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Discussion Starter #1
Hey guys! Rebuilding my engine and I want your input on parts and upgrades!

Long story short, I dropped a valve seat in Cyl 5. It didn't break so the piston and cylinder are fine (yay!). The head is a little dinged where the seat bounced around on top of the valve during my attempts to figure out the issue, but that's the extent of the damage. (Read about my adventure chasing electrical ghosts HERE.)


I now have both heads off and I am piecing together a rebuild plan for preventative replacements and upgrades and I'd like to see what you guys think!
Since the valve seats are a common issue, I definitely want them replaced with a better alternative. Other common Hemi problems (at least on 03-08s) are valve springs and lifters...I want to replace/upgrade all of this NOW before any of it potentially creates bigger problems while I have the engine apart!

First, the heads. I'm planning on having Inertia do my head rebuilds. They have an authorized installer about an hour from me, but I'm not sure if they can do everything there or if I still have to ship to Inertia's main location. Regardless, their head jobs fix and prevent the issue with better parts and I believe pricing INCLUDES shipping. Since I want to fix the other head issues, I will be doing one of their upgraded head packages that includes a full 6.1 valve train, plus head bolts and gaskets. I want to at least do the fuel economy package (ported/blended exhausts), but at that point I might as well go for the full performance (intake & exhaust ports)...however, that's getting pricey with my end goal in mind :|

The lifters. I want to keep MDS and any "upgraded" lifters I can find are MDS delete versions. So, Rock Auto has Melling and Enginetech lifters. I read somewhere that Melling recently (2016?) upgraded their design. I don't think I want to go with Mopar OEMs since I still read about those failing up to 2011, maybe even newer. Thoughts?


I'm also very heavily considering a new cam. In fact, yes, I'm going to do a new cam :laugh2:. I don't plan on doing any racing, so I don't need a really tall one, but I want to do something. I was leaning towards a CompCams 260H-13 but now I think I'm set on a Crazy Jay Plus from Inertia. I like the CJP since Inertia is already doing my heads and valve trains, etc and they seem a bit better, being custom and all. The Plus has better low and mid range over the regular CJ, which is better for towing and for just how heavy the Commanders are (over other Hemi vehicles). Plus, they are the same price! I'll be getting either 6.1 push rods or Inertia's Custom Forged as a result here.


The head rebuild will come with head gaskets, and considering everything else about Inertia, I would assume they are good. So, suggestions on intake seals, valve cover seals, and exhaust gaskets? I saw some people swear by Percy, some by Mopar OEMs.
I need new exhaust bolts: Nord-locks? Suggestions?



While I have the front of the motor off for the cam....should I consider replacing anything?? Other Hemi rebuilds (mostly in the Chargers) suggest so, but most of them are racing....113k miles on everything currently. I know the general idea would be "yes, just replace everything!"....but I'm trying to be realistic here as none of these are THAT complicated to replace later.

Considerations:


  • Water Pump (new one was put on by previous owner. I would guess around ~70k miles)
  • Timing Chain
  • Timing Tensioner
  • Entire timing set? (Cam/Crank gears, chain, & tensioner)
  • Oil Pump

Exhaust. Having the heads off is the best and easiest time to upgrade or replace exhaust manifolds on these beasts....except, no one makes shorty headers for the Jeeps. :frown2:Also that these are the most restrictive part of the engine for us with these ridiculous logs, so upgrading nets the biggest performance boost. I have already exhausted my research with ideas and attempts. I know there's a few GCs and a few of you who have full custom builds, or using stock SRT headers, etc etc etc. Seems like no matter how I go, I'm going to have to have some custom parts. Which gets expensive, and possibly time consuming, in a hurry. I did find that American Racing makes a set of long tube headers (w/ or w/o cats) for the GCs that, I believe, bolts right up to most Cat-Backs and should work on the Commander. Dyno testing with the Borla Cat-Back back for one guy was about +30 or 40hp with everything else stock. BUT at $1500....ehhhh...not to mention, I have to put the heads back on first because long tubes- so this upgrade can be done at any time....however it'll suck. I do already have a Borla Cat-Back, so that's something....

All intake things can be done at any time, so that's not a concern to me at this point.

Other minor things I will be doing:

  • 180* thermostat
  • High Speed fan temps reprogrammed?
  • New Rad cap
  • Belt looks fine, might replace anyways
  • Belt tentioner?
  • EGR valve
  • O2 sensors worth replacing?
  • New oil, coolant.

And obviously a tuner to round it alllll out! I know there's a lot of threads here on tuners, and I haven't dove too deep; but it seems Superchips is the more popular here, all the other Hemi vehicles seem to swear by the Diablo Predator, though. So I'll be diving into different threads more geared on that when I actually get this thing back together!


SOOO...thanks for any input or suggestions!
 

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If you're looking to maybe save a buck, you can swap in a 6.1 cam, that's a real common 5.7 hemi swap part, and since 6.1 owners are always looking for fat cams, the stock ones are a dime a dozen.

As far as lifters go, I believe if I'm remembering correctly, ALL hemi lifters are interchangeable, and rumor is if you order a set of lifters for your hemi (using the part number for your specific vehiy) from the stealership, you'll actually end up receiving hellcat lifters. It could have been a different part other than lifters, I don't remember EXACTLY. But it was a valvetrain part. I'd look into it.

Springs are a good idea to replace, beehive springs are pretty great. But springs can be expensive.

Heads! Before you pull the trigger on inertia for heads, at least look into thitek heads. They are sworn by every hemi owner that has them, and they out perform any other head for hemis manufactured by a significant margin. They flow fantastic and if you ever wanted to get performance parts, that head has a TON of options. Hellcat superchargers fit on them. And I saw 5 for sale a couple weeks ago for $2k a piece brand new, which is an absolute steal.

Sorry, went on a rant there. Hope this was helpful.
 

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Discussion Starter #4 (Edited)
If you're looking to maybe save a buck, you can swap in a 6.1 cam, that's a real common 5.7 hemi swap part, and since 6.1 owners are always looking for fat cams, the stock ones are a dime a dozen.

As far as lifters go, I believe if I'm remembering correctly, ALL hemi lifters are interchangeable, and rumor is if you order a set of lifters for your hemi (using the part number for your specific vehiy) from the stealership, you'll actually end up receiving hellcat lifters. It could have been a different part other than lifters, I don't remember EXACTLY. But it was a valvetrain part. I'd look into it.
I forgot all about looking into 6.1 cams...I'll have to revisit that! I definitely like the idea of a cheaper alternative, I'm not made of money after all :laugh2:
That is interesting about the lifters, I guess I'll dig some more and try to compare Mopar part numbers. I KNOW there is a difference between MDS and Non MDS lifters and the 6.1s DON'T have MDS. However, I keep seeing that the 6.4s do have MDS, I guess because they aren't an SRT motor...?

I wasn't considering complete custom heads. I did look into doing a 6.1 head swap, but that started with different compression ratios, required a different intake and opened up the exhaust issue again. While that'd be nice to drop in an Eagle intake with ported throttle body, headers, etc...that's getting way more expensive than I want this whole thing to be. However, at $2k for a set of custom heads...I'm going to be paying almost that for Inertia.
I haven't researched yet, but with high performance heads like Thitek, do I run the risk of HAVING to run performance tunes and 91 octane or something? While I am doing some performance upgrades, I do want to keep this thing slightly "daily driver-ish" and economical (hence the inertia fuel economy build heads)...


So I have to ask, what are all of these engine upgrades going to cost you?
As the plan sits: Inertia heads will be around $2k depending on the build I go with, and that includes upgraded springs all the other new/upgrades parts I want/need. New lifters will be around $350, Push rods are cheap. A new cam is $150-600 depending on what I decide on and what deals I can find.
Those parts, plus any of the other preventative replacements I mentioned, gaskets, fluids and a tuner- ballpark of $3200? For a peace-of-mind, long term engine with better performance. :wink3:
 

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As the plan sits: Inertia heads will be around $2k depending on the build I go with, and that includes upgraded springs all the other new/upgrades parts I want/need. New lifters will be around $350, Push rods are cheap. A new cam is $150-600 depending on what I decide on and what deals I can find.
Those parts, plus any of the other preventative replacements I mentioned, gaskets, fluids and a tuner- ballpark of $3200? For a peace-of-mind, long term engine with better performance. :wink3:
That's reasonable in the grand scheme of things.
 

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If you're looking to maybe save a buck, you can swap in a 6.1 cam, that's a real common 5.7 hemi swap part, and since 6.1 owners are always looking for fat cams, the stock ones are a dime a dozen.

As far as lifters go, I believe if I'm remembering correctly, ALL hemi lifters are interchangeable, and rumor is if you order a set of lifters for your hemi (using the part number for your specific vehiy) from the stealership, you'll actually end up receiving hellcat lifters. It could have been a different part other than lifters, I don't remember EXACTLY. But it was a valvetrain part. I'd look into it.
I forgot all about looking into 6.1 cams...I'll have to revisit that! I definitely like the idea of a cheaper alternative, I'm not made of money after all /forums/images/JeepCommander_2016/smilies/tango_face_smile_big.png
That is interesting about the lifters, I guess I'll dig some more and try to compare Mopar part numbers. I KNOW there is a difference between MDS and Non MDS lifters and the 6.1s DON'T have MDS. However, I keep seeing that the 6.4s do have MDS, I guess because they aren't an SRT motor...?

I wasn't considering complete custom heads. I did look into doing a 6.1 head swap, but that started with different compression ratios, required a different intake and opened up the exhaust issue again. While that'd be nice to drop in an Eagle intake with ported throttle body, headers, etc...that's getting way more expensive than I want this whole thing to be. However, at $2k for a set of custom heads...I'm going to be paying almost that for Inertia.
I haven't researched yet, but with high performance heads like Thitek, do I run the risk of HAVING to run performance tunes and 91 octane or something? While I am doing some performance upgrades, I do want to keep this thing slightly "daily driver-ish" and economical (hence the inertia fuel economy build heads)...
No I don't believe a higher octane tune would be required. As far as exhaust manifolds go though, I'm not entirely sure. What I do know, is that the thiteks come with new valvetrain as well, well, besides the cam. And the post 2010 intakes are actually cheap ( I sold a brand new one for $250 a while back), although I believe the thiteks are configured to mount ANY intake you want. I'd look into it, but I believe that's the case.
 

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Discussion Starter #7
If I remember right, the main reason for HAVING to swap intake and exhaust manifolds with a 6.1 head is because the ports are different sizes. I want to say the intake is even at a different angle or location? We can swap a 6.1 exhaust manifold to 5.7 heads (with the 6.1 gasket) because the smaller exhaust ports are dumping into a larger manifold opening, you start working against yourself with large ports dumping into a smaller manifold!
The MAIN reason I dropped the 6.1 head idea was the immediate change in compression ratio....while you can fix it, that's more work/effort than I want to do considering the modded stock and custom 5.7 head options out there.
With that said, putting a different intake on 5.7 heads...well, upgrades for a later time :wink3:

I looked a little into a 6.1 stock cam, and the general opinion is that while you can; you will loose some low end and mid-range. Exactly what I DON'T want! This can be slightly remedied by advancing the cam a few degrees, but overall people suggested just saving and getting a cam specifically made for the 5.7s since there's so many now.

I keep looking around at these Thitek heads....the only distributor pricing I found was about $3400 with Beehive springs, $2600 with no valves/springs. Everyone else either doesn't have the heads listed at all (Inertia is a distributor) or I have to call for pricing. Where did you see a deal for $2K? While these would be awesome; at these prices, and with how much I'd take advantage of what they offer, I'm def back at an Inertia build...that extra $1.5k could go towards long tube headers or some other toys!
 

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While those heads are nice, they are unnecessary unless you are planning on forced induction. The Edelbrock heads will outflow the Apache heads and are half the price. Summit sells them for $1100 each. Not bad for 350 cfm head and if your trying to save money, definitely the way to go.
 

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Discussion Starter #9
While those heads are nice, they are unnecessary unless you are planning on forced induction. The Edelbrock heads will outflow the Apache heads and are half the price. Summit sells them for $1100 each. Not bad for 350 cfm head and if your trying to save money, definitely the way to go.
That's what I was thinking...and I have no intention of doing forced induction. I'll look into the Edlebrocks, though!


Anyone have any input on the wear parts I was considering? Oil Pump, Timing set, O2 sensors, etc??
 

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Most definitely worth the investment if you can afford it. I would never spend that kind of money and skimp out on a few extra bucks. My preference is high volume oil pumps. I would also swap in a high end double roller timing chain. You can inspect the waterpump and tensioner pulleys and make a call. I wouldn't replace the egr unless it's defective. Same for the O2's.

My waterpump just blew apart yesterday morning at 93k miles. Just started screaching and bang, no more coolant in 5 blocks. When I stopped, it was literally pouring out the front like out of a hose. One of the pulleys was buzzing for awhile and I was already planning on replacing it but for the extra $25, I got both the tensioner and idler. I went with the 192* . The 180 is too cool unless you are running hot or forced induction and will increase engine wear.

You may aalso wish to consider ARP head studs or at least head bolts for added strength. Pricey but several times the holding strength of factory fasteners. I would also purchase an under drive balancer. I bought the PowerBond 25% piece and will install it now with the waterpump repair.
 

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Discussion Starter #11
Most definitely worth the investment if you can afford it. I would never spend that kind of money and skimp out on a few extra bucks. My preference is high volume oil pumps. I would also swap in a high end double roller timing chain. You can inspect the waterpump and tensioner pulleys and make a call. I wouldn't replace the egr unless it's defective. Same for the O2's.

My waterpump just blew apart yesterday morning at 93k miles. Just started screaching and bang, no more coolant in 5 blocks. When I stopped, it was literally pouring out the front like out of a hose. One of the pulleys was buzzing for awhile and I was already planning on replacing it but for the extra $25, I got both the tensioner and idler. I went with the 192* . The 180 is too cool unless you are running hot or forced induction and will increase engine wear.

You may aalso wish to consider ARP head studs or at least head bolts for added strength. Pricey but several times the holding strength of factory fasteners. I would also purchase an under drive balancer. I bought the PowerBond 25% piece and will install it now with the waterpump repair.
-I was thinking about a High PSI pump, looks like Melling has one on Summit that isn't too expensive. Does this open up the need to change any other parts? Or should I just be able to drop this in and be good? Proper oil passages is another weak design in these motors that helps lead to the higher temperatures and associated failures; so an upgraded pump can help to alleviate this, right?

-Timing Chains, I don't think an adjustable is a necessary expense for me- I don't plan on having any parts or situations where I'm going to want to advance or retard my timing at all....but, looks like double roller chains come with this feature. Since I won't be doing anything crazy (forced induction, high RPM racing, etc) is upgrading to a double roller more of a long-term reliability upgrade in my case? Melling has a single roller "high performance" set that's adjustable for $100 less...

-I know the previous owner had to have a new water pump put in, I just don't know how long ago that was. I have blown water pumps in previous Jeeps, so I am no stranger to the shrieking, smoking, coolant waterfall that happens! :grin2:
I read somewhere on some of the other Hemi vehicle forums that a 180* stat was suggested because the motors commonly run a little hot because of how they were designed (not on purpose) and then how tightly everything is crammed under the hood doesn't help. This is usually what leads to the common engine failures- lifters, valve seats, springs, etc. 180* stat plus changing the temp for the electric fan via a programmer. I WAS set on doing this for these reasons...but now you've got me all conflicted again!

-New head bolts is something I will definitely be doing. Something that I keep seeing suggested any time you pull heads anyways. Interia heads come with new bolts, not sure what brand, tho. ARP is REALLY proud of their bolts! Like, to the point I'm NOT spending $230+ for bolts....I can only assume what I'd get from a performance shop will be more than enough for my needs...

-I've seen in a number of places that O2s should be replaced around 100k miles anyways, as a preventative maintenance type thing since they start to go bad or not read as accurately. My thought is that they are REALLY easy to get to right now, especially the upstreams!

-Underdrive pulleys...don't think I'll be doing that. Lots of people who put them on their commuters/daily drivers (on ANY engine, not just Hemis) usually ended up regretting it- AC doesn't work at idle, dimming lights, etc. While it is a slight performance boost, at 2-5hp...not worth it at the cost of what you're losing.


I'm looking to start dropping money on this project sometime this week, at least the big stuff where my mind is already made up. A lot of these smaller things I'll be getting over the next few weeks/months. My wife just deployed; so I have the time, space and a second vehicle to allow this project to stretch out a little bit! >:)
 

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Discussion Starter #12
As far as lifters go, I believe if I'm remembering correctly, ALL hemi lifters are interchangeable, and rumor is if you order a set of lifters for your hemi (using the part number for your specific vehiy) from the stealership, you'll actually end up receiving hellcat lifters. It could have been a different part other than lifters, I don't remember EXACTLY. But it was a valvetrain part. I'd look into it.
Finally got more info on this, and you are correct! -- The lifters are the same across ALL GenIII Hemi motors 2003-present, the only difference being MDS or non-MDS; with more high-lift, high performance options for non-MDS.
HOWEVER--- The design/build quality WAS improved around 2011 or 2015 or so. Melling changed their part numbers for MDS lifters in 2015. These lifters made it into the 2016 vehicles. Mopar apparently changed their valve springs (softer), cams (harder) and timing chains (better) around this time as well in a kind of "hushed" manner, no new part numbers..... Mopar "claims" this happened in 2011, but there were still lots of people having problems to include a timing chain recall affecting certain 09-14 Eagle motors, so I'm more inclined to believe 2015 is the change. No info on how the design changed, though....

SOO, it would seem that any aftermarket or Mopars that you buy now (as long as they are NEW) WILL be the upgraded design as well as the same parts that are in the SRTs!

Info I got was from an AllPar thread that seems to be a guy with Fleet connections for patrol cars? I also did my own part number cross referencing between my 2006 and a 2015 6.4 Grand Cherokee. --->AllPar: Another bad HEMI lifter
 

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So a few things,

1. I didn't know the price of thiteks, the $2k I was referring to, was $2k each, brand new pull off hellcat superchargers with 5 available. Sorry, that wasn't clarified better.

2. The melling oil pump is a great choice. There is generally 3 oil pumps for the genIII hemi, the 5.7, the 6.1, and the melling. The melling outputs more flow than the 6.1, but fits in the timing cover of both the 5.7 and 6.1.

3. I forgot, lemme look back real quick. Lol

Ok, do not underdrive, just in case you change your mind. I've read that it can cause SERIOUS problems with the genIII hemis as far as the engine goes.
 

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The double roller is strength and durability. The high pressure and volume pumps deliver more oil.

Wrong on the underdrive balancer. I have run underdrives on several mustangs for years with no negative effects. I have run them on my thunderbird supercoupe for many 10 years as well. We installed a 20% Trickflow unit on by brother's Durango 3 months ago with ZERO issues. Hot rod dyno'd it for a consistent 8 hp and no loss of alternator, temperature, power steering or AC. I have the 25% PowerBond SS on mine. They claim 12hp. I drove around for hours today in +33* heat today with ice cold ac and my tunes cranked. No difference from two weeks ago the last time it got this hot. The exception being that it revs up so hard that when it shifts into second gear, the whole jeep bounces up like going over a bump.

Aside for the balancer, I blended the intake opening out to 88 mm, cut of the part of the egr tube that protruded behind the throttle body and swapped to a 193 t stat.
 

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The double roller is strength and durability. The high pressure and volume pumps deliver more oil.

Wrong on the underdrive balancer. I have run underdrives on several mustangs for years with no negative effects. I have run them on my thunderbird supercoupe for many 10 years as well. We installed a 20% Trickflow unit on by brother's Durango 3 months ago with ZERO issues. Hot rod dyno'd it for a consistent 8 hp and no loss of alternator, temperature, power steering or AC. I have the 25% PowerBond SS on mine. They claim 12hp. I drove around for hours today in +33* heat today with ice cold ac and my tunes cranked. No difference from two weeks ago the last time it got this hot. The exception being that it revs up so hard that when it shifts into second gear, the whole jeep bounces up like going over a bump.

Aside for the balancer, I blended the intake opening out to 88 mm, cut of the part of the egr tube that protruded behind the throttle body and swapped to a 193 t stat.
@Flex; I'm no mechanic - I've said that many times - but I can't see how that can possibly be good for the transmission, if it's shifting that hard because the engine is revving so high.
 

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I haven't changed the rpm's that the transmission shifts at. It's just the extra torque and hp that the throttle body, air intake, damper and tuner are adding to the motor. I have seen Grand Cherokee's with a lot more work on you tube videos running 1/4's on a stock transmission so I am not worried.
 

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I haven't changed the rpm's that the transmission shifts at. It's just the extra torque and hp that the throttle body, air intake, damper and tuner are adding to the motor. I have seen Grand Cherokee's with a lot more work on you tube videos running 1/4's on a stock transmission so I am not worried.
Hopefully it does not come back to bite you down the road.

I've added 25-35 HP to my engine with the AFE Magnum Force Stage 2 Intake System; AFE MACH Force-Xp 3" Stainless Steel Cat-Back Exhaust System and the Superchips (3874) F5 Flashpaq Tuner 93 Octane Performance Tune loaded in my ECM; I have noticeably more torque then when my engine was stock and I don't have the shifting issues that you've described.

I played around with some kid in an Audi Sports coupe about a week and a half ago at a dead stop from a red light (he had zoomed by me prior to stopping at the red light, because I typically drive the speed limit or slightly under) The light turned green and I got on Big Blue pretty good (something I typically do not do) and wound her out to about 6,000 rpms on the TAC through L1 & L2 and she shifted as smooth as silk. That poor kid in the Audi didn't know what happened to him....LOL.....it was very apparent that he was shocked that this big bulky Jeep Commander had just dusted him.
 

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My shift issues as you put it bud come from 380 hp and over 400 ft/lbs of tq. Hopefully more once I get the headers and downpipes on. It was fairly snappy stock but the add ons definitely increased the output. When I first built the bored over 460 in my brother's 1978 F150, it had so much hp and tq that it would lift the drivers tire off the ground when you punched it. How often do you punch it though. Unless you have money to burn, most people are easy on the gas with fuel costing what it does.

Good to hear on the Audi punk. I try to resist the urge myself as there are so many of them out there but every once in while I give in. I ran into a residential Mario a few weeks ago in the Durango. It is a bit heavier than the Commander, has 3.55's instead of 3.73's and can't run a custom programmer but it does have the mid length JBA's and full Flowmaster exhaust system, a 90 mm throttle body with cold air along with new MSD coils and wires and the 20% damper. This guy was in a Ford Raptor and kept reving it and racing up to me. The Flowmaster system has dual tailpipes and a really deep tone so he seemed like he wanted to go. I was shocked when he ended up 3 car lengths behind me and just let off.
 

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Good to hear on the Audi punk. I try to resist the urge myself as there are so many of them out there but every once in while I give in. I ran into a residential Mario a few weeks ago in the Durango. It is a bit heavier than the Commander, has 3.55's instead of 3.73's and can't run a custom programmer but it does have the mid length JBA's and full Flowmaster exhaust system, a 90 mm throttle body with cold air along with new MSD coils and wires and the 20% damper. This guy was in a Ford Raptor and kept reving it and racing up to me. The Flowmaster system has dual tailpipes and a really deep tone so he seemed like he wanted to go. I was shocked when he ended up 3 car lengths behind me and just let off.
You gotta love it when that happens though......next time I'm home, I think I'm going to put Big Blue on the dyno and see what she's really putting out. There is a shop that I know of in my area that's set-up to dyno 4x4's.
 
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