Exhaust Valves

SargeIndustries · **Posted:** Tue Jan 07, 2020 12:31 am

Does anyone have an old exhaust valve laying around? I need one to fill out the custom valve order form from Manley Performance.
Thanks

http://manleyperformance.com/dl/custom_valves.pdf

thesameguy · **Joined:** Sat Oct 01, 2016 8:24 pm **Posts:** 652

I think I do.... do you know how to readily tell an intake from an exhaust? They're all mixed together.

SargeIndustries · **Posted:** Tue Jan 07, 2020 6:08 am

I would think the exhaust would be smaller in size compared to the intake.

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krb · **Posted:** Tue Jan 07, 2020 7:12 am

I do too.

My66dodge · **Posted:** Tue Jan 07, 2020 9:08 am

Yep, the exhaust valves are smaller than the intake, if I remember right it’s 1mm, but I know for sure the intake are bigger and when you mix them up the intake stick out of the exhaust seats lol

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geordi · **Posted:** Tue Jan 07, 2020 12:27 pm

The heads of the valves should be the same size, this is a symmetrical head. The way to tell is that the exhaust valve has the alloy section by the head of the valve, where the intake are stainless steel all the way through.

Usually once you clean them it will be apparent.

thesameguy · **Joined:** Sat Oct 01, 2016 8:24 pm **Posts:** 652

I think the intakes are larger - that's a good call!

Here's what I've got:

I just need to remember where I put them last month!

geordi · **Posted:** Tue Jan 07, 2020 3:01 pm

Hard to tell in a picture, I can't zoom in enough to get any real quality detail. But it looks like the far right end valves in both row are exhaust valves. You should be able to confirm this with a magnet, the alloy stem and valve head is not magnetic.

Also - I've installed probably 40 sets of these now. The valves are the same size or very nearly the same. Hold them up against each other, coin to coin - they are the same diameter. The length of the stem can vary a tiny bit b/c of the milling / manufacturing, but that is taken up by the lash adjuster - the lifter.

TKB4 · **Posted:** Tue Jan 07, 2020 4:46 pm

I could ship you a whole bad head with all the valves in it . Then no question which one is which. If interested PM me.

thesameguy · **Joined:** Sat Oct 01, 2016 8:24 pm **Posts:** 652

I got 'em...

For the record,

Intake are 32.3mm
Exhaust are 30.8mm

Height is the same 108.5mm and stem is the same diameter 5.5mm.

Lemme know where they're going, and how fast you want them.

SargeIndustries · **Posted:** Tue Jan 07, 2020 11:20 pm

thesameguy I emailed you...

My66dodge · **Posted:** Tue Jan 07, 2020 11:33 pm

If you put an intake valve in the exhaust side they stick out, my machine shop got 2 mixed up before so I knew they were different diameters as the intake valve being larger never seats so it protrudes a mm or 2

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TURBO-DIESEL-FREAK · **Joined:** Sat Apr 17, 2010 3:29 pm **Posts:** 1167

JUST SOME THOUGHTS, FELLOW CRD OWNERS:

Better exhaust valves are always a good idea, but this will likely not solve the problem of exhaust valve breakage if the problem does not lie with the O.E. exhaust valves.

That metallurgical study on the O.E. exhaust valves that was done and posted on LOSTJEEPS.com is inconclusive at best. Heat may be a factor, but not at the 1200 degree Fahrenheit temperatures quoted by some CRD engine "experts" as being a problem. Even O.E. spec exhaust valves can withstand these temperatures forever and not have a problem. Everyone seems to be avoiding the elephant in the room with regard to exhaust valve failures, and that is to look at ALL other factors and this requires doing some research. Perhaps people can start by reading the following article...

https://www.enginebuildermag.com/2018/0 ... explained/

With regard to the CRD engine and its well documented problems with the aluminum cylinder head warping and the resulting head gasket leaking... I believe the main reason exhaust valves are breaking is because the head is warping so badly that the exhaust valves no longer are perfectly lined up with the valve seats they mate with. The result is the valve experiences side loading and will that will break any valve.

My theory makes sense because the exhaust port area is precisely where a cylinder head will warp the most due to the temperature extremes it experiences even in non-extreme driving conditions.

If I am indeed correct, then this speaks very loudly to CRD owners making very sure that they warm up their engines thoroughly before putting a load on them and subsequently cooling them off gradually by idling them for a couple of minutes or so after driving. This will help to mitigate any thermodynamic issues obviously prevalent in a high compression engine that is boosted and has an aluminum cylinder head, which is the worst case scenario for cylinder head integrity.

I still believe that the development of an iron cylinder head to replace the aluminum one would be a fantastic upgrade to the CRD engine from a durability/longevity point of view. Having a cylinder head made of the same material as the engine block will go a long way to mitigating thermodynamic problems. Did it ever occur to CRD owners that the number 1 reason that engineers use aluminum cylinder heads in their engine designs is not to make the engine lighter, but to limit the life of the engine?

WWDiesel · **Posted:** Sat Sep 03, 2022 12:09 am

TURBO-DIESEL-FREAK wrote:

Better exhaust valves are always a good idea, but this will likely not solve the problem of exhaust valve breakage if the problem does not lie with the O.E. exhaust valves.

If you have any proof of this, PLEASE share it with everyone!

Excerpt from the Report on Valve Failures: wrote:

"Although ~3E8 cycles to failure is a relatively short life for this application, high cycle fatigue was concluded to be a possible mechanism of failure. A future inspection of the exhaust gas recirculation (EGR) equipment may provide further evidence for the cause of this shortened valve life."

Exhaust valve heads snapping off (breaking) certainly speaks loud volumes and provides us with the single point of failure mechanism for engine catastrophic failures while although the absolute "Root Cause" may not be 100% crystal clear, the end result certainly is. It has been a well established fact for some time that when an exhaust valve failure does occur on this engine, it usually happens on higher mileage engines due to the high-cycle fatigue regardless of any whys.

The Bottom Line: IF there is anyway to help prevent these valve failures, many owners would be more than willing to invest in an improved metal composition valve like the *Inconel valves to extend the life of their diesel engine without worry of future and imminent catastrophic failures. Heck, we have enough other issues to worry about without this one! :banghead:

Quote:

*Inconel valves are made from a Nimonic 751 alloy which has better resistance to heat (and abrasion) than stainless steel. Inconel valves are only used for exhaust valves, as it is the only side that it is needed to use a higher temperature alloy. INCONEL valves can withstand an operating temperature of 1,600 F (approx 2200 F EGT). Inconel Valves are the highest quality material available for diesel exhaust valves, they are used in many applications as direct replacements for factory valves especially on higher output engines or where there is a history of early valve failures.

taroo · **Joined:** Sun Apr 27, 2008 2:14 pm **Posts:** 276

So I have done most mods including the ARP studs, SEGar, EGR/FCV delete, etc. I have 150k mikes. I have bypass oil filter and double fuel filter, etc.

Are the valves an issue I should consider? I don’t recall reading much about this issue. Thanks for the thoughts and backstory.

WWDiesel · **Posted:** Sun Sep 11, 2022 3:09 pm

taroo wrote:

So I have done most mods including the ARP studs, SEGar, EGR/FCV delete, etc. I have 150k mikes. I have bypass oil filter and double fuel filter, etc.
Are the valves an issue I should consider? I don’t recall reading much about this issue. Thanks for the thoughts and backstory.

While the root cause of the broken valves has never been 100% ascertained, we do know that it happens in SOME higher mileage engines and when it does, the damage and carnage can be quite severe and very expensive. In most every reported case, the damage to the head required the purchase of a new or used engine head!
In a few rare reported occasions, the engine damage was so severe that it cracked or broke the block and / or the connecting rod causing complete catastrophic damage to the engine block rendering it totally destroyed and un-rebuildable or usable. :grim:

Online Link to Final Report on: Metallurgical Investigation of VM Motori Exhaust Valves

The only 100% proven prevention method found so far is the removal of the engine head and replacement of the exhaust valves when the cyclic life of the valves approach around 200k vehicle miles. $$$

Read these threads on LOSTJeeps, they will enlighten to the issues of broken exhaust valves:
1. > Valve failure research thread - We need your data!

another one:
2. > Broken/Dropped Valves in the VM

Picture of damage due to dropped/broken exhaust valve:

TURBO-DIESEL-FREAK · **Joined:** Sat Apr 17, 2010 3:29 pm **Posts:** 1167

WWDiesel wrote:

TURBO-DIESEL-FREAK wrote:

Better exhaust valves are always a good idea, but this will likely not solve the problem of exhaust valve breakage if the problem does not lie with the O.E. exhaust valves.

If you have any proof of this, PLEASE share it with everyone!

Excerpt from the Report on Valve Failures: wrote:

"Although ~3E8 cycles to failure is a relatively short life for this application, high cycle fatigue was concluded to be a possible mechanism of failure. A future inspection of the exhaust gas recirculation (EGR) equipment may provide further evidence for the cause of this shortened valve life."

Exhaust valve heads snapping off (breaking) certainly speaks loud volumes and provides us with the single point of failure mechanism for engine catastrophic failures while although the absolute "Root Cause" may not be 100% crystal clear, the end result certainly is. It has been a well established fact for some time that when an exhaust valve failure does occur on this engine, it usually happens on higher mileage engines due to the high-cycle fatigue regardless of any whys.

The Bottom Line: IF there is anyway to help prevent these valve failures, many owners would be more than willing to invest in an improved metal composition valve like the *Inconel valves to extend the life of their diesel engine without worry of future and imminent catastrophic failures. Heck, we have enough other issues to worry about without this one! :banghead:

Quote:

*Inconel valves are made from a Nimonic 751 alloy which has better resistance to heat (and abrasion) than stainless steel. Inconel valves are only used for exhaust valves, as it is the only side that it is needed to use a higher temperature alloy. INCONEL valves can withstand an operating temperature of 1,600 F (approx 2200 F EGT). Inconel Valves are the highest quality material available for diesel exhaust valves, they are used in many applications as direct replacements for factory valves especially on higher output engines or where there is a history of early valve failures.

WWDiesel:

The point I clearly made - and one that you seem to overlook - is that the CRD "experts" are focusing in on the quality of the exhaust valves ALONE, WITHOUT REGARD TO ANY OTHER FACTOR that could cause or contribute to exhaust valve failure. This is a mistake, and one that should not be made by someone who is truly trying to deduce the real reason or reasons why this problem is occurring. Focusing on one possible culprit while ignoring other possibilities opens the investigator up to accusations of spin doctoring. Democrats, Liberals and Leftists are world class experts in this tactic... the whole issue of Climate Change has spin-doctoring written all over it. Please avoid this if you want to be taken seriously.

You said it yourself that the metallurgical study was inconclusive; your precise words were "While the root cause of the broken valves has never been 100% ascertained...". You asked for "proof", and yet you provide little of it yourself to make the case that the quality of the exhaust valves are the sole reason for exhaust failures. Seeing as it is unlikely any of us will have the money to thoroughly research this with the CRD engine, we are left with sussing out the problem by looking at the most common reasons why exhaust valves fail in all internal combustion engines, and why exhaust valves fail in turbo-diesel engines that have aluminum cylinder heads in particular.

More to the point, has ANYONE actually done any continuous measuring of exhaust temperatures in CRD engines? This would go a long way to determining if the exhaust temperatures are high enough to lead to exhaust valve erosion issues. REMEMBER that exhaust gas temperatures do not directly correspond to the same temperatures in the valves themselves.... some cooling does indeed occur as the exhaust valve meets the seat

Cylinder head warpage also occurs more frequently as the miles pile up. In the article I posted a link to above, the following is written... "Fatigue from the valve flexing due to being off-center on the seat can also cause failure." The chief cause of an exhaust valve being off-center is from warpage.

All that I am trying to communicate here is to look at ALL the reasons why exhaust valves are failing in Jeep Liberty CRD engines, not just the quality of the valves themselves.

layback40 · **Posted:** Wed Oct 19, 2022 8:58 pm

Has anyone had a valve failure after replacing their original valves?
When heads have been removed to replace valves, are misalignment of the valve seats found? This would answer the suggestion of head warpage being a potential cause.
If one team believe better valves are the solution, then no reason not to do the change even if it costs a few hundred $$ more than replacing with standard valves.
If another team believes that localized head warpage is the problem, let them make suggestions of solutions like head mods. We will all be interested to hear of their suggestions.
This thread is for the Manley Exhaust Valves, Lets have discussions about other causes & solutions in another thread.

TURBO-DIESEL-FREAK · **Joined:** Sat Apr 17, 2010 3:29 pm **Posts:** 1167

layback40 wrote:

Has anyone had a valve failure after replacing their original valves?
When heads have been removed to replace valves, are misalignment of the valve seats found? This would answer the suggestion of head warpage being a potential cause.
If one team believe better valves are the solution, then no reason not to do the change even if it costs a few hundred $$ more than replacing with standard valves.
If another team believes that localized head warpage is the problem, let them make suggestions of solutions like head mods. We will all be interested to hear of their suggestions.
This thread is for the Manley Exhaust Valves, Lets have discussions about other causes & solutions in another thread.

I did previously mention that if the exhaust valves need to be replaced, then it would be a good idea to upgrade to a higher quality valve. All I am stating in this thread is that there is more than one possible explanation for exhaust valve breakage and that people should not expect an exhaust valve upgrade to be the universal answer.

In fact, given the well-documented fact that the R425/R428 engine has head gasket failures and the fact that head warpage is most severe around the exhaust ports, the more likely cause of exhaust valve failures is indeed head warpage.

WWDiesel · **Posted:** Sat Oct 22, 2022 4:09 pm

TURBO-DIESEL-FREAK wrote:

All I am stating in this thread is that there is more than one possible explanation for exhaust valve breakage and that people should not expect an exhaust valve upgrade to be the universal answer.
In fact, given the well-documented fact that the R425/R428 engine has head gasket failures and the fact that head warpage is most severe around the exhaust ports, the more likely cause of exhaust valve failures is indeed head warpage.

While I think in theory most agree with your synopsis of the issue, at the same time we don't know for sure the "Root Cause" of valve failure, but we certainly know the consequences of one breaking and the damage that will incur.
We also know that somewhere around the 200k miles is when most have occurred while a few have happened earlier and some later or some engines never experiencing a failure not at all. Yes we would love to know the WHY!
So at this point, the only known 100% preventive measure that can be done is to replace the original exhaust valves when the mileage gets up close to 200k.
Prevention is the key here, whether we know for sure the cause or not. :2cents:

Unfortunately you are beating a dead horse!
:5SHOTS:

Exhaust Valves

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