

A bracket to dampen the middle or a weight(damper) on the middle of the tube is more then likely going to be the solution.

The bracket failure might have been what saved the engine ironically.

Looks great. Looking forward to reading the second writeup.

 

[honeybadger]

The pickup bracket was destroyed by a resonate frequency on the pickup tube. The seal may have been torn up more when the bracket was attached than after it broke. The energy has to go somewhere and both ends are going to absorb the energy. As soon as the bracket broke the harmonics of the tube changed and couldn’t store energy.

A bracket to dampen the middle or a weight(damper) on the middle of the tube is more then likely going to be the solution.

The bracket failure might have been what saved the engine ironically.

Looks great. Looking forward to reading the second writeup.

That’s a great point as well. Wonder if one could go about finding the proper weight (mass) to weld onto the tube without having access to the level of data Ford has on this motor.

 

[BlackandBlue]

That’s a great point as well. Wonder if one could go about finding the proper weight (mass) to weld onto the tube without having access to the level of data Ford has on this motor.

It would be pure guesswork without Fords model. It might even make it worse.

A small piece of steel welded from the original bracket to the middle of the pickup tube might be a safer option. This is absolutely pure speculation though. I would imagine someone at Ford has had experience with this problem. Unless it was a defective part it seems like it would be repeatable.

To get that level of fatigue in 40 hours is amazing.

 

[DCShelby]

You could measure the length of the bracket as it attaches to the tube and the block. Once you know that distance, use some math to calculate the resonance frequency. Think of it as a tuning stub in a microwave circuit. You could weld another piece of steel on top of the exposed part of the bracket to alter the frequency. But as others have said, you might pick up another one. I doubt Ford did a thorough finite element analyses of this part. Not worth their time since they say race parts are not covered by warranty

 

[JAJ]

So, @honeybadger, if you could weigh that piece and tell us how long it is and the distance that each bracket is from one end or the other, someone with a calculator could bung the numbers into this calculation to see if resonance in the tube is a factor:

 

[shogun32]

I don't 'get' Ford's design for the oil pan. Why isn't the well under the pump at the front of the engine? As far as G-loading is concerned brakes provide FAR more force than acceleration does. The pickup would then be a vertical tube. The pickup has a weight at one end (the cone) and a loong moment till it meets the oil pump, which isn't really secured - it's a modest friction fit into a rubber gromet/sheeth. That bracket is trying to apply some amount of pivot force to keep the pump end in it's hole.

Why did Ford abandon the secured at both ends (flanged pump) design that the lesser 5.0 uses?

What's the incline of the pan floor necessary to counter 0.5-.68G of acceleration, so the oil still flows forward at sufficient rate to keep up with drainage? Hmm, looks like vanes at 35 degrees would counteract the flow to the rear. If the pan floor is already at say 10 degrees, the vane angle could be reduced to 25.

 

[JAJ]

I don't 'get' Ford's design for the oil pan. Why isn't the well under the pump at the front of the engine?

The K-member and steering rack are in the way.

Why did Ford abandon the secured at both ends (flanged pump) design that the lesser 5.0 uses?

The Voodoo has the oil pickup tube molded into the plastic pan, so there's no need for bolts to keep the pickup in place once the pan's installed.

 

[shogun32]

The Voodoo has the oil pickup tube molded into the plastic pan

right, so using the 5.0 (or race car?) pickup on the Voodoo pump was a mistake to begin with...

 

[JAJ]

right, so using the 5.0 (or race car?) pickup on the Voodoo pump was a mistake to begin with...

Not a mistake in the usual sense of the word. @honeybadger said that FP advised him it would work, so he used it. It's possible that the bracket was defective from the start, and it has nothing to do with vibration. There's no way to know, but it does make sense to install a more robust part for the next 40 hours.

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