The good and the bad of a roots supercharger.

[ShadowsPapa]

I'm seeing multiple bad lobes there, a couple look really bad - am I seeing correctly?

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[DAVECS1]

Yeah I would say the while intake cam has seen damage

 

[DAVECS1]

I am really shocked at this damage. Questioning everything right now.

 

[ShadowsPapa]

That sort of damage is just weird - inadequate oil, binding valve spring coils......................

I laugh when people try to argue about oil by saying "well, all modern engines have roller lifers so it doesn't matter". Uh, no, there's still non-rollers out there.

 

[DAVECS1]

So little disturbed and a little relaxed. I need to do more research, but I am pretty sure they put exhaust lifters on my intake cam. These new ones stabalize the rocker way better

 

[ShadowsPapa]

How do they stabilize it more - the rocker should run flat against the cam lobe without any tipping or rocking.
I have to study/find some closeups of that system and see what's up.
These rockers are more followers and should run flat on the cam lobe assuming the lobe is perfectly flat across. There's a lot of force between the rocker and cam lobe, about like the old flat tappet type but with those the lifters rotate because they run off-center and the lifter spins as it's pushed up by the cam lobe, evening pressure and wear.
These are flat, in my mind, there shouldn't be any tendency to shift or rock side to side. The wear looks totally even all across the lobe (severe, but even side to side of the lobe)

 

[DAVECS1]

I just talked to a guy, that is an exhaust lifter. The head is smaller, for the other rocker. So I was probably bypassing oil into the rocker to activate the low lift portion of the rocker.

I imagine my tune is way conservative as I was running highlift from top to bottom.

This is so frustrating!!!

 

[ShadowsPapa]

I just talked to a guy, that is an exhaust lifter. The head is smaller, for the other rocker. So I was probably bypassing oil into the rocker to activate the low lift portion of the rocker.

I imagine my tune is way conservative as I was running highlift from top to bottom.

This is so frustrating!!!

OK, now you have me wondering - if YOUR engine has exhaust lifters on the INTAKE rocker, is your engine an anomaly or - did Jeep get a bunch of engines assembled this way meaning it could have ALL ALONG been the real issue with misfires and engine noise?
Knowing what I know about past decades, you really never had a one-off engine assembled wrong. It's almost always a run or string of units. Engines with push rod tips not heat treated, that sort of thing, don't happen one engine and no others.

 

[DAVECS1]

Yeah I feel like I should contact somebody, not sure if they will believe me, this is nuts. My buddy was shocked big time!

 

[jsalbre]

Well that’s an interesting find. I too can’t help but wonder if there’s a whole string of these engines with the wrong part in place.Any chance they did the opposite to your exhaust cam?

If it’s been screwy the whole time do you expect you’ll find more power in it once you put it right and adjust your tune?

 

[DAVECS1]

I thought about taking the exhaust cam out,. Ut everything looks good and I hate to mess with it. I have a feeling there is a fair bit of power on the table. I have so many misfire strategies in place, I thought it was due to boost on this little engine, but my guess is I was crutching the fact the right side of my engine was running in high lift mode, all the time.

My guess is there are a fair number of these running around, and this is probably alot of the anomalies I see. I would venture to guess this is where unsolved misfires come from. On top of ot they load a new engine, and it probably has the same failure. This is just crazy to me right now

 

[NachoRuby]

I thought about taking the exhaust cam out,. Ut everything looks good and I hate to mess with it. I have a feeling there is a fair bit of power on the table. I have so many misfire strategies in place, I thought it was due to boost on this little engine, but my guess is I was crutching the fact the right side of my engine was running in high lift mode, all the time.

My guess is there are a fair number of these running around, and this is probably alot of the anomalies I see. I would venture to guess this is where unsolved misfires come from. On top of ot they load a new engine, and it probably has the same failure. This is just crazy to me right now

Do you think this explains the rattle some of us are hearing? An exhaust lifter on the intake side? Just seems like an incredible mistake to make.

 

[ShadowsPapa]

I thought about taking the exhaust cam out,. Ut everything looks good and I hate to mess with it. I have a feeling there is a fair bit of power on the table. I have so many misfire strategies in place, I thought it was due to boost on this little engine, but my guess is I was crutching the fact the right side of my engine was running in high lift mode, all the time.

My guess is there are a fair number of these running around, and this is probably alot of the anomalies I see. I would venture to guess this is where unsolved misfires come from. On top of ot they load a new engine, and it probably has the same failure. This is just crazy to me right now

Questions I have -
Are the wrong lifters isolated to the right head? It sounds like it maybe is because so far I've not read or seen or heard of anyone with cam failures on the driver side (the even side)
Are the wrong lifters also running under the exhaust rockers on the right (odd) side?
Are these inserted by hand or by machine?
Some of us have never had any unusual rattle from the engine under any conditions........ but I wonder, what's it take to remove the valve cover and check? Is it worth doing or even telling the dealer shop a person would pay them to take a look?
Someone needs to know about this - it needs to be verified (although I totally trust you and by extension the guy you know who told you - oops, those are wrong......... someone needs to know. Someone needs to know what to look for at dealerships.
When I take mine in in a few days I am going to ask if they've had any engine issues in these, and to suggest to them to keep an eye open on any that they take the valve cover off from for any reason at all. Cam lobe damage is easy to see, and on these especially easy since it always wears down the middle 80% of the cam lobe leaving the sides ok as a way to compare.

Am I wrong in thinking that when half the engine is running on maximum lift even when the other side is on the lower lift profile - it's going to cause some issues (it won't be good for mpg either)

I'm saving copies of your pictures and am going to share them with the local dealer if that's ok.....

 

[DAVECS1]

Do you think this explains the rattle some of us are hearing? An exhaust lifter on the intake side? Just seems like an incredible mistake to make.

Absolutely

 

[DAVECS1]

Questions I have -
Are the wrong lifters isolated to the right head? It sounds like it maybe is because so far I've not read or seen or heard of anyone with cam failures on the driver side (the even side)
Are the wrong lifters also running under the exhaust rockers on the right (odd) side?
Are these inserted by hand or by machine?
Some of us have never had any unusual rattle from the engine under any conditions........ but I wonder, what's it take to remove the valve cover and check? Is it worth doing or even telling the dealer shop a person would pay them to take a look?
Someone needs to know about this - it needs to be verified (although I totally trust you and by extension the guy you know who told you - oops, those are wrong......... someone needs to know. Someone needs to know what to look for at dealerships.
When I take mine in in a few days I am going to ask if they've had any engine issues in these, and to suggest to them to keep an eye open on any that they take the valve cover off from for any reason at all. Cam lobe damage is easy to see, and on these especially easy since it always wears down the middle 80% of the cam lobe leaving the sides ok as a way to compare.

Am I wrong in thinking that when half the engine is running on maximum lift even when the other side is on the lower lift profile - it's going to cause some issues (it won't be good for mpg either)

I'm saving copies of your pictures and am going to share them with the local dealer if that's ok.....

It won't damage anything running different lifts side to side, but it is not ideal. I am curious about all the same things. Is anything else messed up? Who knows. I was thinking about an easy check. I think you may be able to take out the front VVL solenoid and do a bore scope.

This just boggles my mind. My truck ran super quite at idle and up to 3k. It also would not run noisy all the time. A casual user of the engine would have a hard time knowing. Probably attribute hos bad milage to all the above.

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