A little update. I dropped the new cylinder head off at the machine shop and they showed me the video of the pressure test. The leak is by one of the lower pushrod holes. There is seepage through what looks like the casting grains if that makes any sense. There are no visible cracks.

That makes sense, air pocket in the casting process.

Got this thing back together a week ago. It is a beast! Going to need headers and a tune soon. Something else I noticed is that a one of the lobe on the cam had a "chip" on the top of it where it was wearing. The lifter had some shining spots on it but nothing that had started scoring and it still rolled smoothly. Obviously if I had not have the cylinder head issue with would have gone out at some point....

Does anyone have a real answer why hemis eat lifters/cams? I do realize the needle bearings go but is it a material or production defect? I have done some searching and have come up with earlier production of the mds lifters doing this but there is no definitive answer as far as specific part numbers go (at least I didn't find anything). From what I can tell all of the new mds hemis use the same lifter and they have superseded a fair amount of previous lifter models.

So what cam, heads, milled how much if any... did you end up putting in?


As for the lifter, I'm guessing bean counters had something to do with the lifters falling apart, I never seen a 6.1 or 08 back 5.7 do it, something changed in 09+.

I did exactly what you said. Had to grab another new head (drivers side eagle), 6.4 srt cam and springs ,new lifters and took 20 thousandths off. I used all ARP hardware for the hell of it.

Any idea what the compression is after taking 20 off the heads?

I wanted to have the bad head cut apart to see what the heck happened but there was a $150 core charge so I sent it back.

It amazed me how easy this engine was to work on. Almost makes me want to put one in my Challenger.

So you’re running a stock tune with the 6.4 cam?

side track,

my experience with 6.4 heads on 5.7 blocks....stock 3.917 bore.....too close needs to be notched if the factory bores are just slightly off you can have an issue, , 3.937 bore they'll clear ..but best results notch it, don't need much.

I think it has to do with the VVT cam lobes,
53022064BD (cars) duration intake 258* exhaust 288* / lift intake .472 exhaust .461
53022314AD (trucks)duration intake/exhaust 290* / lift intake .472 exhaust .460Automatic 5.7
186/208 (4 lobes are actually 205 on the exhaust for MDS)
499/493 (4 lobes have 486 lift on the exhaust for MDS)
115LSA
103ICL

Not sure why but I think when the oil is cut to the MDS lifters there not enough residual oil to keep the roller lubed and the aggressive nature of the MDS lobe puts more stress on the roller....so it's a design flaw in my opinion...…..Lifters don't fail on the Non VVT cams.

Yup, for now. Waiting on headers (which are freaking expensive for this thing) before a tune. Runs fine....

That makes sense. It looks like there has been a few iterations of lifters since the intro of MDS. I wonder if they have actually solved the issue with new vehicles.

It is definately NOT because of the MDS, I have done many on 3/4 ton trucks including one I bought in tuscon with a flat cam and drove all the way here (2000 miles) and fixed. I still have that cam laying here, is there a way to prove what it came out of?

The non MDS engine has full pressurized lube to the lifter body all the time

Correct,... you have 2500 NON MDS ? what year is it ?

09. It's the one I put the 6.4 SRT cam in.

Interesting. Where they all 5.7s?

2009 through about 2012 5.7 is what I have seen and as low as 101,000 mileson up to my 2011 with almost 300,000 miles. Never an earlier one, no 6.1, 6.2< or 6.4 either flavor. Anything newer is probably ending up at the dealer so I don't know if it's a continuing issue or if they fixed it yet. I am looking for a decent 1/2 ton 4 door 09+ I can buy cheap and swap in my 6.4.

the issue happens with high idle hours, most common is when Idle hours exceeded 7% of total hours. my youngest stepsister works for AutoAssure warranty company and according to their records 90% of all lifter claims are 5.7s with idle hours between 7% and 9% of total hours usage the other 10 are 6.4s with Idle usage above 5%. The Dodge dealership my nephew works at does 2-3 a month same common thread High idle hours ...my brother is a fleet mechanic for a local Municipality, they do 1-2 pursuit charger week and 1-5 1500 2-3 2500 rams a month, keep in mind that when the engine goes in to ECO mod the computer registers that as idle hours,

Dave that 09 2500 you did , did it have solenoids or plugs?