Cknight199 motor build thread

Burn Down

Burn Down

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Sep 14, 2008
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The reason I ask is, because at some point it wasn't... That's the only way it could have gotten that flat spot and discolored so badly from heat. The cam has a nice uniform wear pattern, with no signs of spalling that I can see in the pic. What does the other side of the bad lobe look like?

Do you have the bad lifter? It would be interesting to take it apart and look at the roller and pin.
 
Cknight199

Cknight199

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Burn Down said:
The reason I ask is, because at some point it wasn't... That's the only way it could have gotten that flat spot and discolored so badly from heat. The cam has a nice uniform wear pattern, with no signs of spalling that I can see in the pic. What does the other side of the bad lobe look like?



Do you have the bad lifter? It would be interesting to take it apart and look at the roller and pin.
Click to expand...


I don't have it, but will be able to look at it in a week or so more closely.


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Fingers

Fingers

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Damage was from the lifter, not the cam. Roller stalled, for whatever reason and skidded it's way around the lobe.
 
Cknight199

Cknight199

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CaptPhil said:
The lift side is damaged because it sees the most pressure when trying to open the valve.



That lifter failed at some point, that much is obvious.
Click to expand...


Shouldn't the lobe see equal pressure?

I am just perplexed at how it happened on one of the lobes, and started to happen on another. None of my other bearings show signs of damage from shavings or anything that could have gotten stuck on a lifter. I am not blaming the cam, and don't want to be pointing fingers at parts just yet. I spoke with Jeremy about it and he said he doubt it's the cam as well but wanted to take care of me which I really do appreciate greatly.

Has anyone ever seen this before from a failed lifter?


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CaptPhil

CaptPhil

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Cknight199 said:
Shouldn't the lobe see equal pressure?

I am just perplexed at how it happened on one of the lobes, and started to happen on another. None of my other bearings show signs of damage from shavings or anything that could have gotten stuck on a lifter. I am not blaming the cam, and don't want to be pointing fingers at parts just yet. I spoke with Jeremy about it and he said he doubt it's the cam as well but wanted to take care of me which I really do appreciate greatly.

Has anyone ever seen this before from a failed lifter?


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Click to expand...

In a static environment, yes both sides of the lobe face will see equal pressure. However in a dynamic environment you have the lifting lobe face trying to accelerate the valve open, spring pressure on the nose increases the more the valve is opened. On the downward cycle the valve has inertia on its side because it was just smacked open, so now instead of having to move the valve's weight, overcome guide friction, and accelerate it, the lobe just has to hold back the spring pressure. Just like doing a fast pushup, harder to go up then it is to come down.

I have seen it before on gas engines. Most commonly though the roller bushing fails and or the roller shaft breaks, clocking the roller out of center and seizing it up. You said the roller still spins freely, which is odd, because for some time it was definitely seized for whatever reason.
 
CaptPhil

CaptPhil

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Do a google search for failed roller lifter, you will see a bunch of pictures of cams and lifters that look exactly like yours.

I highly doubt that you floated a valve with the spring pressures you are running unless you had a bad spring or a sticky guide. Bad lifter bounce could have damaged the roller and made it sticky, but i would have expected to see signs of that on the cam.

Although I must say, your lifter is the most uniformly ground roller I have seen, haha.
 
Fingers

Fingers

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The fact that you have two failed would make me think you have a bad combination of aggressive ramp on the cam and high spring pressures. Something was making the roller happier to skid than roll.

I would consider replacing my lifters.
 
Cknight199

Cknight199

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Fingers said:
The fact that you have two failed would make me think you have a bad combination of aggressive ramp on the cam and high spring pressures. Something was making the roller happier to skid than roll.

I would consider replacing my lifters.
Click to expand...


They will all be replaced


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OregonDMAX

OregonDMAX

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Apr 28, 2013
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CaptPhil said:
Do a google search for failed roller lifter, you will see a bunch of pictures of cams and lifters that look exactly like yours.

I highly doubt that you floated a valve with the spring pressures you are running unless you had a bad spring or a sticky guide. Bad lifter bounce could have damaged the roller and made it sticky, but i would have expected to see signs of that on the cam.

Although I must say, your lifter is the most uniformly ground roller I have seen, haha.
Click to expand...

By the looks of it, it either stuck hard or never turned since installed.
 
Cknight199

Cknight199

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CaptPhil said:
Any updates? This thing running again?

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Click to expand...


Truck was back up and running Friday night, so stoked to have it back on the road. Saturday it made 822hp on the dyno and took first place in dirt drags in the modded class, so going with a smaller cam seemed to help, even feels way better on the road. We went with slightly tighter top rings and it seems to have much better starts in the cold, the smaller cam could have helped as well. Turbo response and streetability have increased tremendously as well.


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S

S Phinney

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Aug 15, 2008
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Cknight199 said:
Truck was back up and running Friday night, so stoked to have it back on the road. Saturday it made 822hp on the dyno and took first place in dirt drags in the modded class, so going with a smaller cam seemed to help, even feels way better on the road. We went with slightly tighter top rings and it seems to have much better starts in the cold, the smaller cam could have helped as well. Turbo response and streetability have increased tremendously as well.


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Click to expand...
What did you go to in cam now

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Last edited:
Cknight199

Cknight199

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I never updated this thread lol. Last season on the day of the NADM event... (I must not have much luck at NADM races since the truck broke for the last two years on this day lol) The truck started backfiring in high rpm and became super smoky and sluggish. Like wouldn't even make more than 20 psi. I messed around with it for 2 days changing sensors, ecm's, tunes. Finally called it and pulled my injectors to have them tested as a last resort. Test results came back with scaring on my plungers and super high return rates. Decided it was not worth the risk to run them in the motor, and I did not have money for new ones.

Ended up switching jobs in January to a full time job, going to school in the mornings. Absolutely love that decision and am happy with where I am right now.

I was able to buy some used injectors which are going in soon. I also ordered 2 FASS 220 pumps, billet hold downs, manifolds and up pipes, and an s483 single. Ended up changing my mind today and I am going to try the new s476sxe charger instead. I also have a V2 on the way and am going to attempt to tune it myself lol.

I am also in the process of stripping the frame and Repainting it, and probably have well over 20 hours put into it already.


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