Watch Idle Hours & Change Oil every 3k Miles to Avoid Engine Failure!!

kurek

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Nearly all modern cars won't rev over 4k in neutral but they run up to higher rpm in gear when you're accelerating.

Hemis are just coming into power at 4k.

Unlike my old 5.0 Mustang that's about done by 4k.. well it was anyway we'll see how it runs with the new goodies once the snow melts
 
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David_Jacobs

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The lack of lube on the roller bearings is a well documented shortcoming of the current OHV design, failures resulted when they raised the camshaft and didn't allow sufficient lubrication on the cam-roller interface.

I've got about 250 idle hours and 60kkm's, i inspected my roller bearings when I pulled the cam at 55k km's and they seemed fine, but I changed the rollers as cheap insurance. It's really hit and miss with these hemi's.

PS There no such thing as a "hellcat lifter", the part numbers are all the same.
 

HEMIMANN

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The lack of lube on the roller bearings is a well documented shortcoming of the current OHV design, failures resulted when they raised the camshaft and didn't allow sufficient lubrication on the cam-roller interface.

I've got about 250 idle hours and 60kkm's, i inspected my roller bearings when I pulled the cam at 55k km's and they seemed fine, but I changed the rollers as cheap insurance. It's really hit and miss with these hemi's.

PS There no such thing as a "hellcat lifter", the part numbers are all the same.

Do you happen to know whether the first two Hemi generations were solid lifters?
 

flinkpoyd01

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Curious if someone will provide a mechanical explanation of why disabling MDS will have a positive impact on cam/lifter failure. I’m seeing a lot of anecdotal input related to it but I can’t seem to find the mechanical reasoning behind it. Thanks.
 

2012RAM1500RT

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Curious if someone will provide a mechanical explanation of why disabling MDS will have a positive impact on cam/lifter failure. I’m seeing a lot of anecdotal input related to it but I can’t seem to find the mechanical reasoning behind it. Thanks.
I didn't do it for that reason myself, I did it because of the sound I didn't like and it did nothing for my fuel mileage that I could tell. Also something else that doen't have to work and go bad. There's a lot of things that came on my truck I don't need or use so I'd get rid of them also if I could.
 

alex6666

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I heard recently that there has been a class action lawsuit filed in the united states of america against bm for similar lifter/cam problems. Probably the only redress that will prompt a change.
 

kurek

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Curious if someone will provide a mechanical explanation of why disabling MDS will have a positive impact on cam/lifter failure. I’m seeing a lot of anecdotal input related to it but I can’t seem to find the mechanical reasoning behind it. Thanks.

That should be interesting... especially since non-MDS versions of the engine seem just as likely to experience this failure.
 

HEMIMANN

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Didn't @Hemi395 say his tick went away when he turned MDS back on?
We speculated repressurizing the lifter bore with oil during MDS activation helped lubricate those lifters.
No one knew what happens with non MDS lifters, but the oil galley is likely drilled through the entire block - including non MDS lifters.
This would mean only MDS lifters are starved of oil when MDS is off.
 

Hemi395

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Yep that was me. This is the video that prompted me to turn MDS back on. It shows how the lifters get pressurized oil while in MDS.

 
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