FBO Engine Misfire

[GlassTop09]

Hey Dino, I changed the oil after all this happened. And the old oil did not have any metal debris. Though, I found 2 pin bearings (see image). I also took measurements.View attachment 83295 View attachment 83296

Dino is correct.......those are the cam follower roller bearings from a busted cam follower......more evidence to confirm what your prior pictures show evidence of.

Thanks.
What would cause an intake valve strike on the piston? I am asking this question because ModularHeadShop did all the work on the heads. All I had to do was install them and line up the timing marks on the chain.

Several conditions can cause this, but not all are due to engine timing being off. With this design, if this was due to physical crank to cam timing being off on a bank & the culprit is intake valves then you should have not 1 but 2 intake valves damaged since both intake valves per cyl are operating on same ICL & you'll also have damage in more than 1 cyl on the same bank as well. From your given analysis & pictures I would surmise that engine to cam timing ain't your cause of a single intake valve strike....failure would be constrained to a single valve scenario (why a visual into the cyl head intake ports for damage will help to confirm as well as visual inspection of upper valve train for damage before pulling off head......you'll have to pull both intake manifold & valve cover off anyway so makes sense to start w\ these 2 areas to get damage assessment as well as root cause analysis).

So off the top of my head, a valve spring collaspe causing cam follower to come out & get damaged & valve hang open, cam follower failure causing valve retainer keepers to come out & drop valve, cam follower failure causing valve stem bend to hang valve open, intake valve stem structural failure causing valve to drop & cause cam follower to come out & get destroyed, etc.....can all cause what you're seeing so the only way to determine exactly what happened is to remove the intake manifold & valve cover to inspect all parts, not just the damaged ones but all of them for any clues then replace any\all parts that are determined to have played a part in this to help prevent this from happening again.

2 questions from me........when you replaced the heads, did you also replace all the cam followers\lash adjusters w\ new ones or did you reuse the existing ones? Are the cams stock or aftermarket & if aftermarket which ones?

Hope this helps to answer your question somewhat.

 

[GlassTop09]

You put it in third gear after you crested the hill. Did you over rev and float the valves? I have scattered a couple small blocks doing similar things.
I agree those needle bearings are from a cam follower.

I also agree w\ Midlife here on the possibility of valve float along w\ B1 camshaft over advance rotation off cam phaser inertia from chain tensioner not keeping up w\ chain tension (B1 head will have the lowest operating oil pressure at the VCT solenoid\chain tensioner and PCM will advance the cams back to 0* by design on any throttle decel which is closing the intake valve to piston clearance).

This is why my question to OP of the cams being used......depending on GI IVO point this can close the clearance between an intake valve to piston even more making this scenario even more of a possibility.

 

[Redfire_Jimi]

You put it in third gear after you crested the hill. Did you over rev and float the valves? I have scattered a couple small blocks doing similar things.
I agree those needle bearings are from a cam follower.

Once I hit the bottom of the hill, I was traveling maybe 50-70mph, then I put into third and gave it a little gas, and it immediately started to misfire.

 

[Redfire_Jimi]

@GlassTop09 The rocker arms and lash adjusters were replaced with new FRPP and the cams are CompCams 127500. ModularHeadShop did all the install and timed the camshaft.

 

[Midlife Crises]

If I remember correctly, 127500 cams require a phaser limiter or lockout and Comps heavy springs. Is that how you had it set up. Were the cams degreed when they were installed?

 

[GlassTop09]

If I remember correctly, 127500 cams require a phaser limiter or lockout and Comps heavy springs. Is that how you had it set up. Were the cams degrees when they were installed?

In addition, they're also a high lift cam at .535" I, .550" E at 112* LSA +10* GI advance so I would think they're gonna be very close to min intake valve to piston clearance specs at full advance to ensure that enough exhaust valve to piston clearance is maintained at the 20* max cam retard range (why phaser limiters are required) so not much wiggle room for an intake valve to be floating off a weak spring.

But in all reality, I'm gonna bet on an intake valve cam follower failure causing the strike as these things have a reputation for failure. Those needle bearings found in oil during draining is a dead giveaway.

 

[Dino Dino Bambino]

@GlassTop09 The rocker arms and lash adjusters were replaced with new FRPP and the cams are CompCams 127500. ModularHeadShop did all the install and timed the camshaft.

Well that changes things 'cause it places liability firmly in Modular Head Shop's hands. Therefore I suggest you don't touch the engine and let those guys deal with it. If you haven't done so already, you need to inform them of what happened.
I presume you also had new cam phasers installed, and the 127500 cams definitely call for phaser limiters. As @GlassTop09 correctly pointed out, the higher valve lift on those cams leaves virtually no margin for error when installing and degreeing them in.

I'm gonna bet on an intake valve cam follower failure causing the strike as these things have a reputation for failure. Those needle bearings found in oil during draining is a dead giveaway.

The original stock cam followers do have a reputation for failing, particularly in the 5.4 3V, and it's invariably the roller that gradually begins to drag until it seizes up. It normally gives you ample warning as the engine may tick for thousands of miles until the roller seizes altogether.
In this case, failure was sudden and would be highly unusual for a brand new part. I'd suggest the cam follower was broken when the piston hit the valve, and the root cause was the bank 1 cam timing being slightly out, most likely because the cam was one tooth off during installation. It's also possible the R side phaser limiter was incorrectly installed. One way or another, this looks like installer error and as I see it, they should take responsibility to fix it.

 

[whitmanink]

yea i see alot of red flags at this point,,
*one being how many other little bits made its way through everything in the motor and to what extent?
** two being if this is indeed a fault on modmotors than just you touching it opening it up can void warranty ,, so proceed with caution and ring them first thing this morning ,

-- the oil in the cylinder wall leads me to think the motor is trashed ,, ,might be rebuildable with a bore(s) ,, but its gonna have to be opened up to find the extent of the damaged , ..

i can honestly say i feel your pain, and if your like me , your heart sank the moment you knew it wasn't gonna be an easy fix,, so best of luck with the motor and keep us up to date on what you find and what modmotors says,,

 

[Redfire_Jimi]

Alright gentlemen, thanks for being patient. I pulled the passenger side valve cover last night and made some quick observations (see images below).

• one rocker arm is completely dislodged
• this rocker arm also scored the lobe of the camshaft

Question: How should I proceed next?

 

[Redfire_Jimi]

If I remember correctly, 127500 cams require a phaser limiter or lockout and Comps heavy springs. Is that how you had it set up. Were the cams degrees when they were installed?

Everything you mentioned was done. ModularHeadShop replaced all the seals, springs, locked out phasers, and degreed the camshafts

 

[Redfire_Jimi]

Well that changes things 'cause it places liability firmly in Modular Head Shop's hands. Therefore I suggest you don't touch the engine and let those guys deal with it. If you haven't done so already, you need to inform them of what happened.
I presume you also had new cam phasers installed, and the 127500 cams definitely call for phaser limiters. As @GlassTop09 correctly pointed out, the higher valve lift on those cams leaves virtually no margin for error when installing and degreeing them in.



The original stock cam followers do have a reputation for failing, particularly in the 5.4 3V, and it's invariably the roller that gradually begins to drag until it seizes up. It normally gives you ample warning as the engine may tick for thousands of miles until the roller seizes altogether.
In this case, failure was sudden and would be highly unusual for a brand new part. I'd suggest the cam follower was broken when the piston hit the valve, and the root cause was the bank 1 cam timing being slightly out, most likely because the cam was one tooth off during installation. It's also possible the R side phaser limiter was incorrectly installed. One way or another, this looks like installer error and as I see it, they should take responsibility to fix it.

I plan to contact ModularHeadShop as soon possible. I just want to eliminate any installation errors I may have made (ie. Timing chain). This was suppose to be a simple straightforward install.

 

[Dino Dino Bambino]

I plan to contact ModularHeadShop as soon possible. I just want to eliminate any installation errors I may have made (ie. Timing chain). This was suppose to be a simple straightforward install.

So you installed the timing kit while MHS installed the heads, camshafts, phaser lockouts, and degreed the camshafts?
You'd have to pull the front cover to either confirm or eliminate an error on your part but if you go any further than you have now, MHS may refuse to take any responsibility even if you did your part correctly, and the whole repair cost will be on you.
I suggest you reinstall the valve cover without disturbing anything else, call MHS first thing this morning, send them photos of the damage, and wait to find out what they advise.
FWIW, if there had been a cam timing error, I would have expected both of the no.1 intake valves to have been hit by the piston instead of one. That said, I also see some scoring of the other no.1 intake cam lobe so who knows?
The most severe damage on the front no.1 intake cam lobe is only on one side, and that's a dead giveaway that the cam follower failure was sudden.

 

[GlassTop09]

Man, that sucks........................

Now these pictures are showing a classic example of why you shouldn't be so fast to think there was a cam timing issue as these pictures of the upper valve train clearly show that the other intake valve on the same cylinder shows no damage & both intake cam lobes are on the same ICL on camshaft so if this was due to physical cam timing being off then BOTH intake valve cam followers should have been destroyed, BOTH intake valves should have struck the piston thus BOTH intake valves should be either bent or broken......this engine design will not allow 1 intake valve on the same ICL & lift rate to hit & not the other in the same cylinder. The piston design doesn't have valve reliefs cut into them to incur the possibility that 1 relief was cut a little deeper than the other to potentially allow such a possibility.........

Just a fact, folks. These pictures clearly show this to be isolated to a single intake valve failure which is not related to cam timing\degreeing............

This is why I keep saying to not assume things as it is entirely possible & plausible that a cam follower can structurally fail (I've witnessed this 1st hand), even a new one......especially when a stronger\higher tensioned valve spring vs stock is used & engine operating conditional parameters come into play (remember the shift into 3rd gear around 50-70 MPH off a neutral downhill coast so engine was decoupled from drive train thus w\ accel pedal at rest which has engine around idle RPM's prior this happening....I understand OP tried to use APP to increase engine RPM's but was this done just before clutch engagement or just after.....either way you're taking the engine from very low RPM's to very high RPM's much faster than the engine can achieve on its own).....the sudden initially fast engine accel revs will incur an extra loading onto the cam followers until engine levels out inducing extra harmonics thru the cam follower body from the heavier valve spring's tension causing 1 lash adjuster to potentially slightly back off lash inducing play thus amplifying the harmonics on cam follower roller\body exceeding its structural limits....or as Midlife suggested, also potentially causing the 1 intake valve spring to excessively float due to it being weak enough to allow this to happen in this moment closing the clearance to piston.

You may look into the cyl head intake ports & find that both valve heads are still intact & both appear to be fully seated (judging by the valve stem height of both intake valves in pictures) or 1 of the valve heads either bent\broken or both of them bent\broken visually..........but until the intake manifold is pulled & intake valve ports visually inspected...........

Not good in any case here..........hope the folks at the shop will work w\ you.

 

[Redfire_Jimi]

So you installed the timing kit while MHS installed the heads, camshafts, phaser lockouts, and degreed the camshafts?
You'd have to pull the front cover to either confirm or eliminate an error on your part but if you go any further than you have now, MHS may refuse to take any responsibility even if you did your part correctly, and the whole repair cost will be on you.
I suggest you reinstall the valve cover without disturbing anything else, call MHS first thing this morning, send them photos of the damage, and wait to find out what they advise.
FWIW, if there had been a cam timing error, I would have expected both of the no.1 intake valves to have been hit by the piston instead of one. That said, I also see some scoring of the other no.1 intake cam lobe so who knows?
The most severe damage on the front no.1 intake cam lobe is only on one side, and that's a dead giveaway that the cam follower failure was sudden.

MHS assembled all the aforementioned components and shipped the heads to me. I did the final installtion

 

[Redfire_Jimi]

Man, that sucks........................

Now these pictures are showing a classic example of why you shouldn't be so fast to think there was a cam timing issue as these pictures of the upper valve train clearly show that the other intake valve on the same cylinder shows no damage & both intake cam lobes are on the same ICL on camshaft so if this was due to physical cam timing being off then BOTH intake valve cam followers should have been destroyed, BOTH intake valves should have struck the piston thus BOTH intake valves should be either bent or broken......this engine design will not allow 1 intake valve on the same ICL & lift rate to hit & not the other in the same cylinder. The piston design doesn't have valve reliefs cut into them to incur the possibility that 1 relief was cut a little deeper than the other to potentially allow such a possibility.........

Just a fact, folks. These pictures clearly show this to be isolated to a single intake valve failure which is not related to cam timing\degreeing............

This is why I keep saying to not assume things as it is entirely possible & plausible that a cam follower can structurally fail (I've witnessed this 1st hand), even a new one......especially when a stronger\higher tensioned valve spring vs stock is used & engine operating conditional parameters come into play (remember the shift into 3rd gear around 50-70 MPH off a neutral downhill coast so engine was decoupled from drive train thus w\ accel pedal at rest which has engine around idle RPM's prior this happening....I understand OP tried to use APP to increase engine RPM's but was this done just before clutch engagement or just after.....either way you're taking the engine from very low RPM's to very high RPM's much faster than the engine can achieve on its own).....the sudden initially fast engine accel revs will incur an extra loading onto the cam followers until engine levels out inducing extra harmonics thru the cam follower body from the heavier valve spring's tension causing 1 lash adjuster to potentially slightly back off lash inducing play thus amplifying the harmonics on cam follower roller\body exceeding its structural limits....or as Midlife suggested, also potentially causing the 1 intake valve spring to excessively float due to it being weak enough to allow this to happen in this moment closing the clearance to piston.

You may look into the cyl head intake ports & find that both valve heads are still intact & both appear to be fully seated (judging by the valve stem height of both intake valves in pictures) or 1 of the valve heads either bent\broken or both of them bent\broken visually..........but until the intake manifold is pulled & intake valve ports visually inspected...........

Not good in any case here..........hope the folks at the shop will work w\ you.

Man, that sucks........................

Now these pictures are showing a classic example of why you shouldn't be so fast to think there was a cam timing issue as these pictures of the upper valve train clearly show that the other intake valve on the same cylinder shows no damage & both intake cam lobes are on the same ICL on camshaft so if this was due to physical cam timing being off then BOTH intake valve cam followers should have been destroyed, BOTH intake valves should have struck the piston thus BOTH intake valves should be either bent or broken......this engine design will not allow 1 intake valve on the same ICL & lift rate to hit & not the other in the same cylinder. The piston design doesn't have valve reliefs cut into them to incur the possibility that 1 relief was cut a little deeper than the other to potentially allow such a possibility.........

Just a fact, folks. These pictures clearly show this to be isolated to a single intake valve failure which is not related to cam timing\degreeing............

This is why I keep saying to not assume things as it is entirely possible & plausible that a cam follower can structurally fail (I've witnessed this 1st hand), even a new one......especially when a stronger\higher tensioned valve spring vs stock is used & engine operating conditional parameters come into play (remember the shift into 3rd gear around 50-70 MPH off a neutral downhill coast so engine was decoupled from drive train thus w\ accel pedal at rest which has engine around idle RPM's prior this happening....I understand OP tried to use APP to increase engine RPM's but was this done just before clutch engagement or just after.....either way you're taking the engine from very low RPM's to very high RPM's much faster than the engine can achieve on its own).....the sudden initially fast engine accel revs will incur an extra loading onto the cam followers until engine levels out inducing extra harmonics thru the cam follower body from the heavier valve spring's tension causing 1 lash adjuster to potentially slightly back off lash inducing play thus amplifying the harmonics on cam follower roller\body exceeding its structural limits....or as Midlife suggested, also potentially causing the 1 intake valve spring to excessively float due to it being weak enough to allow this to happen in this moment closing the clearance to piston.

You may look into the cyl head intake ports & find that both valve heads are still intact & both appear to be fully seated (judging by the valve stem height of both intake valves in pictures) or 1 of the valve heads either bent\broken or both of them bent\broken visually..........but until the intake manifold is pulled & intake valve ports visually inspected...........

Not good in any case here..........hope the folks at the shop will work w\ you.

My thoughts exactly. The only reason I brought up the timing is because I spent a great of time making sure I installed the chains correctly (1.5 weeks to be exact). I checked and double checked all the timing marks lined up correctly. And I drove the car for 1500 miles without any issues. I sent Lito multiple datalogs and nothing was out of normal operating range.

 

[Midlife Crises]

If I understand correctly, MHS assembled the heads and mounted the cams. Then you installed the heads yourself and lined up the timing marks. That means your cams have been indexed to the stock timing marks. Unless you mounted a degree wheel to the crank and verified the cams lobe center the cams have not been degreed. This also involves an adjustable gear on the crank to move the cam timing and simply cannot be done with the heads off. Assembly terms aside, I strongly believe when you let the clutch out in 3rd gear while coasting, the engine over reved and lost control of valves. There may very well be other pistons with kiss marks you haven’t found yet.

 

[Redfire_Jimi]

If I understand correctly, MHS assembled the heads and mounted the cams. Then you installed the heads yourself and lined up the timing marks. That means your cams have been indexed to the stock timing marks. Unless you mounted a degree wheel to the crank and verified the cams lobe center the cams have not been degreed. This also involves an adjustable gear on the crank to move the cam timing and simply cannot be done with the heads off. Assembly terms aside, I strongly believe when you let the clutch out in 3rd gear while coasting, the engine over reved and lost control of valves. There may very well be other pistons with kiss marks you haven’t found yet.

Your are correct. MHS assembled the heads and degreed the cams. I simply lined up the marks on the locked out phasers + timing chain + crank gear.

 

[whitmanink]

Assembly terms aside, I strongly believe when you let the clutch out in 3rd gear while coasting, the engine over reved and lost control of valves. There may very well be other pistons with kiss marks you haven’t found yet.

i respectfully disagree ,,, ive run my motor up to 6500 rpm , alot , dumped the clutch alot ,, beat mine alot,, and never had that happen, with the stock valve train,,,

i think its as simple as the roller follower bearings might have been defective causing it to spit it out,, i also see the other cam lobe looks like the roller follower was seizing up , just by how the lobe looks,, or was it oil starved?

not to mention people with the on3 turbo kits with stock valve train beating the piss out of em and this isnt happening ,,,

unless he uped the rpm rev limiter ,, valve float wont happen ,, not on a NA motor ,,

 

[whitmanink]

regardless ,,, you have 2 of i think like 6 roller bearings?? so they went somewhere ,, hardened steel too,,
thats gonna destroy any soft metal it touches , i wouldnt turn the motor over untill its pulled and ripping stuff apart,,, hopefully mod motors will take care of you as i dont think this is your fault,, and this isnt due to knock or pre dentation

 

[Midlife Crises]

unless he uped the rpm rev limiter

The rev limiter plays no role in what happens when the clutch is let out, in gear while coasting. I agree the story will unfold when the engine is torn down. I’m betting on more than one valve strike and I would definitely check the valve springs on a spring tester. Pull the heads and have a look.